Tracking the Progression of the Simulated Bronze Disease-A Laboratory X-ray Microtomography Study.

The internal three-dimensional characteristics of X-ray microtomography (micro-CT) has great application potential in the field of bronze corrosion. This work presents a method of simulating bronze disease based on an in situ micro-CT image to study the characteristics of the oxidative hydrolysis reactions of copper(I) chloride and copper(II) chloride dihydrate. A series of high-resolution reconstruction images were obtained by carrying out micro-CT at three key points throughout the experiment. We found that the reactions of copper(I) chloride and copper(II) chloride dihydrate showed different characteristics at different stages of the simulation in the micro-CT view. The method proposed in this work specifically simulated one single type of bronze corrosion and characterized the evolution characteristics of simulated bronze disease. It provides a new perspective to investigate bronze disease and can help improve the subsequent use of micro-CT to distinguish real bronze corrosions.

Drift correction in laboratory nanocomputed tomography using joint feature correlation.

Laboratory nanocomputed tomography (nano-CT), which can provide a spatial resolution of up to 100 nm, has been widely used due to its volume advantage. However, the drift of the x-ray source focal spot and the thermal expansion of the mechanical system can cause projection drift during long-time scanning. The three-dimensional result reconstructed from the drifted projections contains severe drift artifacts, which reduce the spatial resolution of nano-CT. Registering the drifted projections using rapidly acquired sparse projections is one of the mainstream correction methods, but the high noise and contrast differences of projections in nano-CT affect the correction effectiveness of existing methods. Herein, we propose a rough-to-refined projection registration method, which fully combines the information of the features in the gray and frequency domains of the projections. Simulation data show that the drift estimation accuracy of the proposed method is improved by 5× and 16× compared with the mainstream random sample consensus and locality preserving matching based on features. The proposed method can effectively improve the imaging quality of nano-CT.

Cullin 4A/protein arginine methyltransferase 5 (CUL4A/PRMT5) promotes cell malignant phenotypes and tumor growth in nasopharyngeal carcinoma.

Targeted therapy is an important therapeutic strategy currently, however, the development of targeted therapy for nasopharyngeal carcinoma (NPC) is relatively lagging. Cullin 4A (CUL4A) was reported to be overexpressed in NPC; nevertheless, the specific role of CUL4A remains unrevealed. NPC cells and tumor-bearing mice were cultivated to explore the role and mechanism of CUL4A in NPC. After evaluating CUL4A levels in NPC cells, functional experiments were carried out to investigate the effects of CUL4A knockdown and overexpression on cell proliferative, invasive and migratory aptitude as well as NF-κB signaling. Following the GeneMANIA database predicted that protein arginine methyltransferase 5 (PRMT5) was downstream of CUL4A, the mediated role of PRMT5 in the regulation of CUL4A on cells was then determined. Moreover, the tumor volumes and weights of tumor-bearing mice were recorded, and the levels of proliferation-, migration-, and NF-κB signaling-related proteins in the tumor were determined. Herein, CUL4A was enhanced in NPC cells, and its knockdown and overexpression separately suppressed and promoted cell proliferative, invasive, and migratory aptitude as well as NF-κB signal activation. Novelty, PRMT5 knockdown reversed the influences of CUL4A overexpression on these aspects. In addition, its knockdown likewise reversed the facilitating impact of CUL4A expression on tumor growth and declined the expression levels of proliferation-, migration-, and NF-κB signaling-related protein in the tumor. Together, this paper indicated that CUL4A promoted the proliferative, invasive, and migratory aptitude of NPC cells as well as tumor growth by promoting PRMT5 to activate NF-κB signaling.

The protective effect of olfactory ensheathing cells on post-injury spiral ganglion cells.

CONCLUSIONS: Transplantation of OECs into the cochlea may protect and increase the survival of SGCs. OBJECTIVE: To investigate the protective effect of the transplantation of olfactory ensheathing cells (OECs) on injured spiral ganglion cells (SGCs) in rats. METHODS: OECs were transplanted into the cochlea in rats with SGCs that were injured by kanamycin sulfate (KM). An equal volume of D-Hanks was injected into the cochlea of control rats. Auditory brainstem responses (ABRs) were recorded from the rats in both groups to monitor changes in hearing thresholds. Immunofluorescence was employed to examine the density and morphology of SGCs to assess the ototoxic condition of the cochlea. RESULTS: There was no significant difference in the ABR threshold at each frequency between the control and experimental groups. Notably, in the experimental group, a number of Hoechst 3334-labeled nuclei were detected from the apex to the basal turn of the cochlea, demonstrating that the OECs were successfully transplanted and survived in the cochlea. In the experimental group, most of the SGCs were tightly arranged, and the nuclear membrane, chromatin, and nucleolus were all clear. The SGCs in the control group were loosely arranged, and only a few normal SGCs were observed in this group.

Pedicled local mucosal flap and autogenous graft for the closure of nasoseptal perforations.

CONCLUSION: The results suggest that the procedure is effective in the repair of nasal septal perforations (10-20 mm in diameter). Therefore, we consider it to be a good alternative for repairing nasal septal perforations. OBJECTIVE: To introduce and evaluate a technique of pedicled local mucosal flap with the interposition of an autogenous graft in the repair of nasal septal perforations. METHODS: Between 2004 and 2008, the clinical notes of 28 patients with nasal septal perforations (10-20 mm in diameter) undergoing the surgery of pedicled local mucosal flap with the interposition of an autogenous graft were reviewed. RESULTS: Complete perforation closure was achieved in 26 cases (92.9%). Two patients had a reperforation, one receiving a second technique and a subsequent successful closure of the perforation; the other case with an asymptomatic perforation did not undergo further surgery. No serious complications were encountered.

[Ototoxicity of kanamycin sulfate in adult rats and its underlying mechanisms].

The aim of the present study was to assess the ototoxicity of kanamycin sulfate (KM) in adult rats and its underlying mechanism. Forty male Sprague-Dawley rats (6-7 weeks old) were randomly divided into the experimental group and the control group. The animals in the experimental group were injected subcutaneously with KM (500 mg/kg per day) for two weeks, and the control group received equal volume of normal saline. To assess the ototoxicity of KM, the auditory brainstem response (ABR) was recorded to monitor the changes in hearing thresholds, and the density of spiral ganglion cells (SGCs) and morphology of cochlea were observed using surface preparations and frozen sections of cochlea. The results showed that the hearing threshold of rats in the experimental group was elevated by more than 60 dB across all the frequencies two weeks after the first administration of KM. And in the experimental group, the density of SGCs became lower, and organ of Corti suffered loss of hair cells. The loss of outer hair cells (OHCs) was more severe than that of inner hair cells (IHCs), correlated with the density decrease of SGCs. We conclude that the ototoxicity of KM in the adult rats was apparent and the underlying mechanism is associated with the loss of SGCs and hair cells.

Management of maxillary sinus inverted papilloma via transnasal endoscopic anterior and medial maxillectomy.

OBJECTIVE: To introduce and evaluate the effectiveness and safety of transnasal endoscopic anterior and medial maxillectomy (TEAMM) in the treatment of Krouse stage III inverted papilloma (IP) originating from the maxillary sinus. METHODS: A retrospective chart review was performed for 33 patients with Krouse stage III IP undergoing TEAMM in our hospital between 2003 and 2008. RESULTS: Tumors were completely resected through TEAMM. Sixteen cases had type I TEAMM, during which the nasolacrimal duct was preserved; 17 had type II TEAMM, during which the nasolacrimal duct was resected. The inferior turbinate was partially preserved in 26 cases. Patients were followed for a mean of 40.4 months. Recurrence developed in 2 patients, dry nose syndrome in 5 patients, and epiphora in 1 patient. Squamous cell carcinoma occurred in 1 patient. CONCLUSIONS: TEAMM is an effective and safe technique in the management of Krouse stage III IP and provides good exposure of operative cavities during follow-up.

Survival-enhancing of spiral ganglion cells under influence of olfactory ensheathing cells by direct cellular contact.

The efficacy of cochlear implantation is primarily associated with the quantity and health of the remaining spiral ganglion cells (SGCs). Olfactory ensheathing cells (OECs) are capable of expressing a variety of growth factors and adhesion molecules, playing an important role in enhancing cellular survival. To investigate the effect of OECs on the survival of SGCs, co-cultures of OECs and SGCs were developed in this study. In addition, OECs conditioned medium (OEC-CM) was employed to culture SGCs in contrast with the co-cultures. OECs were identified immunocytochemically by low-affinity nerve growth factor receptor p75 (P75NTR) and glial fibrillary acidic protein (GFAP), while SGCs were stained with neuron-specific markerbetaIII-tubulin. SGCs survival was assessed in different conditions. To explore the underlying mechanism, growth factors, adhesion molecules and their receptors were investigate using RT-PCR. Our results indicate that the co-cultures of OECs and SGCs can be successfully established and that both OECs and OEC-CM promote SGCs survival in vitro. SGCs survival was most enhanced when co-cultured with OECs. Both Olfactory bulb (OB) and OECs were proved to express BMP-4 and NCAM while BMPR-1A and a7 integrin were also detected in cochlea and SGCs. In conclusion, our results suggest that enhancement in co-cultures is in part due to direct cellular contact. Transplantation of OECs may be a cell-based therapy for the application of neurotrophic factors to the inner ear.