Mild Hypothermia Protects Brain Injury After Intracerebral Hemorrhage in Mice Via Enhancing the Nrdp1/MyD88 Signaling Pathway

BACKGROUND

Mild hypothermia has been identified to reduce brain injury following intracerebral hemorrhage (ICH) by protecting neuron cells through several pathways. However, the role of hypothermia in brain function following ICH and the related mechanisms have not been well identified. Ubiquitination-mediated inflammation plays important roles in the pathogenesis of immune diseases. The experiment analyzed anti-inflammatory effects of mild hypothermia following ICH.

METHODS

The model of ICH was induced by injecting autologous blood. Neuregulin receptor degradation protein-1 (Nrdp1) and downstream molecule were analyzed. In addition, brain inflammatory response, brain edema, and neurological functions of ICH mice were also assessed.

RESULTS

We found that mild hypothermia attenuated proinflammatory factors production after ICH. Mild hypothermia significantly inhibited BBB injury, water content, and neurological damage following ICH in vivo. Moreover, mild hypothermia also increased Nrdp1/MyD88 levels and thus affect neuronal apoptosis and inflammation.

CONCLUSIONS

Taken together, these results suggest that mild hypothermia can attenuate the neuroinflammatory response and neuronal apoptosis after ICH through the regulation of the Nrdp1 levels.

Canonical Wnt signaling works downstream of iron overload to prevent ferroptosis from damaging osteoblast differentiation

Excessive iron has emerged in a large population of patients suffering from degenerative or hematological diseases with a common outcome, osteoporosis. However, its underlying mechanism remains to be clarified in order to formulate effective prevention and intervention against the loss of bone-forming osteoblasts. We show herein that increased intracellular iron by ferric ammonium citrate (FAC) mimicking the so-called non-transferrin bound iron concentrations leads to ferroptosis and impaired osteoblast differentiation. FAC upregulates the expression of Trfr and DMT1 genes to increase iron uptake, accumulating intracellular labile ferrous iron for iron overload status. Then, the excessive ferrous iron generates reactive oxygen species (ROS) and lipid peroxidation products (LPO), causing ferroptosis with its typical mitochondrial morphological changes, such as shrinkaged and condensed membrane with diminution and loss of crista and outer membrane rupture. We further examined that ferroptosis is the main cause responsible for FAC-disrupted osteoblast differentiation, although apoptosis and senescence are concurrently induced as well. Mechanistically, we revealed that iron dose-dependently down-regulates the expression of Wnt target genes and inhibits the transcription of Wnt reporter TopFlash construct, so as to inhibit the canonical Wnt signaling. Wnt agonist, ferroptosis inhibitor, or antioxidant melatonin reverses iron-inhibited canonical Wnt signaling to restore osteoblast differentiation by reducing ROS and LPO production to prevent ferroptosis notably without reducing iron overload. This study proposes a working model against excessive iron-induced osteoporosis: iron chelator deferoxamine or the above three drugs prevent ferroptosis, restore traditional Wnt signaling to maintain osteoblast differentiation no matter whether iron overload is removed or not. Additionally, iron chelator should be used to a suitable extent because iron itself is necessary for osteogenic differentiation.

Dexmedetomidine inhibits cerebral nerve cell apoptosis after cerebral hemorrhage in rats via the Nrf2/HO-1/NQO1 signaling pathway

OBJECTIVE

To investigate the effect of dexmedetomidine on the apoptosis of cerebral nerve cells after cerebral hemorrhage (CH) in rats and its molecular mechanism.

MATERIALS AND METHODS

The rat model of CH was established by autologous blood injection. A total of 60 specific pathogen-free (SPF)-grade rats were randomly divided into sham-operation group, model group and dexmedetomidine group, and each group involved 20 rats. Rat brain water content was compared among the three groups. Besides, rat neurological function of the three groups was evaluated at 3, 5 and 7 d after operation by neurological function scoring. Western blotting assay was adopted to detect protein levels of apoptosis-related genes [B-cell lymphoma-2 (Bcl-2) and Bcl-2-associated X protein (Bax)] in rat brain tissues in the three groups. Moreover, the apoptosis level in the brain tissues in the groups was measured through terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay. Biochemical tests were conducted to determine activities of reduced glutathione (GSH), superoxide dismutase (SOD) and malondialdehyde (MDA) in the brain tissues among the three groups. Furthermore, the activation of the nuclear factor erythroid 2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1)/NAD(P)H quinone oxidoreductase 1 (NQO1) signaling pathway in the brain tissues of the three groups of rats was examined via Western blotting assay. An in vitro oxygen-glucose deprivation (OGD) model was prepared using SH-SY5Y cells. In addition, Nrf2 was intervened in SH-SY5Y cells by small hairpin ribonucleic acid (shRNA) transfection. Finally, flow cytometry and Annexin V/PI assay were performed to detect the response of cells to dexmedetomidine in OGD + dexmedetomidine + sh-Nrf2 group.

RESULTS

The brain water content and the neurological function score at 3, 5 and 7 d after operation were remarkably reduced in dexmedetomidine group compared with those in model group. The results of Western blotting and TUNEL assays indicated that dexmedetomidine group had a notably lowered apoptosis level in the brain tissues. Additionally, the biochemical test results manifested that activities of GSH and SOD were enhanced and that of MDA decreased in the brain tissues of dexmedetomidine group. Protein levels of Nrf2, HO-1 and NQO1 in the brain tissues were distinctly higher in dexmedetomidine group than those in model group. According to the results of flow cytometry, the apoptosis rate in OGD + dexmedetomidine + sh-Nrf2 group rose prominently compared with that in OGD + dexmedetomidine group.

CONCLUSIONS

Dexmedetomidine inhibits the nerve cell apoptosis in rat brain tissues by activating the Nrf2/HO-1/NQO1 signaling pathway in rat CH models.

Genome-wide identification studies - A primer to explore new genes in plant species

Genome data have accumulated rapidly in recent years, doubling roughly after every 6 months due to the influx of next-generation sequencing technologies. A plethora of plant genomes are available in comprehensive public databases. This easy access to data provides an opportunity to explore genome datasets and recruit new genes in various plant species not possible a decade ago. In the past few years, many gene families have been published using these public datasets. These genome-wide studies identify and characterize gene members, gene structures, evolutionary relationships, expression patterns, protein interactions and gene ontologies, and predict putative gene functions using various computational tools. Such studies provide meaningful information and an initial framework for further functional elucidation. This review provides a concise layout of approaches used in these gene family studies and demonstrates an outline for employing various plant genome datasets in future studies.

Unicondylar knee replacement versus total knee replacement for the treatment of medial knee osteoarthritis: a systematic review and meta-analysis

BACKGROUND

Since the optimal surgery for isolated medial knee osteoarthritis (OA) is unclear, this study aimed at comparing the effectiveness of unicondylar knee replacement (UKR) with total knee replacement (TKR) for simple medial knee OA.

METHODS

Literature searches of PubMed, Embase, Web of Science, and the Cochrane Library were searched up to 1th April 2020. Only studies comparing UKR with TKR for isolated medial knee OA were included. Data collection and extraction, quality assessment, and data analyses were performed according to the Cochrane standards.

RESULTS

A total of 13 articles with 1888 patients were included, among which, 944 and 944 underwent UKR and TKR, respectively. The analyzed postoperative outcomes were mostly within 5 years of follow-up. The meta-analysis showed that UKR improved knee general function (P < 0.00001) and health (P = 0.02), moreover, reduced post-operative pain (P = 0.01) and complications (P < 0.05) more than TKR. There were no significant differences in postoperative revision (P = 0.252), high-activity arthroplasty score (HAAS) (P = 0.307) and Oxford knee score (OKS) (P = 0.15) between the two techniques.

CONCLUSIONS

The patients of UKR could achieve better clinical results than that of TKR, moreover, there were negligible differences between the two techniques in postoperative revision in the early and mid-term follow-up and surgeons should be aware of the important reasons for revision of UKR. Thus, UKR instead of TKR should be performed in patients with late-stage isolated medial knee OA.

MicroRNA-15a inhibits inflammatory response and apoptosis after spinal cord injury via targeting STAT3

OBJECTIVE

To clarify the function of microRNA-15a in the spinal cord injury (SCI) and its potential mechanism.

PATIENTS AND METHODS

The plasma levels of microRNA-15a and signal transducer and activator of transcription 3 (STAT3) in SCI patients were determined by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). The correlation between the expressions of microRNA-15a and STAT3 was analyzed. The in vitro SCI model was established in H2O2-induced C8-D1A and C8B4 cells, and in vivo SCI model was established in mice by hitting T10. The mRNA and protein expressions of tumor necrosis factor-α (TNF-α) and interleukin 6 (IL-6) were detected in the SCI model. The apoptosis was examined by flow cytometry or TUNEL staining, respectively. The motor function of mouse hindlimb was evaluated using the Basso Beattie Bresnahan (BBB) standard scale. The target gene of microRNA-15a was predicted by bioinformatics and further verified by dual-luciferase reporter gene assay. The expression changes of target genes in C8-D1A and C8B4 cells with microRNA-15a overexpression or knockdown were examined by qRT-PCR and Western blot. Finally, rescue experiments were performed to evaluate the regulatory effects of microRNA-15a and STAT3 on cell apoptosis.

RESULTS

MicroRNA-15a was lowly expressed in plasma of SCI patients, while STAT3 was highly expressed with a negative correlation to microRNA-15a. Identically, microRNA-15a was lowly expressed in H2O2-induced C8-D1A and C8B4 cells, and STAT3 was highly expressed. MicroRNA-15a overexpression downregulated mRNA and protein levels of TNF-α and IL-6 in C8-D1A and C8B4 cells. BBB score was markedly low in SCI mice relative to controls. SCI mice injected with microRNA-15a mimics had higher BBB score than those injected with negative control. Besides, SCI mice with microRNA-15a overexpression had downregulated expressions of STAT3, TNF-α, and IL-6 in the impaired spinal cord tissues, as well as lower apoptotic rate. Through bioinformatics, we found binding sites between STAT3 and microRNA-15a. Their binding conditions were further verified by dual-luciferase reporter gene assay. Moreover, STAT3 expression was negatively regulated by microRNA-15a. Finally, rescue experiments showed that STAT3 overexpression could reverse the regulatory effects of microRNA-15a on expressions of TNF-α and IL-6, as well as apoptosis.

CONCLUSIONS

MicroRNA-15a expression decreases in the SCI model, which participates in the process of SCI by regulating inflammatory response and cell apoptosis via targeting STAT3.

MiRNA-494 enhances M1 macrophage polarization via Nrdp1 in ICH mice model

Background

Ubiquitination-mediated M1/M2 macrophage polarization plays important roles in the pathogenesis of immune disease. However, the regulatory mechanism of ubiquitination during M1/M2 macrophage polarization following intracerebral hemorrhage (ICH) has not been well studied.

Methods

In the experiment, macrophages were administered with erythrocyte lysates, and then miR-494-, Nrdp1-, and M1/M2-related markers were analyzed. Brain inflammatory response, brain edema, and neurological functions of ICH mice were also assessed.

Results

We found that miR-494 levels increased while Nrdp1 levels decreased in macrophages after ICH. We also demonstrated that miR-494 inhibited Nrdp1 expression by directly binding its 3′-untranslated region. MiR-494 attenuated C/EBP-β activation and downstream proinflammatory factor production. Upregulation of Nrdp1 in macrophages significantly promoted M2 macrophage polarization via ubiquitinating and activating C/EBP-β. Moreover, the results indicated that miR-494 could enhance M1 macrophage polarization, promote brain edema, and impair neurological functions in ICH mice.

Conclusions

Taken together, our results demonstrated that Nrdp1 contributed to M1/M2 macrophage polarization and neuroinflammation via ubiquitination and activation of C/EBP-β in ICH. miR-494 may provide a promising therapeutic clue for ICH.

Prediction and identification of novel HLA-A*0201-restricted cytotoxic T lymphocyte epitopes from endocan

Background

Prediction and identification of cytotoxic T lymphocyte (CTL) epitopes from tumor associated antigens is a crucial step for the development of tumor immunotherapy strategy. Endocan has been identified as antigen overexpressed in various tumors.

Methods

In this experiment, we predicted and identified HLA-A2-restricted CTL epitopes from endocan by using the following procedures. Firstly, we predicted the epitopes from the amino acid sequence of endocan by computer-based methods; Secondly, we determined the affinity of the predicted peptide with HLA-A2.1 molecule by peptide-binding assay; Thirdly, we elicited the primary T cell response against the predicted peptides in vitro; Lastly, we tested the specific CTLs toward endocan and HLA-A2.1 positive target cells.

Results

These data demonstrated that peptides of endocan containing residues 4–12 and 9–17 could elicit specific CTLs producing interferon-γ and cytotoxicity.

Conclusions

Therefore, our findings suggested that the predicted peptides were novel HLA-A2.1-restricted CTL epitopes, and might provide promising target for tumor immunotherapy.

Dendritic cells transduced with glioma-expressed antigen 2 recombinant adenovirus induces specific cytotoxic lymphocyte response and anti-tumor effect in mice

Introduction

Glioma is an aggressive common cancer with high mortality worldwide. Up to date, the effective medical therapeutical strategy is limited. Numerous previous studies have indicated that glioma-expressed antigen 2 (GLEA2) might be an attractive prognostic glioma biomarker.

Methods

In this experiment, dendritic cells (DCs) transduced with GLEA2 recombinant adenovirus were utilized to generate cytotoxic lymphocytes (CTLs) in vitro. Additionally, trimera mice were immunized with the transduced DCs to generate CTLs in vivo.

Results

The data demonstrated that GLEA2 transduced DCs could effectively generate specific CTL response against glioma without lysing autologous lymphocytes. Moreover, GLEA2 transduced DCs significantly attenuated the tumor growth and prolonged the life span of tumor bearing mice.

Conclusions

These findings suggested that DCs transduced with GLEA2 recombinant adenovirus could generate effective CTL mediated anti-tumor response, and might represent insight in glioma therapy.

MicroRNA-23b attenuates the H2O2-induced injury of microglial cells via TAB3/NF-κB signaling pathway

Apoptosis of microglia is one of the most important pathophysiologic changes after spinal cord injury (SCI). Recently, microRNAs (miRNAs) have been reported to play a crucial role in the regulation of neuronal apoptosis. However, the exact role and underlying mechanisms of miRNAs in the regulation of microglial apoptosis remain unclear. We first performed miRNA microarray to analyze the miRNA expression patterns in a rat SCI model. The expression of microRNA-23b (miR-23b) in spinal cord after contusion SCI was determined by quantitative reverse transcriptase polymerase chain reaction (qRT-PCR). BV-2 cells were exposed to H₂O₂ conditions to establish an in vitro model of SCI. Then, the effects of miR-23b on the apoptosis were investigated through both gain- and loss-of-function studies in this cellular model of SCI. Also, the expression of the main proteins in NF-κB signaling was assessed by Western Blot. Furthermore, bioinformatics analysis was used to predict the target of miR-23b in BV-2 cells, which was validated with a dual-luciferase reporter assay, qRT-PCR, and Western blot analysis. The expression of TGF-β-activated kinase 1 binding protein 3 (TAB3) in cells was overexpressed by transfection with pcDNA-TAB3, and the effects of TAB3 overexpression on miR-23b-mediated apoptosis were detected. Here, we demonstrated that miR-23b was significantly down-regulated in SCI rat model. We also found that the expression level of phosphorylated p65 (p-p65) protein was increased in the SCI rat model. Subsequently, treatment of BV-2 cells with H₂O₂ decreased the levels of miR-23b and activated NF-κB pathway in a dose dependent manner. Furthermore, overexpression of miR-23b inhibited the BV-2 apoptosis and NF-κB activation, while miR-23b inhibition enhanced the apoptosis and NF-κB activation induced by H₂O₂. Moreover, our data showed TAB3, an upstream positive regulator of the NF-κB pathway, was proven to be a target of miR-23b in BV-2 cells. Most importantly, we demonstrated that overexpression of miR-23b attenuated the apoptosis by inhibiting the expression of TAB3. These findings suggested that miR-23b protected BV-2 cells from apoptosis by modulating the NF-κB pathway and could serve as a new strategy for the treatment of SCI.

miR‑186 functions as a tumor suppressor in osteosarcoma cells by suppressing the malignant phenotype and aerobic glycolysis

Osteosarcoma (OS) is the most common primary bone malignancy among children and adolescents. Deregulation of microRNAs has been well documented in OS, while the putative effects of miR‑186 have not been identified yet. In the present study, we assessed the expression of miR‑186 in a cohort of 40 OS tissues and explored its effects on OS cells. As expected, miR‑186 was suppressed in OS tissues compared with relative normal tissues. Overexpression of miR‑186 inhibited cell proliferation, arrested the cell cycle progression and suppressed the cell invasion of the HOS and U2 OS cell lines. These results indicated the tumor‑suppressive role of miR‑186 in OS. Among the target genes of miR‑186, we found that pituitary tumor transforming gene 1 (PTTG1) may be a target gene of miR‑186 in OS and that the overexpression of PTTG1 could partially abolish miR‑186‑mediated suppressive effects on OS cells. Aerobic glycolysis is the major way of energy supply and is one of the characteristic phenotypes of tumor cells. In addition, we found that overexpression of miR‑186 significantly suppressed the expression of hypoxia‑inducible factor 1 (HIF‑1) and inhibited the glucose uptake and lactate production of OS cells. Collectively, our findings demonstrated that miR‑186 functions as a tumor suppressor in OS cells partially by targeting PTTG1 and that HIF‑1‑mediated suppression of aerobic glycolysis may be also involved in its suppressive effects.

miR-124 represses the mesenchymal features and suppresses metastasis in Ewing sarcoma

Metastasis is the most powerful predictor of poor outcome of Ewing sarcoma (ES). Thus, identification of new molecules involved in tumor metastasis is of crucial importance to reduce morbidity and mortality of this devastating disease. In this study, we found that miR-124, a highly conserved miRNA, was suppressed in ES tissues and might be associated with tumor metastasis through suppressing its mesenchymal features. Overexpression of miR-124 suppressed the invasion of ES cells in vitro and tumor metastasis in vivo, which might be achieved through suppressing its mesenchymal features, as overexpression of miR-124 could repress the mesenchymal genes expression, and inhibit cell differentiation to mesenchymal lineages in ES cells. However, when SLUG was experimentally restored in these cells, mesenchymal features including suppressed expression of mesenchymal genes and decreased invasive ability were observed. We also found that cyclin D2 (CCND2) was a novel target gene of miR-124, and was directly involved in miR-124-mediated suppressive effects on cell growth. Lastly, we found that treatment with 5-Aza-CdR restored the expression of miR-124, accompanied with suppressed cell proliferation, invasion and mesenchymal features of ES cells, which demonstrated that hypermethylation might be involved in the regulation of miR-124 expression. Collectively, our data suggest that hypermethylation-mediated suppression of miR-124 might be involved in the tumor initiation and metastasis through suppressing the mesenchymal features of ES cells.

Protein arginine methyltransferase 5 functions as an epigenetic activator of the androgen receptor to promote prostate cancer cell growth

Protein arginine methyltransferase 5 (PRMT5) is an emerging epigenetic enzyme that mainly represses transcription of target genes via symmetric dimethylation of arginine residues on histones H4R3, H3R8 and H2AR3. Accumulating evidence suggests that PRMT5 may function as an oncogene to drive cancer cell growth by epigenetic inactivation of several tumor suppressors. Here, we provide evidence that PRMT5 promotes prostate cancer cell growth by epigenetically activating transcription of the androgen receptor (AR) in prostate cancer cells. Knockdown of PRMT5 or inhibition of PRMT5 by a specific inhibitor reduces the expression of AR and suppresses the growth of multiple AR-positive, but not AR-negative, prostate cancer cells. Significantly, knockdown of PRMT5 in AR-positive LNCaP cells completely suppresses the growth of xenograft tumors in mice. Molecular analysis reveals that PRMT5 binds to the proximal promoter region of the AR gene and contributes mainly to the enriched symmetric dimethylation of H4R3 in the same region. Mechanistically, PRMT5 is recruited to the AR promoter by its interaction with Sp1, the major transcription factor responsible for AR transcription, and forms a complex with Brg1, an ATP-dependent chromatin remodeler, on the proximal promoter region of the AR gene. Furthermore, PRMT5 expression in prostate cancer tissues is significantly higher than that in benign prostatic hyperplasia tissues, and PRMT5 expression correlates positively with AR expression at both the protein and mRNA levels. Taken together, our results identify PRMT5 as a novel epigenetic activator of AR in prostate cancer. Given that inhibiting AR transcriptional activity or androgen synthesis remains the major mechanism of action for most existing anti-androgen agents, our findings also raise an interesting possibility that targeting PRMT5 may represent a novel approach for prostate cancer treatment by eliminating AR expression.

The role of video-assisted thoracoscopic surgery in management of the multiple ground-glass nodules

OBJECTIVE

We investigated the outcomes of patients with multiple ground-glass nodules (GGNs) to identify the role of video-assisted thoracoscopic surgery (VATS) in diagnosis and treatment.

PATIENTS AND METHODS

We included patients with multiple GGNs who were qualified for thoracoscopic surgery resection and analyzed the statistics.

RESULTS

Fifty-one GGNs were detected in 21 patients. There were 40 pure GGNs and 11 part-solid ones. Around 46 of the 51 lesions were resected via VATS. Four pure GGNs <10 mm and deep in the lung were proceeded with continuous follow-up. One pure GGN measuring 16 mm considered as subnodule and also deep in the lung underwent stereotactic ablative radiotherapy. Resection methods included lobectomy (1), segmentectomy (1), lobectomy + segmentectomy (6), lobectomy + wedge resection (10), and segmentectomy + wedge resection (3). Of the 46 resected lesions, 4 (8.7%) were atypical adenomatous hyperplasia (AAH), 23 (50%) were adenocarcinoma in situ(AIS), 15 (32.7%) were minimally invasive adenocarcinoma (MIA), 2 (4.3%) were invasive adenocarcinoma, one was pulmonary sclerosing hemangioma, and one was nonspecific fibrosis. Intersegmental lymph node metastasis was found in one of the 21 patients. No postoperational complication occurred in any of the patients.

CONCLUSION

Multiple GGNs were generally independent primary lung cancers, mainly including AAH, AIS, MIA, rather than intrapulmonary metastasis. VATS was superior to thoracotomy for less invasive and shorter hospital stay.

[Influence of isobar ttl dynamic internal fixation system on adjacent segment degeneration by mri measurement of lumbar nucleus pulposus volume]

OBJECTIVE

?To investigate the influence of ISOBAR TTL dynamic internal fixation system on degeneration of adjacent intervertebral disc by MRI measurement of lumbar nucleus pulposus volume in treating lumbar degenerative disease after operation.

METHODS

?Between March 2010 and October 2011, 34 patients with lumbar intervertebral disc herniation (23 cases of paracentral type and 11 cases of lateral type) underwent operation with ISOBAR TTL dynamic internal fixation system for fixation of single segment, and the clinical data were analyzed retrospectively. There were 20 males and 14 females, aged 39-62 years (mean, 47.5 years). The disease duration was 6-18 months (mean, 14 months). Involved segments included L_{4, 5} in 21 cases and L₅, S₁ in 13 cases. The X-ray films and MRI images were taken at 6, 12, 18, 24, 36, and 48 months after surgery. Based on X-ray films, the height of intervertebral space was measured using angle bisectrix method. The nucleus pulposus volume was measured based on the MRI scan. The postoperative change of nucleus pulposus volume and intervertebral disc height were used to evaluate the influence of ISOBAR TTL system on degeneration of adjacent intervertebral disc nucleus pulposus.

RESULTS

?Thirty patients were followed up 48 months. The height of intervertebral space showed no significant difference between at pre-and post-operation (P>0.05). The nucleus pulposus volume increased after operation, showing no significant difference at 6, 12, and 18 months when compared with preoperative value (P>0.05), but significant difference was found at 24, 36, and 48 months when compared with preoperative value (P<0.05). The height of nucleus pulposus increased after operation but the width was decreased; the values showed no significant difference at 6, 12, and 18 months when compared with preoperative ones, but showed significant difference at 24, 36, and 48 months when compared with preoperative ones (P<0.05). The diameter of nucleus pulposus at 18, 24, 36, and 48 months after operation was significantly langer than that at preoperation (P<0.05).

CONCLUSIONS

?ISOBAR TTL dynamic internal fixation system can prevent or delay the degeneration of intervertebral discs.

Comparing Single Versus Double Screw-Rod Anterior Instrumentation for Treating Thoracolumbar Burst Fractures with Incomplete Neurological Deficit: A Prospective, Randomized Controlled Trial

Background

Following a thoracolumbar burst fracture (TCBF), anterior screw-rods apply pressure upon the graft site. However, there is limited evidence comparing single screw-rod anterior instrumentation (SSRAI) to double screw-rod anterior instrumentation (DSRAI) for TCBFs. Our objective was to compare SSRAI versus DSRAI for TCBFs with incomplete neurological deficit.

Material/Methods

A total of 51 participants with T11-L2 TCBFs (AO classification: A3) were randomly assigned to receive SSRAI or DSRAI. Key preoperative, perioperative, and postoperative data were collected. Statistical analysis was conducted to determine the independent factors associated with inferior clinical outcomes, as well as the comparative efficacy of SSRAI and DSRAI.

Results

There were no significant differences in the key demographic and clinical characteristics between the two groups (all p>0.05). Smoking status was significantly associated with inferior three-month and six-month Denis pain scores (Wald statistic=4.246, p=0.039). Both SSRAI and DSRAI were significantly effective in improving three-month and six-month postoperative degree of kyphosis, three-month and six-month postoperative ASIA impairment scale scores, three-month and six-month postoperative Denis pain score, and three-month and six-month postoperative Denis work score (all p<0.001). Although there were no significant differences between DSRAI and SSRAI with respect to all outcomes (all p>0.05), DSRAI displayed significantly longer operating times, as well as significantly larger operative blood losses (both p<0.001).

Conclusions

SSRAI may be preferable over DSRAI for TCBFs with incomplete neurological deficit due to its lower operating time and amount of operative blood loss.

Anti-inflammatory effects of three kinds of traditional Mongolian medicine monomer and its combination on LPS-stimulated RAW264.7 macrophages

OBJECTIVE

Traditional Mongolian Medicine (TMM) exhibits useful biological activities including antifungal, antibacterial, and anti-inflammatory actions. The mechanisms of TMM in anti-inflammation were still unclear. The aim of this study was to investigate the effects of the three main monomers (geniposide, gallate, berberine hydrochloride and a mixture of them) of a traditional Mongolian medicine on cell survival and the proinflammatory cytokines signaling pathways which are activated by bacterial lipopolysaccharides (LPS).

MATERIALS AND METHODS

Mouse macrophage-like cell line RAW264.7 was used as a model of inflammation to investigate the anti-inflammatory effects of three TMM momomers and their combination. RT-PCR and Western blot was used to quantify the change of mRNA and protein levels of cytokines, Toll-like receptor-4 (TLR4) and Nuclear Factor-κB (NF-κB) and its inhibitor IκB. The non-radioactive electrophoresis mobility shift assay (EMSA) was used to evaluate the binding activity of NF-κB.

RESULTS

The monomers and their combination exhibited a potent anti-inflammatory effect for suppressing the LPS-evoked secretion of proinflammatory cytokines IL-1β, IL-6 and TNFα. Furthermore, the monomers and their combination attenuated activation of NF-κB and expression of TLR4 at both mRNA and protein levels, the upstream player of the LPS-TLR4-cytokines/ NF-κB signaling pathway.

CONCLUSIONS

The Mongolia herbal compound exerts a potent anti-inflammatory effect and could potentially be developed as a useful agent for the chemo-prevention of inflammatory diseases.

Complex doping chemistry owing to Mn incorporation in nanocrystalline anatase TiO2 powders

Mn-doped TiO2 powders with a wide range of nominal doping levels were fabricated using a one-step hydrothermal method followed by 400 °C annealing. Anatase powders with a uniform size distribution below 10 nm were obtained. The maximum solubility of Mn in the TiO2 lattice was around 30%, beyond which the Mn3O4 compound appeared as a secondary phase. The optical absorption edges for Mn-doped anatase TiO2 were red-shifted effectively through increasing Mn content. Alloying chemistry and associated elemental valences were elaborated through combining X-ray photoelectron spectroscopy (XPS), X-ray absorption spectroscopy (XAS), and theoretical simulation in the framework of density functional theory (DFT). The results showed that the Mn species exhibited mixed valence states of 3+ and 4+ in anatase TiO2, with the latter being the key to remarkable photocatalytic performance.

Risk factors contributing to postoperative delirium in geriatric patients postorthopedic surgery

INTRODUCTION

Postoperative delirium is a common clinical manifestation in geriatric patients, resulting in prolonged hospitalization and increased economic burden, in addition to higher morbidity and mortality rates. Therefore, identifying non-obvious risk factors that contribute to the development of postoperative delirium in geriatric patients is crucial.

METHODS

From January 2011 to June 2013, 200 geriatric patients of over 65 years of age scheduled for orthopedic surgery were randomly selected and statistically analyzed with respect to the effects of the following 12 factors on postoperative delirium: sex, age, anesthesia type, surgical type (i.e. spine, hip replacement, and pelvic or femoral fracture repair), operative duration, intraoperative hypoxia, intraoperative hypercapnia, intraoperative hypotension, intraoperative blood loss, preoperative affective state, postoperative sleep disorders, and underlying disease (i.e. hypertension, coronary heart disease, diabetes, hyperlipidemia, and chronic bronchitis).

RESULTS

Seven factors--age, anesthesia type, duration of operation, intraoperative hypercapnia, intraoperative hypotension, preoperative affective state, and postoperative sleep disorders--were found to be significantly differentiated, suggesting that these factors have an impact on the development of postoperative delirium. Sex, surgical type, intraoperative hypoxia, intraoperative blood loss (with 300 ml as a cutoff value), and underlying disease were not directly related to the development of postoperative delirium.

DISCUSSION

Advanced age (>70 years), the use of general anesthesia, longer surgical duration (>3 hours), the presence of intraoperative hypercapnia and hypotension, the presence of preoperative affective dysfunction, and the presence of postoperative sleep disorders appear to be associated with the development of postoperative delirium in geriatric patients after orthopedic surgery.

K63-linked ubiquitination of FANCG is required for its association with the Rap80-BRCA1 complex to modulate homologous recombination repair of DNA interstand crosslinks

DNA interstrand crosslinks (ICLs) are extremely deleterious lesions that are repaired by homologous recombination (HR) through coordination of Fanconi anemia (FA) proteins and breast cancer susceptibility gene 1 (BRCA1) product, but the exact role these proteins have remains unclear. Here we report that FANCG was modified by the addition of lysine63-linked polyubiquitin chains (K63Ub) in response to DNA damage. We show that FANCG K63Ub was dispensable for monoubiquitination of FANCD2, but was required for FANCG to interact with the Rap80-BRCA1 (receptor-associated protein 80-BRCA1) complex for subsequent modulation of HR repair of ICLs induced by mitomycin C. Mutation of three lysine residues within FANCG to arginine (K182, K258 and K347, 3KR) reduced FANCG K63Ub modification, as well as its interaction with the Rap80-BRCA1 complex, and therefore impeded HR repair. In addition, we demonstrated that K63Ub-modified FANCG was deubiquitinated by BRCC36 complex in vitro and in vivo. Inhibition of BRCC36 resulted in increased K63Ub modification of FANCG. Taken together, our results identify a new role of FANCG in HR repair of ICL through K63Ub-mediated interaction with the Rap80-BRCA1 complex.

Analysis of survival factors in patients with intermediate-advanced hepatocellular carcinoma treated with transcatheter arterial chemoembolization combined with sorafenib

PURPOSE

To retrospectively analyze the efficacy and safety of transcatheter arterial chemoembolization (TACE) in combination with sorafenib for the treatment of patients with intermediate-advanced hepatocellular carcinoma (HCC) and assess the prognostic impact of baseline characteristics.

METHODS

Patients with intermediate-advanced HCC received TACE combined with sorafenib in this Phase 2 clinical trial. The primary outcome was median time to disease progression (mTTP). Secondary outcomes were median overall survival (mOS), the disease benefit rate and the sorafenib-related adverse events (AEs). Baseline characteristics' impacts on prognosis were analyzed by univariate COX proportional hazards regression model.

RESULTS

From June 2008 to June 2013, 75 patients were enrolled. At the end of the study, 54 patients were dead or lost to follow-up and 21 patients survived. This combination therapy resulted in a mTTP of 7.09 months (95 % CI, 1.5-45 months) and a mOS of 11.44 months (95 % CI, 1.5-45 months). The disease benefit rate was 88 %. Child-Pugh score (P = 0.000), Eastern Cooperative Oncology Group performance status (P = 0.001), Barcelona Clinic Liver Cancer stage (P = 0.000), sorafenib treatment regimen (P = 0.001), presence of extrahepatic metastasis (P = 0.002), and type of tumor (P = 0.027) were significantly correlated with OS. Multivariate analysis revealed Child-Pugh score (P = 0.001) and BCLC stage (P = 0.002) as significant independent prognostic predictors for OS. AEs were HFSR (18.7 %), gastrointestinal reactions (13.3 %), liver dysfunction (6.7 %), myelosuppression (5.3 %), fatigue (4 %), and hypertension (1.3 %).

CONCLUSIONS

TACE in combination with sorafenib might have acceptable safety and efficiency in the treatment of intermediate-advanced HCC.

Novel ZnO nanorod films by chemical solution deposition for planar device applications

Smooth and continuous ZnO films consisting of densely packed ZnO nanorods (NRs), which can be used for electronic device fabrication, were synthesized using a hydro-thermo-chemical solution deposition method. Such devices would have the novelty of high performance, benefiting from the inherited unique properties of the nanomaterials, and can be fabricated on these smooth films using a conventional, low cost planar process. Photoluminescence measurements showed that the NR films have much stronger shallow donor to valence band emissions than those from discrete ZnO NRs, and hence have the potential for the development of ZnO light emission diodes and lasers, etc. The NR films have been used to fabricate large area surface acoustic wave devices by conventional photolithography. These demonstrated two well-defined resonant peaks and their potential for large area device applications. The chemical solution deposition method is simple, reproducible, scalable and economic. These NR films are suitable for large scale production on cost-effective substrates and are promising for various fields such as sensing systems, renewable energy and optoelectronic applications.

Abstract P6-04-12: Novel selective estrogen receptors degraders regress tumors in pre-clinical models of endocrine-resistant breast cancer

80% of all breast cancers express the estrogen receptor alpha (ERα) and thus are treated with anti-hormonal therapies that directly block ER function (e.g. Tamoxifen) or hormone synthesis (Aromatase Inhibitors). While these therapies are initially effective, acquired resistance invariably emerges. Importantly, the majority of these tumors continue to depend on ERα for growth and survival. The emerging evidence that ERα can signal in both a ligand-dependent and ligand-independent manner supports the development of agents that are not only competitive ERα antagonists but also reduce steady state levels of the receptor and thus limit both modes of signaling.

We have identified novel, non-steroidal ERα antagonists that induce degradation of ERα in breast cancer cell lines at picomolar concentrations resulting in significant reduction in steady state ERα protein levels. Using peptide-based conformational profiling, we show that these Selective Estrogen Receptor Degraders (SERDs) induce estrogen receptor conformations that are distinct from both fulvestrant and tamoxifen indicating a unique mechanism of action. This unique biological profile coupled with good oral pharmacokinetics produces tumor regressions in both tamoxifen-sensitive and -resistant models of breast cancer in vivo. Recent pre-clinical and clinical data indicate that PI3K pathway signaling can contribute to the endocrine resistant state. In a preclinical model of tamoxifen resistant breast cancer in which SERD monotherapy only produces tumor growth inhibition, SERD therapy in combination with torc1/2 inhibition results in frank tumor regressions. These orally bioavailable SERDs hold promise as a next generation therapy for the treatment of ER+ breast cancer as monotherapy, as well as in combination with agents that target other pathways involved in both intrinsic and acquired endocrine resistance.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P6-04-12.

Investigation of the hydrogen bonding in ice Ih by first-principles density function methods

It is a well recognized difficult task to simulate the vibrational dynamics of ices using the density functional theory (DFT), and there has thus been rather limited success in modelling the inelastic neutron scattering (INS) spectra for even the simplest structure of ice, ice Ih, particularly in the translational region below 400 cm(-1). The reason is partly due to the complex nature of hydrogen bonding (H-bond) among water-water molecules which require considerable improvement of the quantum mechanical simulation methods, and partly owing to the randomness of protons in ice structures which often requires simulation of large super-lattices. In this report, we present the first series of successful simulation results for ice Ih using DFT methods. On the basis of the recent advancement in the DFT programs, we have achieved for the first time theoretical outcomes that not only reproduce the rotational frequencies between 500 to 1200 cm(-1) for ice Ih, but also the two optic peaks at ∼240 and 320 cm(-1) in the translational region of the INS spectra [J. C. Li, J. Chem. Phys 105, 6733 (1996)]. Besides, we have also investigated the impact of pairwise configurations of H(2)O molecules on the H-bond and found that different proton arrangements of pairwise H(2)O in the ice Ih crystal lattice could not alter the nature of H-bond as significantly as suggested in an early paper [J. C. Li and D. K. Ross, Nature (London) 365, 327 (1993)], i.e., reproducing the two experimental optic peaks do not need to invoke the two H-bonds as proposed in the previous model which led to considerable debates. The results of this work suggest that the observed optic peaks may be attributed to the coupling between the two bands of H-O stretching modes in H(2)O. The current computational work is expected to shed new light on the nature of the H-bonds in water, and in addition to offer a new approach towards probing the interaction between water and biomaterials for which H-bond is essential.

Expression of SP-C and Ki67 in lungs of preterm infants dying from respiratory distress syndrome

This study aimed at exploring the expression of Surfactant protein-C (SP-C) and Ki67 in autopsy lung tissues of premature infants dying from respiratory distress syndrome (RDS) who were exposed to mechanical ventilation and elevated oxygen concentrations. The possible influence of pulmonary surfactant (PS) on the expression of SP-C and Ki67 was also investigated. Thirty preterm infants were selected who were histologically and clinically diagnosed as RDS. Preterm infants with RDS were divided into 4 groups, according to the time of death: infants ventilated for 1–3 days, 4–8 days, 9–16 days and >6 days. Five premature infants died within 1 day after delivery for non- pulmonary reasons served as controls. The expression of SP-C and Ki67 in lungs was detected by immunohistochemistry. Compared with the control group, the expression of SP-C and Ki67 in RDS infants decreased significantly after 1–3 days of ventilation, but increased after 4 days and reached peak value after 9–16 days. No significant difference in the expression of SP-C and Ki67 was found between infants treated with PS and those without. Thus our results suggest SP-C and Ki67 may have participated in the pulmonary pathological process in ventilated/oxygen treated preterm infants with RDS, and exogenous surfactant had no effect on the expression of SP-C and Ki67 in the lungs of ventilated/oxygen treated preterm infants with RDS.

[Failure cause of posterior approach orthopaedic operation of thoracolumbar hemivertebra and strategies of revision]

OBJECTIVE

To explore the failure cause of posterior approach orthopaedic operation of thoracolumbar hemivertebra, and to summary strategies of revision.

METHODS

The clinical data from 9 cases undergoing posterior approach orthopaedic operation failure of thoracolumbar hemivertebra between June 2003 and June 2008, were retrospectively analyzed. There were 5 males and 4 females with a median age of 12 years (range, 1 year and 10 months to 24 years). All malformations were identified as fully segmented hemivertebra from the original medical records and X-ray films, including 2 cases in thoracic vertebra, 5 cases in thoracolumbar vertebra, and 2 cases in lumbar vertebra. The preoperative scoliotic Cobb angle was (45.4 +/- 17.4) degrees, and kyphotic Cobb angle was (29.8 +/- 22.0) degrees. The reason of primary surgical failure were analyzed and spinal deformity was corrected again with posterior revision.

RESULTS

All surgeries were finished successfully. The operation time was 3.0-6.5 hours (mean, 4.5 hours), and the perioperative bleeding was 400-2 500 mL (mean, 950 mL). All incisions healed by first intention; no infection or deep venous thrombosis occurred. Numbness occurred in unilateral lower extremity of 1 case postoperatively, and the symptom was relieved completely after treatment of detumescence and neural nutrition. All cases were followed up 12-30 months (mean, 18 months). No pseudoarthrosis and implant failure occurred. The X-ray films showed that the bone grafts completely fused within 8-14 months (mean, 11 months) after operation. The Cobb angles of scoliosis and kyphosis at 1 week after operation and the last follow-up were obviously improved when compared with preoperative ones, showing significant differences (P < 0.05). No obvious correction loss was observed either in coronal or sagittal plane.

CONCLUSION

The failure causes of posterior approach orthopaedic operation are hemivertebra processing, selection of fixation and fusion range, and selection of internal fixation. If the strategies of revision are made after the above-mentioned failure causes are considered, the clinical results will be satisfactory.

[Confidence high viscosity bone cement system and postural reduction in treating acute severe osteoporotic vertebral compression fractures]

OBJECTIVE

To evaluate the effectiveness of Confidence high viscosity bone cement system and postural reduction in treating acute severe osteoporotic vertebral compression fracture (OVCF).

METHODS

Between June 2004 and June 2009, 34 patients with acute severe OVCF were treated with Confidence high viscosity bone cement system and postural reduction. There were 14 males and 20 females with an average age of 72.6 years (range, 62-88 years). All patients had single thoracolumbar fracture, including 4 cases of T11, 10 of T12, 15 of L1, 4 of L2, and 1 of L3. The bone density measurement showed that T value was less than -2.5. The time from injury to admission was 2-72 hours. All cases were treated with postural reduction preoperatively. The time of reduction in over-extending position was 7-14 days. All patients were injected unilaterally. The injected volume of high viscosity bone cement was 2-6 mL (mean, 3.2 mL).

RESULTS

Cement leakage was found in 3 cases (8.8%) during operation, including leakage into intervertebral space in 2 cases and into adjacent paravertebral soft tissue in 1 case. No clinical symptom was observed and no treatment was performed. No pulmonary embolism, infection, nerve injury, or other complications occurred in all patients. All patients were followed up 12-38 months (mean, 18.5 months). Postoperatively, complete pain relief was achieved in 31 cases and partial pain relief in 3 cases; no re-fracture or loosening at the interface occurred. At 3 days after operation and last follow-up, the anterior and middle vertebral column height, Cobb angle, and visual analogue scale (VAS) score were improved significantly when compared with those before operation (P < 0.05); and there was no significant difference between 3 days and last follow-up (P > 0.05).

CONCLUSION

Confidence high viscosity bone cement system and postural reduction can be employed safely in treating acute severe OVCF, which has many merits of high viscosity, long time for injection, and easy-to-control directionally.

Metastable Phase Transformations in Ti-40Al-10V Alloy

The microstructures in arc melted ingots and melt spun ribbons have been investigated by electron microscopy and thermodynamic modelling has been used to study the phase transformations. In the ingot, solidification starts with the bcc β phase and at room temperature the structure consists of B2, ωordered, γ and α2 phases. The calculated equilibrium phase transformation sequence during cooling is L → L+ β→β→β + α→β2+α → α+β2+γ → α2+γ + B2. The phase transformation sequence is dramatically changed by rapid quenching from the melt. Athermal ordered w phase is formed in metastable B2 and the α→α2 ordering process is completely suppressed in the melt spun ribbons. The volume fraction of the α precipitates is also dependent on cooling rates.

Calculation of Phase Competition and Selection in Solidification Using a Combined Nucleation and Calphad Approach

Thermodynamic data derived by the CALPHAD method has been extended to undercooled melts to study phase competition and the role of time dependent and steady state nucleation in rapidly solidified materials. The theoretical predictions made about phase competition between hcp α, bcc β and Ll0 γ in some Al(Ti,V) alloys are compared with experimental results. It is shown that high melt cooling rates introduce significant transient nucleation effects on phase nucleation.

Use of chemical characteristics to predict the relative bioavailability of supplemental organic manganese sources for broilers1

Twelve organic Mn sources and MnSO4 were evaluated by polarographic analysis and via solubility in buffers (pH 5 and 2) and deionized water. Fractions from solubility tests were evaluated by gel filtration chromatography for structural integrity. Organic Mn sources included five Mn methionine complexes (Mn Met A to Mn Met E), two Mn proteinates (Mn Pro A and Mn Pro B), and five Mn amino acids (Mn AA A to Mn AA E). Sources varied considerably in chemical characteristics. Chelation strength (Qf) ranged from weak (1.9 Qf-values) to strong complexes (115.4 Qf-values). No complexed Mn was found in filtrates at pH 2.0 or 5.0. A 42-d bioassay was used to estimate relative bioavailability of Mn sources for chicks fed diets supplemented with 60, 120, or 180 mg Mn/kg. Bone Mn, heart Mn, heart manganese-superoxide dismutase activity (MnSOD), and heart MnSOD mRNA increased (P < 0.001) as dietary Mn increased. Only heart MnSOD mRNA tended (P < 0.10) to differ among dietary Mn sources. For bioassays of Mn, the MnSOD mRNA level in heart was more sensitive than the MnSOD activity in heart or other indices. Relative to MnSO4 (assigned 100%), slope ratios of MnSOD mRNA levels in heart gave bioavailabilities of 99, 132, and 113% for Mn Met E, Mn AA B, and Mn AA C sources with weak, moderate, and strong chelation strength, respectively. The bioavailability of Mn was more closely related to chelation strength as measured by polarography than to chemical traits assessed by solubility or structural integrity.

[Imaging evaluation and interventional therapy of hepatic metastases from small intestinal leiomyosarcoma]

OBJECTIVE

To evaluate the imaging appearances and the short-term curative effect of hepatic metastases from small intestine leiomyosarcoma treated by interventional methods.

METHODS

Seven cases with 46 lesions of hepatic metastases from small intestinal leiomyosarcoma were analyzed retrospectively. The diameters of the metastases were from 2 cm to 18 cm. CT triphasic scan and hepatoarterial angiography were performed in all cases. The interventional therapy methods included transcatheter arterial chemoembolization (TACE) (all 7 cases), percutaneous left subclavian artery port-catheter system implantation (PCS) (1 case). Three cases were also treated with percutaneous tumor necrosis drainage (PTND) because of obvious liquefaction necrosis within the tumor.

RESULTS

The lesions were substantial occupation and some were mixed density with cystic component. The cystic component increased in the larger tumor. The hepatic metastases were enhanced remarkably during the hepatic arterial-dominant phase scan and had abundant tumor vascular and tumor stain on hepatoarterial angiography. The size of tumor in 4 cases was reduced after TACE. The tumor in the patient who was treated with PCS had no changed. The size of the tumor in 3 cases was slightly enlarged. The tumors in the 3 patients treated with PTND were reduced remarkably.

CONCLUSIONS

The predominant blood-supply of the hepatic metastases from small intestinal leiomyosarcoma is the hepatic artery abundant in blood vessels. TACE, PCS and PTND are effective methods to treat hepatic metastases from small intestinal leiomyosarcoma.

Ligand-dependent degradation of retinoid X receptors does not require transcriptional activity or coactivator interactions

Cells utilize ubiquitin-mediated proteolysis to regulate the activity of numerous proteins involved in signal transduction, cell cycle control, and transcriptional regulation. For a number of transcription factors, there appears to be a direct correlation between transcriptional activity and protein instability, suggesting that cells use targeted destruction as one method to down-regulate or attenuate gene expression. In this report we demonstrate that retinoid X receptors (RXRs) which function as versatile mediators of nuclear hormone-dependent gene expression are marked for destruction upon binding agonist ligands. Interestingly, when RXR serves as a heterodimeric partner for retinoic acid (RAR) or thyroid hormone (TR) receptors, binding of agonists by RAR or TR leads to degradation of both the transcriptionally active RAR or TR subunits as well as the transcriptionally inactive RXR subunit. Furthermore, using a series of mutants in the ligand-dependent activation domain (activation function 2), we demonstrate that agonist-stimulated degradation of RXR does not require corepressor release, coactivator binding, or transcriptional activity. Taken together, the data suggest a model for targeted destruction of transcription factors based on structural or conformational signals as opposed to functional coupling with gene transcription.

An efficient room-temperature silicon-based light-emitting diode

There is an urgent requirement for an optical emitter that is compatible with standard, silicon-based ultra-large-scale integration (ULSI) technology. Bulk silicon has an indirect energy bandgap and is therefore highly inefficient as a light source, necessitating the use of other materials for the optical emitters. However, the introduction of these materials is usually incompatible with the strict processing requirements of existing ULSI technologies. Moreover, as the length scale of the devices decreases, electrons will spend increasingly more of their time in the connections between components; this interconnectivity problem could restrict further increases in computer chip processing power and speed in as little as five years. Many efforts have therefore been directed, with varying degrees of success, to engineering silicon-based materials that are efficient light emitters. Here, we describe the fabrication, using standard silicon processing techniques, of a silicon light-emitting diode (LED) that operates efficiently at room temperature. Boron is implanted into silicon both as a dopant to form a p-n junction, as well as a means of introducing dislocation loops. The dislocation loops introduce a local strain field, which modifies the band structure and provides spatial confinement of the charge carriers. It is this spatial confinement which allows room-temperature electroluminescence at the band-edge. This device strategy is highly compatible with ULSI technology, as boron ion implantation is already used as a standard method for the fabrication of silicon devices.