[Prediction of pathological remission of head and neck squamous cell carcinoma patients after neoadjuvant immunochemotherapy and construction of clinical model based on clinical features and inflammatory markers]

Objective: To analyze the potential clinical biological factors influencing the major pathological response (MPR) to neoadjuvant immunochemotherapy in patients with resectable head and neck squamous cell carcinoma (HNSCC). Methods: This retrospective study enrolled patients with resectable HNSCC who underwent neoadjuvant immunochemotherapy at Sun Yat-sen University Cancer Center from June 1, 2019 to December 31, 2021. Binary logistic regression was used to analyze the correlation between clinical characteristics, inflammatory markers and MPR, and a nomogram model was constructed. The calibration curve and decision curve analysis were used to verify the predictive ability and accuracy of the nomogram model. Results: A total of 173 patients were included in the study, with 141 males and 32 females, aged from 22 to 83 years. After pathological assessment, the patients were divided into two groups: MPR group (108 cases) and non MPR group (65 cases). Logistics regression analysis indicated that the patients with HPV+oropharyngeal cancer, partial response or complete response by imaging assessment, low pre-treatment platelet/lymphocyte ratio, low pre-treatment C reactive protein/albumin ratio and lower pre-and post-treatment C reactive protein/albumin ratio difference were more likely to have MPR (all P<0.05). Nomogram model was constructed based on the above factors, with a C-index of 0.826 (95%CI: 0.760-0.892), and the calibration curve and decision curve analysis confirmed the prediction accuracy of the model. Conclusion: This study shows that many factors are related to MPR of patients with resectable HNSCC receiving neoadjuvant immunochemotherapy and the constructed nomogram model helps to develop personalized treatment strategies for the patients.

Anomalous staged hot-electron acceleration by two-plasmon decay instability in magnetized plasmas

We present a staged hot-electron acceleration mechanism of the two-plasmon decay (TPD) instability in the transverse magnetic field under the parameters relevant to inertial confinement fusion experiments. After being accelerated by the forward electron plasma wave (FEPW) of TPD, the hot-electrons can be anomalously accelerated again by the backward electron plasma wave (BEPW) of TPD and then obtain higher energy. Moreover, the surfatron acceleration mechanism of TPD in the magnetic field is also confirmed, the electrons trapped by the TPD daughter EPWs are accelerated in the direction along the wave front. Interestingly, the velocity of electrons accelerated by surfing from the FEPW is quite easily close to the BEPW phase velocity, which markedly enhances the efficiency of the staged acceleration. The coexistence of these two acceleration mechanisms leads to a significant increase of energetic electrons generated by TPD in the magnetic field. Meanwhile the EPWs are dissipated, TPD instability is effectively suppressed, and the laser transmission increases.

Kinetic model and Vlasov simulation verification of two-ion decay instability

A kinetic theory is developed to describe the longitudinal decay of two-ion decay (TID): The pump ion-acoustic wave (IAW) decays into two daughter IAWs with a longer wavelength. The instability growth rate and threshold are given by the theory. Both the simulations of full kinetic Vlasov and hybrid Vlasov (kinetic ions and Boltzmann electrons) are employed to verify the theory and have a high quantitative agreement with the theory for 8≤ZT_{e}/T_{i}≤15, where Z is the ion charge number and T_{i}(T_{e}) is the ion (electron) temperature. The kinetic model developed here solves a long-standing problem that the simple fluid theory underestimates growth rate by a factor of 2∼3. Also, a reasonable explanation is given to the typical characteristics of TID that the dependence curves of subharmonic growth rate γ and wave number k.

[Clinical application of a classification based on crucial curvature of coronal imbalance in degenerative lumbar scoliosis]

Objective: To present efficacy of clinical application of a classification based on crucial curvature of coronal imbalance in degenerative lumbar scoliosis (DLS). Methods: A case series study. Clinical data of 61 cases (8 males, 53 females) who underwent posterior correction surgery for DLS from January 2019 to January 2021 were retrospectively analyzed. The mean age was (71.7±6.2) years (ranged 60-82 years). According to the direction of C₇ plumb line (C₇PL) deviated from central sacral vertical line (CSVL) and orientation of L₄ coronal tilt, the author determined which one was the crucial curve. If C₇PL deviated from CSVL in the same direction as concave side of the thoracolumbar curve and L₄ coronally tilts opposite direction of C₇PL deviates from CSVL, then the crucial curve was thoracolumbar curve (type 1). On the contrary, if C₇PL deviated from CSVL in the same direction as concave side of the lumbosacral curve and L₄ coronally tilts consist with direction of C₇PL deviates from CSVL, then the crucial curve was lumbosacral curve (type 2). According to absolute value of coronal balance distance (|CBD|), each type of patients was divided into two groups, respectively, namely coronal balance (CB) (|CBD|≤3 cm) and coronal imbalance (CIB) (|CBD|>3 cm). Changes of Cobb angles of thoracolumbar curve and lumbosacral curve and CBD were recorded and analyzed. Results: The rate of preoperative CIB was 55.7% (34/61) in all the patients. Of the patients, 23 cases were classified as type 1 and 38 cases as type 2. The rate of preoperative CIB was 34.8% (8/23) in type 1 patients and 68.4% (26/38) in type 2. The rate of postoperative CIB was 27.9% (17/61) in all the patients, with 13.0% (3/23) in type 1 and 36.8% (14/38) in type 2. The |CBD| of CB group in type 1 patients decreased from (2.6±1.4) cm before the operation to (1.5±1.0) cm after (P=0.015); and the correction rate of thoracolumbar curve (68.8%±18.4%) was significantly higher than that of lumbosacral curve (34.5%±23.9%) (P=0.005). The |CBD| of CB group in type 2 patients decreased from (2.6±3.0) cm before the operation to (1.6±1.2) cm after (P=0.027); the correction rate of lumbosacral curve (71.3%±18.6%) was higher than that of thoracolumbar curve (57.3%±21.1%), but the difference was not statistically significant (P=0.546). There was no significant difference in |CBD| of CIB group in type 2 patients before and after the operation (P=0.222); the correction rate of lumbosacral curve (38.3%±14.8%) was significantly lower than that of thoracolumbar curve (53.6%±16.0%) (P=0.001). There was a correlation between the change of CBD (3.8±1.5) cm and the difference in correction rate between thoracolumbar and lumbosacral curve (32.3%±19.6%) in CB group in type 1 patients after surgery (r=0.904, P<0.001). There was a correlation between the change of CBD (1.9±2.2) cm and the difference in correction rate between lumbosacral and thoracolumbar curve (14.0%±26.2%) in CB group in type 2 patients after surgery (r=0.960, P<0.001). Conclusion: Clinical application of a classification based on crucial curvature of coronal imbalance in DLS is satisfactory, and its combination with matching correction can effectively prevent the occurrence of coronal imbalance after spinal correction surgery.

[Association between obesity and the prevalence of type 2 diabetes mellitus among Chinese adults aged 18-65 years in 15 provinces in 2018]

Objective: To analyze the association between different types of obesity, BMI, and waist circumference (WC) and the risk of type 2 diabetes mellitus (T2DM) in Chinese adults. Methods: Based on the China Health and Nutrition Survey data in 2018, different types of obesity were defined across different BMI and WC combinations based on Criteria of weight for adults (WS/T 428-2013), including non-obesity, simple general obesity, simple central obesity, and complex obesity. The associations of different types of obesity, BMI, and WC with T2DM risk were explored using two-level mixed-effects logistic regression and restricted cubic spline models. Results: A total of 7 030 subjects aged 18-65 were included in this study. The prevalence of general obesity and central obesity were 16.29% (502/3 082), 42.28% (1 303/3 082) in males, and 14.41% (569/3 948), 37.87% (1 495/3 948) in females. The prevalence of complex obesity was 14.70% and 12.97% in males and females, respectively. The prevalence of T2DM was 11.28% in participants, and the prevalence in complex obesity (18.98%, 22.07%) was higher than in simple central obesity (16.24%, 15.26%) and non-obesity (9.65%, 5.18%) in males and females, respectively. Multilevel regressions showed that males with simple central obesity and complex obesity had 1.61 (95%CI: 1.24-2.08) and 2.11 (95%CI: 1.56-2.86) times the odds of T2DM, respectively, as compared with the non-obesity; and the odds of T2DM in females were 2.70 (95%CI: 1.16-6.28) times for simple general obesity, 2.62 (95%CI: 2.01-3.40) times for simple central obesity, and 4.47 (95%CI: 3.35-5.98) times for complex obesity. A nearly linear positive association was observed between BMI and T2DM risk. WC was also positively associated with T2DM risk and a non-linearly increased risk in females (P for non-linear=0.024). The risk of T2DM increased when BMI ≥22.5 kg/m² and 23.0 kg/m², WC ≥85.0 cm and 80.0 cm in males and females, respectively. Conclusions: Complex obesity adults are more likely to suffer from T2DM. The risk of T2DM increases significantly when BMI is at the normal high values and waist circumference at the stage of pre-central obesity.

[The role of preventive pancreatic duct stent placement in preventing acute pancreatitis after endoscopic retrograde cholangiopancreatography]

The aim of this study was to investigate the preventive effect of pancreatic duct stent on acute pancreatitis after endoscopic retrograde cholangiopancreatography. A retrospective analysis of the case data of patients who first underwent endoscopic retrograde cholangiopancreatography for choledocholithiasis in the Beijing Friendship Hospital from January 2015 to December 2019 for 5 years. According to whether the pancreatic duct stent was indwelled during the operation, they were divided into pancreatic duct stent group (147 cases) and non-indwelling pancreatic duct stent group (192 cases). The incidence of acute pancreatitis after endoscopic retrograde cholangiopancreatography was compared between the two groups according to COTTON criteria. Independent sample t test, Pearson Chi-square test (χ²) and Fisher's exact test were used to compare groups' differences. There were 2 cases of acute pancreatitis in the pancreatic duct stent group, all of which improved after 48 hours. There were 22 cases of acute pancreatitis in the non-indwelling pancreatic duct stent group, of which 20 cases improved within 48 hours, and the other 2 cases had severe pancreatitis, which improved and discharged after 30 days of treatment. There was significant difference in the incidence of acute pancreatitis between the pancreatic duct stenting group (1.4%) and the group without placement of pancreatic duct stents (11.5%) (χ²=12.905,P<0.001). In conclusion, Pancreatic duct stent may be an effective method to prevent PEP.

Polarization conversion in the caviton driven by linearly polarized lasers

In one-dimensional particle-in-cell simulations of a plasma irradiated by linearly polarized lasers from both sides of boundaries, it is found that there is an appreciable growth of the electromagnetic field in cavitons in the transverse direction perpendicular to the direction of polarization, which indicates the polarization conversion of the electromagnetic field in cavitons. This paper demonstrates the mechanism of this phenomenon based on parametric resonance induced by ponderomotive force with twice the frequency of the electromagnetic radiation in the caviton. We develop a theoretical model and verify it with simulation results. This phenomenon contributes to the heating and acceleration of particles and traps more EM energy in cavitons.

[Meta-analysis of the effects of triamcinolone acetonide alone and in combination with 5-fluorouracil for treating keloids]

Objective: To compare the efficacy and safety of triamcinolone acetonide (TA) alone and in combination with 5-fluorouracil (5-FU) for treating keloids using meta-analysis. Methods: Databases including PubMed, Embase, and Cochrane Library were retrieved with the search terms of " triamcinolone acetonide, 5-fluorouracil, glucocorticoid, fluorouracil, keloid, scar, TAC, 5-FU, hypertrophic scar " and databases including Chinese Journal Full-Text Database, Chinese Biomedical Database, and Wanfang Data were retrieved with the search terms of ",, 5-,," in Chinese to obtain the publicly published randomized controlled trials about the effects of TA alone and in combination with 5-fluorouracil for treating keloids from the establishment of each database to august 2019. The outcome indexes included effective proportion of treatment, incidence proportion of adverse reactions, and recurrence proportion of keloids. RevMan 5.3 and Stata 14.0 statistical software were used to conduct a meta-analysis of eligible studies. Results: A total of 1 326 patients with keloids were included in 14 studies, including 668 patients in TA+ 5-fluorouracil group whose keloids were injected with TA and 5-fluorouracil and 658 patients in TA alone group whose keloids were injected with TA alone. A total of 7 articles achieved 1 to 3 points in modified Jadad score, while 7 articles achieved 4 to 7 points in modified Jadad score. Patients in TA+ 5-fluorouracil group had a higher effective proportion of treatment than that of TA alone group (relative risk=1.28, 95% confidence interval=1.16-1.41, P<0.01). Subgroup analysis showed that the quality of the included literature and ethnic factors might be the source of heterogeneity in effective proportion of treatment. Patients in TA+ 5-fluorouracil group had a lower incidence proportion of adverse reactions than that of TA alone group (relative risk=0.44, 95% confidence interval=0.25-0.75, P<0.01). Patients in TA+ 5-fluorouracil group had a lower recurrence proportion of keloids than that of TA alone group (relative risk=0.25, 95% confidence interval=0.14-0.44, P<0.01). There was no publication bias in incidence proportion of adverse reactions (P>0.05), while the effective proportion of treatment and recurrence proportion of keloids had publication bias (P<0.05). Conclusions: TA combined with 5-fluorouracil is more effective than TA alone for treating keloids, with less incidence of adverse reactions and recurrence.

Analyses of microRNA166 gene structure, expression, and function during the early stage of somatic embryogenesis in Dimocarpus longan Lour

MicroRNA166 (miR166) contributes to post-transcriptional regulation by binding the mRNAs of HD-ZIP III genes, which affects plant growth and development. The structural characteristics, expression, and functions of miR166 genes during the early somatic embryogenesis stage in Dimocarpus longan remain unknown. We isolated the transcripts of pri-miR166 S78 with two transcription initiation sites (TSSs) and pri-miR166 S338 with one TSS. These sequences contain potential smORFs and encode different miRNA peptides (miPEPs). Additionally, their promoters contain cis-acting elements responsive to diverse stimuli. The pre-miR166 S78 and pre-miR166 S338 expression levels were up-regulated in response to 2,4-D, abscisic acid, and ethylene. Although the expression patterns induced by hormones were similar, there were differences in the extent of the response, with pre-miR166 S338 more responsive than pre-miR166 S78. Thus, miRNA transcription and maturation are not simply linearly correlated. Moreover, pre-miR166 S78 and pre-miR166 S338 expression levels were down-regulated, whereas ATHB15 (target gene) expression was up-regulated, from the longan embryonic callus to the globular embryo stages. These results are indicative of a negative regulatory relationship between miR166 and ATHB15 during the early somatic embryogenesis stage in longan. At the same stages, miR166a.2-agomir, miR166a.2-antagomir, and miPEP166 S338 increased or decreased the expression of miR166a.2 and ATHB15, but with no consistent patterns or linear synchronization, from which we've found some reasons for it.

[A study on the targeted nanoparticles of isosorbide mononitrate on reducing the levels of inflammatory factors in rabbit models of rhinosinusitis]

Objective: To investigate the effect of isosorbide mononitrate (ISMN) targeted nanoparticles on inflammatory factors of sinusitis by establishing a rabbit model of rhinosinusitis. Methods: Thirty healthy rabbits, male and female, weighing 2.5-3.5 kg, were randomly divided into 6 groups with 5 rabbits in each group. Group A was the control group. The model of rabbit sinusitis was established in group B to F, and CT was used to confirm the model was successful. After placing tubes into the maxillary sinus in the group C to F, saline, 45 mg/ml ISMN, 45 mg/ml ISMN nanoparticles and 45 mg/ml ISMN targeted nanoparticles were used to wash the maxillary sinus, respectively. Blood samples were collected from the ear vein of rabbits on day 7, 14, 21, 28, 35 and 42 after modeling respectively. Changes in the expression levels of inflammatory factors in rabbits during the modeling process and after drug washing were detected by ELISA. After the drug intervention, the maxillary sinus mucosa was taken for real-time quantitative PCR to detect the changes in the mRNA level of inflammatory factors. SPSS 22.0 software was used to process the data. Results: Rabbit model of sinusitis was successfully established. ELISA showed that after the action of ISMN targeted nanoparticles of 1 week (42th day after modeling), the levels of (interleukin, IL) 4, IL-8, IL-17A and interferon γ (IFN-γ) in the blood were lower compared with that of 35th day after modeling, the difference was statistically significant (5.57±1.20 vs 19.73±0.68, 66.41±11.87 vs 154.68±13.13, 17.96±1.87 vs 28.23±0.80, 53.56±5.66 vs 111.93±7.29, all P<0.05). Compared with the ISMN nanoparticles and ISMN, the ISMN targeted nanoparticles reduced the levels of IL-4, IL-8, IL-17A and IFN-γ more obviously, the differences were statistically significant (13.26±1.43 vs 8.81±1.33 vs 7.14±2.16, 89.47±17.80 vs 41.07±7.77 vs 15.84±3.72, 10.28±2.07 vs 3.06±1.62 vs 1.82±0.90, 62.16±6.18 vs 35.12±4.62 vs 27.89±10.18, all P<0.05). Real-Time PCR showed that after the flushing of ISMN targeted nanoparticles, the levels of IL-4, IL-8, IL-17A and IFN-γ mRNA were lowest compared with that of the model group, ISMN nanoparticles and ISMN group. Conclusion: ISMN targeted nanoparticles can reduce the level of inflammatory factors in rabbit sinusitis model.

[The etiological analysis of 260 hospitalized cases with bilateral adrenal lesions]

Objective: To summarize the etiologies of bilateral adrenal lesions and the changes of the disease profile in hospitalized patients. Methods: Bilateral adrenal lesion screening was conducted in all patients admitted to Peking University Third Hospital from 1994 to 2017. The etiologies and disease profiles of bilateral adrenal lesions were retrospectively analyzed. Results: A total of 260 patients with bilateral adrenal lesions were included in the study. There were 146 males and 114 females with a mean age of (55.4±16.2) years. The most common adrenal lesion was bilateral adrenal hyperplasia (75 cases, 28.8%), followed by bilateral adrenal adenomas (71 cases, 27.3%), metastatic carcinoma (51 cases, 19.6%), discordant bilateral adrenal lesions (27 cases, 10.4%), bilateral pheochromocytomas (13 cases, 5.0%), and others. The clear data of endocrine function evaluation could be found in 184 patients. Among them, 111 cases (60.3%) were nonfunctioning lessions, 34 cases (18.5%) with primary aldosteronism, 15 cases (8.1%) with pheochromocytoma, 13 cases (7.1%) with congenital adrenal hyperplasia, 6 cases (3.3%) with primary hypoadrenocorticism, and 5 cases (2.7%) with Cushing syndrome. Using every 8 years as a period of time, the number of hospitalized patients with bilateral adrenal lesions increased with years in three periods (8, 41 and 211 cases, respectively). Conclusions: The most common cause of bilateral adrenal lesions is adrenal hyperplasia in the hospitalized patients. More than half of bilateral adrenal lesions are nonfunctioning. In functional bilateral lesions, primary aldosteronism and pheochromocytoma account for a large proportion.

Influence of tool edge waviness on the diffraction effect of diamond-turned optics: theoretical simulation and experimental validation

In this work, the influence of tool edge waviness on the diffraction effect of diamond-turned optics is simulated theoretically and further validated experimentally. In simulation, a 3D surface topography model with consideration of the influence of tool edge waviness is established, in which the variation of tool edge profile is estimated by a linear model in relation to the cutting distance. The results show that the diffraction effect represented in simulation is consistent with the experimental observation. With the deterioration of tool edge waviness, the diffraction efficiency of the specular light decreases, but the high-order diffracted light intensively distributes in the horizontal direction on the receiving screen. Such observation can be attributed to the subgrating effect induced by the periodic duplication of the tool edge profile on the machined surface, which heavily depends on the deterioration of tool edge waviness. Finally, a waviness-controlled diamond tool is recommended to finish a diffraction-free optics by the diamond turning process. Moreover, the diffraction effect can also be employed to monitor the dynamic wear of the cutting tool in diamond turning.

[Clinical analysis of combined treatment in 87 patients with recurrent allergic fungal rhinosinusitis]

Objective:To evaluate the effects of combined treatment with FESS on postoperative recurrent allergic fungal rhinosinusitis treatment.Method:Eighty-seven patients with allergic fungal sinusitis under combined treatment were investigated.Result:All patients were followed up for more than one year.Clinical symptoms had greatly improved after treatment compared with before treatment.Postoperative VAS score and Lund-Mackay score were lower than preoperative ones.Out of 87 patients,42 patients were successfully cured, 37 patients showed improvement, but there was no change in other 8 patients. The total efficacy rate was 90.81%.Conclusion:The combined treatment of recurrent allergic fungal rhinosinusitis treatment has achieved good effect. We should not only open sinus and remove the fungi, but also should pay attention to the elimination of inflammatory response in the treatment of recurrent allergic fungal rhinosinusitis.

[Clinical analysis of individualized nasal cavity ventilation expansion techniques for treatment of OSAHS patients]

Objective:To investigate efficacy of individualized nasal cavity ventilation expansion techniques for OSAHS patients with nasal obstruction. Method:One hundred and twelve OSAHS patients with nasal obstruction were included in this study. Nasal cavity ventilation expansion techniques were performed. Every patient took the examination of acoustic rhinometry, nasal respiration volume, rhinomanometry and polysomnography, and filled VAS of nasal obstruction and Epworth Sleep Scores(ESS) before surgery and three months after surgery. Result:Follow-up was for 6－12 months. Of all the patients, 39 cases were cured, 37 cases were remarkably improved, 21 cases were effective, and 15 cases were of no effect, respectively. Compared with pre-operative examination data in all OSAHS patients, nasal ventilation was markedly improved, the ESS was significantly decreased, the AHI was significantly decreased, LSaO2 and MSaO2 were significantly increased, and sleep structure did not change significantly in all OSAHS patients 6 month after nasal surgery. Conclusion:Individualized nasal cavity ventilation expansion techniques is an effective treatment for OSAHS patients with nasal obstruction，improves the safety of patients with UPPP surgery, and the tolerability of CPAP in some patients with ineffective surgery.

[Thoughts on enacting and carrying out for reoperative procedures in thyroid surgery]

In recent years, with the improvement of the incidence of thyroid tumors and the extensive development of thyroid surgery in primary hospitals, the proportion of thyroid cancer patients requiring reoperation has continued to increase. In spite of different reasons of reoperation, the risk of serious complications will increase after reoperation compared with first operation. Undoubtedly, the doctors will have to face new challenges to make more appropriate surgery program. Before reoperation, both the operation benefits and the corresponding risks should be considered comprehensively. As far as possible, the individual treatment should be recommended on the basis of standardized treatment, and it will be better to strike a balance between radical surgery and function protection. Consequently, low-grade doctors should be cautious to perform these reoperations.

Potential role of S-adenosylmethionine in osteosarcoma development

The metastatic form of osteosarcoma is a life threatening one since it metastasizes to the lungs. The major cause of metastatic osteosarcoma is hypomethylation of numerous genes that undergo overexpression to enable the progression of the disease. In the present study, S-adenosylmethionine (SAM), a predominant methyl donor, was administered to find out its effects on osteosarcoma progression. As evidence of tumor suppression, the SAM-treated mouse tissue was analyzed histologically, which exemplifies the control that SAM has over abnormal cell proliferation, especially on primary osteosarcoma, but it lacks positive effects on metastatic osteosarcoma. At the molecular level, the successful inhibition of primary osteosarcoma was found to be associated with a lower expression of Sox2, a protein highly expressed in osteosarcoma stem cells, along with an upregulated expression of TCTP. The data suggest that the administration of SAM has a positive role in treating primary osteosarcoma, but it has no role in suppressing metastatic osteosarcoma. The decreased expression of Sox2 together with upregulation of TCTP following SAM administration indicates that SAM has a control over primary osteosarcoma.

Quantification of protein interaction kinetics in a micro droplet

Characterization of protein interactions is essential to the discovery of disease biomarkers, the development of diagnostic assays, and the screening for therapeutic drugs. Conventional flow-through kinetic measurements need relative large amount of sample that is not feasible for precious protein samples. We report a novel method to measure protein interaction kinetics in a single droplet with sub microliter or less volume. A droplet in a humidity-controlled environmental chamber is replacing the microfluidic channels as the reactor for the protein interaction. The binding process is monitored by a surface plasmon resonance imaging (SPRi) system. Association curves are obtained from the average SPR image intensity in the center area of the droplet. The washing step required by conventional flow-through SPR method is eliminated in the droplet method. The association and dissociation rate constants and binding affinity of an antigen-antibody interaction are obtained by global fitting of association curves at different concentrations. The result obtained by this method is accurate as validated by conventional flow-through SPR system. This droplet-based method not only allows kinetic studies for proteins with limited supply but also opens the door for high-throughput protein interaction study in a droplet-based microarray format that enables measurement of many to many interactions on a single chip.

miR-71b regulation of insulin/IGF-1 signaling during starvation in planarians

Planarians, which have a large population of stem cells called neoblasts, are molecularly tractable model systems used in the study of regeneration. However, planarians have strong resistance to hunger and have developed growth arrest strategies. For example, they can change their size and undergo growth regression during starvation periods. The results of the current study show that the microRNA, miR-71b, and the insulin/IGF-1 signaling pathway have important functions in the development of starvation-induced planarians. We demonstrate tissue-specific expression of miR-71b using in situ hybridization. By employing real-time polymerase chain reaction, we provide evidence that miR-71b is upregulated in starvation-induced planarians. Furthermore, we validate and verify the target genes of miR-71b.

Unusual fast secondary relaxation in metallic glass

The relaxation spectrum of glassy solids has long been used to probe their dynamic structural features and the fundamental deformation mechanisms. Structurally complicated glasses, such as molecular glasses, often exhibit multiple relaxation processes. By comparison, metallic glasses have a simple atomic structure with dense atomic packing, and their relaxation spectra were commonly found to be simpler than those of molecular glasses. Here we show the compelling evidence obtained across a wide range of temperatures and frequencies from a La-based metallic glass, which clearly shows two peaks of secondary relaxations (fast versus slow) in addition to the primary relaxation peak. The discovery of the unusual fast secondary relaxation unveils the complicated relaxation dynamics in metallic glasses and, more importantly, provides us the clues which help decode the structural features serving as the ‘trigger' of inelasticity on mechanical agitations.

Mechanical relaxation processes in glasses can provide information on the structural and mechanical properties of glasses. Here, the authors observe a fast secondary relaxation process in La-based metallic glasses, providing information on the inelasticity of metallic glasses.

Identification of small non-coding RNAs in the planarian Dugesia japonica via deep sequencing

Freshwater planarian flatworm possesses an extraordinary ability to regenerate lost body parts after amputation; it is perfect organism model in regeneration and stem cell biology. Recently, small RNAs have been an increasing concern and studied in many aspects, including regeneration and stem cell biology, among others. In the current study, the large-scale cloning and sequencing of sRNAs from the intact and regenerative planarian Dugesia japonica are reported. Sequence analysis shows that sRNAs between 18nt and 40nt are mainly microRNAs and piRNAs. In addition, 209 conserved miRNAs and 12 novel miRNAs are identified. Especially, a better screening target method, negative-correlation relationship of miRNAs and mRNA, is adopted to improve target prediction accuracy. Similar to miRNAs, a diverse population of piRNAs and changes in the two samples are also listed. The present study is the first to report on the important role of sRNAs during planarian Dugesia japonica regeneration.

Cloning and identification of microRNAs in earthworm (Eisenia fetida)

MicroRNAs (miRNAs) (noncoding RNAs of 20-25 nucleotides) play important roles in the post-transcriptional regulation of gene expression in various eukaryotes and prokaryotes. Piwi-interacting RNAs function by combining with PIWI proteins to regulate protein synthesis and to stabilize mRNA, the chromatin framework, and genome structure. This study investigates the role of miRNAs in regeneration. A scrDNA library was constructed, and 17 noncoding RNAs from Eisenia fetida (an optimal model for the study of earthworm regeneration) were cloned and characterized. In addition, reverse transcription polymerase chain reaction was performed to analyze the expression of four small RNAs during different developmental stages. The expression levels of these RNAs in regenerating tissue were higher than in normal tissue, and the expression patterns of these small RNAs were unique during development.

Promoter hypermethylation of cyclooxygenase-2 gene in esophageal squamous cell carcinoma

Cyclooxygenase-2 (COX-2) is overexpressed in various types of human malignancies including esophageal squamous cell carcinoma (ESCC). However, a subset of ESCC either do not express COX-2 or show low level of expression. It is well established that promoter methylation is a major mechanism that mediates transcriptional silencing of COX-2 in gastric and colorectal cancer, but the data on ESCC are very limited. In this study, we attempted to determine whether COX-2 expression was also regulated by promoter methylation in human ESCC cell lines. We examined the methylation status of the COX-2 promoter in five human ESCC cell lines (EC109, EC9706, KYSE 410, KYSE 150, TE-1) using bisulfite sequencing analysis. Western blot analysis was used to determine COX-2 expression. Quantitative real-time polymerase chain reaction was used to determine COX-2 mRNA level. Prostaglandin (PG) E(2) was detected by ELISA. The promoter was densely methylated in TE-1 and KYSE 150, which had a low level of COX-2 expression and less methylated in other three cell lines (EC109, EC9706, KYSE 410), with high level of COX-2 expression. Treatment with 5-aza-deoxycytidine (5-aza-DC), a DNA methyltransferase inhibitor, demethylated the promoter and upregulated COX-2 expression, as well as PGE(2) production in TE-1 and KYSE 150. However, no such effects were observed in EC109. COX-2 protein was negative, but mRNA was positive in TE-1. After treatment with 5-aza-DC, both COX-2 mRNA and protein level had increased. These findings suggest that the promoter methylation may be one of the mechanisms that regulate COX-2 expression in ESCC.

Co-overexpression of PpPDI enhances secretion of ancrod in Pichia pastoris

Ancrod, a serine protease purified from the venom of Agkistrodon rhodostoma, is highly specific for fibrinogen. It causes anticoagulation by defibrinogenation and has been used as a therapeutic anticoagulant for the treatment of moderate to severe forms of peripheral arterial circulatory disorders in a variety of countries. The DNA of ancrod was amplified by recursive PCR with a yeast bias codon and cloned into the pGEM-T Easy vector. In order to achieve a high level secretion and a full activity expression of ancrod in Pichia pastoris (P. pastoris), the P. pastoris protein disulfide bond isomerase (PpPDI) was co-overexpressed in the strain. The secretion characteristics of ancrod with and without PpPDI were examined. With co-overexpression of PpPDI, the production of recombinant ancrod (rAncrod) was increased to 315 mg/L in the culture medium, which is twofold higher than the control strain carrying only the ancrod gene. Through purified by Ni²⁺ affinity chromatography and phenyl Sepharose column, the purity of rAncrod was found to be as high as 95.2%. The fibrinogenolytic and zymographic activities of the rAncrod were determined and found to be similar to that of the native protein. This improved expression system can facilitate further studies and the industrial production of ancrod.

Effects of cyclooxygenase-2 non-selective and selective inhibitors on proliferation inhibition and apoptosis induction of esophageal squamous carcinoma cells

The objective of this study is to investigate the effects of aspirin and nimesulide on cell proliferation, apoptosis and its potential mechanisms in EC9706 and EC109 esophageal squamous carcinoma cells. EC9706 and EC109 cells were incubated with varying concentrations of aspirin and nimesulide, and the effects on cell proliferation and apoptosis were monitored by 3-(4,5-dimethyl-thiazol-2yl)-2,5-diphenyltetrazolium bromide and flow cytometry. Reverse transcription-polymerase chain reaction and Western blot assays were used to investigate expression of Bcl-2 and Bax. Prostaglandin E2 production was measured by enzyme linked immunosorbent assay. Pretreatment with aspirin and nimesulide inhibited EC9706 and EC109 cell growth in a time and dose-dependent manner, accompanied with a decrease of prostaglandin E2 production. In EC9706 cells, the mechanism of aspirin and nimesulide induced growth inhibition was a consequence of cell cycle arrest at the G(0)/G(1) check point. In EC109 cells, growth arrest was by induction of apoptosis, associated with downregulation of Bcl-2, but not Bax. In conclusion, aspirin and nimesulide could inhibit cell proliferation and induce apoptosis in esophageal squamous carcinoma cells. Cyclooxygenase-2 inhibitor may be a promising therapeutic agent for human esophageal squamous cell carcinoma.

Microcycle conidiation and medusa head conidiophores of aspergilli on indoor construction materials and air filters from hospitals

Microcycle conidiation and microniche colonization by aspergilli was observed in-situ on various indoor construction and finishing materials. Microcycle conidiation, direct conidiogenesis from a conidium or spore with minimal intervening hyphal development, for several decades has been considered a survival mechanism during stress for a variety of moulds. Adhesive transparent tape mounts and bulk materials from various indoor materials, including air filters from hospitals and healthcare institutions, were transported to the laboratory for light microscopic and scanning electron microscopic observations. Additional materials were held in moist chambers over nonsterile soils and examined periodically for fungal development. Microcycle conidiation was observed usually in areas of sparse fungal development, mostly in association with isolations of members of the Aspergillus flavus-, A. versicolor-, A. niger groups. Branched conidiophores and medusa heads, more often associated with colonization by Eurotium spp., were observed on some preserved woods. These conidiogenesis processes might be factors in the survival and blooms of indoor aspergilli.

Expression, purification, and activity identification of Alfimeprase in Pichia pastoris

Alfimeprase (ALF) is a truncated form of non-hemorrhagic zinc metalloproteinase fibrolase. In order to achieve a high level secretion and full activity expression of ALF, the Pichia pastoris (P. pastoris) expression system was used. ALF coding sequence fused with a 6 *histidine tag and an enterokinase recognition site at the N-terminus was cloned into the expression vector pPIC9K and then expressed in P. pastoris strains of GS115 and KM71 by methanol induction. SDS-PAGE and Western blotting analysis showed that the secreted recombinant ALF (rALF) had a molecular weight of 23.8 kDa and was bound specifically to mouse anti-His. tag monoclonal antibody. Under the optimized culture parameters of pH value, initial A(600) value, methanol daily addition concentration and induction time length, the production of rALF reached up to 510 mg/L and 465 mg/L of the GS115 and KM71 transformants, respectively. It also appeared that KM71 was producing a more pure protein than GS115 while GS115 was producing more rALF per unit volume. Through one-step affinity chromatography, the purity of rALF was as high as 96%. The fibrinolytic activity of rALF revealed by the modified fibrin plate method indicated that the protein was efficiently secreted and functionally expressed, and thrombolysis of rALF was demonstrated to be dose-dependent and time-relative. The improved expression system will facilitate further studies and industrial production of ALF.

Expression of Soluble and Functional Snake Venom Fibrinolytic Enzyme Fibrolase Via the Co-Expression of DsbC in Escherichia coli

Fibrolase is a non-hemorrhagic zinc metalloproteinase found in southern copperhead snake venom (Agkistrodon contortrix contortrix). It is capable of degrading fibrin clots that result from purified fibrinogen or blood plasma. The DNA of fibrolase was amplified by recursive PCR, and cloned into the pET25b(+) expression vector. The effect of co-expression of signalless versions of catalysts or molecular chaperones FkpA, Skp and DsbC in cytoplasm was examined. When co-expressed with DsbC, compared to the totally insoluble inclusion bodies of fibrolase expressed separately, more than 90 % of recombinant fibrolase was soluble, according to denaturing polyacrylamide gel electrophoresis analysis. We also determined that FkpA and Skp had no effects on the solubility of target protein when co-expressed with fibrolase in Escherichia coli. Fibrolase was successfully purified using metal ion affinity chromatography and hydrophobic chromatography, and a maximum yield of 20 mg/L fibrolase was obtained. Fibrinolytic activity of recombinant fibrolase was demonstrated using fibrin plate assays and fibrinogen hydrolysis.

Increased frequency of the mannose-binding lectin LX haplotype in Chinese systemic lupus erythematosus patients

Mannose-binding lectin (MBL) is an important complement-activating protein of the human immune system. As a result of one of three structural gene mutations in exon 1 (variants B, C and D) and/or the presence of a low-efficiency promoter polymorphism, MBL deficiency may be associated with increased susceptibility to infectious diseases and to autoimmune disorders, including systemic lupus erythematosus (SLE). Using a combined approach of heteroduplex generator and polymerase chain reaction, a systematic search for mutations in exon 1 and the promoter region of the MBL gene was performed in a Chinese study population comprising 41 SLE patients and 111 healthy controls. Two alleles, a wild-type allele A and a variant allele B (a previously reported mutation of GGC to GAC at codon 54), were identified in MBL exon 1. The frequency of the B allele (0.15) was higher in the SLE patients than in the healthy controls (0.09), but the difference did not attain statistical significance (P > 0.05). However, for two polymorphisms at positions -550 and -221 in the promoter region, the frequency of the low-MBL-producing haplotype (LX) in the patients (0.2073) was significantly higher than that in the controls (0.0855) (P = 0.003, relative risk = 2.79). Our results suggest that the LX haplotype represents a strong risk factor among Chinese SLE patients. Although of lesser importance, the MBL B allele also may be a risk component in the developing process of SLE in Chinese patients.

The vascular and glandular organoprotective properties of metronidazole in the rodent stomach

BACKGROUND

The gastroprotective action of metronidazole, an antimicrobial used in the therapy against Helicobacter pylori infection, is unclear. Thus, the aim of the present investigation was to study the organoprotective action and antiulcer mechanisms of this drug in rodents.

METHODS AND RESULTS

Metronidazole (10 mg/kg), given either per os or intraperitoneally, 30 min beforehand, reduced ethanol (40%, 10 mL/kg, p.o.)-induced gastric mucosal damage in male rats. Likewise, oral administration of metronidazole dose-dependently attenuated the indomethacin (30 mg/kg, p.o.)-induced gastric lesion formation and the concurrent depletion of mucosal mucus. However, metronidazole did not affect the basal mucosal prostaglandin E2 content. In an ex vivo gastric chamber preparation, 40% ethanol incubation markedly lowered transmucosal potential difference and increased mucosal vascular permeability in rat stomachs. Incubation with all doses of metronidazole did not modulate gastric mucosal blood flow nor transmucosal potential difference, either before or after ethanol treatment. Nevertheless, the increase in vascular permeability by 40% ethanol was significantly alleviated by either p.o. or i.p. metronidazole pretreatment. In addition, exposure of the isolated rabbit gastric gland preparation to metronidazole (10(-5) and 10(-4) M) significantly attenuated the damaging action of 10% ethanol.

CONCLUSION

It is concluded that metronidazole possesses a direct vascular and glandular organoprotective property in the rodent stomach. However, the anti-ulcer action does not appear to involve prostaglandins nor act through the improvement of gastric mucosal blood flow. Preservation of intramucosal mucus may partly contribute to the prevention of indomethacin-induced ulceration in rats.

[Lipid peroxidation injury to red blood cells during extracorporeal circulation: mechanism and protection]

Twelve dogs were subjected to cardiopulmonary bypass with membrane oxygenator for 120 minutes. The effect of lipid peroxide injury on red blood cells was studied by measurement of plasma and erythrocyte membrane lipid peroxide, deformabioity of erythrocyte, plasma free hemoglobin, superoxide dismutase, Na(+)-K(+)-ATPase and Ca(2+)-Mg(2+)-ATPase of erythrocytes. The effect of vitamin E on red blood cells was also investigated. The findings indicated that vitamin E might protect red blood cells from lipid peroxide injury during extracorporeal circulation. The mechanism of damage effect of lipid peroxide and the protective effect of vitamin E on red blood cells were briefly discussed.

[Effects of water hardness and salt intake on the formation and disappearance of experimental atherosclerosis]

The present study examined the effects of water-hardness and salt-intake, both of which were higher in north China than in the south, on experimental atherosclerosis in quail. At the end of the experiment atherosclerotic lesions in the high-salt groups were found to be more marked than those in the low-salt groups. No significant difference in total cholesterol value was found between the two groups. There was a significant positive correlation between the degree of atherosclerosis and serum-sodium value (r = 0.501, P < 0.01). There was no difference in all values between hard-water or soft-water groups. Our study suggested that high salt-intake stimulated and enhanced the formation of atherosclerosis while it delayed and impeded its disappearance, but water-hardness did not.