How Does Spino-Pelvic Fixation Affect Post-Operative Compensatory Mechanisms in Adult Spinal Deformity?

STUDY DESIGN

Retrospective single-center multi-surgeon cohort study.

OBJECTIVES

Compare the post-operative changes in the compensatory mechanisms of the sagittal balance according to the type of pelvic fixation: S2-Alar-iliac screws (S2AI) vs iliac screws (IS) in patients with Adult spine deformity (ASD).

METHODS

ASD patients who underwent spino-pelvic fixation and remained with a PI-LL >10° mismatch post-operatively were included. Pre-operative and 1-year-follow-up PI, Lumbar lordosis (LL), pelvic tilt (PT), sacral slope (SS), thoracic kyphosis (TK), femur obliquity angle (FOA), knee flexion angle (KFA) and ankle flexion angle (AFA) were analyzed on EOS imaging. Patients were categorized based on their pelvic fixation type (S2AI vs IS), and the pre-operative to 1-year-post-operative changes (ΔX°) in the compensatory mechanisms were compared between groups.

RESULTS

Patients with S2AI (n = 53) and those with IS (n = 26) screws were comparable at baseline. ΔSS averaged 9.87° in the S2AI compared to 13.2° in the IS (P = .001), whereas the ΔKFA reached 6.01° in the S2AI as opposed to 3.06° in the IS (P = .02). The ΔPT was comparable between both groups (6.35°[S2AI group] vs 5.21°[ISgroup], P = .42). ΔTK, ΔLL, ΔFOA and ΔAFA were comparable between both groups.

CONCLUSION

The type of pelvic fixation impacts significantly the post-operative compensatory mechanisms in patients with ASD. Patients with S2AI screws are more likely to compensate their remaining post-operative PI-LL mismatch through their knees and less likely through their pelvis compared to patients with IS, despite similar changes in PT. This could be explained by an increased SI joint laxity in ASD patient and the lower resistance of the iliac connectors to the junctional mechanical stresses, allowing for sacro-iliac joint motion in patients with IS.

MiR-140 targets Wnt1 to inhibit the proliferation and enhance drug sensitivity in osteosarcoma cells

MicroRNAs (miRNAs) have been documented to function differently in numerous human cancers. Our study planned to investigate the role of microRNA-140 (miR-140) and to identify its possible target in osteosarcoma (OS) to predict their mechanism in OS. The miR-140 was down-regulated in OS, and its high expression decreased MG63 cell proliferation. At the molecular level, Wnt1 was a target of miR-140, and its expression could be suppressed by miR-140. Besides, miR-140 overexpression decreased drug resistance in OS cells treated by doxorubicin. Collectively, overexpression of miR-140 may inhibit human OS cell proliferation and may enhance drug sensitivity by direct regulation of Wnt/β-catenin signaling.

Embedded AI system for interactive vision screen based on human action recognition

In recent years, vision screening has emerged globally for employment (on a yearly basis) within primary and high schools since myopia heavily affects school-aged children. However, this is a laborious and time-consuming task. This article proposes an intelligent system for "self-service" vision screening. Individuals can accomplish this task independently-without any assistance by technical staff. The technical solution involved within this platform is human action recognition realized by pose estimation (real-time human joint localization in images, including detection, association, and tracking). The developed system is based on a compact and embedded artificial intelligence platform, aided by a red-green-blue-D sensor for ranging and pose extraction. A set of intuitive upper-limb actions was designed for unambiguous recognition and interaction. The deployment of this intelligent system brings great convenience for large-scale and rapid vision screening. Implementation details were extensively described, and the experimental results demonstrated efficiency for the proposed technique.

Short-term starvation synergistically enhances cytotoxicity of Niraparib via Akt/mTOR signaling pathway in ovarian cancer therapy

Background

Short-term starvation (STS) has gradually been confirmed as a treatment method that synergistically enhances the effect of chemotherapy on malignant tumours. In clinical applications, there are still some limitations of poly (ADP-ribose) polymerase inhibitors (PARPi), including understanding their effectiveness and side effects. Here, we sought to investigate the effect and mechanism of the combined use of STS and niraparib in the treatment of ovarian cancer.

Methods

In in vitro experiments, SKOV3 and A2780 ovarian cancer cells were treated with STS and niraparib alone or in combination. Cell viability was assessed with CCK-8, and cell cycle, apoptosis, DNA damage repair and autophagy were examined to explore the molecular mechanisms. Akt and mTOR inhibitors were used to examine any changes in DNA damage repair levels. Xenograft animal models were treated with STS and niraparib, and HE staining and immunohistochemistry were performed to examine the effects.

Results

The combined use of STS and niraparib inhibited cell proliferation and increased apoptosis more than niraparib application alone. In addition, compared with the niraparib group, the STS + niraparib group had increased G2/M arrest, DNA damage and autophagy, which indicated that STS pretreatment enhanced the cytotoxicity of niraparib. In animal experiments, STS did not affect the growth of transplanted tumours, but the combined treatment synergistically enhanced the cytotoxicity of niraparib. In in vivo experiments, STS did not affect the growth of transplanted tumours, but the combined treatment synergistically enhanced the cytotoxicity of niraparib and reduced the small intestinal side effects caused by niraparib chemotherapy.

Conclusion

STS pretreatment can synergistically enhance the cytotoxicity of niraparib. STS + niraparib is a potentially effective strategy in the maintenance therapy of ovarian cancer.

Regression of Left Ventricular Hypertrophy in Patients Combined with Peritoneal Dialysis and Hemodialysis

METHODS

This retrospective study enrolled 58 patients at The Second Affiliated Hospital of Soochow University who switched from PD to PHD. Clinical data and echocardiographic examination results were collected. Data from the two groups with a normal distribution were compared with the paired t-test. A pvalue <0.05 (two-tailed) was considered statistically significant.

RESULTS

A total of 58 subjects were enrolled, including 46 males and 12 females, with a median age of 50.2 ± 11.1 (47-68) years. The mean duration of peritoneal dialysis was 67.2 ± 33.6 months. Before and after PHD, the ultrafiltration volume (p = 0.021) and hemoglobin (p = 0.001) were increased, while SBP (p = 0.002), DBP (p = 0.002), phosphorus (p < 0.001), and ESA dosage (p < 0.001) were decreased. Before and after combined dialysis (PHD), the incidence of LVH was 76.4% and 61.8%, respectively (p = 0.013), and LVMI decreased from 173.8 ± 86.2 g/m² to 160.6 ± 78.5 g/m² (p < 0.001).

CONCLUSION

Compared with PD alone, the combination of PD and HD resulted in regression of LVH and reduced LVMI.

Risk Factors for Anorectal Dysfunction After Interspincteric Resection in Patients With Low Rectal Cancer

Purpose: The objective of this study was to explore the risk factors for anorectal dysfunction after intersphincteric resection in patients with low rectal cancer. Methods: A total of 251 patients who underwent intersphincteric resection from July 2014 to June 2020 were included in this study, for which the Kirwan's grade, Wexner score, and anorectal manometric index were used to evaluate the anorectal function and other parameters including demographics, surgical features, and clinical and pathological characteristics. These parameters were analysed to explore the potential risk factors for anorectal function after intersphincteric resection. Results: In the 251 included patients, 98 patients underwent partial intersphincteric resection, 87 patients underwent subtotal intersphincteric resection, and 66 patients underwent total intersphincteric resection. There were 53 (21.1%) patients who had postoperative complications, while no significant difference was observed between the three groups. Furthermore, 30 patients (45.5%) in the total intersphincteric resection group were classified as having anorectal dysfunction (Kirwan's grade 3-5), which was significantly higher than that in the partial intersphincteric resection group (27.6%) and subtotal intersphincteric resection group (29.9%). The mean Wexner score of patients that underwent total intersphincteric resection was 7.9, which was higher than that of patients that had partial intersphincteric resection (5.9, p = 0.002) and subtotal intersphincteric resection (6.4, p = 0.027). The initial perceived volume was lower in the total intersphincteric resection group than in the partial and subtotal intersphincteric resection groups at 1, 3, and 6 months after intersphincteric resection. In addition, the resting pressure, maximum squeeze pressure, and maximum tolerated volume in the total intersphincteric resection group were worse than those in the partial and subtotal groups at 3 and 6 months after intersphincteric resection. Univariate and multivariate analyses suggested that an age ≥65, total intersphincteric resection, and preoperative chemoradiotherapy were independent risk factors for anorectal dysfunction (P = 0.023, P = 0.003, and P = 0.008, respectively). Among the 66 patients who underwent total intersphincteric resection, 17 patients received preoperative chemoradiotherapy, of which 12 patients (70.6%) were classified as having anorectal dysfunction. Conclusion: The current study concluded that age ≥65, total intersphincteric resection, and preoperative chemoradiotherapy were risk factors for anorectal dysfunction after intersphincteric resection. The morbidity of anorectal dysfunction after total intersphincteric resection for patients who received preoperative chemoradiotherapy was relatively high, and the indication should be carefully evaluated.

Sex-Related Outcomes of Successful Drug-Coated Balloon Treatment in De Novo Coronary Artery Disease

PURPOSE

Although drug-coated balloon (DCB) treatment is known to be effective for de novo lesions, the influence of sex on angiographic and clinical outcomes remains unknown. This study aimed to investigate the angiographic and clinical impact of DCB treatment in patients with de novo coronary lesions according to sex.

MATERIALS AND METHODS

A total of 227 patients successfully treated with DCB were retrospectively enrolled and divided into two groups according to sex. The primary endpoint was late lumen loss (LLL) at 6-month angiography, and the secondary endpoint was target vessel failure (TVF), which included cardiac death, target vessel myocardial infarction, target lesion revascularization, and target vessel thrombosis.

RESULTS

The study enrolled 60 women (26.4%) and 167 men (73.6%). Compared to men, women had a smaller vessel size, larger DCB to reference vessel ratio, and more dissections after DCB treatment (55.0% vs. 37.1%, p=0.016). Women also had a significantly higher LLL compared to men (0.12±0.26 mm vs. 0.02±0.22 mm, p=0.012) at the 6-month follow-up angiography. During a median follow-up of 3.4 years (range 12.7-28.9 months), TVF was similar (women 6.7% vs. men 7.8%, p=0.944). In multivariable analysis, women were independently associated with a higher LLL.

CONCLUSION

LLL was higher in women, but there was no difference in TVF between women and men. Based on multivariable analysis, the women sex was an independent predictor of higher LLL (Impact of Drug-coated Balloon Treatment in de Novo Coronary Lesion; NCT04619277).

Drug-coated balloon treatment for nonsmall de-novo coronary artery disease: angiographic and clinical outcomes

OBJECTIVES

Although drug-coated balloons (DCBs) are established for de-novo lesions in small coronary arteries, the impact of DCB treatment according to the reference vessel diameter (RVD) remains poorly defined. This study aimed to evaluate the angiographic and long-term clinical outcomes of DCB treatment for de-novo coronary lesions according to RVD.

METHODS AND RESULTS

A total of 227 patients were retrospectively enrolled and stratified according to an RVD >2.5 mm [nonsmall vessel disease (NSVD) group, n = 100] and ≤2.5 mm [small vessel disease (SVD) group, n = 127]. The primary endpoint was late lumen loss (LLL) at a 6-month follow-up, and the secondary endpoint was target vessel failure (TVF, a composite of cardiac death, target vessel myocardial infarction, target vessel revascularization and target vessel thrombosis). The LLL among the 206 patients (90.8%) returning for scheduled angiography at 6 month was similar (NSVD, 0.03 ± 0.22 mm vs. SVD, 0.06 ± 0.25 mm; P = 0.384). TVF was also comparable in both groups at a median follow-up of 3.4 years (NSVD, 7.0 vs. SVD, 7.9 %; P = 0.596). At baseline, there were numerically more dissections in the SVD group compared to the NSVD group (47.2 vs. 35.0 %; P = 0.064); however, most of these had disappeared in both groups at a 6-month follow-up. In a multivariable analysis, the presence of dissection was not associated with LLL or TVF in either group.

CONCLUSIONS

The safety and efficacy of DCB treatment for de-novo coronary lesions, in terms of LLL and TVF, was unrelated to RVD.

Learning curve of robotic distal and total gastrectomy

BACKGROUND

This study aims to assess the learning curve of robotic distal gastrectomy (RDG) and robotic total gastrectomy (RTG) for gastric cancer.

METHODS

Data on consecutive patients who underwent robotic gastrectomy for gastric cancer by five surgeons between March 2010 and August 2019 at two high-volume institutions were collected. The learning curve was determined based on the analyses of operation time and postoperative complications within 30 days. Cumulative sum analysis (CUSUM) and risk-adjusted-CUSUM (RA-CUSUM) were applied to identify the turning points (TPs).

RESULTS

A total of 899 consecutive patients were included. The mean number of patients needed to overcome the learning curve for operation time of RDG and RTG were 22 and 20, respectively. The number of patients needed to overcome the learning curve for postoperative complications after RDG and RTG were 23 and 18, respectively. The surgical outcomes in the post-TP group were better than in the pre-TP group and improved as surgeons' experience increased. Also, increased case numbers in RDG promoted the RTG learning process.

CONCLUSION

The present study demonstrated a substantial influence of surgical cumulative volume on improved surgical outcomes in robotic gastrectomy. Increased experience in RDG may help surgeons to achieve proficiency faster in RTG.

Evaluation on reprogramed biological processes in transgenic maize varieties using transcriptomics and metabolomics

Genetic engineering (GM) has great potential to improve maize productivity, but rises some concerns on unintended effects, and equivalent as their comparators. There are some limitations through targeted analysis to detect the UE in genetically modified organisms in many previous studies. We here reported a case-study on the effects of introducing herbicides and insect resistance (HIR) gene cassette on molecular profiling (transcripts and metabolites) in a popular maize variety Zhengdan958 (ZD958) in China. We found that introducing HIR gene cassette bring a limited numbers of differential abundant genes (DAGs) or differential abundant metabolites (DAMs) between transgenic events and non-transgenic control. In contrast, averaged 10 times more DAGs and DAMs were observed when performed comparison under different growing environments in three different ecological regions of China than the numbers induced by gene effects. Major biological pathways relating to stress response or signaling transduction could explain somehow the effects of growing environments. We further compared two transgenic events mediated ZD958 (GM-ZD958) with either transgenic parent GM-Z58, and other genetic background nonGM-Z58, nonGM-ZD958, and Chang7-2. We found that the numbers of DAGs and DAMs between GM-ZD958 and its one parent maize variety, Z58 or GM-Z58 is equivalent, but not Chang7-2. These findings suggest that greater effects due to different genetic background on altered molecular profiling than gene modification itself. This study provides a case evidence indicating marginal effects of gene pleiotropic effects, and environmental effects should be emphasized.

Impact of Dissection after Drug-Coated Balloon Treatment of De Novo Coronary Lesions: Angiographic and Clinical Outcomes

PURPOSE

Dissection after plain balloon angioplasty is required to achieve adequate luminal area; however, it is associated with a high risk of vascular events. This study aimed to examine the relationship between non-flow limiting coronary dissections and subsequent lumen loss and long-term clinical outcomes following successful drug-coated balloon (DCB) treatment of de novo coronary lesions.

MATERIALS AND METHODS

A total of 227 patients with good distal flow (Thrombolysis in Myocardial Infarction flow grade 3) following DCB treatment were retrospectively enrolled and stratified according to the presence or absence of a non-flow limiting dissection. The primary endpoint was late lumen loss (LLL) at 6-month angiography, and the secondary endpoint was target vessel failure (TVF, a composite of cardiac death, target vessel myocardial infarction, target vessel revascularization, and target vessel thrombosis).

RESULTS

The cohort consisted of 95 patients with and 132 patients without a dissection. There were no between-group differences in LLL (90.8%) returning for angiography at 6 months (0.05±0.19 mm in non-dissection and 0.05±0.30 mm in dissection group, p=0.886) or in TVF (6.8% in non-dissection and 8.4% in dissection group, p=0.799) at a median follow-up of 3.4 years. In a multivariate analysis, the presence of dissection and its severity were not associated with LLL or TVF. Almost dissections (93.9%) were completely healed, and there was no newly developed dissection at 6-month angiography.

CONCLUSION

The presence of a dissection following successful DCB treatment of a de novo coronary lesion may not be associated with an increased risk of LLL or TVF (Impact of Drug-coated Balloon Treatment in de Novo Coronary Lesion; NCT04619277).

Jumonji domain containing-3 (JMJD3) inhibition attenuates IL-1β-induced chondrocytes damage in vitro and protects osteoarthritis cartilage in vivo

OBJECTIVES

This study aimed to explore the effects and relative mechanism of JMJD3 on knee osteoarthritis (OA).

METHODS

In this study, we first analyzed the expression of JMJD3 in OA cartilage using western blot and immunohistochemistry. In an in vitro study, the effects of GSK-J4, JMJD3 inhibitor, on ATDC-5 chondrocytes were evaluated by CCK-8 assay. Real-time PCR and western blot were used to examine the inhibitory effect of GSK-J4 on the inflammation and ECM degradation of chondrocytes. NF-κB p65 phosphorylation and nuclear translocation were measured by western blot and immunofluorescence. In the animal study, twenty mice were randomized into four experimental groups: sham group, DMM-induced OA + DMSO group, OA + low-dose GSK-J4 group, and OA + high-dose GSK-J4 group. After the treatment, hematoxylin-eosin and safranin O/fast green staining were used to evaluate cartilage degradation of knee joint, with OARSI scores for quantitative assessment of cartilage damage.

RESULTS

Our results revealed that JMJD3 was overexpressed in OA cartilage and GSK-J4 could suppress the IL-1β-induced production of pro-inflammatory cytokines and catabolic enzymes, including IL-6, IL-8, MMP-9 and ADAMTS-5. Consistent with these findings, GSK-J4 could inhibit IL-1β-induced degradation of collagen II and aggrecan. Mechanistically, GSK-J4 dramatically suppressed IL-1β-stimulated NF-κB signal pathway activation. In vivo, GSK-J4 prevented cartilage damage in mouse DMM-induced OA model.

CONCLUSIONS

This study elucidates the important role of JMJD3 in cartilage degeneration in OA, and our results indicate that JDJM3 may become a novel therapeutic target in OA therapy.

Long Noncoding RNA Myocardial Infarction-Associated Transcript as a Cancer Promoting Factor in Colon Cancer Development

Objection: The study aimed to explain the effects and mechanisms of long noncoding RNA (lncRNA) MIAT in development of colon cancer. Methods: The adjacent and cancer tissues which were collected from 30 cases colon cancer patients were evaluated pathology by HE staining and lncRNA MIAT expression by ISH assay. In the vitro study, SW620 cells were divided into NC, siRNA-control and siMIAT groups. Measuring cell proliferation, apoptosis, cell cycle, invasion and migration by CCK-8, flow cytometry, transwell and wound healing, and evaluating the relative proteins expressions by WB assay. Results: Compared with adjacent normal tissues, the lncRNA MIAT was significantly up-regulation in colon cancer tissues (P < 0.001). By cell experiment, with lncRNA MIAT knockdown, the cell proliferation was significantly depressed (P < 0.001) via significantly improving cell apoptosis and keeping the cell in the G1 phase (P < 0.001, respectively); the invasion SW620 cell number and wound healing rate were significantly suppressed (P < 0.001, respectively). The relative proteins (CDK2, Cyclin D3 and MMP-9) expressions of siMIAT group were significantly down-regulation compared with those of NC group (P < 0.001, respectively). Conclusion: Our study found that lncRNA MIAT expression is closely associated with colon cancer and may be one of key roles in progression and metastasis in colon cancer.

Risk Assessment and Hydrodissection Technique for Radiofrequency Ablation of Thyroid Benign Nodules

Purpose: This retrospective study aimed to explore the importance of risk assessment and hydrodissection pre-treatment for radiofrequency ablation of thyroid nodules and initially establish the concept of thyroid nodule risk assessment and the corresponding ablation norms.

Method: Based on the specific location of thyroid nodules, risk assessment and the corresponding preventive measures for thyroid ablation were established. During the period of 2015.10-2017.5, a total of 382 patients were enrolled to compare the safety and efficacy of the ablation for patients with or without risk assessment and the corresponding preventive measures. Statistical analysis encompassed Independent T test for continuous variables and Fisher's exact test/Chi-square test for categorical variables.

Result: Of all 382 patients, 188 patients underwent ablation with risk assessment and the corresponding preventive measures before ablation and 194 without, respectively. The patient characteristics, risk grading, ablation time, thyroid function after ablation and the complete ablation rate showed no statistical differences exsisted between two groups (P>0.05). The complication in very high risk nodules was avoided in the group of patients with risk assessment and preventive measures before ablation.

Conclusion: It is a very safe and effective way to carry out radiofrequency ablation after pre-treatment of thyroid nodules by hydrodissection technique according to risk assessment. It will provide clinicians with greater help in the ablation treatment of thyroid nodules, and improve the safety of the thyroid ablation.

Apoptosis and necroptosis of mouse hippocampal and parenchymal astrocytes, microglia and neurons caused by Angiostrongylus cantonensis infection

BACKGROUND

Angiostrongylus cantonensis has been the only parasite among Angiostrongylidae to cause human central nervous system infection characterized by eosinophilic meningitis or meningoencephalitis. The mechanism of the extensive neurological impairments of hosts caused by A. cantonensis larvae remains unclear. The aim of the present study was to investigate apoptosis, necroptosis and autophagy in the brains of mice infected with A. cantonensis, which will be valuable for better understanding the pathogenesis of angiostrongyliasis cantonensis.

METHODS

Functional and histological neurological impairments of brain tissues from mice infected with A. cantonensis were measured by the Morris water maze test and haematoxylin and eosin (H&E) staining, respectively. The transcriptional and translational levels of apoptosis-, necroptosis- and autophagy-related genes were quantified by quantitative real-time polymerase chain reaction (RT-PCR), and assessed by western blot and immunohistochemistry (IHC) analysis. Apoptotic and necroptotic cells and their distributions in infected brain tissues were analysed by flow cytometry and transmission electron microscopy (TEM).

RESULTS

Inflammatory response in the central nervous system deteriorated as A. cantonensis infection evolved, as characterized by abundant inflammatory cell infiltration underneath the meninges, which peaked at 21 days post-infection (dpi). The learning and memory capacities of the mice were significantly decreased at 14 dpi, indicating prominent impairment of their cognitive functions. Compared with those of the control group, the mRNA levels of caspase-3, -4, -6, and RIP3 and the protein levels of caspase-4, cleaved caspase-3, cleaved caspase-6, RIP3, and pRIP3 were obviously elevated. However, no changes in the mRNA or protein levels of FADD, Beclin-1 or LC3B were evident, indicating that apoptosis and necroptosis, but not autophagy, occurred in the brain tissues of mice infected with A. cantonensis. The quantitative RT-PCR, western blot, IHC, flow cytometry and TEM results further revealed the apoptotic and necroptotic microglia, astrocytes and neurons in the parenchymal and hippocampal regions of infected mice.

CONCLUSIONS

To our knowledge, we showed for the first time that A. cantonensis infection causes the apoptosis and necroptosis of microglia and astrocytes in the parenchymal and hippocampal regions of host brain tissues, further demonstrating the pathogenesis of A. cantonensis infection and providing potential therapeutic targets for the management of angiostrongyliasis.

New time-space-time optical packet switching node based on nonlinear polarization rotation of a semiconductor optical amplifier

In this paper, we establish a simple model to analyze the semiconductor optical amplifier's (SOA) nonlinear polarization rotation (NPR) and acquire the variable curves of phase difference between TE and TM modes with bias current, pump power, probe power, and linewidth enhancement factor (LEF). The results indicate that the optical switch based on the SOA's NPR can be realized by changing the pump's optical power and the main operating parameters, such as bias current and hold beam power, and then the pump power can be determined. On this basis, a time-space-time (T-S-T) optical packet switching node is proposed, in which the SOA's NPR switch is the basic element. Then, the T-S and S-T experimental systems are set up, and the experimental results demonstrate that the proposed switch scheme can implement the optical switching function in accordance with the routing requirement. The signal-to-noise ratio (SNR) exceeds 20 dB, and the extinction ratio (ER) is more than 10 dB after being delayed and switched in the node.

An extract of Perilla stem inhibits Src homology phosphatase-1 (SHP)-1 and influences insulin signaling

Protein tyrosine phosphatases (PTPs) are enzymes that catalyze protein tyrosine dephosphorylation of which Src homology phosphatase-1 (SHP-1) is one of the best-validated, a widely distributed intracellular tyrosine phosphatase that contains two SH2 domains. Down regulation of SHP-1 tyrosine phosphatases was significantly increased sensitivity to insulin in insulin signaling pathway. Through in vitro enzymatic reaction kinetics experiment, we found that the extract of Perilla stem was a potential inhibitor to δSHP-1, the catalytic domain of SHP-1 protein tyrosine phosphatase, and its IC(50) was 4ug/ml, and was more sensitive towards SHP-1than other PTPs, which indicated that SHP-1 might be a target of the extract of Perilla stem. It can strengthened the level of tyrosine phosphorylation of insulin receptor (IR) and extracellular signal-regulated protein kinase (ERK) in HepG2 cells, and then activated the insulin signaling pathway through inhibiting the protein phosphorylation of SHP-1. These results demonstrated that the extract of Perilla stem could play an important role for diabetes treatment through inhibiting the level of SHP-1 in insulin signaling pathway.

[Study of feasibility of verifying setup errors for patients with head tumor by observing patients' SSD]

OBJECTIVE

To verify the feasibility of setup error verification by observing patents' source-skin distance (SSD) for patients of head tumor.

METHODS

Films for 21 patients with head tumor were recorded using simulator (Varian Acuity 8.6), and comparison with reference digitally reconstructed radiograph (DRR) from Treatment plan system (TPS). The deviation of setup for 21 patients in the left-right, anterior-posterior and superior-inferior directions were measured by using 2D match, and SSD error was recorded when gantry angle was 0 degrees, 45 degrees, 315 degrees. Then setup error and corresponding SSD error were analyzed.

RESULTS

The systematic errors and random errors of 21 patients in the left-right, anterior-posterior and superior-inferior directions were (1.1 +/- 11.6) mm, (0.7 +/- 1.2) mm, (0.9 +/- 1.5) mm, and (1.51 +/- 3.1) mm, (1.05 +/- 3.3) mm, (1.60 +/- 2.3) mm. The systematic SSD errors and random SSD errors were (1.25 +/- 1.3) mm, (1.04 +/- 1.3) mm. (1.10 +/- 2.3) mm, and (2.03 +/- 1.7) mm, (2.81 +/- 2.3) mm, (2.33 +/- 3.0) mm for gantry angle was 0 degrees, 45 degrees, 315 degrees, respectively.

CONCLUSIONS

It is simple and feasible for setup error verification by observing patients' SSD and can be auxiliary to other verification means.

A fundamental regulatory role of formate on thuringiensin production by resting cell of Bacillus thuringiensis YBT-032

In this work, a fundamental regulatory role of formate on thuringiensin production by resting cell of Bacillus thuringiensis YBT-032 was investigated. Nicotinamide adenine dinucleotide (NADH) production and formate dehydrogenase activity increased with formate addition from 0.5 to 2.0 g/L, respectively. However, with the formate addition of 1.5 g/L, the activities of pyruvate kinase and glucose 6-phosphate dehydrogenase reached a peak and increased by 316 and 150% relative to those of the control, respectively. In addition, intracellular production of pyruvate, aspartate, citrate and adenine were significantly enhanced by 75, 66, 32 and 78% as well. An improvement (90%) of thuringiensin production was also successfully obtained. Interestingly to point out, thuringiensin yield was closely correlative with adenine production, and the linear relationship was also observed. The results suggest that appropriate formate addition did act as a modulator and facilitate carbon flux in glycolysis and pentose phosphate pathway to synthesize adenine and thuringiensin via intracellular NADH availability.

Stromal cell-derived factor-1 promotes bone marrow-derived cells differentiation to cardiomyocyte phenotypes in vitro

OBJECTIVE

Recent studies have demonstrated the potential of bone marrow-derived cells (BMDC) to differentiate into cardiomyocytes. Up-regulation of stromal cell-derived factor-1 (SDF-1), a member of the chemokine CXC subfamily, mediating recruitment of BMDC has been documented in infarcted myocardium; however, it remains unknown whether SDF-1 plays a role in cardiomyogenesis of BMDC.

MATERIALS AND METHODS

Adherent BMDCs were cultured with SDF-1, or specific inhibitor for PI3K, CXCR4 or Akt with SDF-1, respectively. After 2 weeks, mRNAs and proteins from BMDCs were examined.

RESULTS

Two weeks after supplementation with SDF-1, either murine or human adherent BMDC cultured in vitro expressed cardiac specific mRNAs (NKX2.5, atrial natriuretic factor and heavy chain beta-myosin) and proteins (troponin I and heavy chain cardiac myosin), and expression levels were partly decreased by combined treatment of CXCR4, PI3K or Akt inhibitor, with SDF-1.

CONCLUSIONS

The novel findings suggest that beyond its role in mobilization and homing of BMDC, SDF-1 can promote BMDC to give rise to cardiomyocyte phenotypes in vitro, and the SDF-1/CXCR4/PI3K/Akt pathway may be one of the molecular mechanisms regulating cardiomyogenesis.

A novel low k thin film based on plasma-polymerized 1- cyano isoquinoline

A novel low dielectric constant polymer, plasma-polymerized 1-cyano isoquinoline (PPCIQ) was prepared by plasma polymerization for the first time. The structure and surface compositions of the deposited PPCIQ thin films were investigated by Fourier transform infrared (FTIR) and X-ray photoelectron spectroscopy (XPS). The results show that a high retention of the aromatic ring structure of the starting monomer in the deposited plasma films is obtained when a low discharge power of 15 W was used during film formation. In the case of higher discharge power of 35 W, more severe monomer molecular fragmentation can be observed. The dielectric properties measurements show that a low dielctric constant of 2.62 can be obtained for PPCIQ thin film deposited at 15 W.

IL-15 Activates Telomerase and Minimizes Telomere Loss and May Preserve the Replicative Life Span of Memory CD8+T Cells In Vitro

The preservation of the replicative life span of memory CD8(+) T cells is vital for long-term immune protection. Although IL-15 plays a key role in the homeostasis of memory CD8(+) T cells, it is unknown whether IL-15 regulates the replicative life span of memory CD8(+) T cells. In this study, we report an analysis of telomerase expression and telomere length in human memory phenotype CD8(+) T cells maintained by IL-15 in vitro. We demonstrate that IL-15 is capable of activating telomerase in memory CD8(+) T cells via Jak3 and PI3K signaling pathways. Furthermore, IL-15 induces a sustained level of telomerase activity over long periods of time, and in turn minimizes telomere loss in memory CD8(+) T cells after substantial cell divisions. These findings suggest that IL-15 activates stable telomerase expression and compensates telomere loss in memory phenotype CD8(+) T cells, and that telomerase may play an important role in memory CD8(+) T cell homeostasis.

Scaling property and multi-resonance of PCF-based long period gratings

In a long period grating (LPG) made on a silica-based single material photonic crystal fibre (PCF), the effect of material dispersion on the resonance wavelength of the LPG is negligible. The resonance wavelength, the period and length of the LPG, and the diameter and pitch of the air-hole lattice of the PCF are found to obey a scaling law that is derived from the scaling property of the Maxwell's Equations. Simulations show that the resonance wavelength has a non-monotonic dependence on the grating period and, for a particular grating period, there could exist multiple resonance wavelengths and hence multiple transmission dips due to phase matching between the fundamental core mode and a cladding mode simultaneously at multiple wavelengths.

Full-vectorial analysis of complex refractive index photonic crystal fibers

We investigated the modal properties of complex refractive-index core photonic crystal fibers (PCFs) with the supercell model. The validity of the approach is shown when we compare our results with those reported earlier on a step complex refractive-index profile. The imaginary part of the electric field results in wave-front distortion in the complex refractive-index profile PCFs, which means that the power flows out or into the doped region according to the sign of the imaginary part of the refractive index. A simple formula is proposed for calculating the gain or loss coefficients of these fibers. The numerical results obtained by the approximation formula agree well with the full-vectorial results.

Compact supercell method based on opposite parity for Bragg fibers

The supercell- based orthonormal basis method is proposed to investigate the modal properties of the Bragg fibers. A square lattice is constructed by the whole Bragg fiber which is considered as a supercell, and the periodical dielectric structure of the square lattice is decomposed using periodic functions (cosine). The modal electric field is expanded as the sum of the orthonormal set of Hermite-Gaussian basis functions based on the opposite parity of the transverse electric field. The propagation characteristics of Bragg fibers can be obtained after recasting the wave equation into an eigenvalue system. This method is implemented with very high efficiency and accuracy.

Dependence of mode characteristics on the central defect in elliptical hole photonic crystal fibers

Some mode characteristics are obtained by the full vector supercell overlap method that has been developed to model triangular lattice elliptical hole photonic crystal fibers regardless of whether the light is guided by total internal reflection or a photonic bandgap mechanism. When the central defect hole is large enough, the modes are disordered. Birefringence (Deltan) dependence on the central defect is discussed in detail by numerical analysis.

Mode classification and degeneracy in photonic crystal fibers

Based on supercell lattice method, a novel full vector model is presented to analyze the photonic crystal fibers (PCF). From symmetry analysis of modes of a waveguide, we classify the modes of PCF into nondegenerate or degenerate pairs according to the minimum waveguide sectors and its appropriate boundary conditions. We present the modes of PCF can be labeled by its step index fiber analogs, except the modes with the same symmetry as PCF. The doublet of the degenerate pairs in which both have the same symmetry as PCF will be split into two nondegenerate modes.

Supercell lattice method for photonic crystal fibers

A supercell lattice method, believed to be novel, deduced from the plane-wave expansion method and the localized basis function method, is presented for analyzing photonic crystal fibers (PCFs). The electric field is decomposed by use of Hermite-Gaussian functions, and the dielectric constant of PCFs missing a central air hole is considered as the sum of two virtual different periodic dielectric structures of perfect photonic crystals (PCs). The structures of both virtual PCs are expanded in cosine functions. From the wave equation and the orthonormality of the Hermite-Gaussian functions, the propagation characteristics of the PCFs, such as the mode field distribution, the effective area, and the dispersion property, are obtained. The accuracy of the novel method is demonstrated as we obtain the same results when the dielectric constant is split into two virtual ideal PCs in different ways.

Loss properties due to Rayleigh scattering in different types of fiber

The effects of fiber structure on Rayleigh scattering were investigated in detail. Some step-index fibers such as GeO2- and F-doped silica-based fibers and total-internal-reflection photonic crystal fiber are examined. The Rayleigh scattering loss (RSL) depends on the fiber materials and index profiles, and different types of fiber have different dependencies on those parameters because of the different optical power confinement factors in every layer. On the basis of these results, the RSL can be optimized by adjusting the fiber structure or by selecting different materials.

Modeling of branching structures of plants

Previous studies of branching structures generally focused on arteries. Four cost models minimizing total surface area, total volume, total drag and total power losses at a junction point have been proposed to study branching structures. In this paper, we highlight the branching structures of plants and examine which model fits data of branching structures of plants the best. Though the effect of light (e.g. phototropism) and other possible factors are not included in these cost models, a simple cost model with physiological significance, needs to be verified before further research on modeling of branching structures is conducted. Therefore, data are analysed in this paper to determine the best cost model. Branching structures of plants are studied by measuring branching angles and diameters of 234 junctions from four species of plants. The sample includes small junctions, large junctions, two- and three-dimensional junctions, junctions with three branches joining at a point and those with four branches joining at a point. First, junction exponents (x) were determined. Second, log-log plots indicate that model of volume minimization fits data better than other models. Third, one-sided t -tests were used to compare the fitness of four models. It is found that model of volume minimization fits data better than other cost models.

Accuracy in the determination of isoelectric points of some proteins and a peptide by capillary isoelectric focusing: utility of synthetic peptides as isoelectric point markers

To evaluate the accuracy ofisoelectric point determination by capillary isoelectric focusing, the pI values of nine proteins and a peptide, the pI values of which had been determined by other methods and ranging pI 3.55-9.60, were determined by capillary isoelectric focusing by cofocusing of recently developed peptide pI markers ranging 3.38-10.17, and the consistency of the pI values was examined. Isoelectric focusing was carried out in neutral polymer-coated capillaries, and the pH gradient was mobilized by pressure toward the cathode, to detect samples with absorption at 280 nm at a fixed detection point. Carrier ampholytes from two different suppliers and in different pH ranges were used. The sharp peaks of the highly pure peptide pI markers greatly facilitated the unambiguous identification of the peaks. When a carrier ampholyte ranging over the acidic side was used, the detection of acidic pI samples was anomalously delayed. This could be partly mitigated by reducing the viscosity of the anode solution in comparison with the pH gradient formed in the capillary. Since the detection times vs the pH relationships were not linear in most cases, the use of a linear calibration line over an entire pH gradient would be erroneous. Instead, the pI values of samples were calculated by assuming a linear relation for pH against detection time between two flanking marker peptides. Close agreement between the pI values, determined by capillary isoelectric focusing, and the reference values of the samples was observed within an average difference range of 0.04-0.08 pH unit with a sample consumption of 10-100 ng within 30-60 min. Some carrier ampholytes were preferentially more effective at either the acidic or the basic side of the pH gradient. For confirmation of the completion of focusing, the use of two different focusing times is recommended.

In vitro reconstitution of the 24-meric E2 inner core of bovine mitochondrial branched-chain alpha-keto acid dehydrogenase complex: requirement for chaperonins GroEL and GroES

We have investigated the in vitro reconstitution of the 24-meric inner core domain (E2c) of the transacylase (E2) component of bovine branched-chain alpha-keto acid dehydrogenase complex. The yield of recombinant E2c (amino acid residues 161-421 of bovine E2) expressed in Escherichia coli was markedly increased by fusing the bacterial maltose-binding protein (MBP) to the amino terminus of bovine E2c. Following factor Xa digestion to remove the MBP moiety, E2c was completely unfolded in 4.5 M guanidine HCl (Gdn.HCl). The denatured E2c monomers (apparent M(r) = 27,000) were diluted 100-fold at 25 degrees C into a refolding buffer containing 5 mM Mg-ATP and a 4-fold molar excess of chaperonins GroEL and GroES. Full E2 activity was recovered in 45 min. Omission of the chaperonins in the refolding buffer failed to recover any E2 activity. Recovery of E2 activity obeyed hyperbolic kinetics as a function of the chaperonin-to-E2c molar ratio and showed a requirement for hydrolysis of Mg-ATP. A stable GroEL-E2c complex was isolated which, in the presence of GroES and Mg-ATP, generated active E2c 24-mers. Dissociation of recombinant E2c 24-mers into active trimers was achieved by incubation in 1.5 M Gdn.HCl at 25 degrees C. The E2c trimers with an apparent M(r) of 84,000 were isolated by sucrose density gradient centrifugation in the presence of the chaotropic reagent. Removal of 1.5 M Gdn.HCl resulted in the spontaneous reassembly of trimers into the native 24-mer structure independent of chaperonins.(ABSTRACT TRUNCATED AT 250 WORDS)

Renaturation of citrate synthase: influence of denaturant and folding assistants

Citrate synthase (CS), which has been denatured in either guanidine hydrochloride (GdnHCl) or urea can be assisted in its renaturation in a variety of ways. The addition of each of the assistants--bovine serum albumin (BSA), oxaloacetate (OAA), and glycerol--promotes renaturation. In combination, the effect of these substances is additive with respect to the yield of folded CS. The report of Buchner et al. (Buchner, J., Schmidt, M., Fuchs, M., Jaenicke, R., Rudolph, R., Schmid, F.X., & Kiefhaber, T., 1991, Biochemistry 30, 1586-1591) that refolding of CS is facilitated by the GroE system (an Escherichia coli chaperonin [cpn] that is composed of GroEL [cpn60] and GroES [cpn10]) has been confirmed. However, we observed substantially higher yield of reactivated CS, 82%, and almost no reactivation in the absence of GroES, < 5%, whereas Buchner et al. reported 28% and 16%, respectively. In addition, we find that GroE-assisted refolding is more efficient for CS denatured in GdnHCl than for CS denatured in urea. This result is discussed in light of the known difference in the denatured states generated in GdnHCl and urea. Because GroEL inhibits the BSA/glycerol/OAA-assisted refolding, this system will be useful in future studies on the mechanism of GroE-facilitated refolding.

Increased systemic B- and T-lymphocyte responses in hereditary motor and sensory neuropathy (HMSN I)

Immune mechanisms of possible importance for the development and maintenance of peripheral nerve myelin breakdown in HMSN I were analysed by measuring B- and T-cell activation in blood, bone marrow and cerebrospinal fluid. Patients with polyneuropathies of other etiologies served as one control group and patients with tension headache as another. Flow cytometry of blood and bone marrow mononuclear cells revealed that an increased number of CD3+, CD4+ and CD4- CD8- T-cells expressed a late stage activation marker (Ta1). Analysis of T-cells primed for myelin antigens, by studies of IFN-gamma secretion in response to antigen in vitro, showed that both HMSN I and other polyneuropathy patients had low (but significant) numbers of T-cells recognizing whole PNS-myelin. Increased numbers of IgG- and IgM-producing cells were found in blood and bone marrow in the HMSN I patients. Patients with both HMSN I and the other polyneuropathies had few cells in peripheral blood and in bone marrow producing antibodies binding to P2, MAG and MBP in a solid phase immunospot assay. Many cells in the cerebrospinal fluid produced antibodies against MAG. Thus, there was a strong general activation of B- and T-cells in HMSN I while the immunity directed toward peripheral nerve was only slightly elevated. It is an open question if this immune activation is related to the primary gene defect or a secondary event to the nerve damage. The pathogenetic importance of the immune response in maintaining the nerve damage in HMSN I is unclear.

Conformational stability of pig citrate synthase and some active-site mutants

The conformational stabilities of native pig citrate synthase (PCS), a recombinant wild-type PCS, and six active-site mutant pig citrate synthases were studied in thermal denaturation experiments by circular dichroism and in urea denaturation experiments by using DTNB to measure the appearance of latent SH groups. His274 and Asp375 are conserved active-site residues in pig citrate synthase that bind to substrates and are implicated in the catalytic mechanism of the enzyme. By site-directed mutagenesis, His274 was replaced with Gly and Arg, while Asp375 was replaced with Gly, Asn, Glu, or Gln. These modifications were previously shown to result in 10(3)-10(4)-fold reductions in enzyme specific activities. The thermal unfolding of pig citrate synthase and the six mutants in the presence and absence of substrates showed large differences in the thermal stabilities of mutant proteins compared to the wild-type pig citrate synthase. The functions of His274 and Asp375 in ligand binding were measured by oxalacetate protection against urea denaturation. These data indicate that active-site mutations that decrease the specific activity of pig citrate synthase also cause an increase in the conformational stability of the protein. These results suggest that specific electrostatic interactions in the active site of citrate synthase are important in the catalytic mechanism in the chemical transformations as well as the conformational flexibility of the protein, both of which are important for the overall catalytic efficiency of the enzyme.

Immunological mapping of fine molecular surface structures of citrate synthase enzymes from different cell types

Citrate synthase (EC 4.1.3.7), which is present in all living organisms as a key enzyme in aerobic energy metabolism, is one of the most highly phylogenetically conserved enzymes known in terms of its primary and active site structure. However, in terms of other parameters such as in vitro stability, tolerance to changes in pH, degree of self-polymerization, etc., citrate synthases from different sources are markedly different. These divergences can be observed even between isoforms of the enzyme within the same species. Data documenting these diversities suggest that a high degree of difference in tertiary structures may occur. Therefore, the surface profiles of citrate synthase enzymes from yeast, pig, rat, tomato and Escherichia coli were investigated with immunological methods using monoclonal antibody families generated against either pig citrate synthase (alpha-PCS) or yeast citrate synthase-2 (alpha-YCS-2). A high degree of homology of enzyme epitopes was detected on the mitochondrial citrate synthases originating from yeast, tomato, pig and rat cells. Major differences were found between the hexameric citrate synthase originating from E. coli compared with those dimeric forms prepared from eukaryotic cells. Only modest similarities were detected between the highly homologous peroxisomal and mitochondrial yeast citrate synthases. Furthermore, a point mutation of one of the catalytic residues (H274R on recombinant pig and H313R on yeast enzyme) of mitochondrial citrate synthase (CS-1) resulted in a significant increase in immunological similarity with the peroxisomal isoenzyme (CS-2). These findings are discussed in terms of the possible mechanism of evolution of CS-2 in yeast.

Mutation of essential catalytic residues in pig citrate synthase

Two amino acid residues, His274 and Asp375, were replaced singly in the active site of pig citrate synthase (PCS) with Gly274, Arg274, Gly375, Asn375, Glu375, and Gln375. The nonmutant protein and the mutant proteins were expressed in and purified from Escherichia coli, and the effects of these amino acid substitutions on the overall reaction rate and conformation of the PCS protein were studied by initial velocity and full time course kinetic analysis, behavior during affinity column chromatography, and monoclonal antibody reactivity. Native and mutant proteins purified similarly had a subunit molecular weight of 50,000 and were homologous when examined with 10 independent a-PCS monoclonal IgGs or with a polyclonal anti-PHCS serum. No activity was detected for Asn375 or Gln375. The kcats of the other purified mutant proteins, however, were decreased by about 10(3) compared to the nonmutant enzyme activity. The Km for oxalacetate was decreased 10-fold in the Glu375 protein and was reduced by half in Gly274 and Arg274 PCSs, while the Km for acetyl-CoA was decreased 2-3-fold in Gly274, Arg274, and Gln375 PCSs. A mechanism is proposed that electrostatically links His274 and Asp375.