Machine learning based prediction models for analyzing risk factors in patients with acute abdominal pain: a retrospective study.

Background: Acute abdominal pain (AAP) is a common symptom presented in the emergency department (ED), and it is crucial to have objective and accurate triage. This study aims to develop a machine learning-based prediction model for AAP triage. The goal is to identify triage indicators for critically ill patients and ensure the prompt availability of diagnostic and treatment resources. Methods: In this study, we conducted a retrospective analysis of the medical records of patients admitted to the ED of Wuhan Puren Hospital with acute abdominal pain in 2019. To identify high-risk factors, univariate and multivariate logistic regression analyses were used with thirty-one predictor variables. Evaluation of eight machine learning triage prediction models was conducted using both test and validation cohorts to optimize the AAP triage prediction model. Results: Eleven clinical indicators with statistical significance (p < 0.05) were identified, and they were found to be associated with the severity of acute abdominal pain. Among the eight machine learning models constructed from the training and test cohorts, the model based on the artificial neural network (ANN) demonstrated the best performance, achieving an accuracy of 0.9792 and an area under the curve (AUC) of 0.9972. Further optimization results indicate that the AUC value of the ANN model could reach 0.9832 by incorporating only seven variables: history of diabetes, history of stroke, pulse, blood pressure, pale appearance, bowel sounds, and location of the pain. Conclusion: The ANN model is the most effective in predicting the triage of AAP. Furthermore, when only seven variables are considered, including history of diabetes, etc., the model still shows good predictive performance. This is helpful for the rapid clinical triage of AAP patients and the allocation of medical resources.

Water Impalement Resistance and Drag Reduction of the Superhydrophobic Surface with Hydrophilic Strips.

Superhydrophobic surfaces (SHS) offer versatile applications by trapping an air layer within microstructures, while water jet impact can destabilize this air layer and deactivate the functions of the SHS. The current work presents for the first time that introducing parallel hydrophilic strips to SHS (SHS-s) can simultaneously improve both water impalement resistance and drag reduction (DR). Compared with SHS, SHS-s demonstrates a 125% increase in the enduring time against the impact of water jet with velocity of 11.9 m/s and a 97% improvement in DR at a Reynolds number of 1.4 × 104. The key mechanism lies in the enhanced stability of the air layer due to air confinement by the adjacent three-phase contact lines. These lines not only impede air drainage through the surface microstructures during water jet impact, entrapping the air layer to resist water impalement, but also prevent air floating up due to buoyancy in Taylor-Couette flow, ensuring an even spread of the air layer all over the rotor, boosting DR. Moreover, failure modes of SHS under water jet impact are revealed to be related to air layer decay and surface structure destruction. This mass-producible structured surface holds the potential for widespread use in DR for hulls, autonomous underwater vehicles, and submarines.

Characterization relationship between multinuclide nonequilibrium gamma radiation dose rate and 226Ra activity concentration in contaminated soil around uranium mines.

According to the characteristics of contaminated soil around uranium mines, combined with the pollution path of soil, the response relationship between the gamma radiation dose rate and radium activity concentration in contaminated soil was proposed by using a numerical model and subequilibrium theory. The results showed that the topsoil (depth 20 cm) made the mainly contribution of gamma dose rate (above 88%), and the main nuclide of concern was radium. Additionally, the uranium-radium equilibrium coefficient between 0 and 0.3 had a great influence on the gamma dose rate. The method proposed in this study could quickly identify the radium activity concentration in topsoil by using on-site gamma dose rate monitoring data. Compared with the actual monitoring results within ±10% error control, which had strong operability. This method could quickly identify the location and scope of contaminated soil and guide the on-site monitoring points around uranium mines.

Effect of biaxial stretching on the microstructure evolution, optical, mechanical and oxygen barrier properties of biodegradable poly(lactic acid) (PLA)/poly(butylene adipate-co-terephthalate) (PBAT) films.

The poly(butylene adipate-co-terephthalate) (PBAT)/poly(lactic acid) (PLA) films have been widely used due to their biological degradability and excellent comprehensive properties. However, the reports regarding biodegradable PLA/PBAT films are rather scarce. In this work, systematical investigations of biaxially stretched PLA/PBAT films were performed. Compared with unstretched films, the PLA/PBAT 75/25 films with the stretching ratio of 5 × 1 exhibited an improvement on the crystallinity of PLA from 6 % to 58.6 %. According to 2D-WAXS results, the orientation of the α crystal in the MD increased with the increase of the stretching ratio. The stretched films showed favorable barrier properties. The oxygen permeability (OP) of 2 × 2 PLA/PBAT 75/25 films shows a decrement of 22 % compared with that of the unstretched films. Interestingly, the uniaxially stretched PLA/PBAT 75/25 films exhibits increased surface roughness (Ra) for 3 × 1 film whereas decreased Ra for the 5 × 1 film, which could be related to the phase separation under stretching. The tensile strength in the machine direction (MD) of the PLA/PBAT 75/25 films was improved up to 51.6 MPa for 5 × 1 film, which is 45 % higher than that of unstretched counterpart. The stretched films exhibit excellent mechanical and barrier properties, which could be utilized in packaging industry with high potential.

The Investigation of Copolymer Composition Sequence on Non-Isothermal Crystallization Kinetics of Bio-Based Polyamide 56/512.

A new bio-based polyamide 56/512 (PA56/512) has been synthesized with a higher bio-based composition compared to industrialized bio-based PA56, which is considered a lower carbon emission bio-based nylon. In this paper, the one-step approach of copolymerizing PA56 units with PA512 units using melt polymerization has been investigated. The structure of the copolymer PA56/512 was characterized using Fourier-transform infrared spectroscopy (FTIR) and Proton nuclear magnetic resonance (1H NMR). Other measurement methods, including relative viscosity tests, amine end group measurement, thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC), were used to analyze the physical and thermal properties of the PA56/512. Furthermore, the non-isothermal crystallization behaviors of PA56/512 have been investigated with the analytical model of Mo's method and the Kissinger method. The melting point of copolymer PA56/512 exhibited a eutectic point at 60 mol% of 512 corresponding to the typical isodimorphism behavior, and the crystallization ability of PA56/512 also displayed a similar tendency.

Laser-Heat Surface Treatment of Superwetting Copper Foam for Efficient Oil-Water Separation.

Oil pollution in the ocean has been a great threaten to human health and the ecological environment, which has raised global concern. Therefore, it is of vital importance to develop simple and efficient techniques for oil-water separation. In this work, a facile and low-cost laser-heat surface treatment method was employed to fabricate superwetting copper (Cu) foam. Nanosecond laser surface texturing was first utilized to generate micro/nanostructures on the skeleton of Cu foam, which would exhibit superhydrophilicity/superoleophilicity. Subsequently, a post-process heat treatment would reduce the surface energy, thus altering the surface chemistry and the surface wettability would be converted to superhydrophobicity/superoleophilicity. With the opposite extreme wetting scenarios in terms of water and oil, the laser-heat treated Cu foam can be applied for oil-water separation and showed high separation efficiency and repeatability. This method can provide a simple and convenient avenue for oil-water separation.

Effect of Process Parameters on Weld Quality in Vortex- Friction Stir Welding of 6061-T6 Aluminum Alloy.

Vortex- friction stir welding (VFSW) utilizes a stir bar made of an identical material to the workpiece to rub the workpiece's top surface, which avoids the keyhole defect in conventional friction stir welding. It presents great potential in the repair field of aluminum alloys. In this study, the effect of stir bar diameter, rotation speed, and welding speed on the weld formation was investigated in the VFSW of 6061-T6 aluminum alloy. The weld macrostructure, penetration, and mechanical properties were characterized. The results show that a large diameter of the stir bar can enhance the vortex material flow, increase the heat input, and eliminate the incomplete-penetration defect. The increase in rotation speed within limits can enhance the weld penetration and the mechanical properties of the weld nugget zone (WNZ). However, too high a rotation speed reduces the weld penetration and weakens the mechanical properties of the WNZ. The increase in welding speed reduces the weld penetration but enhances the mechanical properties of the heat affected zone. The incomplete-penetration defect significantly weakens the ductility of the VFSW joint. It can be eliminated by enlarging the stir bar diameter and choosing a moderate rotation speed and a lower welding speed.

Effects of RFRP­3 on an ovariectomized estrogen­primed rat model and HEC­1A human endometrial carcinoma cells.

The hypothalamic peptide gonadotropin inhibitory hormone (GnIH) is a relatively novel hypothalamic neuropeptide, identified in 2000. It can influence the hypothalamic-pituitary-gonadal axis and reproductive function through various neuroendocrine systems. The present study aimed to explore the effects and potential underlying molecular mechanism of RFamide-related peptide-3 (RFRP-3) injection on the uterine fluid protein profile of ovariectomized estrogen-primed (OEP) rats using proteomics. In addition, the possible effects of RFRP-3 on the viability and apoptosis of the human endometrial cancer cell line HEC-1A and associated molecular mechanism were investigated. The OEP rat model was established through injection with GnIH/RFRP-3 through the lateral ventricle. At 6 h after injection, the protein components of uterine fluid of rats in the experimental and control groups were analyzed using liquid chromatography (LC)-tandem mass spectrometry (MS/MS). Differentially expressed proteins (DEPs) were analyzed using the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases. Protein-protein interactions (PPI) were investigated using the STRING database. PPI networks were then established before hub proteins were selected using OmicsBean software. The expression of one of the hub proteins, Kras, was then detected using western blot analysis. Cell Counting Kit-8, Annexin V-FITC/PI, reverse transcription-quantitative PCR and western blotting were also performed to analyze cell viability and apoptosis. In total, 417 DEPs were obtained using LC-MS/MS, including 279 upregulated and 138 downregulated proteins. GO analysis revealed that the majority of the DEPs were secretory proteins. According to KEGG enrichment analysis, the DEPs found were generally involved in tumor-associated pathways. In particular, five hub proteins, namely G protein subunit α (Gna)13, Gnaq, Gnai3, Kras and MMP9, were obtained following PPI network analysis. Western blot analysis showed that expression of the hub protein Kras was downregulated following treatment with 10,000 ng/ml RFRP-3. RFRP-3 treatment (10,000 ng/ml) also suppressed HEC-1A cell viability, induced apoptosis, downregulated Bcl-2 and upregulated Bax protein expression, compared with those in the control group. In addition, compared with those in the control group, RFRP-3 significantly reduced the mRNA expression levels of PI3K, AKT and mTOR, while upregulating those of LC3-II. Compared with those in the control group, RFRP-3 significantly decreased the protein expression levels of PI3K, AKT, mTOR and p62, in addition to decreasing AKT phosphorylation. By contrast, RFRP-3 significantly increased the LC3-II/I ratio and G protein-coupled receptor 147 (GPR147) protein expression. In conclusion, the present data suggest that RFRP-3 can alter the protein expression profile of the uterine fluid of OEP rats by upregulating MMP9 expression whilst downregulating that of key hub proteins Gna13, GnaQ, Gnai3 and Kras. Furthermore, RFRP-3 can inhibit HEC-1A cell viability while promoting apoptosis. The underlying molecular mechanism may involve activation of GPR147 receptor by the direct binding of RFRP-3, which further downregulates the hub protein Kras to switch on the PI3K/AKT/mTOR pathway. This subsequently reduces the Bcl-2 expression and promotes Bax expression to induce autophagy.

Diagnosis of Nonperitonealized Colorectal Cancer with Computerized Tomography Image Features under Deep Learning.

This study aimed to explore the value of abdominal computerized tomography (CT) three-dimensional reconstruction using the dense residual single-axis super-resolution algorithm in the diagnosis of nonperitonealized colorectal cancer (CC). 103 patients with nonperitonealized CC (the lesion was located in the ascending colon or descending colon) were taken as the research subjects. The imagological tumor (T) staging, the extramural depth (EMD) of the cancer tissues, and the extramural vascular invasion (EMVI) grading were analyzed. A dense residual single-axis super-resolution network model was also constructed for enhancing CT images. It was found that the CT images processed using the algorithm were clear, and the peak signal-to-noise ratio (PSNR) and structural similarity (SSIM) were 33.828 dB and 0.856, respectively. In the imagological T staging of CC patients, there were 17 cases in the T3 stage and 68 cases in the T4 stage. With the EMD increasing, the preoperative carcinoembryonic antigen (CEA) highly increased, and the difference was statistically significant (P < 0.05). The postoperative hospital stays of patients were also different with different grades of EMVI. The hospital stay of grade 1 patients (19.45 days) was much longer than that of grade 2 patients (13.19 days), grade 3 patients (15.36 days), and grade 4 patients (14.36 days); the differences were of statistical significance (P < 0.05). It was suggested that CT images under the deep learning algorithm had a high clinical value in the evaluation of T staging, EMD, and EMVI for the diagnosis of CC.

Down-Regulation of miR-138 Alleviates Inflammatory Response and Promotes Wound Healing in Diabetic Foot Ulcer Rats via Activating PI3K/AKT Pathway and hTERT.

Objective: To study the role of miR-138 on the repair of diabetic foot ulcer (DFU) and further to explore its possible mechanism. Materials and Methods: miR-138 inhibitor, IGF-1, LY294002 were used in DFU rat mode, and the mRNA expression of miR-138 was detected. HE staining was used to observe the histological changes of skin ulcer in rats. The level of inflammation, wound healing, and blood vessel formation-related factors were detected by ELISA and immunohistochemical. The expression of VEGF and PI3K/AKT pathway-related proteins were detected by Western blot. To further determine the underlying mechanism of miR-138 in the repair of DFU, telomerase inhibitor BIBR-1232 was used in HUVECs. Dual-luciferase assay was used to determine the target relationship between miR-138 and hTERT. CCK-8, transwell, and tube formation assays were conducted to observe the biological behavior of HUVECs. Inflammatory cytokines and PI3K/AKT pathway-related proteins were also measured by ELISA and Western blot. Results: The mRNA expression of miR-138 in DFU rat was increased and ulcer of diabetic foot rats was improved after silencing miR-138. The results of cellular bioactivity in vitro experiment were consistent with that in vivo. Meanwhile, after silencing miR-138, the level of inflammatory cytokines was decreased, while the level of anti-inflammatory and healing factors was increased in vivo and vitro. Moreover, the ratios of p-PI3K/PI3K and p-AKT/AKT were upregulated after treated with miR-138 inhibitor and miR-138 was negatively regulated the expression of hTERT. However, the inhibitory effect on inflammatory response and the promotion effect on wound healing of miR-138 inhibitor were reversed by LY294002 and BIBR-1232. Conclusion: Down-regulation of miR-138 could alleviate inflammatory response and promote wound healing in DFU rats by activating PI3K/AKT pathway and hTERT.

Microstructural Evolutions of 2N Grade Pure Al and 4N Grade High-Purity Al during Friction Stir Welding.

The grain refinement mechanisms along the material flow path in pure and high-purity Al were examined, using the marker insert and tool stop action methods, during the rapid cooling friction stir welding using liquid CO2. In pure Al subjected to a low welding temperature of 0.56Tm (Tm: melting point), the resultant microstructure consisted of a mixture of equiaxed and elongated grains, including the subgrains. Discontinuous dynamic recrystallization (DDRX), continuous dynamic recrystallization (CDRX), and geometric dynamic recrystallization are the potential mechanisms of grain refinement. Increasing the welding temperature and Al purity encouraged dynamic recovery, including dislocation annihilation and rearrangement into subgrains, leading to the acceleration of CDRX and inhibition of DDRX. Both C- and B/-type shear textures were developed in microstructures consisting of equiaxed and elongated grains. In addition, DDRX via high-angle boundary bulging resulted in the development of the 45° rotated cube texture. The B/ shear texture was strengthened for the fine microstructure, where equiaxed recrystallized grains were fully developed through CDRX. In these cases, the texture is closely related to grain structure development.

Sericin inhibits MDA­MB­468 cell proliferation via the PI3K/Akt pathway in triple­negative breast cancer.

Triple negative breast cancer (TNBC) is a subtype of breast cancer characterized by an aggressive histology and poor prognosis, with limited treatment options in the clinic. In the present study, the effect of sericin, as an anti­cancer drug, on TNBC cell proliferation was investigated using a MTT assay, a colony formation assay and immunocytochemistry staining of Ki67. Results from the flow cytometry demonstrated that sericin induced G0/G1 cell cycle arrest and promoted cellular apoptosis. Cell cycle and apoptosis­related proteins were detected via western blot analysis. Immunocytochemistry staining identified that P21 was translocated into the nucleus. Additionally, several pathways were significantly enriched in TNBC based on the Gene Expression Omnibus database, with the most prominent pathway being the PI3K/Akt signaling pathway. In TNBC MDA­MB­468 cells, sericin suppressed the PI3K/Akt pathway. All these findings suggested that sericin served a critical role in suppressing TNBC cell proliferation, inducing cell cycle arrest and promoting cellular apoptosis. The results indicated that the underlying molecular mechanism was, at least partially, via the downregulation of the PI3K/Akt signaling pathway.

Crystal Structure and Mechanical Properties of Uniaxially Stretched PA612/SiO2 Films.

Stretching has a significant effect on the microstructure and ultimate performance of semi-crystalline polymers. To investigate the effect of stretching on structure and mechanical properties of uniaxial stretched PA612/SiO2, PA612 and PA612/SiO2 films were prepared at four temperatures close to the glass transition temperature at various strain. The samples were characterized by a transmission electron microscope (TEM), wide-angle X-ray diffractometer (WAXD), Two-dimensional wide-angle X-ray Scattering (2D-WAXS), differential scanning calorimeter (DSC), dynamic mechanical analyzer (DMA), and stretching tests. The results showed that the α phase was the dominant phase in PA612 casting film, no obvious γ phase was observed, while both stretching and the presence of SiO2 can induce the generation of α phase and improve the crystallinity of PA612. Crystals were oriented along the stretching direction and the b axis was parallel to the equatorial direction after stretching. The interplanar spacing of (010/110) decreased with the increasing stretching temperature and expanded with the increasing strain, while stretching temperature and strain present negligible effect on the interplanar spacing of (100). The grain size increased with the stretching temperature while decreased with strain. The presence of SiO2 led to reduce the yield stress and the stress drop beyond yielding of the composite. Uniaxial stretching gave rise to a significant improvement in the fracture stress and the glass transition temperature.

[Clinical path of mechanical ventilation and atomization inhalation therapy].

In recent years, atomization inhalation therapy has been more and more commonly used in patients with mechanical ventilation. However, the establishment of artificial airway has changed the environment and mode of aerosol delivery. Currently, Expert consensus on atomization inhalation during mechanical ventilation has been established to guide clinical practice. However, many ventilators do not support the treatment of aerosol inhalation due to the tedious procedures and numerous drugs. At the same time, the therapeutic effect of atomization inhalation is affected by many factors, such as ventilator mode selection, parameter setting, heating and humidification, using of artificial nose and filter, etc., which often results in poor clinical effects or even damage to the ventilator. In order to standardize the clinical application of mechanical ventilation atomization inhalation technology and avoid many possible problems in operation, the committee members of Respiratory Therapy Group of Severe Medicine Branch of Henan Medical Association discussed and concluded this clinical path, so as to provide clinical reference for the actual operation and drug administration of mechanical ventilation atomization.

Primary Intracranial Squamous Cell Carcinoma Arising De Novo: A Case Report and Review of the Literature.

BACKGROUND: Primary intracranial squamous cell carcinoma (PISCC) is extremely rare, and most cases are caused by malignant changes in an epidermoid cyst or a dermoid cyst. We report a case of intracranial squamous cell carcinoma (SCC) that arose without a preexisting tumor. In addition, the literature on PISCC is reviewed. CASE DESCRIPTION: A 20-year-old man presented with a 4-day history of headache. Magnetic resonance imaging of the brain showed a heterogeneous and irregularly marginated solid-cystic lesion in the left lateral ventricle, which enhanced dramatically. The patient underwent removal of the lesion, and a postoperative histologic examination showed SCC. The patient did not undergo postoperative radiotherapy and was admitted to the hospital again 40 days later because of dizziness, right lower extremity pain, and difficulty in bending. Computed tomography showed hydrocephalus. The cerebrospinal fluid examination confirmed an intracranial infection. The patient was discharged after treatment. The patient survived for 9 months from the onset of the disease. CONCLUSIONS: Most cases of PISCC arise from the malignant transformation of epidermoid cysts. However, SCC arising de novo is even less common. Although rare, the malignant transformation of intracranial epithelial cysts has a poor prognosis. Future prospective trials are necessary to evaluate the optimal treatment modality for patients with PISCC.

[Mobilization and collection of autologous peripheral blood stem cells by CIE or IEV protocol in children with malignant solid tumors].

OBJECTIVE: Autologous peripheral blood stem cell transplantation (APBSCT) is an important method for treatment of malignant solid tumors in children. The mobilization and collection of blood stem cells is crucial for APBSCT. This study aimed to evaluate the clinical efficacy of mobilization and collection of blood stem cells by CIE or IEV chemotherapy protocol in APBSCT in children with neuroblastoma (NB) or rhabdomyosarcoma. METHODS: The protocols of CIE (cisplatin, etoposide) and IEV (vincristine, dosfamide, etoposide) were used as mobilization chemotherapy in 8 cases of NB with stage IV and 3 cases of rhabdomysacoma with stage III, respectively. The results of the mobilization of blood stem cells were observed. RESULTS: Of the 11 cases, mononuclear cells (MNC) and CD34+ cells were successfully collected and the volume of MNC and CD34 averaged (5.55 ± 1.43)× 10(8)/kg and (4.88 ± 2.48) × 10(6)/kg, respectively. No severe complications were observed during the mobilization and collection. A rapid hemopoietic reconstitution was observed in 10 children after APBSCT. One with NB out of the 10 children died of left heart failure 32 days after APBSCT. Others (9 cases) showed a nearly normal result of routine peripheral blood test 60 days after APBSCT. CONCLUSIONS: CIE or IEV protocol is effective and safe for the mobilization and collection of peripheral blood stem cells in children with NB or rhabdomysacoma.

[ATP-Sensitive potassium channel function during the progression of pressure overload heart failure in rats].

OBJECTIVE: To investigate K(ATP) channel function of cardiomyocytes isolated from the left ventricular wall of rats with or without abdominal aortic constriction at different time points under normal or simulated ischemic conditions. METHODS: Male Wistar rats were randomized into 4 groups (n = 10 - 13): 4-week sham-operated group (F4), 4-week aortic-banded group (T4), 12-week sham-operated group (F12), 12-week aortic-banded group (T12). Chronic pressure overload model was established by abdominal aortic constriction. Left ventricular myocytes were isolated by modified Langendorff perfusion method post in vivo hemodynamical measurements. The whole-cell patch-clamp technique was used to record transient outward current of K(ATP) channel on myocytes under normal and simulated ischemic perfusion conditions. The current densities of K(ATP) channel between F4 and T4 group, F12 and T12 group were compared under 0 mV of test potential. RESULTS: SBP, DBP and MBP were significantly increased in T4 group compared to F4 group, but were similar between T12 and F12 groups. LVEDP and +/- dp/dtmax were similar between T4 and F4 groups and LVEDP was significantly increased while +/- dp/dtmax significantly reduced in T12 group than that in F12 group. Whole-cell membrane current densities were similar between F4 and T4 group or F12 and T12 group under normoxic condition, the K(ATP) current densities increased dramatically in T12 group [(28.11 +/- 3.91) pA/pF vs (11.55 +/- 1.17) pA/pF, P < 0.01], but not in T4 group [(14.09 +/- 5.74) pA/pF vs (11.74 +/- 3.68) pA/pF, P > 0.05] in myocytes exposed to ischemic solution for 25 minutes. The total number of K(ATP) channel in ventricular myocytes was similar between F4 and T4 group or F12 and T12 group. CONCLUSIONS: The sarcolemmal K(ATP) channel was more sensitive to ischemia and the current magnitude was significantly increased at the stage of congestive heart failure. The functional change of K(ATP) channel occurred before the increase of total number of K(ATP) channel.

[Expression of odorant receptor genes on the olfactory epithelium following olfactory nerve disconnection].

OBJECTIVE: To constitute the animal model of unilateral olfactory nerve transection and observe the expression level and distribution of odorant receptors. METHODS: Thirty-two rats were divided into two groups: the olfactory nerve transection group (20) and the control group (12). The former group received the operation to transect the left olfactory nerve following the left olfactory bulb was exposed under microscope and the latter group did not give any disposal. At every stage of five days, two weeks, four weeks and six weeks after the operation, five rats from the nerve transection group and three from the control group were anaesthetized simultaneously, and olfactory epithelium were taken out after transcardial perfusion, then paraffin imbedding. Coronal sections were sliced for HE staining to observe the thickness changes of the olfactory epithelium, and for in situ hybridization (ISHs) to investigate the expression of olfactory receptor genes (Olr287, Olr226, Olr1493 and Olr1654) in the epithelium, also to evaluate the changes of the expression level and location of the selected receptors during the regeneration of olfactory epithelium. RESULTS: HE staining showed that 5 days after the operation cell quantity and thickness of the olfactory epithelium decreased obviously, which increased gradually 2 or 4 weeks after operation. After 6 weeks' recovery, the thickness of the epithelium could reach the control level. The pattern of cell staining by ISH showed a specific spatial distribution along the anteroposterior (AP) and dorsoventral (DV) axis. Evidence suggested that odorant receptors were distributed in continuous and multiple overlapping bands in the normal or nerve transected-recovered epithelium rather than in the conventionally accepted three or four zones. The data also demonstrated that the distribution of sensory neuron types, as identified and defined by odorant receptor expression, was restored to normal or nearly so by 6 weeks after operation. Likewise, the numbers of probe-labeled neurons in the nerve transected-recovered had an obvious decrease 5 days after olfactory nerve transection. Reactive cells (x(-) +/- s) of Olr1493 in the operated side was (53.9 +/- 19.9), compared with (419.0 +/- 21.2) in the unoperated side, there was statistic significance between them (t = 63.960, P < 0.01). Reactive cells increased gradually according to the regeneration of the epithelium, and were nearly equivalent to the normal side 6 weeks later without significant differentiation (t = 2.600, P > 0.05), according to the absolute positive cells in the operated and unoperated side of (417.8 +/- 32.4) and (445.3 +/- 10.0) respectively. CONCLUSION: The regeneration of the sensory neurons and receptors, both the number and the distribution, can recover to normal after olfactory nerve transection.

Effects of glucocorticoid on cyclic nucleotide-gated channels of olfactory receptor neurons.

OBJECTIVE: Cyclic adenosine monophosphate (cAMP) and cyclic nucleotide-gated (CNG) channels play an important role in olfactory perception. The purpose of this study was to explore the effect of glucocorticoid on the CNG channels of olfactory receptor neurons (ORNs). METHODS: For in vivo studies, rats were injected with dexamethasone 1 mg/kg body weight intraperitoneally once or once a day for 2 weeks. After 24 hours or 2 weeks, the difference in CNGA2 (the principal subunit of CNG channels) messenger ribonucleic acid (mRNA) in the ORNs was detected. For in vitro studies, the ORN membrane was extracted and incubated with 0.1 or 1 mg/mL dexamethasone for 5 or 30 minutes, respectively, and then the concentrations of cAMP were measured. For all experiments, normal saline was used as the control. RESULTS: For in vivo studies, compared with the normal saline group, CNGA2 mRNA could be upregulated in the 2-week group (p < .01) but not in the 24-hour group (p > .05). For in vitro studies, dexamethasone of both 0.1 and 1 mg/mL raised the concentration of cAMP in the ORNs at 5 and 30 minutes, respectively (p < .05), and the concentration of cAMP was higher in the 1 mg/mL groups than in the 0.1 mg/mL groups (p < .05). However, there was no significant difference between the 5-minute and 30-minute groups with either concentration. CONCLUSIONS: Glucocorticoid enhanced both the mRNA expression of CNG channels and the production of cAMP, which might be a possible pathway for treating olfactory disorders. The effect of glucocorticoid was dose-dependent.

Molecular regulation of vasculogenic mimicry in human uveal melanoma cells: role of helix-loop-helix Id2 (inhibitor of DNA binding 2).

BACKGROUND: Vasculogenic mimicry (VM) is a tumor angiogenesis process in which highly aggressive melanoma cells form patterned, tubular networks in an in vitro, three-dimensional culture that mimics vasculogenic networks formed by endothelial cells. These cells also express endothelial cell-associated genes such as vascular endothelial-cadherin (VE-cadherin) and are correlated with poor clinical prognosis in patients. However, the molecular underpinnings of this phenomenon remain elusive. METHODS: Three-dimensional cultures of highly and poorly aggressive uveal melanoma cells were observed by inverted light microscope and scanning electronic microscope for VM. RNAi (RNA interference) technology was used to examine whether inhibitor of DNA binding 2 (Id2) was involved in the uveal melanoma vasculogenic mimicry. Western blot analysis showed changes of Id2 and VE-cadherin expression in highly and poorly aggressive melanoma cells in vitro. Migration analysis of highly and poorly aggressive uveal melanoma cells in vitro illuminated the role of Id2 in tumor cells migration. RESULTS: We show here that a transient knockdown of Id2 by RNA interference abrogates VM and VE-cadherin expression in highly aggressive uveal melanoma cells. Furthermore, inhibition of Id2 changes cellular stability and creates a more dynamic condition. Transfected cells also migrate better than untransfected cells. CONCLUSIONS: This study shows that Id2 is an important regulator of VM. Specifically, Id2 affects VE-cadherin expression, and is critical for the formation of vasculogenic-like networks.