[Analysis of clinicopathological features and prognosis of sporadic synchronous multiple primary colorectal cancers]

Objective: To investigate the impact of relative locations of multiple foci and microsatellite status of sporadic, synchronous, multiple, primary, colorectal carcinomas on clinicopathological features and prognosis. Methods: The clinicopathologic and prognostic data of 278 patients with sporadic, synchronous, multiple, primary, colorectal carcinomas who had been admitted to the Department of Colorectal Surgery at Zhejiang Cancer Hospital from January 2008 to July 2022 were retrospectively collected. The patients were categorized into three groups based on the relative locations of their multiple cancer foci: (1) a right-sided group that comprised patients with multiple cancer foci in the cecum, ascending colon, hepatic flexure of the colon, and transverse colon; (2) a left-sided group that comprised patients with multiple cancer foci in the splenic flexure of the colon, descending colon, sigmoid colon, and rectum; and (3) a left- and right-sided group that comprised patients with multiple cancer foci in the right half of the colon and left half of the colon/rectum. Additionally, the patients were further divided into two groups based on microsatellite status: a high microsatellite instability (MSI-H) and a low MSI/stable MSI (MSI/L&MSS) group. We compared differences in clinical characteristics and prognostic indicators between these groups. The χ2 test was utilized to compare selected clinical characteristics, whereas Kaplan-Meier survival analyses and log-rank tests were performed to compare their effects on prognosis. Result: Among 278 patients with SSCRC, 256 (92.1%) presented with two cancer foci and 22 (7.9%) with more than two foci. Additionally, 255 patients (91.7%) had adenocarcinomas, whereas the remaining 23 (8.3%) had mucinous adenocarcinomas. Lymph node metastases were identified in 136 patients (48.9%); the cancer foci had infiltrated beyond the muscular layer in 238 (85.6%); and 147 patients (52.9%) were diagnosed with TNM Stage III-IV disease. There were 155 patients (55.8%) in the left-sided group, 55 (19.8%) in the right-sided group, and 68 (24.5%) in the left- and right-sided group. Immunohistochemical examination of all four mismatch repair proteins were performed in 199 cases, revealing that 166 of these patients had MSI/L&MSS and 33 MSI-H disease. In the left-sided, left- and right-sided, and right-sided groups, the proportion of women was 16.8% (26/155), 26.5% (18/68), and 49.1% (27/55), respectively; these differences are statistically significant (χ2=22.335, P<0.001). The proportions of patients with more than three cancer foci were 5.2% (8/155), 16.2% (11/68), and 5.5% (3/55), respectively; these differences are statistically significant (χ2=8.438, P=0.015). The proportions of mucinous adenocarcinomas were 4.5% (7/155), 8.8% (6/68), and 18.2% (10/55), respectively; these differences are statistically significant (χ2=10.026, P=0.007). The proportions of patients with lymph node metastases were 55.5% (86/155), 48.5% (33/68), and 30.9% (17/55); these differences are statistically significant (χ2=9.817, P=0.007). The proportions of patients with Stage T3 & T4 disease in each group according to location were 81.3% (126/155), 88.2% (60/68), and 94.5% (52/55), respectively; these differences are statistically significant (χ2=6.293,P=0.043). The proportions of TNM Stage III-IV tumors were 59.4% (92/155), 54.4% (37/68), and 32.7% (18/55), respectively; these differences are statistically significant (χ2=11.637, P=0.003). Age, size of cancer foci, presence of distant metastasis, adenoma, nerve invasion, and vascular invasion did not differ significantly between the three groups (all P>0.05). Compared with those with MSI-H, patients with MSI/L&MSS disease were more likely to be aged >65 years and male (50.6% [84/166] vs. 15.2% [5/33], χ2=13.994,P<0.001; 80.7% [134/166] vs. 54.5% [18/33], χ2=10.457,P=0.001), more likely to be in the left-sided group (63.3% [105/166] vs. 24.2% [8/33], χ2=18.232, P<0.001), had a higher proportion of cancer foci of diameter <4 cm (54.8% [91/166] vs. 33.3% [11/33], χ2=5.086,P=0.024), and a lower proportion of mucinous adenocarcinomas (4.2% [7/166] vs. 27.3% [9/33], χ2=19.791,P<0.001), more likely to develop distant metastases (22.3% [37/166] vs. 6.1% [2/33], χ2=4.601,P=0.032), more likely to have lymph node metastases (57.2% [95/166) vs. 24.2% [8/33], χ2=11.996,P<0.001) and nerve invasion (28.9% [48/166] vs. 6.1% [2/33], χ2=7.643, P=0.006), had a higher proportion of TNM Stage III-IV disease (60.2% [100/166] vs. 24.2% [8/33], χ2=14.374, P<0.001), and a smaller proportion of family history of tumors (28.9% [48/166] vs. 60.6% [20/33], χ2=12.228, P<0.001). All the above-listed differences are statistically significant (all P<0.05). The differences in number of cancer foci, depth of infiltration, presence or absence of adenomas, and vascular invasion were not statistically significant (all P>0.05). In the 33 patients with MSI-H status and mismatch repair protein loss, the highest frequency of deletion was found in PMS-2 (66.7%, 22/33), followed by MLH-1 (57.6%, 19/33), whereas the proportions of MSH-2 (33.3%, 11/33) and MSH-6 (24.2%, 8/33) deletions were relatively low. There were statistically significant differences in the 3-year overall survival rates among the groups according to relative locations of cancer foci. The 3-year overall survival rates were 96.8%, 79.6%, and 88.5% in the right-sided, left- and right-sided, and left-sided groups, respectively (P=0.021). As to microsatellite status, the 3-year overall survival rate of patients with MSI-H disease was 93.8%, which is significantly better than the 78.4% for those with MSI/L & MSS (P=0.026). Conclusions: Among sporadic, synchronous, multiple, primary, colorectal carcinomas, those with right-sided disease had the deepest local infiltration, whereas those with left-sided disease had the greatest number of lymph node metastases, most advanced clinical TNM stage, lowest percentage of MSI-H disease, and the poorest prognosis.

The choice of spectral similarity algorithms influences suspected soil sample provenance

Similarity algorithms are commonly used in soil forensic applications to help identify similar samples from an existing reference library as possible source locations of unknown target samples. These algorithms are well-suited to compare soil spectra. However, different similarity algorithms may lead to different clusters of similar samples, and thus different strengths of evidence in forensic investigations. To quantify this, we conducted a study to evaluate the influence of seven similarity algorithms on soil provenance, using as a sample set a soil spectral library consisting of 280 soil profiles from Anhui Province, China. This library includes three spatial scales of datasets: provincial (DS_p), county (DS_c) and field (DS_f). A set of ten samples covering a wide range of spectra variations were selected from the DS_f dataset as the "unknown" samples, with the remaining being used as the reference samples. This study aimed to: (1) evaluate how several commonly-used similarity algorithms, namely Euclidean distance (ED), Mahalanobis distance (MD), Spectral angle mapper (SAM), and Spectral information divergence (SID), as well as variants of several of these measured in standardized principal component space computed from the spectra (ED_PCA, MD_PCA and SAM_PCA), influence the identification of the matched similar samples; (2) determine the overlap in sample selection between different similarity algorithms; (3) propose best practices for similarity algorithms applied to soil forensic analysis using spectroscopy. The use of different similarity algorithms did influence the selection of most similar samples. The similarity algorithms calculated in PC space (ED_PCA, MD_PCA and SAM_PCA) performed slightly better than their counterparts calculated in spectral space. Due to the availability of a detailed spectral library, regardless of the different similarity algorithms used, the matched most similar samples were all located close to the unknowns, mostly within 3 km, with one exception. That is, the varied choices of different similarity algorithms hardly influenced the conclusion of soil provenance in this case. In general, MD_PCA, SAM and ED were the best similarity algorithms overall. However, since there was no single best algorithms for all cases, we recommend the joint use of MD_PCA, SAM and ED as an ensemble. Indications of possible sample provenance from these similarity measured can be useful evidence to complement evidence from other methods in a forensic investigation.

[The correlation between methylation in HPV16 long control region and cervical intraepithelial neoplasia grade 2 or more: a Meta-analysis]

Objective: To investigate the correlation between methylation in human papillomavirus 16 (HPV16) long control region (LCR) and cervical intraepithelial neoplasia grade ≥2 (CIN2+). Methods: The literature retrieval was conducted by using the databases of PubMed, Embase, Cochrane Library, Web of Science, CNKI, Wanfang data and Weipu according to the inclusion and exclusion criteria, and the retrieval period was from the establishment of the databases to February 27^th, 2022. Software RevMan 5.3 and Stata 15.1 were used for Meta-analysis. Results: A total of 17 literatures were included involving 1 421 subjects. Results of Meta-analysis showed that OR of the correlation between methylation of HPV16 LCR and CIN2+ was 1.56 (95%CI: 0.70-3.47). Subgroup analysis showed that methylation of the 5' terminal, enhancer and promoter regions were not associated with CIN2+, while in four E2 binding sites (E2BS), the methylation of E2BS1, E2BS3 and E2BS4 increased the risk of CIN2+, with the ORs of 3.92 (95%CI: 1.92-7.99), 10.50 (95%CI: 3.67-30.04) and 3.65 (95%CI: 1.58-8.41), respectively. However, subgroup analysis on E2BS2 was not performed due to the limitation of the number of literatures. According to the different sources of population, the risk of CIN2+ in Chinese population was associated with methylation of HPV16 LCR (OR=2.14, 95%CI: 1.31-3.50). There was a correlation between the risk of CIN2+ and HPV16 LCR methylation in the population with pyrosequencing of HPV16 LCR, and OR was 1.75 (95%CI: 1.03-2.98). Conclusion: The risk of CIN2+ is correlated with the methylation of E2BS in HPV16 LCR, which can be used as potential biomarkers.

[Progress in research of genomic epidemiology of pathogenic fungi]

Genomic epidemiology, based on whole-genome sequencing technology and bioinformatics analysis, can make up for the shortcomings of traditional molecular typing methods and provide a novel insight for the genetic evolution and transmission of pathogenic fungi. The combination of genetic information and epidemiological methods of pathogenic fungi can predict fungi transmission routes and risks, and provide a theoretical basis for the development of public health strategies for fungi infection prevention and control. This paper summarizes the development of molecular epidemiology and genomic epidemiology, as well as the application of genomic epidemiology methods in the analyses of genetic relationship, origin, evolution, drug resistance, virulence, and genome-wide association of pathogenic fungi, and discusses the development of pathogenic fungi genomic epidemiology.

[CT-based morphological and hemodynamics analysis for rupture risk of mirror intracranial aneurysm]

Objective: To compare the morphological and hemodynamic features of mirror intracranial aneurysms (MIAs) on CT angiography (CTA), and to elucidate the rupture risk factors of MIAs. Methods: This study retrospectively collected 29 patients with 58 digital subtraction angiography (DSA) or surgically confirmed MIAs from January 2010 to December 2016 in Jinling Hospital, Medical School of Nanjing University. Among them, there are 6 males and 23 females, aged from 40 to 83 (61±11) years old. Based on the results of hemorrhagic manifestation, 58 MIAs were divided as the ruptured (n=29) group and unruptured group (n=29). In addition, according to the location of aneurysms, they were further divided into the subgroup of posterior communicating MIAs (n=32) and non-posterior communicating MIAs (n=26). Clinical data of the patients and the morphological parameters of the MIAs were collected. Computational fluid dynamics (CFD) analysis was performed to obtain hemodynamic parameters, such as pressure (P), wall shear stress (WSS), wall shear stress gradient (WSSG), and oscillatory shear index (OSI). The coefficient of variation (CV) was used to describe the aforementioned hemodynamic parameters of intracranial aneurysms, so the index after CV adjustment is expressed as P_CV , WSS_CV , WSSG_CV , OSI_CV . Characteristics between ruptured and unruptured groups were compared. Conditional logistic regression analysis was conducted to evaluate the rupture risk factors of MIAs. Results: Among the 29 pairs of mirror aneurysms, 16 pairs were distributed in bilateral posterior communicating arteries (55%), 9 pairs distributed in bilateral middle cerebral arteries (31%), and 4 pairs distributed in bilateral internal carotid arteries (14%). Compared with the unruptured MIAs group, the ruptured aneurysms group usually had a larger maximum diameter, neck width, and size ratio (SR) [4.98 (3.18, 6.79) mm vs 3.20 (2.10, 4.31) mm, 4.19 (3.46, 5.95) mm vs 4.05 (3.23, 5.02) mm, 1.69 (0.81, 2.28) vs 0.96 (0.67, 1.49)] (all P<0.05). In the subgroup hemodynamic analysis of MIAs, the ruptured aneurysms had higher WSS_CV and WSSG_CV than the contralateral unruptured ones [1.00(0.87, 1.21) vs 0.65(0.57, 0.87), 1.09(0.56, 1.90) vs 0.57(0.50, 1.13), 1.52 (1.34, 1.80) vs 1.21 (1.07, 1.38), 1.52±0.46 vs 1.21±0.23] (all P<0.05), while the P_CV was lower than the contralateral unruptured ones [0.004 (0.002, 0.008) vs 0.010 (0.006, 0.013), 0.003 (0.002, 0.011) vs 0.009 (0.002, 0.066)] (both P<0.05). Logistic regression analysis showed that high WSSG_CV was an independent risk factor for MIAs rupture (OR=279.20(95%CI:1.10-71 028.28)). Conclusion: The maximum diameter, neck width, and SR were considered as a reliable morphological parameters to distinguish the ruptured status of MIAs, higher WSSG_CV in the aneurysm sac are highly correlated with MIAs rupture.

Application of principal component analysis with instrumental analysis and sensory evaluation for assessment of chicken breast meat juiciness

1. The objectives of this study were to use principal component analysis (PCA) to analyse the variability of the three instrumental and 14 descriptive sensory properties of chicken breast meat. The meat was cooked until the internal temperature reached 85°C and further cooked for 0, 20, and 40 min. The second objective was to identify the most critical variables for assessing meat juiciness.2. Cooking loss and moisture content exhibited high correlation with sensorial moisture release and mouth feel.3. The distribution of objects on the axes of the first two principal components (PCs) enabled the identification of three groups undergoing different cooking durations. The four major PCs explained 80.0% of the total variability.4. Cooking loss, moisture content, water-holding capacity, sensorial moisture release and mouth feel were demonstrated as the most effective variables for the first two PCs. PCA with instrumental and sensory analyses proved an effective procedure for systematically and comprehensively judging chicken meat juiciness.

Forensic soil source identification: comparing matching by color, vis-NIR spectroscopy and easily-measured physio-chemical properties

This study evaluates to what degree soil samples associated in characteristic space are also close in geographical space, i.e., the possible location from which an unknown sample was obtained in a forensic investigation. The study compares similarity computed from Munsell colors, RGB colors, and full visible-near infrared (vis-NIR) spectra by the spectral angle mapper with similarity based on six easily-measured physio-chemical properties. The reference area is Anhui Province, China with three scales of datasets: provincial, county, and field. Ten diverse "unknown" samples were selected by the Kennard-Stone algorithm from the field-scale dataset and their matches in characteristic space from the several datasets were found by the different methods. The geographic distances of the matches to the "unknowns" were used to evaluate the source identification ability. When a detailed library with local samples is present, a limited set of physio-chemical properties achieved higher geographic accuracy than the color and spectral methods. However, with a regional library the spectral and color methods are superior. Distances in RGB space reveal finer differences than exact matching in Munsell space, but whole-spectra matching outperforms both, because of the rich information influenced by more soil properties than influencing color. We recommend the use of soil vis-NIR spectra as a priority indicator for forensic soil analysis because of its success in this study and its ability to work non-destructively on small quantities of soil.

MiR-136 triggers apoptosis in human gastric cancer cells by targeting AEG-1 and BCL2

OBJECTIVE

Gastric cancer is the second most prevalent cancer across the globe and accounts for about 10% of new cancer cases. It is one among the leading causes of cancer-related deaths around the world. Recently, microRNAs have been identified as important therapeutic targets for the treatment of several cancers owing to their potential to target multiple genes and hinder several biological processes such as proliferation and apoptosis. In the current study, we investigated the potential of miR-136 as therapeutic target for gastric cancer.

MATERIALS AND METHODS

Total RNA was isolated by RNeasy RNA isolation kit and cDNA was prepared byRevertAid cDNA synthesis kit. The transcript analysis was carried out by quantitative RT-PCR. The transfection of miR-136 mimics or plasmids was carried out by using the Lipofectamine 2000 reagent. Apoptosis was detected by DAPI and acridine orange/ethidium bromide (AO/EB) staining. Protein expression was examined by Western blotting.

RESULTS

The results indicated that the expression of miR-136 is significantly downregulated in gastric cancer cells. Transfection and subsequent overexpression of miR-136 in gastric cancer cells significantly promoted apoptosis as evident from DAPI and OA staining. In silico analysis revealed AEG-1 and BCL2 to be the potential targets of miR-136. Therefore, the expression of AEG-1 and BCL2 was determined in untreated control, cisplatin treated control and miR-136 transfected AGS gastric cancer cells. The results revealed that overexpression of miR-136 expression causes significant downregulation of AEG-1 and BCL2 protein expression.

CONCLUSIONS

Taken together, we conclude that miR-136 promotes apoptosis in gastric cancer cells by targeting AEG-1 and BCL2. Therefore, miR-136 may prove as a potential therapeutic target for the treatment of gastric cancer.

Diode-wing-pumped electro-optically Q-switched 2 μm laser with pulse energy scaling over ten millijoules

Characteristics of diode-wing-pumped highly efficient Tm:LuAG lasers running both in continuous wave (CW) and electro-optical Q-switching regimes have been investigated. Using a simple plane-plane cavity, a maximum CW output power of 8.5 W has been achieved with a corresponding slope efficiency of 44.5% by "wing pumping" at 790 nm. With a V-shaped cavity, a diode-wing-pumped MgO:LiNbO₃ crystal based electro-optically Q-switched Tm:LuAG laser at 2022.9 nm delivered a maximum pulse energy of 10.8 mJ and a minimum pulse width of 52 ns at a corresponding repetition rate of 100 Hz. To the best of our knowledge, the achieved CW output power and Q-switched pulse energy have both set records for all-solid-state Tm:LuAG lasers, which well reveals an efficient way to generate high-power and high-energy lasers at 2 μm wavelength.

[Preoperative dynamic contrast-enhanced MRI can reduce the rate of tumor-positive resection margins after breast conserving surgery in patients with early non-mass breast carcinoma]

Objective: To investigate the value of preoperative dynamic contrast-enhanced MRI in reducing the rate of tumor-positive resection margins after breast conserving surgery in patients with early non-mass breast carcinoma. Methods: Seventy-two patients with early non-mass breast carcinoma received ultrasonographic and mammographic examination and subsequently underwent dynamic contrast-enhanced MRI examination before breast conserving surgery. The control group consisted of 74 patients who had early non-mass breast carcinoma. They only received ultrasonographic and mammographic examination and didn't undergo contrast-enhanced MRI examination. The comparison of the rate of tumor-positive resection margins between two groups was performed. The MRI findings that had the significant influence on the rate of tumor-positive resection margins were analyzed using Logistic regression model. Results: In 28 patients (28/72, 38.9%), dynamic contrast-enhanced MRI could correct or supplement the ultrasonographic and mammographic findings and resulted in the reasonable change of surgical program. The preoperative MRI examination group (n=30) had lower rate of tumor-positive resection margins than control group for invasive ductal carcinoma (23.3% vs 40.0%, P=0.02), but there was no significant difference (21.4% vs 26.9%, P=0.10) between two groups for ductal carcinoma in situ (n=28). The preoperative MRI examination group (n=14) had lower rate of tumor-positive resection margins than control group for the other pathologic types of breast carcinoma (14.3% vs 38.9%, P=0.02). The statistical analysis on the basis of Logistic regression model showed that some main MRI findings, including change surrounding the tumor, distance between tumor and nipple and tumor size, had the significant influence on the rate of tumor-positive resection margins. Conclusion: Preoperative dynamic contrast-enhanced MRI significantly increased the accuracy of resection margins evaluation, and greatly reduced the rate of tumor-positive resection margins after breast conserving surgery in patients with early non-mass breast carcinoma.

Role of microRNAs in the treatment of type 2 diabetes mellitus with Roux-en-Y gastric bypass

The aim of this study was to investigate the effect of Roux-en-Y gastric bypass (RYGB) on the peripheral blood microRNAs (miRNAs) of patients with type 2 diabetes mellitus (T2DM). miRNAs are small 20- to 22-nucleotide (nt) noncoding RNAs. They constitute a novel class of gene regulators that negatively regulate gene expression at the post-transcriptional level. miRNAs play an important role in several biological processes. Twelve patients with T2DM who were scheduled to undergo laparoscopic RYGB surgery were separated into two groups, using a body mass index of 30 kg/m² as a cut-off point. Venous blood was collected before operation and 12 months after operation. A significant change was observed in the peripheral blood miRNA expression profile of both groups after RYGB surgery compared with those before operation. The expression levels of hsa-miR-29a-3p, hsa-miR-122-5p, hsa-miR-124-3p, and hsa-miR-320a were downregulated. The methylation state of the CpG sites within an approximately 400-bp genomic DNA fragment of each of the four miRNA genes, including about 200 bp upstream and 100 bp downstream of the pre-miRNA, did not vary after RYGB surgery. With remission of T2DM in both groups, RYGB could modulate the expression level of many peripheral blood miRNAs associated with lipid metabolism, insulin secretion, beta-cell function, and insulin resistance. The expression level of peripheral blood diabetes-related miRNA varied in patients with T2DM after receiving RYGB surgery, laying a strong foundation for future studies on this subject. The molecular mechanisms underlying RYGB surgery that can cause aberrant expression of miRNA remains to be determined.

Composite artificial semi-knee joint system

OBJECTIVES

The purpose of the study was to investigate the clinical implantation protocol of custom-made artificial semi-knee joint based on computer-aided design so as to improve the limb salvage efficiency.

MATERIALS AND METHODS

The custom-made artificial semi-knee joint was designed and manufactured based on rapid prototyping technology. The repeated modifications were carried out in the design and manufacture of the semi-knee joint, together with the operation protocol. Clinical trial was conducted on 2 cases of osteosarcoma, one receiving allograft prosthesis composite transplantation, and the other receiving synthetic bone graft prosthesis composite transplantation. The clinical outcomes of the 2 patients were evaluated.

RESULTS

The custom-made artificial semi-knee joint met the clinical customization needs. In clinical trial, 18-month follow-up demonstrated the satisfactory knee joint function recovery in near future.

CONCLUSIONS

The custom-made artificial semi-knee joint based on computer-aided design can afford satisfactory knee joint function recovery following allograft bone transplantation.

Diode-pumped continuous wave tunable and graphene Q-switched Tm:LSO lasers

We have investigated the lasing characteristics of Tm:LSO crystal in three operation regimes: continuous wave (CW), wavelength tunable and passive Q-switching based on graphene. In CW regime, a maximum output power of 0.65 W at 2054.9 nm with a slope efficiency of 21% was achieved. With a quartz plate, a broad wavelength tunable range of 145 nm was obtained, corresponding to a FWHM of 100 nm. By using a graphene saturable absorber mirror, the passively Q-switched Tm:LSO laser produced pulses with duration of 7.8 μs at 2030.8 nm under a repetition rate of 7.6 kHz, corresponding to pulse energy of 14.0 μJ.

Establishing a new electrical conduction pathway by anastomosis of the right auricle and right ventricle assisted by mesenchymal stem cells in a canine model

BACKGROUND

Electronic pacemakers are the primary treatment of complete atrioventricular (AV) block, but their use is associated with many complications. The aim of the present study was to create an alternative treatment for these patients.

MATERIALS AND METHODS

Mesenchymal stem cells (MSCs) isolated from the bone marrow of a 3-month-old dog were cultured in vitro. The MSCs were labeled with 4', 6-diamidino-2-phenylindole (DAPI) before transplantation. We anastomosed the right auricle and right ventricle in 24 dogs, and transplanted labelled MSCs into the anastomotic area of 8 dog hearts. Using immunostaining we assessed survival and differentiation of the implanted cells at 8 weeks posttransplantation. Electrocardiography confirmed the secondary electrical conduction pathway.

RESULTS

The ventricular current was captured by the electronic pacemaker in 21 dogs. Compared with the control group (surgery alone), pacemaker stimulus current was significantly less in the MSC group (surgery+MSCs).

CONCLUSIONS

Anastomosis of the right auricle and right ventricle assisted by MSCs may be a new treatment for patients with complete AV block in the future.

Anti-angiogenesis by lentivirus-mediated small interfering RNA silencing of angiopoietin-2 gene in pancreatic carcinoma

Angiopoietin-2 (Ang2) has been shown highly expressed in resected human pancreatic carcinoma samples, but the role of it is less clear. We were, therefore, interested in exploring the effects of Ang2 silencing on the angiogenesis and growth of pancreatic carcinoma. Lentivirus mediated Ang2 small hairpin RNA (LV-RNAi) were transfected into pancreatic carcinoma cell line MIA PaCa-2. Three groups were designed in this study: the control group (Mia PaCa-2 cells), the LV-NC group (cells transfected with the control GFP-lentivirus) and the LV-RNAi group (cells transfected with LV-RNAi). The mRNA and protein level of Ang2 gene were detected by real-time polymerase chain reaction and Western blot respectively. MTT assay and Flow Cytometry were used to detect the cell growth and apoptosis. Anti-angiogenesis effect was measured by chick embryo chorioallantoic membrane (CAM) assay. In nude mice bearing tumors, after treatment with intratumoral injection of LV-RNAi, mice growth and tumor volume were observed, and the expression of Ang2, VEGF and CD34 were measured by immunohistochemistry. Compared with the control group and the LV-NC group, the mRNA and protein level of Ang2 gene were successfully knocked down in LV- RNAi group. Also the vessel count was decreased in CAM assay after LV-RNAi transfection. Meanwhile, no obvious cell viability and apoptosis changes were found in MTT assay and Flow Cytometry, respectively. LV-RNAi inhibited pancreatic carcinoma angio- genesis and growth by downregulating the expression of VEGF and CD34. These findings demonstrate that Ang2 gene silencing may exert a anti-angiogenesis effect in vitro and in vivo, and Ang2 targeted gene therapy has the potential to serve as a novel way for pancreatic carcinoma treatment.

Upregulation of miR-27a contributes to the malignant transformation of human bronchial epithelial cells induced by SV40 small T antigen

The introduction of the Simian virus 40 (SV40) early region, the telomerase catalytic subunit (hTERT) and an oncogenic allele of H-Ras directly transforms primary human cells. SV40 small T antigen (ST), which forms a complex with protein phosphatase 2A (PP2A) and inhibits PP2A activity, is believed to have a critical role in the malignant transformation of human cells. Recent evidence has shown that aberrant microRNA (miRNA) expression patterns are correlated with cancer development. Here, we identified miR-27a as a differentially expressed miRNA in SV40 ST-expressing cells. miR-27a is upregulated in SV40 ST-transformed human bronchial epithelial cells (HBERST). Suppression of miR-27a expression in HBERST cells or lung cancer cell lines (NCI-H226 and SK-MES-1) that exhibited high levels of miR-27a expression lead to cell growth arrested in the G(0)-G(1) phase. In addition, suppression of miR-27a in HBERST cells attenuated the capacity of such cells to grow in an anchorage-independent manner. We also found that suppression of the PP2A B56γ expression resulted in upregulation of miR-27a similar to that achieved by the introduction of ST, indicating that dysregulation of miR-27a expression in ST-expressing cells was mediated by the ST-PP2A interaction. Moreover, we discovered that Fbxw7 gene encoding F-box/WD repeat-containing protein 7 was a potential miR-27a target validated by dual-luciferase reporter system analysis. The inverse correlation between miR-27a expression levels and Fbxw7 protein expression was further confirmed in both cell models and human tumor samples. Fbxw7 regulates cell-cycle progression through the ubiquitin-dependent proteolysis of a set of substrates, including c-Myc, c-Jun, cyclin E1 and Notch 1. Thus, promotion of cell growth arising from the suppression of Fbxw7 by miR-27a overexpression might be responsible for the viral oncoprotein ST-induced malignant transformation. These observations demonstrate that miR-27a functions as an oncogene in human tumorigenesis.

Cloning, expression and characterization of the serine protease gene from Chaetomium thermophilum

AIMS

Microbial proteases play an essential role in scientific research and commercial applications. This study is to clone, sequence, and express a thermostable protease gene from the thermophilic fungi Chaetomium thermophilum and to generate yeast strains expressing C. thermophilum protease suitable for industrial applications.

METHODS AND RESULTS

Degenerate primers were designed based on the conserved domain of other identified serine proteases and cDNA fragment of C. thermophilum gene pro was obtained through reverse transcriptase-polymerase chain reaction (RT-PCR). The full-length cDNA of 2007 bp was generated using RACE amplification. The cDNA contains an open reading frame of 1596 bp encoding 532 amino acids. Sequence analysis of the deduced amino acid sequence revealed high homology with the catalytic domains of the subtilisin serine proteases. The C. thermophilum gene pro was expressed in Escherichia coli BL21 (DE3) and Pichia pastoris, respectively and soluble protein was obtained in P. pastoris. The expressed protease was secreted into the culture medium by the yeast in a functional active form and the purified recombinant protease exhibits optimum catalytic activity at pH 8.0 and 60 degrees C. The enzyme is stable at 60 degrees C. The integration of gene pro into P. pastoris genome is stable after 10 generations and the yeast transformants showed a consistent protease expression.

CONCLUSIONS

Gene pro encoding a serine protease from C. thermophilum was cloned, sequenced, and overexpressed successfully in P. pastoris. The expressed protease was purified and the properties of the recombinant protease are characterized.

SIGNIFICANCE AND IMPACT OF THE STUDY

Chaetomium thermophilum is a soil-borne thermophilic fungus and the protease cloned from it is stable in a high temperature and a wide rage of pH. The overexpression of the enzyme in a mesophilic micro-organism offers a potential value for scientific research and commercial applications.

Mechanical properties and in-vivo performance of calcium phosphate cement—chitosan fibre composite

Self-hardened calcium phosphate cement (CPC) sets to form hydroxyapatite and possesses excellent osteoconductivity. However, lack of macroporosity and low strength constrain its application in bone tissue engineering. Recent studies have incorporated various fibres into CPC to improve its mechanical strength. The present approach focused on the reinforcement of CPC with chitosan fibres and then the effects of the fibre structure on the mechanical properties and macrochannels formation characteristics of CPC—fibre composite were investigated. Chitosan fibres of diameter 200 μm were used to fabricate two types of three-dimensional structure, which were then coated with collagen and incorporated into CPC to fabricate CPC—fibre implants with a fibre volume content of 5 per cent. The compressive strength of the CPC—fibre implant was 33 MPa when the strain was 2.4 per cent, which is fourfold higher than that of the CPC control. Nine cylindrical implants including six CPC—fibre implants were implanted in the bone defects of nine dogs and were then post-operatively observed. After 20 weeks in vivo, new callus from the healthy tissue of the defect entirely integrated with the CPC—fibre implant and new bone was formed as the implant degraded. Scanning electronic microscopy images indicated that macrochannels were formed in the CPC—fibre implants with the degradation of fibres, but only micropores with a scale of less than 50 μm could be observed in the CPC control. Briefly, the incorporation of a suitable chitosan-fibre structure into a CPC implant not only could improve its mechanical properties but also facilitated the bone repair process in vivo.

Molecular genetic analysis for Ax phenotype of the ABO blood group system in Chinese

BACKGROUND AND OBJECTIVES

To elucidate the molecular genetic background of the Ax phenotype in the Chinese population.

MATERIALS AND METHODS

The ABO genes of eight Ax phenotype samples, four Ax and four AxB, were amplified by polymerase chain reaction (PCR) and were cloned, along with those of 10 random A(1) Chinese subjects. We analysed the ABO gene transcript structure and the sequences of two exons and one intron at the ABO locus.

RESULTS

Among the four Ax phenotype samples, we identified one Ax02, two Ax03 and one novel Ax allele with the 543G > T mutation in the A102 background. Two of five family members also carry the allele. Of the four AxB phenotypes, one was designated as cis-AB-1/B101; the other three were shown to carry one B allele and one O with the nt261G deletion. The B alleles of the latter three were identical to B101 except for single point mutation at nt700C > G, nt640A > G and nt641T > C, respectively. The novel B101-like alleles were first associated with A(weak)B phenotypes.

CONCLUSIONS

Two ABO*B(A) alleles and an Ax allele clearly differ from all previously reported ABO alleles, suggesting that the molecular genetic background of Ax is heterogeneous in the Chinese population.

Identification of a new HLA allele, A*1114, in a Chinese family

A novel HLA-A allele, A*1114, was initially detected in two generations of a Chinese family by unusual polymerase chain reaction based sequence-specific primers ( PCR-SSP) reaction patterns and ambiguous sequence-based typing (SBT). Molecular cloning and sequencing analysis indicated that this new allele differs from HLA-A*1102 by three nucleotide substitutions in exon 3, 524 A-->G, 526 G-->C, and 527 C-->G, thus changing codon 175 from His to Arg (CAT-->CGT) and codon 176 from Ala to Arg (GCG-->CGG). Segregation analysis showed that the proband inherited his mother's HLA haplotype A*1114, B*5801, DRB1*1405. The serologic equivalent of A*1114 is a split antigen HLA-A11.2. A PCR-SSP method was developed to distinguish A*1114 from other A*11 alleles. No further individuals with A*1114 were found in 5000 Chinese bone marrow donors.

Identification of a novel allele HLA-B*5610 in a Chinese potential bone marrow donor

A novel HLA-B allele, B*5610, has been identified in a potential bone marrow donor, his mother and brother using DNA-based typing and molecular cloning methods. The B*5610 allele differs from the closest matching HLA sequence of B*5602 by two nucleotide substitutions in exon 3, 559 C-->A and 560 T-->C, resulting in an amino acid change from Leu (CTG) to Thr (ACG) at codon 187. This new allele was segregated together with A*24020101 and DRB1*140101 in the proband's family. Serology study revealed that B*5610 is associated with B22 specificity. A PCR-SSP method was developed to distinguish B*5610 from other B*56 alleles. No further individuals with B*5610 were detected in 5000 Chinese bone marrow blood donors.

[Effects of noise and music on EEG power spectrum]

Objective. To observe the effect of noise and music on EEG power spectrum. Method. 12 healthy male pilots aged 30 +/- 0.58 years served as the subjects. Dynamic EEG from 16 regions was recorded during quiet, under noise or when listening to music using Oxford MR95 Holter recorder. Changes of EEG power spectrum of delta, theta, alpha1, alpha2, beta1 and beta2, frequency components in 16 regions were analyzed. Result. The total alpha1 power was significantly decreased, while the total theta power was significantly increased when listening to music; It implies that the interhemispheric transmission of information in the frontotemporal areas might be involved. Conclusion. The changes of the EEG power spectrum were closely related to man's emotions; relaxation was associated with music; Individual difference exists in the influence of sound on EEG.

Distribution of ion transport mRNAs throughout murine nose and lung

Evidence of absorptive or secretory ion transport in different respiratory regions of the mouse was sought by assessing the regional distribution of alpha-, beta-, and gamma-epithelial sodium channel (ENaC; Na(+) absorptive), cystic fibrosis transmembrane conductor regulator (CFTR), and Na(+)-K(+)-2Cl(-) cotransporter mRNAs. High levels of ENaC subunit expression were found in nasal surface epithelium and gland ducts. CFTR was expressed in both superficial nasal respiratory epithelium and glands. These results are consistent with basal amiloride-sensitive Na(+) absorption and cAMP-dependent Cl(-) secretion in murine nasal epithelia. Expression of all three ENaC subunits increased progressively from trachea to terminal bronchioles. Intermediate levels of CFTR and cotransporter expression in bronchial epithelium diminished in bronchioles. The low abundance of CFTR mRNA throughout murine pulmonary epithelium is consistent with functional data that attributes Cl(-) secretion predominantly to an alternative Cl(-) channel. alpha-ENaC as the only mRNA found in all regions of airway epithelia is consistent with the alpha-subunit as requisite for Na(+) absorption, and the increased expression of alpha-, beta-, and gamma-ENaC in distal airways suggests a greater absorptive capability in this region.

Unsymmetrical response features of left and right brain to signals from left and right visual fields at different cognitive levels

OBJECTIVE

To study the response characteristics of left and right brain to signals from left (LVF) and right (RVF) visual fields during cognitive activity.

METHOD

ERPs at 9 locations to LVF and RVF signals were compared in 23 normal subjects in 3 task conditions: looking forward only (VC); making switch response to target signals (T) only (SR); making switch response to T differentially (DR).

RESULT

(1) Significant difference in ERPs was found between that induced by LVF and RVF signals on left brain especially at frontal location (F5), which appeared as slow negative deflection induced by T and NT from RVF in SR and DR; (2) Condition-dependent unsymmetrical features between left and right brain were found: the slow potential at F5 was significantly more negative in T and contralateral spatial relation (i. e., left brain for RVF) but more positive in NT and ipsilateral relation than that at F6.

CONCLUSION

Signals with psychological meaning in RVF might cause more psychological load as suggested by the results obtained in this study.

[Transposition of muscular skeletal flap pedicled with straight head of rectus femoris for treatment of avascular necrosis of femoral head]

OBJECTIVE

To investigate the clinical results of transposition of muscular skeletal flap pedicled with straight head of rectus femoris for treatment of avascular necrosis of adult femoral head.

METHODS

Eight patients with avascular necrosis of femoral head were adopted in this study. There were 6 males and 2 females, the ages were ranged from 24 to 56 years. According to the criteria of Ficat, there were 5 cases in stage II and 3 cases in stage III. The Smith-Peterson incision was used to expose the capsule of the hip. After complete curettage of the necrotic bone from the femoral head, the muscular skeletal flap pedicled with straight head of rectus femoris was resected and transposited into femoral head. Finally, conventional decompression of head was performed.

RESULTS

All the cases were followed up for 1 to 3 years. There were excellent results in 5 cases, good in 2 cases and moderate in 1 case. The rate of excellent and good results were 87.5%.

CONCLUSION

Comparing with other pedicled bony flaps, the muscular skeletal flap pedicled with straight head of rectus femoris is characterized by its convenience and efficacy. It is suitable for the treatment of avascular necrosis of femoral head in stage II or III, but the contour of the femoral head should be nearly normal.

[EEG synchronization index spectrum: definition, calculation and the changes related to visual selective response]

OBJECTIVE

EEG synchronization is usually estimated in terms of coherence amplitude, but the estimation is with apparent uncertainty because of the poor resolution both in time and frequency. The purpose of this work is to surmount this problem.

METHOD

A new definition of EEG synchronization index spectrum [SynI(f)] was developed basing on the distribution characteristics of EEG coherence phase which was calculated by a tested algorithm with 1 s and 1 Hz resolution. The basic feature and its changes during visual selective responses were calculated in 25 normal subjects. EEG signals were recorded from 9 locations in two conditions: looking at the central LED only(VC) and making switch response to the target LED flash signals (T) differentially (DR): switch to left or right for Ts from left (LVF) or right (RVF) visual field, repectively but making no response to the non-target ones (NT).

RESULT

(1) The frequency dependency of SynI varied with brain location, e.g., SynI was higher in alpha range than others at frontal locations but the situation reversed at posterior locations. (2) The SynIs between midline and right brain locations were higher than that between mid line and left ones. (3) As compared with VC, SynI was increased in DR condition at central and posterior brain locations but not frontal ones, it happened mainly in 7-23 Hz at central locations but in 1-4 Hz at posterior ones. (4) The augmentation of SynI in DR was greater for T than for NT signals.

CONCLUSION

The results indicated that the SynI(f) was meaningful for studying the frequency-spatial feature of EEG synchronization change among brain locations related to cognitive activities.

[The value of hybridization-in-situ technique in the diagnosis of condyloma acuminatum]

By using 35S-dCTP labelled HPV16 probe, the HPV DNA sequence in 32 cases of condyloma acuminatum and suspicious condyloma acuminatum of vulva and vagina as well as 18 cases of papillomas at different anatomical sites were detected. The results showed that the HPV DNA sequences were positive in all 25 cases of condyloma acuminata which were typical both clinically and pathologically and in 6/7 of the suspicious cases; whereas in only 1/18 of the papillomas at various sites were they positive. Thus, nucleic acid hybridization-in-situ technique combined with histopathology seemed to be of great value for the diagnosis and differential diagnosis of condyloma acuminatum.

Detection of cellular ki-ras oncogene and Epstein-Barr viral DNA by polymerase chain reaction in situ

A newly established technique of polymerase chain reaction (PCR) in situ is reported. The process involved the use of the PCR technique to amplify the target gene and to generate the radiolabelled products which was used as a probe to hybridize the target gene in situ. Ki-ras oncogene in human pancreatic carcinoma cell line (PC-2) and EBV DNA in Raji cell line were detected in situ by this technique with encouraging results. This technique has the advantages of both PCR and in situ hybridization, i.e., high sensitivity, quick amplification and precise localization. It is a rapid, simple, economical and reliable method.

[Oncogene expression and point mutation in human pancreatic adenocarcinomas]

By nucleic acid hybridization and PCR techniques, oncogene expression in normal human pancreatic tissue as well as 4 human pancreatic adenocarcinoma cell lines were studied. Additionally, c-Ki-ras gene point mutation were also detected in the paraffin embedded sections collected from 34 cases of surgical specimens resected due to pancreatic adenocarcinoma. The results showed that none of the 5 oncogenes described was expressed in the normal human pancreatic tissue, whereas, all the human pancreatic adenocarcinoma cell lines expressed c-myc and c-Ki-ras oncogenes. 28 out of 34 cases (82.4%) of human pancreatic adenocarcinomas had c-Ki-ras gene codon 12 point mutation.

[Expression of c-myc and c-ki-ras oncogene in human pancreatic carcinoma]

Using Northern blot technique, the oncogene expression in normal pancreatic tissue and human pancreatic carcinoma PC-2 and PC-3 cell lines was studied. Four oncogene probes (c-N-ras, c-ki-ras, c-myc and c-fos) consisting of recovered endonuclease digested fragments were nick translated. After hybridization and autoradiography, none of the four oncogenes was expressed in the normal human pancreatic tissue, but the human pancreatic carcinoma PC-2 and PC-3 cell lines expressed the c-myc and c-ki-ras genes. Their transcripts were 2.7 and 6.0 kb, respectively. Expression of the other two oncogenes (c-N-ras and c-fos) was not detected. The results of this study together with those reported in the literature verify the fact that the expression of c-myc and c-ki-ras oncogenes may play a very important role in the development of human pancreatic carcinoma.

[Expression of cellular oncogenes in human primary liver cell carcinoma]

With DNA-mRNA hybridization in situ technique, the expression of five oncogenes, c-N-ras, c-K-ras, c-H-ras, c-myc and c-fos, was observed in two cases of human hepatocellular carcinoma. The expression of c-N-ras, c-fos was greatly enhanced in tumor tissues of the two cases, and about 25%-50% of the tumor cells showed positive expression. The other three oncogenes namely c-K-ras, c-H-ras and c-myc, were not detected in these two carcinomas or the non-cancerous liver tissue adjacent to the carcinomas. It is surmised that c-N-ras and c-fos may play coordinative role in maintaining the malignant phenotype of human primary hepatocellular carcinoma.

Gastric gastrinoma

Two patients with Zollinger-Ellison Syndrome were diagnosed and treated in PUMC Hospital, the primary tumors were found in the stomach. On sectioning of the gastrectomized specimens, 85 tumors ranging from 0.1 to 1.0 cm in diameter were disclosed in Case 1, and a large ulcero-infiltrative carcinoma-like tumor in Case 2. Both tumors had already metastasized to regional lymph nodes and/or liver. Tumor cells in both cases exhibited gastrin, NSE, GH and hCG alpha immunoreactivity immunocytochemically, and abundant neurosecretory granules of 100-250 nm in diameter under electron microscope. The clinicopathological, immunocytochemical and ultrastructural findings of tumors from these two cases met the criteria of primary malignant gastrinoma of the stomach.

[Comparative study on protein components of ouabain resistant mutant and wild cells of Chinese hamster V79 cell line by two-dimensional gel electrophoresis]

In the sense of gene expression, the primary and direct change in mutant cells should be involved in the protein component. Two-dimensional polyacrylamide gel electrophoresis has been used to compare the protein components of ouabain resistant mutant cells (ouaR) and sensitive wild type cells (ouaS) of chinese hamster lung cell line V79. The procedure is based on O'Farrell's method and we have made some modifications. In order to make the study reliable, we took twenty polypeptide spots as a reference marker. These marker spots could always be reproduced in a series of parallel experiments with both mutant and wild cells. In addition, these markers covered different small areas, representing different isoelectric point (pI) and molecular weight (MW) on the electrophoretogram. With reference to these marker spots, some polypeptide spots showed variations in their position, size and density. It is notable that the changes appeared in the small area 4 (pI/MW:5.0/28-30kd) and the small area (pI/MW:6.3/39kd) is highly reproducible and significant, so that these changes might be specific to ouabain resistant mutant of V79 cells. Since the level of genetic polymorphism of mammalian cells on two-dimensional gel electrophoresis is quite low, these specific changes might reflect the differences in gene structure and expression. This primary study should enhance the usefulness of two-dimensional gel electrophoresis for mutagenesis research with cultured mammalian somatic cells.

Carbamyl phosphate synthetase I. A novel marker for gastric carcinoma

Carbamyl phosphate synthetase I (CPS1) is an initial enzyme of urea synthetase system. It exists exclusively in liver cells and epithelial cells of the small intestine. By immunocytochemistry, 70.5% of 88 surgically resected gastric carcinomas (42 advanced and 46 early gastric carcinomas) was found to be CPS1 immunoreaction positive, whereas all other carcinomas (of the esophagus, colon, pancreas, lung, breast, ovary, kidney, prostate and urinary bladder) tested were negative. CPS1 expression in gastric carcinoma was closely related to the types of mucin secreted by the carcinoma cells. Most carcinomas secreting sialomucin were CPS1 positive, yet those secreting sulfomucin or neutral mucin did not express CPS1. The types of intestinal metaplasia adjacent to the carcinoma correlated neither with CPS1 expression nor with the histological types of carcinoma. Owing to the fact that gastric carcinomas with CPS1 expression possess the characteristics of small intestinal epithelium, it is very likely that CPS1 can be used as a novel marker for gastric carcinoma originating from complete type intestinal metaplasia.

Effect of diallyl sulfide on rat liver microsomal nitrosamine metabolism and other monooxygenase activities

It has been reported that p.o. administration of diallyl sulfide (DAS), a naturally occurring component of garlic (Allium sativum), inhibits 1,2-dimethylhydrazine-induced colon and liver cancer in rodents. A possible mechanism for this protective effect is inhibition of hepatic activation of the procarcinogen. The effect of DAS on P450IIE1, an isozyme of cytochrome P-450 which is active in the oxidative metabolism of dimethylhydrazine, was conveniently assayed in the present study by determination of N-dimethylnitrosamine demethylase (NDMAd) activity at 1 mM N-dimethylnitrosamine in Sprague-Dawley rat liver microsomal incubations. DAS was found to be a competitive inhibitor of NDMAd, in contrast to the irreversible inactivation of NDMAd produced by carbon tetrachloride incubated under similar conditions. The inhibition by DAS of the demethylation of several substrates was selective. The thioether was most potent against N-dimethylnitrosamine, less effective against N-nitrosomethylbenzylamine, and essentially ineffective against benzphetamine and ethylmorphine. Microsomes prepared at 3 h after DAS administration (200 mg/kg in corn oil intragastrically) showed moderate inhibition (less than 30% inhibition compared to control microsomes) of several demethylase activities; however, microsomes prepared 18 h posttreatment showed a marked decrease (about 80% inhibition compared to controls) in NDMAd activity, minor effects on other demethylase activities, and a 6-fold increase in pentoxyresorufin dealkylation. These trends at 18 h agreed with immunoblot analyses which showed suppression in the level of P450IIE1 and an elevation in P450IIB1. The selective inhibition of P450IIE1 activity and suppression of its level in microsomes may contribute to the reported chemoprotective effects of DAS.

Mechanism of induction of cytochrome P-450ac (P-450j) in chemically induced and spontaneously diabetic rats

Previous studies demonstrated that a microsomal high-affinity N-nitrosodimethylamine demethylase activity and cytochrome P-450ac (an acetone/ethanol-inducible form) were induced by streptozotocin-induced diabetes in rats. In the present work, the induction was studied in detail in two chemically induced (by streptozotocin and alloxan) diabetic rat models and one spontaneously (BB/Wor) diabetic rat model. All the diabetic conditions caused increases in three parameters: (a) microsomal N-nitrosodimethylamine demethylase activity which is known to be a good indicator of the level of P-450ac; (b) the levels of P-450ac as determined by immunoblot analysis; and (c) the levels of mRNA of P-450ac as determined by hybridization assays with a cDNA probe for this enzyme. These increases were abolished by treatment of the diabetic rats with insulin. The results suggest that the pathophysiological condition of diabetes is responsible for the induction of P-450ac and elevation of mRNA is involved in all of the three diabetic models investigated.