A decision tree model to distinguish between benign and malignant pulmonary nodules on CT scans.

OBJECTIVE: Chest computed tomography (CT) is increasingly being used to screen for lung cancer. Machine learning models could facilitate the distinction between benign and malignant pulmonary nodules. This study aimed to develop and validate a simple clinical prediction model to distinguish between benign and malignant lung nodules. PATIENTS AND METHODS: Patients who underwent a video thoracic-assisted lobectomy between January 2013 and December 2020 at a Chinese hospital were enrolled in the study. The clinical characteristics of the patients were extracted from their medical records. Univariate and multivariate analyses were used to identify the risk factors for malignancy. A decision tree model with 10-fold cross-validation was constructed to predict the malignancy of the nodules. The sensitivity, specificity, and area under the curve (AUC) of a receiver operatic characteristics curve were used to evaluate the model's prediction accuracy in relation to the pathological gold standard. RESULTS: Out of the 1,199 patients with pulmonary nodules enrolled in the study, 890 were pathologically confirmed to have malignant lesions. The multivariate analysis identified satellite lesions as an independent predictor for benign pulmonary nodules. Conversely, the lobulated sign, burr sign, density, vascular convergence sign, and pleural indentation sign were identified as independent predictors for malignant pulmonary nodules. The decision tree analysis identified the density of the lesion, the burr sign, the vascular convergence sign, and the drinking history as predictors of malignancy. The area under the curve of the decision tree model was 0.746 (95% CI 0.705-0.778), while the sensitivity and specificity were 0.762 and 0.799, respectively. CONCLUSIONS: The decision tree model accurately characterized the pulmonary nodule and could be used to guide clinical decision-making.

[Comparative analysis of population distribution, severity, emotional, and cognitive characteristics among different side idiopathic tinnitus patients].

To provide basis for prevention and treatment by analyzing the clinical features, emotional and cognitive states and their correlations of idiopathic tinnitus. Cross-sectional study was used. Thirty-six right, 44 left, and 46 bilateral idiopathic tinnitus patients diagnosed in Beijing Tongren Hospital were prospectively enrolled from October, 2020 to February, 2022. The clinical data was recorded and the THI, DBI, STAI, and MoCA were evaluated. The clinical features and the incidence of severe tinnitus, hearing lose, anxiety, and cognitive impairment were compared by one-way ANOVA, Kruskal-Wallis H, and chi-square test. The correlation between tinnitus or hearing and emotional and cognitive states were evaluated by multivariable correlation analysis. There was no significant difference in age, BMI, years of education, tinnitus duration, and the incidence of hearing loss among groups (F=0.730,P=0.484;F=1.535,P=0.219;F=1.506,P=0.226;χ²=4.242,P=0.120;χ²=6.672,P=0.083). In right, left, and bilateral tinnitus patients, the number of severe tinnitus was 12, 7, and 20 cases and the incidence was 33.3%, 15.9%, and 43.5%; the number of depression was 13, 14, and 26 cases and incidence was 36.1%, 31.8%, and 53.5%; the number of trait anxiety was 3, 2, and 10 cases and the incidence was 8.3%, 4.5%, and 21.7%. Compared with left tinnitus patients, the incidence of severe tinnitus, depression, and trait anxiety was higher in bilateral tinnitus patients (χ²=8.139,P=0.004;χ²=5.558,P=0.018;χ²=5.753,P=0.007). The incidence of state anxiety and cognitive impairment were no significant difference among groups (χ²=0.142,P=0.931;χ²=1.338,P=0.512). The overall incidence of state anxiety and cognitive impairment were 16.7%(21/126) and 37.3%(47/126) respectively. There was positive correlation between THI score and BDI, S-AI, and T-AI scores (r=0.529,P=0.001; r=0.649,P<0.001; r=0.483,P=0.003) and negative correlation between THI and MoCA scores (r=-0.364,P=0.029) in right tinnitus group. The positive correlation was found between THI score and BDI, S-AI, and T-AI scores in left tinnitus group (r=0.508,P<0.001; r=0.506,P<0.001; r=0.357,P=0.017). The positive correlation between THI score and BDI, S-AI, and T-AI scores (r=0.753,P<0.001; r=0.527,P<0.001; r=0.536,P<0.001) and the positive correlation between tinnitus duration and MoCA score(r=0.334,P=0.023) were also found in bilateral tinnitus group.

[Application of lymphocytes test in peripheral blood of patients with systemic sclerosis during the treatment].

OBJECTIVE: To explore the significance of lymphocytes in systemic sclerosis (SSc), by detecting the levels of T lymphocytes, B lymphocytes and natural killer (NK) cells, and analyzing the correlation between the lymphocytes and clinical laboratory indexes. METHODS: The numbers and proportion of T, CD4+T, CD8+T, B, and NK cells were detected by flow cytometry in peripheral blood of 32 SSc patients who had taken immunosuppressive drugs and 30 healthy controls (HC). The comparison of the lymphocyte subsets in SSc with them in the HC groups, and the correlation between the lymphocytes and other clinical and laboratory indicators were analyzed by the relevant statistical analysis. RESULTS: Compared with the HC group, the numbers of T, CD4+T, CD8+T, and NK cells in peripheral blood of SSc group, who had taken immunosuppressive drugs, were significantly decreased (P < 0.05). More-over, the proportion of NK cells in peripheral blood of the SSc group was also significantly lower than that in the HC group (P=0.004). In addition, all the lymphocyte subsets were decreased in peripheral blood of more than 65% of the SSc patients who had taken immunosuppressive drugs. Compared with CD4+T normal group, the positivity of Raynaud's phenomenon, erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) was significantly increased in CD4+T reduction group, respectively (P＝0.024, P < 0.001, P=0.018). ESR was higher in CD8+T reduction group than CD8+T normal group (P＝0.022). The prevalence of fingertip ulcer was significantly increased in B cell decrease group (P=0.019). Compared with NK cell normal group, the prevalence of fingertip ulcer was significantly increased in NK cell lower group (P=0.033), IgM was remarkablely decreased yet (P=0.049). The correlation analysis showed that ESR was negatively correlated with the counts of T lymphocytes (r＝－0.455, P＝0.009), CD4+T lymphocytes (r＝－0.416, P＝0.018), CD8+T lymphocytes (r＝－0.430, P=0.014), B cells (r＝－0.366, P＝0.039). CONCLUSION: The number of CD4+T, CD8+T, B, and NK cells significantly decreased in peripheral blood of SSc patients who had used immunosuppressive drugs, some lymphocyte subsets might be related with Raynaud's phenomenon and fingertip ulcer, and reflected the disease activity by negatively correlated with ESR and CRP; the numbers of lymphocyte subsets in peripheral blood should be detected regularly in SSc patients who had taken immunosuppressive drugs.

Low expression of CircRNA HIPK3 promotes osteoarthritis chondrocyte apoptosis by serving as a sponge of miR-124 to regulate SOX8.

OBJECTIVE: CircRNA, a type of circular RNA, has recently been shown to be a potential target for osteoarthritis (OA). Circular RNA HIPK3 (CircHIPK3) is reported to be abnormally expressed in various disease tissues and affects the occurrence and development of the disease. However, the role and underlying mechanism of CircRNA HIPK3 in osteoarthritis are still unclear. The purpose of this study is to explore the effect of CircRNA HIPK3 on osteoarthritis and analyze its regulatory mechanism. PATIENTS AND METHODS: We took human OA tissues, normal knee cartilage, human OA chondrocytes and normal chondrocytes as the research objects. Real Time-quantitative Polymerase Chain Reaction (RT-qPCR) was used to detect CircHIPK3 expression level, its target gene miRNA 124 (miR-124) and downstream target molecule SOX8. Flow cytometry analysis was applied to discover the apoptosis of CircHIPK3 and miR-124 on OA cartilage in different transfection situations. Moreover, Western blot and RT-qPCR were used to detect the expression of caspase-3 in OA chondrocytes. The binding site of CircRNA HIPK3 and miR-124, miR-124, and SOX8 were verified by using Dual-Luciferase assay. RESULTS: High expressed CircHIPK3 and low expressed miR-124 were found in OA tissues and OA chondrocytes. In addition, the Dual-Luciferase report showed CircHIPK3 acted as a sponge of miR-124 in OA chondrocytes. CircHIPK3 and miR-124 expression in OA tissue were confirmed to be negatively correlated. To our surprise, knocking down CircHIPK3 and transfected miR-124 mimics both inhibited the apoptosis of OA chondrocytes. Further experiments verified that the downstream target molecule of miR-124 was SOX8 in OA chondrocytes. Besides, miR-124 inhibitors reversed the knockdown of CircHIPK3 while si-SOX8 reversed the miR-124 inhibitors effect of apoptosis on OA chondrocytes. CONCLUSIONS: Our results demonstrated that CircHIPK3 was significantly upregulated in OA cartilage tissue and cells. Low expression of CircHIPK3 promoted the apoptosis of OA chondrocytes by promoting miR-124 to suppress SOX8 expression. The molecular mechanism of CircHIPK3 in present study is expected to provide new ideas for the treatment of osteoarthritis.

[Correlation analysis of Sema4D with rheumatoid arthritis disease activity, bone destruction and rheumatoid arthritis-related interstitial lung disease].

Objective: To explore the correlation between Semaphorin 4D (Sema4D) and rheumatoid arthritis (RA) clinical manifestations, laboratory indexes, bone destruction and rheumatoid arthritis related interstitial lung disease(RA-ILD), and to analyze its significance in evaluating the severity of patients with rheumatoid arthritis. Methods: A total of 108 RA patients and 50 healthy controls from September 2018 to October 2019 were collected from the Department of Rheumatology and Immunology, Peking University People's Hospital and Beijing Haidian Hospital. According to the DAS 28 score, RA patients were divided into active disease group (DAS28>2.6) and stable disease group (DAS28 ≤ 2.6). Fifty healthy controls. The levels of Sema4D in serum were detected by enzyme-linked immunoassay method (ELISA), and their correlation with clinical manifestations of RA, laboratory indicators, degree of bone damage and RA-ILD were analyzed. Results: The level of serum Sema4D in RA active group was significantly higher than that in stable group and healthy control group (P<0.05). The concentration serum Sema4D was positively correlated with C-reactive protein(CRP) (r=0.28, P<0.05), rheumatoid factor(RF) (r=0.25, P<0.05) and the 28-joint disease activity score (DAS28) (r=0.45, P<0.01). The concentration serum Sema4D was positively correlated with ß-Crosslaps(r=0.20, P<0.05) and Sharp-van der Heijde score (SHS)(r=0.13, P<0.05). The concentration serum Sema4D was positively correlated with Vascular endothelial growth factor (VEGF)(r=0.25, P<0.05) and Warrick score of chest CT in RA patients(r=0.27, P<0.05). The anti-cyclic citrullinated peptid(CCP) antibody, DAS28, VEGF and the incidence of RA-ILD were significantly higher than that in Sema4D negative group (P<0.05). Conclusions: Serum Sema4D level in RA patients is closely related to the disease activity, bone destruction and RA-ILD. Serum Sema4D can be used as an indicator of disease monitoring and prognosis evaluation in RA patients.

[Congenital microtia with aural atresia or stenosis accompany with first branchial cleft anomaly: report of 5 cases].

Objective: To summarize the experience of the diagnosis, treatment and effects of the cases with coexistence of first branchial cleft anomaly(FBCA) and microtia with congenital aural atresia or stenosis(external auditory canal stenosis, EACS). Method: This was a retrospective study. The clinical data of 5 patients with microtia and EACS in Beijing Tongren Hospital of Capital Medical University from October 2015 to March 2018 were collected, including 3 males and 2 females, aged from 5 to 28 years. The clinical characteristics, imaging findings, treatment methods and effects of 5 patients were analyzed. Result: The 5 cases were all coexistence of EACS and FBCA, three of who associated with cholesteatoma of external auditory canal. CT showed external auditory canal stenosis with soft tissue shadow, sometimes gas or bone septum found inside, filling in the external auditory canal, combined with canal bone destruction irregularly. All patients underwent surgical resection of FBCA, 3 patients accompanied by cholesteatoma resection and canalplasty. The postoperative follow-up ranged from 10 to 39 months, and no recurrence of infection was observed. Conclusions: EACS and FBCA both result from maldevelopment of the first branchial cleft. These two malformations, FBCA and EACS with or without cholesteatoma, can occur simultaneously, in which situation CT shows external auditory canal stenosis with soft tissue shadow inside. These patients underwent surgical resection of FBCA combined with cholesteatoma resection with good result.

[An analysis of the results of video head impulse test in benign paroxysmal vertigo of childhood].

Objective:This study was to analyze the results of video head impulse test (vHIT) of benign paroxysmal vertigo of childhood (BPVC) in order to determine the potential value of vHIT in the diagnosis and treatment for BPVC and to discuss its possible pathogenesis of BPVC. Method:Thirty-six children with BPVC were enrolled. No hearing loss and skull abnormality were found in these children as assessed by pure tone audiometry, acoustic impedance, CT or MRI scan. The vHIT was carried out, and main outcome measures were the gain of vestibulo-ocular reflex, gain asymmetry, and refixation saccades. Eleven healthy children were selected as normal control who came to our hospital for doing a routine checkup and have no history of dizziness. The differences of vHIT results between these two groups were analyzed. Result:①The vHIT results in control group were normal. In all BPVC subjects, abnormalities were detected in 9 patients (25.0%),including vHIT gains decline in 3 patients, abnormal symmetry in 4 patients, and abnormal isolated overt saccades in 2 patients.②The average saccadic gain in different canals of BPVC group was 1.03±0.14, 1.01±0.15, 1.13±0.31, 1.18±0.36, 1.21±0.33, 1.14±0.30 in left horizontal, right horizontal, left anterior, right posterior, right anterior, left posterior canal, respectively; while in normal group, it was 1.14±0.15, 1.18±0.09, 1.16±0.30, 1.18±0.40, 1.34±0.26, 1.30±0.20, respectively. Significant statistical difference was found only in horizontal canals between these two groups (P<0.05). ③Asymmetry of the three pairs of conjugated semicircular canals was 0.04±0.07 (horizontal canal), 0.06±0.04 (left anterior and right posterior canal), 0.06±0.04 (right anterior and left posterior canal) in BPVC group, respectively; while in control group, it was 0.02±0.02, 0.04±0.03, 0.04±0.04,respectively. There was no statistical difference between the two groups (P>0.05). Conclusion:A certain proportion of abnormal peripheral vestibule function in children with BPVC was found. vHIT is a "child friendly," relatively easytouse, and simple tool to evaluate each of the 6 semicircular canals, which may offer some potential clinical information for assessing the vestibule dysfunction for BPVC.

[The implantation of Bonebridge in bilateral congenital malformation of external and middle ear].

Objective: To evaluate the auditory efficacy of Bonebridge implantation in patients with bilateral congenital malformation of external and middle ear. Methods: Eleven cases (6 males and 5 females) had unilateral Bonebridge implantation. The age ranged from 8 to 26 and the average age was 16.9. Seven to ten days after operation, the first fitting was undergone. In acoustic sound field, the average auditory thresholds were respectively measured for unaided ears and Bonebridge implanted ears by pure tone auditory (PTA, 0.25, 0.5, 1, 2 and 4 kHz). For the group over 12-year-old, MSTM was applied to evaluate speech discrimination score (SDS). For the other cases, MLNT was used as the test material. The auditory efficacy post Bonebridge implantation would be analyzed and evaluated by comparing the differences between unaided ears and Bonebridge implanted ears. Results: The bone conduction audibility threshold after Bonebridge implantation was as well as the preoperative. The auditory threshold with Bonebridge aided was improved to 25-35 dB HL, when compared to that of the unaided ears in the sound field. The SDS in the group over 12-year-old was improved about 50%; the efficacy was slightly limited for the other two cases (both less than 12 years old). Statistical analysis showed that there were significant differences between unaided ears and Bonebridge implanted ears in the sound field and SDS(P<0.05). Conclusions: The auditory efficacy of Bonebridge is significant and noticeable in patients with bilateral congenital malformation of external and middle ear. Bonebridge provides a new and effective way for patient with congenital malformation of external and middle ear to reconstruct hearing.

[Vibrant soundbridge implantation of congenital atresia of oval window(with summary of nine cases].

Objective:To investigate the surgical effects of round window implantation of vibrant soundbridge(VSB)for patients with congenital oval window atresia.Method:Retrospectively analyze the clinical information of 9 cases of congenital oval window atresia as well as the pre-and post-operative hearing and speech results. Three of them had undergone or attempted the vestibulotomy but obtained poor results. All cases underwent round window implantation of VSB. Result:All patients obtained an improvement of 21-33 dBHL after implantation. In the speech recognition rate test, the average increase of disyllabic words was 62%, and 60% in the sentence test. During the follow-up of 51 months in average, 2 cases had a decline of auditory benefit and finally 1 case regained the improvement after reoperation. Conclusion:Round window implantation can get a fairly good result in congenital oval windows atresia cases.

Overexpression of Wild-Type p53-Induced Phosphatase 1 Confers Poor Prognosis of Patients with Nasopharyngeal Carcinoma.

This study aimed to analyze the expression, clinical significance of proto-oncogene in nasopharyngeal carcinoma and the biological effect in its cell line by siRNA targeting wild-type p53-induced phosphatase 1 (Wip1). Immunohistochemistry and western blot were respectively used to analyze Wip1 protein expression in 85 cases of nasopharyngeal cancer and normal tissues to study the relationship between Wip1 expression and clinical factors. Wip1 siRNA was transiently transfected into papillary nasopharyngeal carcinoma cell by liposome-mediated method and was detected by Quantitative real-time RT-PCR (qRT-PCR) and western blot. MTT assay, cell apoptosis, migration and invasion were also conducted as to the influence of the down-regulated expression of Wip1 that might be found on CNE2 cells biological effect. The level of Wip1 protein expression was found to be significantly higher in nasopharyngeal cancer tissue than normal tissues (P <0.05). There were significant differences between Wip1 expression and T stages, lymph node metastasis, clinical stages, tumor differentiation and radiotherapy response (P < 0.05), regardless of age, gender (P > 0.05). Meanwhile, Increased expression of Wip1 was significantly with poor overall survival time by Kaplan-Meier analysis (P < 0.05). Wip1 expression deletion determines independent risk factors for prognosis of patients with nasopharyngeal carcinoma in addition to tumor T stage, clinical stage, histological grade and lymph node metastasis outside by Cox-2 in the regression analysis (P < 0.05). qRT-PCR and Western blot showed that CNE2 cell transfected Wip1 siRNA had a lower relative expressive content than normal cell (P < 0.05). MTT assay, cell apoptosis, cell cycles demonstrated that CNE2 cell transfected Wip1 siRNA had a lower survival fraction, higher cell apoptosis, more percentage of the G0/G1 phases, significant decrease in migration and invasion, and higher P53 and P16 protein expression compared with CNE2 cell untransfected Wip1 siRNA (P < 0.05). Wip1 protein was increased in nasopharyngeal carcinoma, specifically in T stages, lymph node metastasis, clinical stages and tumor differentiation. Wip1 may involved in the biological processes of nasopharyngeal cancer cell proliferation, apoptosis, and migration and invasion by regulation P53 and P16 protein expression.

γ-Aminobutyric acid-mediated neurotransmission in cerebellar-hypothalamic circuit attenuates gastric mucosal injury induced by ischemia-reperfusion.

BACKGROUND: Excessive greater splanchnic nerve (GSN) activation contributes to the progression of gastric ischemia-reperfusion (GI-R) injury. This study was designed to investigate the protective mechanism of cerebellar fastigial nucleus (FN) stimulation against GI-R injury. METHODS: The GI-R injury model was induced in rats by clamping the celiac artery for 30 min, and then reperfusion for 30 min, 1, 3, 6, or 24 h, respectively. KEY RESULTS: Microinjection of L-Glu (3, 6, 12 µg) into the FN dose-dependently attenuated GI-R injury and GSN activity. In addition, there was an enhancement of gastric mucosal blood flow in GI-R rats. Pretreatment with the glutamic acid decarboxylase antagonist into the FN, the GABAA receptor antagonist into the lateral hypothalamic area or lesion of superior cerebellar peduncle all reversed the protective effects of the FN stimulation. Furthermore, the FN stimulation reduced the TUNEL-positive gastric mucosal cell and Bax-positive gastric mucosal cell in GI-R rats. CONCLUSIONS & INFERENCES: These results indicate that the protective effects of the FN stimulation against GI-R injury may be mediated by attenuation of the excessive GSN activation, gastric mucosal cell apoptosis, and Bax expression in GI-R rats.

Morphological variation of mutant sunflowers (Helianthus annuus) induced by space flight and their genetic background detection by SSR primers.

After sunflower seeds were exposed to space conditions, various mutant plants were screened from the descendent plants. The morphological characters of plants changed in flower color from golden to yellow, light yellow, or even to yellowish green. The ligulate petals of the unisexual floret broadened, or became thin, while the short tubular petals of bisexual floret elongated to some extent, or even turned into semi-ligulate petals or ligulate petals, making the phenotype of the whole inflorescence like a chrysanthemum. The shape and thickness of leaves varied in some of these plants. Absolute sterile plants in mutant plants were found to possess neither normal bisexual florets nor unisexual florets, but the "pseudo-floret" only consisted of pieces of shield-like bracts on protuberant floral disc. Thirty-five pairs of simple sequence of repeat primers were used to detect the genetic variation of the plants, and the results showed that only a variation was tested in the mutant plants from 4 primers. The different PCR products obtained were extracted for sequencing and alignment analysis, and the aligned results showed that the DNA sequence changed by deletion, insertion and replacement that occurred at some sites. The results proved the high mutagenic efficacy of space flight, and ways of DNA transformation due to space conditions.

An optimized preparation method to obtain high-quality RNA from dry sunflower seeds.

In an attempt to isolate high-quality, intact total RNA from sunflower (Helianthus annuus) seeds for investigation of the molecular mechanisms of mutations, we tested various procedures, using kits, including RNAiso Plus, RNAiso Plus+RNAiso-mate for Plant Tissue, Trizol, and the Qi method, but no high-quality total RNA of high integrity was obtained with any of these methods, probably due to the high content of polyphenols, polysaccharides, and secondary metabolites in mature sunflower seeds. Modifications were made to the Qi method. To avoid polyphenol oxidation, frozen dry seeds free of the seedcase were ground in a mortar with an equal amount of PVP30, and the fine ground powder was transferred to an extraction buffer with 2% PVP30 (w/v), 5% ß-mercaptoethanol (v/v) and LiCl (8 M). A sample homogenate was extracted with chloroform prior to acidic phenol-chloroform extraction. The total RNA was precipitated with 1/4 volume of NaAc and 2 volumes of absolute ethanol to prevent contamination by polysaccharides. The yield of total RNA was 29.95 µg/100 mg husked dry seeds; the ratios of A260/A230 and A260/A280 were 2.44 and 2.09, respectively. Electrophoretic analysis clearly showed 28S and 18S ribosomal RNA bands. Using the extracted RNA, a fragment of the actin gene was successfully expressed by RT-PCR. This modified protocol is suitable for isolating high-quality total RNA from sunflower seeds for molecular research.

EZH2 silencing by RNA interference inhibits proliferation in bladder cancer cell lines.

The Enhancer of Zeste homologue2 gene (EZH2) is frequently expressed at high levels in malignant tumours, including bladder cancer. It functions as a transcriptional regulator to the maintenance of cell identity, cell cycle regulation and oncogenesis. In the study, we detected EZH2 expression in bladder cancer tissues. These results showed EZH2 high expression in bladder cancer tissue at level of transcript and protein compared with normal bladder tissue and EZH2 expression correlated positively with tumour stage and grade. Then, we used RNA interference to inhibit EZH2 expression in bladder cancer EJ cell line. Efficient downregulation of EZH2 resulted in significantly decreased cell proliferation in EJ cells and retarded transition of G(1) phase to S phase. Our data suggest that EZH2 is involved in the tumourigenesis of bladder cancer and EZH2 downregulation contributes to inhibiting malignant growth by retarding cell entrance to S phase.

Effects of hydrogen plasma treatment on the electrical and optical properties of ZnO films: identification of hydrogen donors in ZnO.

Wurtzite ZnO has many potential applications in optoelectronic devices, and the hydrogenated ZnO exhibits excellent photoelectronic properties compared to undoped ZnO; however, the structure of H-related defects is still unclear. In this article, the effects of hydrogen-plasma treatment and subsequent annealing on the electrical and optical properties of ZnO films were investigated by a combination of Hall measurement, Raman scattering, and photoluminescence. It is found that two types of hydrogen-related defects, namely, the interstitial hydrogen located at the bond-centered (H(BC)) and the hydrogen trapped at a O vacancy (H(O)), are responsible for the n-type background conductivity of ZnO films. Besides introducing two hydrogen-related donor states, the incorporated hydrogen passivates defects at grain boundaries. With increasing annealing temperatures, the unstable H(BC) atoms gradually diffuse out of the ZnO films and part of them are converted into H(O), which gives rise to two anomalous Raman peaks at 275 and 510 cm(-1). These results help to clarify the relationship between the hydrogen-related defects in ZnO described in various studies and the free carriers that are produced by the introduction of hydrogen.

Expression and role of Oct3/4, Nanog and Sox2 in regeneration of rat tracheal epithelium.

OBJECTIVES: To explore the role of Oct3/4, Nanog and Sox2 in regeneration of rat tracheal epithelium. MATERIALS AND METHODS: An ex vivo model of rat tracheal epithelial regeneration using 5-fluorouracil (5-FU) was developed, to induce injury. Expression levels of Oct3/4, Nanog and Sox2 were examined using Western blot analysis, RT-PCR or microscopically observed immunofluorescence, and cell morphological changes were observed using HE staining, during the recovery process. RESULTS: Oct3/4, Nanog and Sox2 were not detectable in normal tracheal epithelium. After treatment with 5-FU, the normally proliferating tracheal epithelium desquamated and only a few cells in G0 phase of the cell cycle were left on the basement membrane and Oct3/4, Nanog and Sox2 could be observed at this time. Thereafter, the number of Oct3/4-, Nanog- and Sox2-positive cells increased gradually. When the cells differentiated into ciliate cells, mucous cells or basal cells, and restored pseudostratified mucociliary epithelium, the number of Oct3/4-, Nanog- and Sox2-positive cells decreased and gradually disappeared. CONCLUSIONS: G0 phase cells with resistance to 5-FU damage expressed Oct3/4, Nanog and Sox2. This indicated that these cells were undifferentiated, but had the ability to terminally differentiate into downstream-type cells. They possessed stem cell properties. The results are consistent with Oct3/4, Nanog and Sox2-expressing cells being considered as tracheal stem cells.

Expression and role of Notch signalling in the regeneration of rat tracheal epithelium.

OBJECTIVES: This study is to explore the role of Notch signalling during the regeneration of rat tracheal epithelium after injury induced by 5-fluorouracil (5-FU). MATERIALS AND METHODS: We developed an ex vivo model of rat tracheal epithelial regeneration using 5-FU to induce injury. Expression levels of members of the Notch signalling pathway, ABCG2, CK19, and proliferating cell nuclear antigen (PCNA) were examined by reverse transcription-polymerase chain reaction, Western blot, and immunofluorescence. One group of tracheas were cultured in the medium with a gamma-secretase inhibitor or Jag-1 peptide after 5-FU treatment and another group were pre-treated with the gamma-secretase inhibitor or Jag-1 peptide before 5-FU treatment. The expression changes of ABCG2, CK19, and PCNA were examined by Western blot or immunofluorescence and the morphologic changes were observed by haematoxylin and eosin stain during the recovery process. RESULTS: Expression levels of Notch3, Jagged1, and Hey1 were increased in rat tracheal epithelial cells after treatment with 5-FU. During injury recovery, disruption of Notch signalling by treatment with the gamma-secretase inhibitor reduced expression of ABCG2 and PCNA, but promoted expression of CK19, while persistent activation of Notch signalling promoted expression of ABCG2 and PCNA, but reduced expression of CK19. Under both conditions, recovery from injury was reduced. However, blocking Notch signalling prior to 5-FU treatment led to the complete blockage of recovery, while activating Notch signalling before 5-FU treatment promoted recovery. CONCLUSIONS: During tracheal epithelial regeneration, Notch signalling maintains an undifferentiated state and promotes proliferation among a population of tracheal epithelial cells.

Differential gene expression profiling in aggressive bladder transitional cell carcinoma compared to the adjacent microscopically normal urothelium by microdissection-SMART cDNA PCR-SSH.

Identifying novel and known genes that are differentially expressed in aggressive bladder transitional cell carcinoma (BTCC) has important implications in understanding the biology of bladder tumorigenesis and developing new diagnostic and therapeutic agents. In this study we identified the differential gene expression profiles comparing tumor to the adjacent microscopically normal mucosa by manual microdissection on frozen sections. The RNAs extracted from microdissected tissues were amplified by SMART cDNA PCR technology to generate forward subtractive cDNA library by suppressive subtractive hybridization (SSH). We obtained 376 positive clones, one hundred clones of aggressive BTCC subtracted cDNA library were selected at random and inserts were reamplified by PCR. After differential screening by reverse dot blotting, 73 positive clones, that contend inserts putatively upregulated in aggressive BTCC, were further analysed by DNA sequencing, GenBank and EST database searching. Sequencing results showed that 66 clones stand for 23 known genes and 7 clones for three new EST (Genbank number: DN236875, DN236874 and DN236873). In conclusion, microdissection-SMART cDNA PCR-SSH allowed for an efficient way to identify aggressive BTCC-specific differential expressed genes that may potentially be involved in the carcinogenesis and/or progression of aggressive BTCC. These differentially expressed genes may be of potential utility as therapeutic and diagnostic targets for aggressive BTCC.