Meta-structure enhanced second harmonic S0 waves for material microstructural changes monitoring

Cumulative second harmonic Lamb waves in nonlinear media feature increasing amplitudes with propagation distance, conducive to the monitoring of material microstructural changes in structures. The phenomenon can be readily generated by zero-order symmetric (S0) mode waves in the low-frequency range. However, in a practical piezoelectric-transducer-activated system, both S0 and A0 (zero-order antisymmetric) mode Lamb waves are inevitably excited, while only the former is responsible for cumulative effects. The generation efficiency of the cumulative second harmonics is then affected by the presence of the A0 waves. To tackle the problem, this study develops a metamaterial structure, referred to as a meta-structure, to tactically enhance the cumulative second harmonic S0 Lamb waves by converting the A0 mode components into S0 mode waves. Topology optimization is conducted to design the meta-structure, which is surface-mounted onto the structure under inspection, to achieve high-efficiency A0-to-S0 wave mode conversion. Through tuning the parameters and constraints of the optimization, the designed single-sided meta-structure breaks the structural symmetry in the thickness direction, while facilitating its practical implementation. Typical scenarios with different meta-structure materials are discussed. Numerical simulations demonstrate that the strain amplitudes of the fundamental S0 mode waves can be increased by 60% with the deployment of the meta-structure, alongside an enhancement of the second harmonic S0 mode waves at different sensing distances. Finally, the designed meta-structure is fabricated via 3D printing technique and tested experimentally on an aluminum plate subjected to thermal aging treatment for monitoring the heating-induced microstructural changes inside the structure. Experimental results confirm an increase in the wave amplitudes of the linear S0 mode waves with the assistance of the meta-structure. The developed system improves the sensitivity of nonlinear Lamb wave-based monitoring methods in characterizing material microstructural changes, which shows great promise for detecting incipient damage in practical structural health monitoring applications.

"Cumulative effect" of second harmonic Lamb waves in a lossy plate

The second harmonic Lamb waves have high sensitivity to microstructural defects in materials and are therefore promising for incipient damage detection and monitoring of thin-walled structures. Existing studies have shown that the second harmonic Lamb waves can be cumulative with increasing propagation distance under the internal resonance conditions, which is conducive to nonlinear wave measurements in view of structural health monitoring. However, when propagating in a lossy structure with damping, the cumulative properties of the second harmonic Lamb waves are affected by energy dissipation and thus need to be re-examined. In this paper, a method for predicting the cumulative characteristics of second harmonic Lamb waves in damped plates is proposed. Instead of using material damping parameters which are difficult to obtain in practice, the proposed method relies on the attenuation patterns of Lamb waves at fundamental and double frequencies while taking into account the influence of the wave beam divergence. The proposed methodology is validated by finite element simulations and experiments. The results show that the cumulative second harmonic Lamb waves in the damped plate tend to increase and then decrease, and a "sweet" zone of relatively large amplitude can be predicted using the proposed method. The elucidation of the cumulative characteristics of the second harmonic Lamb waves provides guidance for effective system design for structural damage detection and monitoring applications.

Surface Dose and Skin Toxicity Analysis in Breast Cancer Radiotherapy after Conserving Surgery with Five Treatment Modalities

PURPOSE/OBJECTIVE(S)

The present study aimed to evaluate surface dose and skin toxicity in breast cancer after breast-conserving surgery with five treatment modalities: flattening filter mode of intensity modulated radiation therapy (IMRT-FF,6MV), flattening filter-free mode of intensity modulated radiation therapy (IMRT-FFF,6MV), direct mode of TOMO (TOMO-direct, FFF, 6MV), helical mode of TOMO (TOMO-helical, FFF, 6MV), intensity modulated proton therapy (IMPT, spot scanning).

MATERIALS/METHODS

Ten patients with breast cancer treated at our institution after breast-conserving surgery were randomly selected for this study. Five plans were designed for each patient with the same target coverage and the prescription of 50Gy/25f, IMRT-6FF, IMRT-6FFF, TOMO-direct, TOMO-helical, and IMPT. Based on CT datasets, IMRT-6FFF, TOMO-direct, TOMO-helical, and IMPT were compared to IMRT-6FF with skin dose and skin toxicity. Among the five plannings, the angles of the IMRT-6FF vs. IMRT-6FFF and TOMO-direct were the same. We extracted the relative complement in the Body of its 3Derosion defined by a spherical structuring element of radius r = 3 mm and r = 5mm (skin3 and skin5). To calculate the relative Dose-surface histograms (DSH), we used the surface of patients receiving at least 5Gy to delimit the breast region's skin area and normalize the absolute DSH. Skin dose were assessed with V5Gy, V10Gy, V15Gy, V20Gy, V25Gy, V30Gy, V40Gy, V45Gy, V50Gy of the structure of skin3 and skin5. The published NTCP LKB (normal tissue complication probability, Lyman-Kutcher-Burman) model (TD50 = 39 Gy,m = 0.14,n = 0.38) was employed to evaluate severe acute radiation-induced skin toxicity.

RESULTS

There was no statistically significant difference between the structure of skin3 and skin5 between IMRT-6FF and IMRT-6FFF. For the same PTV coverage, the TOMO-helical plans had significantly higher surface dose in terms of V5Gy, V10Gy, and V15Gy than the IMRT plans (p <0.005). For structure of skin3, mean V30Gy, V35Gy, V40Gy, V45Gy, V50Gy were (64.0%,65.8%,79.0%,70.0%,64.6%), (51.3%,55.4%,74.3%,61.7%,59.5%), (32.4%,36.6%,65.2%,53.0%,53.0%), (13.7%,14.1%,45.8%,35.7%,37.6%), (1.6%/0.8%/12.2%,6.6%,1.0%). For the structure of skin5, mean V30Gy, V35Gy, V40Gy, V45Gy, V50Gy were (66.1%,67.1%,76.4%,68.6%,62.6%), (57.9%,60.4%,72.3%,61.2%,57.7%), (45.5%,48.4%,65.2%,53.9%,51.8%), (28.4%,30.8%,51.2%,42.0%,40.0%), (6.8%,6.3%,22.6%,17.9%,8.0%).Compared to IMRT-6FF, TOMO-direct and TOMO-helical had higher surface dose(p<0.05). For IMRT-6FF/IMRT-6FFF/TOMO-direct/TOMO-helical/IMPT, the mean ratio of severe acute radiational skin toxicity were14.7%,17.1%,46.3%,29.4%, and 24.1%.

CONCLUSION

For TOMO-direct and TOMO-helical planning, the skin dose and toxicity ratio were higher than IMRT-6FF. Compared to IMRT-6FF, V45Gy of skin3 and V40Gy of skin5 of IMPT were higher than IMRT-6FF, while the skin toxicity ratio was no significant difference.

[Ten-year changes in clinical characteristics and antiviral treatment patterns of chronic hepatitis B in China: a CR-HepB-based real-world study]

Objective: To understand ten-year changes in clinical characteristics and antiviral treatment patterns of chronic hepatitis B in China. Methods: Patients with chronic HBV infection:demographic, virologic, hematologic, blood biochemistry, and antiviral treatment data were extracted from the China Registry of Hepatitis B (CR-HepB) database between 2012 and 2022 for descriptive statistics and change trend analysis. Multiple group comparisons were conducted using the Kruskal Wallis H test, while counting data was compared between groups using χ (2) test. Results: A total of 180 012 patients with chronic HBV infection were included, with a median age of 40 years old, and a male proportion accounting for 60.2%. The HBeAg positive rate was 43.3%. Over time, the median age of new patients each year increased from 39 to 47 years, while the HBeAg positive rate decreased from 51.3% to 32.8%. The initial diagnosis of patients was mainly CHB (71.4%), followed by hepatitis B cirrhosis (11.8%), inactive HBsAg carrier status (10.6%), and chronic HBV carrier status (6.2%). Among the newly registered patients every year from 2012 to 2022, the proportion of hepatitis B cirrhosis remained stable, but after 2019, the proportion of CHB increased and the proportion of other diagnoses decreased. The proportion of patients with cirrhosis increased with age in different age groups, with 3.5%, 19.3%, and 30.4% in the < 40, 40-69, and≥70 age groups, respectively. The proportion of women in patients with cirrhosis also increased with age, from 16.1% in those < 30 years old to 44.3% in those≥80 years old. From 2012 to 2022, the proportion of patients receiving first-line nucleos(t)ide analog antiviral treatment increased year by year, from 51.0% in 2012-2013 to 99.8% in 2022. Conclusion: The CR-HepB registration data reflect the changes in clinical characteristics and antiviral treatment patterns in patients with chronic HBV infection in China over the past ten years and can thus provide a reference to promote hepatitis B diagnosis and treatment practice, as well as scientific research.

Comparison of higher-order aberrations between implantable collamer lens V4c implantation and simulated spectacle correction in patients with high myopia

PURPOSE

To investigate the differences in higher-order aberrations between non-toric or toric implantable collamer lens (ICL or TICL) V4c implantation and simulated spectacle correction.

METHODS

Patients with high myopia who underwent ICL/TICL V4c implantation were enrolled. The "total no defocus" pattern of iTrace aberrometry to simulate the condition of spectacle correction was measured before ICL/TICL implantation, and higher-order aberrations in this condition were compared to those 3 months after surgery. Related factors with changes in coma were comprehensively analyzed.

RESULTS

A total of 89 right eyes of 89 patients were included. Compared to simulated spectacle correction, total-eye coma (P<0.0001 ICL, P<0.0001 TICL) and internal coma (P<0.0001 ICL, P<0.001 TICL) decreased in the ICL- and TICL-treated groups after surgery. Total-eye secondary astigmatism (P<0.0001 ICL, P=0.007 TICL) and internal secondary astigmatism (P<0.0001 ICL, P=0.009 TICL) were also decreased in both groups postoperatively. Spherical error showed positive correlations with variation in total-eye coma (r=0.37, P=0.004 ICL; r=0.56, P=0.001 TICL) and internal coma (r=0.30, P=0.02 ICL and r=0.45, P=0.01 TICL). Axial length revealed negative correlations with changes in total-eye coma (r=-0.45, P<0.001 ICL; r=-0.39, P=0.03 TICL) and internal coma (r=-0.28, P=0.03 ICL and r=-0.42, P=0.02 TICL).

CONCLUSIONS

Both ICL- and TICL-treated groups demonstrated a decrease in coma and secondary astigmatism after 3 months, postoperatively. ICL/TICL may confer a compensatory effect on coma aberration and secondary astigmatism. Patients with a higher myopia achieved a greater improvement in coma and may benefit more from ICL/TICL implantation than from spectacle correction implantation than from spectacle correction.

Elastic wave propagation in thick-walled hollow cylinders for damage localization through inner surface sensing

Thick-walled hollow cylinders (TWHCs) are widely used in engineering structures and transportation systems, exemplified by train axles. The real-time and online health monitoring of such structures is crucial to ensure their structural integrity and operational safety. While elastic-wave-based structural health monitoring (SHM) shows promise, the development of feasible methods strongly relies on a good understanding and exploitation of the wave propagation properties and their interaction with structural defects. TWHCs usually bear multiple wave modes, which is a less investigated and explored topic as compared with thin-walled structures. This work examines this issue and proposes a dedicated damage localization strategy by using the selected waves captured on the inner surface of a TWHC. It is shown that, alongside the quasi-surface-waves on the outer surface, longitudinal waves converted from the thickness-through shear bulk waves are generated to propagate along the inner surface. Their propagation characteristics are exploited for damage localization based on hyperbolic loci methods through inner surface sensing. Numerical studies are conducted to validate the method and assess different transducer configurations, alongside experimental verifications on a benchmark TWHC containing a notch-type defect. Studies provide guidance on damage detection in TWHCs and sensor network design.

AB0649 Myositis Specific Antibodies - Who orders them and what are the results? A retrospective audit of two large referral centers

Background

Idiopathic inflammatory myopathies are a group of disorders associated with myositis-specific antibodies (MSA) and myositis-associated antibodies (MAA) (1). MSA and MAA are helpful in classifying clinical syndromes with both treatment and prognostic implications (2). Ordering of MSA and MAA has increased in recent years. We report the hospital services that ordered MSA and MAA and follow-up investigations performed in two large referral centers in Melbourne, Australia.

Objectives

To explore and investigate the testing patterns of MSA and subsequent follow up.

Methods

We identified all patients who underwent MSA and MAA testing between January 1 2019 and December 31 2020. Relevant demographic and clinical data were obtained by chart review.

Results

Over the 2-year study period, 294 MSA tests were ordered, alongside 275 ANA and 266 ENA. Of these, 60 (20.4%) were positive and 9 (3.1%) tested positive to more than one MSA. Interstitial lung disease (ILD) was the most common extra-muscular manifestation, 42 (14.2%) had muscle disease manifestations. Respiratory (41%), rheumatology (24%) and neurology (15%) were the top three specialties ordering the most MSA, with the highest proportion of positive MSA originating from rheumatology (38.5%). The rheumatology service was involved in 131 (41.0%) of the MSA ordered as the primary treating unit or as a consultation service. Anti-Scl100 was the most common MSA (n=10, 15.6%). Among the 60 patients with positive MSA, 39 (65%) was given a definitive diagnosis, 13 (21.7%) underwent MRI of muscles, 10 (16.7%) open muscle biopsy, and 5 (8.3%) a skin biopsy. Thirty-two (53.3%) of MSA positive patients underwent high-resolution CT chest; 26 (81.3) % had findings suggestive of a fibrotic process and 12 (20.0%) had a formal diagnosis of ILD. A cancer screen was performed in 23 (38.3%) of the MSA positive patients and no malignancy was identified within the cohort.

Conclusion

Among MSA studies performed in two large centers, 20.4% of results were positive. Respiratory ordered the most numerous tests predominantly to evaluate ILD, a higher proportion of tests recommended by the rheumatology service was positive.

References

[1]Targoff IN. Update on myositis-specific and myositis-associated autoantibodies. Curr Opin Rheumatol. 2000;12(6):475-81.

[2]Betteridge Z, McHugh N. Myositis-specific autoantibodies: an important tool to support diagnosis of myositis. J Intern Med. 2016;280(1):8-23.

Disclosure of Interests

None declared

[The relationship between adenovirus infection and severe acute hepatitis of unknown etiology]

Adenovirus infection can occur in all regions or countries of the world, with no obvious seasonality, but pandemics mostly occur in winter or early spring. Adenovirus infection is self-limited among immunocompetent host with supportive care, however fatal infection can occur among immunocompromised patients, mainly affecting respiratory, gastrointestinal tract and adjunctiva and very rarely causing hepatitis, cholecystitis, pancreatitis, hemorrhagic cystitis, myocarditis, meningitis or encephalitis. Adenovirus hepatitis mainly occur in malignant tumors or organ transplantation patients, but acute severe hepatitis can occur even in immunocompetent children or adults. On 5 April 2022, WHO was notified of 10 cases of severe acute hepatitis of unknown etiology in children. As of 21 April 2022, at least 169 cases of acute hepatitis of unknown origin have been reported from 12 countries (including 11 WHO European Region countries and the United States). Adenovirus has been detected in at least 74 cases; SARS-CoV-2 was identified in 20 cases of those that were tested. Furthermore, 19 were detected with a SARS-CoV-2 and adenovirus co-infection. At present, the etiology has not been fully elucidated. The leading hypotheses center around adenovirus, and the relationship with SARS-CoV-2 needs to be further ruled out.

[Hepatic manifestations of hematological diseases]

Liver involvement is often observed in hematological disorders, resulting in liver abnormality, including unconjugated hyperbilirubinemia, monoclonal hyperglobulinemia, portal vein, or hepatic vein thrombosis or portal hypertension, hepatosplenomegaly, or iron accumulation in the liver. Here we summarize the major hematological diseases that often affect the liver: hemolytic anemia, defect in coagulation or anti-coagulation factors, myeloproliferative neoplasm, hemophagocytic lymphohistiocytosis, multiple myeloma, leukemia, and lymphoma. We hope this review will help clinicians diagnose and manage the patients with liver involvement by hematological disorders.

Two-dimensional scattering features of the mixed second harmonic A0 mode Lamb waves for incipient damage localization

Inspection of incipient structural damage is of great significance. Existing techniques based on nonlinear guided waves have shown great promise for the detection of incipient damage due to material microstructure changes, but with only limited success for damage localization, which is technically more challenging. Our previous work uncovered the existence of the second harmonic A0 mode Lamb waves in a PZT-driven system, as a result of the mixing of the primary A0 and S0 mode Lamb waves, thus pointing at the possibility of performing damage localization through tuning the size of the wave mixing zone. In the present study, a two-dimensional incipient damage localization method is proposed based on this newly discovered wave phenomenon. By visualizing the nonlinear wave field, damage-induced nonlinear wave scattering features are first investigated. A dedicated localization algorithm is then proposed and evaluated. Numerical results show that the energy of the scattered nonlinear wave is mainly confined to a narrow region along the actuator-damage path, the spatial variation of which can be approximated by a simple Gaussian function. Embedding this information into the proposed localization strategy, damage localization can be achieved using a simple physical system. Experiments are finally carried out to validate the 2nd A0 wave scattering features and the proposed damage localization method.

Proteomic profiling of Arachis hypogaea in response to drought stress and overexpression of AhLEA2 improves drought tolerance

Drought is the main factor restricting peanut growth, but the molecular mechanism underlying peanut drought tolerance remains unclear. Herein, the seedling stage of drought-resistant peanut cultivar J11 was subjected to drought stress, and its proteomic profile was systematically analysed by isobaric tags for relative and absolute quantification (iTRAQ), the results of which were further complemented with our previous transcriptome results. A total of 4,018 proteins were identified by proteomic analysis, which revealed that the expression levels of 69 proteins were altered under drought stress. Among the differentially expressed proteins (DEPs), 50 were upregulated, and 19 were downregulated. The most enriched metabolic pathways for these DEPs were those involving phenylpropanoid biosynthesis, flavonoid biosynthesis, and plant hormone signal transduction. The proteomic data and previous transcriptome results revealed 44 groups of genes/proteins with the same expression trend, including a LEA (Late embryogenesis abundant) gene, AhLEA2. Our present study showed that overexpression of the AhLEA2 gene enhanced the drought resistance of transgenic Arabidopsis plants, and the activities of related antioxidant enzymes in the transgenic plants significantly changed. The AhLEA2 gene was found to be located in the cytoplasm and cell membrane by subcellular localization experiments. This work systematically analysed the differentially expressed proteins in peanut in response to drought stress, providing important candidates for further functional analysis of the stress response of peanut. Our results also indicated that AhLEA2 plays an important role in the peanut response to drought stress.

The cross-talk of NLRP3 inflammasome activation and necroptotic hepatocyte death in acetaminophen-induced mice acute liver injury

Overdose acetaminophen (APAP) can result in severe liver injury, which is responsible for nearly half of drug-induced liver injury in western countries. Previous studies have found that there existed massive hepatocellular necrosis and severe inflammatory response in APAP-induced liver injury. However, the mechanistic linkage between necroptosis and NLRP3 inflammasome pathway in APAP-induced hepatotoxicity remains poorly understood. In order to investigate the relationship between inflammation and hepatocytes death in APAP hepatotoxicity, a time-course model for APAP hepatotoxicity in C57/BL6 mice was established by intraperitoneal (i.p) injection of 300 mg/kg APAP in this study. The activity of serum enzymes and pathological changes of APAP-treated mice were evaluated, and the critical molecules in necroptosis and NF-κB-NLRP3 inflammasome signaling pathway were determined by immunoblot and immunofluorescence analysis. The results demonstrated that APAP overdose resulted in a severe liver injury. Furthermore, the expression of critical molecules in NLRP3 inflammasome and necroptosis pathways peaked at 12-24 h, and then was decreased gradually, which is consistent with the pattern of pathological injury induced by APAP. Our further investigation found that the level of IL-1β in mouse liver was closely correlated with the level of phosphorylated MLKL following exposure to APAP. Furthermore, inhibition of necroptosis with necrostatin-1 significantly suppressed the activation of NLRP3 inflammasome signaling. Taken together, our results highlighted that the cross-talk between necroptosis and NLRP3 inflammasome played a critical role for promoting APAP-induced liver injury. Inhibition of the interaction of inflammation and necroptosis by pharmaceutical methods may represent a promising therapeutic strategy for APAP-induced liver injury.

[Research progress of pyroptosis in respiratory diseases]

Pyroptosis is a programmed death mode dependent on Caspase-1/4/5/11, which is caused by activation of inflammasome, accompanied by cell membrane rupture, pore formation and cell content release. As a new type of cell death, it is widely involved in respiratory diseases, such as pulmonary fibrosis, acute lung injury, bronchopulmonary dysplasia, chronic obstructive pulmonary disease and asthma. This article reviews the mechanism of pyroptosis and its role in different respiratory diseases, in order to provide new ideas for the treatment of respiratory diseases.

[Systematic evaluation of clinical trial protocols of new drugs as a cure of chronic hepatitis B]

Objective: To describe the current status of registration and design characteristics of clinical trials of new drugs for curing hepatitis B through domestic and foreign websites, so as to provide references for the follow-up clinical trials of new hepatitis B drugs. Methods: A search was conducted on the US Clinical Trials Database and the Chinese Clinical Trial Registry Center. The search date was from the establishment of the database to May 26, 2020, and the registration trials of new drugs for curing hepatitis B at home and abroad were included. Two researchers independently searched and screened the literature and extracted the data. Results: A total of 106 registered clinical trials of new drugs for curing hepatitis B were included (94 English registration websites and 12 Chinese registration websites), and the number of registrations had increased year by year. Among them, the proportion of therapeutic vaccines and core protein inhibitors were the highest, accounting for 27.4% (n = 29) and 22.6% (n = 24), respectively. The vast majority of clinical trials (n = 96, 90.6%) were in the early stages (Phase I and II). The subjects in phase I clinical trial were mainly healthy people and treated CHB patients, while the subjects in phase II clinical trial were mainly CHB patients who had achieved viral suppression after initial or post-treatment. The main evaluation indicators of Phase I clinical trials were the safety and tolerability of new drugs. The main evaluation indicators in about half of Phase II clinical trials were HBsAg negative conversion/quantitative decline. Overall, the number of clinical trials with the new design was small, accounting for 3.8% (4 / 106). There were relatively few trials of new drugs for curing hepatitis B on domestic registration websites, and the information provided was incomplete. Conclusion: The number of clinical trials of new hepatitis B drugs at home and abroad is increasing year by year, but most of them are in phase I and II, with few adopting new designs. In addition, the information integrity of the domestic website registration center needs to be improved.

Distributions of time, place, and population of novel coronavirus disease 2019 (COVID-19) from January 20 to February 10, 2020, in China

Background and objective

Since December 2019, increasing cases of novel coronavirus disease 2019 (COVID-19) are being detected worldwide. The purpose of this paper is to provide a scientific reference for the global prevention and control of COVID-19.

Methods

General demographic characteristics, epidemiological history, and clinical symptoms of COVID-19 were collected that had been reported on the websites of multiple Municipal Health Commissions in China. We herein describe distributions in time, place, and population of COVID-19.

Results

As of midnight on February 10, 2020, the number of confirmed cases of COVID-19 in China was 42,638, and the province with the largest number of confirmed cases was Hubei (31,728), followed by Guangdong (1177), Zhejiang (1117), and Henan (1105) province. The number of cases and the speed of confirmed cases in provinces other than Hubei were more moderate than those of the Hubei province. The median (interquartile range) age of 1740 patients with COVID-19 was 44 (33, 54) years, with a range of 10 months to 89 years.

Conclusions

The COVID-19 epidemic should be considered a global threat and the steps for control include early diagnosis and treatment, as well as isolation.

[Distributions of time, place, and population of novel coronavirus disease 2019 (COVID-19) from January 20 to February 10, 2020, in China]

Background and objective

Since December 2019, increasing cases of novel coronavirus disease 2019 (COVID-19) are being detected worldwide. The purpose of this paper is to provide a scientific reference for the global prevention and control of COVID-19.

Methods

General demographic characteristics, epidemiological history, and clinical symptoms of COVID-19 were collected that had been reported on the websites of multiple Municipal Health Commissions in China. We herein describe distributions in time, place, and population of COVID-19.

Results

As of midnight on February 10, 2020, the number of confirmed cases of COVID-19 in China was 42,638, and the province with the largest number of confirmed cases was Hubei (31728), followed by Guangdong (1177), Zhejiang (1117), and Henan (1105) province. The number of cases and the speed of confirmed cases in provinces other than Hubei were more moderate than those of the Hubei province. The median (interquartile range) age of patients with COVID-19 was 44 (33, 54) years, with a range of 10 months to 89 years.

Conclusions

The COVID-19 epidemic should be considered a global threat and the steps for control include early diagnosis and treatment, as well as isolation.

New nonlinear ultrasonic method for material characterization: Codirectional shear horizontal guided wave mixing in plate

A nonlinear ultrasonic method is proposed based on a group of newly discovered wave triplets where two primary codirectional shear-horizontal SH0 waves mix in a weakly nonlinear plate and generate a cumulative S0 Lamb wave at the sum frequency. Theoretical analyses show that any combination of two primary SH0 waves whose frequencies sum to the frequency at which the SH0 mode intersects the S0 Lamb wave mode results in an internally resonant secondary S0 Lamb wave. Moreover, the relationship between the frequency combination and the nonlinear Lamb wave generation efficiency is revealed, which guides further engineering applications. Finite element validations are carried out with the aid of a subtraction method for the nonlinear feature extraction. The cumulative effect of the generated S0 Lamb wave at the sum frequency as well as the influence of the frequency combinations on the nonlinear Lamb wave generation efficiency is confirmed. Experiments are performed to validate the proposed method as well as demonstrate its use for material characterization. The experiments require a gel filter to mitigate the influence of the undesired nonlinear sources. With the gel filter, the cumulative effect of the secondary S0 Lamb wave is verified and the corresponding slope is extracted and further used to characterize the material status of the fatigue samples. Results demonstrate the proposed method provides high sensitivity to early fatigue damage, which makes it promising for the further early damage detection applications.

Higher lncRNA CASC15 expression predicts poor prognosis and associates with tumor growth in cervical cancer

OBJECTIVE

To investigate the role of long non-coding RNA Cancer Susceptibility Candidate 15 (CASC15) in cervical cancer and its potential molecular mechanism.

PATIENTS AND METHODS

The CASC15 expression was measured in cervical cancer tissues and cell lines by using quantitative Real-time polymerase chain reaction (qRT-PCR) analysis. Cell counting kit-8 (CCK8), flow cytometry analysis and transwell cell invasion assays were employed to detect the capacities of cell proliferation and cell invasion. Furthermore, Western blot analysis was applied to detected the E-cadherin and N-cadherin expression in EMT pathway.

RESULTS

We demonstrated that lncRNA CASC15 expression was higher in cervical cancer tissues compared to adjacent normal tissues. Higher lncRNA CASC15 expression associated with lymph node metastasis and FIGO stage. Moreover, our results showed that higher lncRNA CASC15 expression predicted poor prognosis of cervical cancer. Functional assays showed that knockdown of lncRNA CASC15 suppressed cell proliferation and cell cycle progression in cervical cancer. Moreover, we also found that knockdown of lncRNA CASC15 inhibited cell invasion ability and Epithelial-Mesenchymal Transition (EMT) signaling pathway by upregulating E-cadherin and downregulating N-cadherin expression in cervical cancer.

CONCLUSIONS

These results indicated that lncRNA CASC15 expression may be a prognostic biomarker and contributed to cell proliferation and invasion in cervical cancer.

[The study of life quality in children with obstructive sleep apnea]

AbstractObjective:To study the effect of obstructive sleep apnea(OSA) on the life quality of children. Method: Forty-four OSA children diagnosed with overnight polysomnography were selected as the research object, 35 cases of pediatric no snoring healthy children were as control. The inventory of subjective life quality and children's self-rating anxiety scale were used to assess children' s life quality. Result: Depending on the data of the inventory of subjective life quality questionnaire, each level and dimension of children' s life quality satisfaction scores in OSA group were significantly lower than that in healthy controls(P<0.05), especially in the cognitive component of school life(3.78±1.73) and the affective component of depression experience(3.70±2.18). The score of anxiety disorder in OSA group (21.39±10.49) was higher than that in healthy control group(14.21±9.69)( P<0.05). The rate of anxiety disorder in OSA group was higher than that in healthy control group(P<0.05). Conclusion:Children in OSA group had higher incidence of unsatisfactory life quality in all levels and dimensions. OSA group children dissatisfied with the life quality in each level, each dimensions have significant statistical difference, especially in the cognitive component of school life and affective components of depression experience. The OSA group had higher anxiety disorders than healthy ones.

Gene structure and expression characteristic of a novel odorant receptor gene cluster in the parasitoid wasp Microplitis mediator (Hymenoptera: Braconidae)

Odorant receptors (ORs) expressed in the antennae of parasitoid wasps are responsible for detection of various lipophilic airborne molecules. In the present study, 107 novel OR genes were identified from Microplitis mediator antennal transcriptome data. Phylogenetic analysis of the set of OR genes from M. mediator and Microplitis demolitor revealed that M. mediator OR (MmedOR) genes can be classified into different subfamilies, and the majority of MmedORs in each subfamily shared high sequence identities and clear orthologous relationships to M. demolitor ORs. Within a subfamily, six MmedOR genes, MmedOR98, 124, 125, 126, 131 and 155, shared a similar gene structure and were tightly linked in the genome. To evaluate whether the clustered MmedOR genes share common regulatory features, the transcription profile and expression characteristics of the six closely related OR genes were investigated in M. mediator. Rapid amplification of cDNA ends-PCR experiments revealed that the OR genes within the cluster were transcribed as single mRNAs, and a bicistronic mRNA for two adjacent genes (MmedOR124 and MmedOR98) was also detected in female antennae by reverse transcription PCR. In situ hybridization experiments indicated that each OR gene within the cluster was expressed in a different number of cells. Moreover, there was no co-expression of the two highly related OR genes, MmedOR124 and MmedOR98, which appeared to be individually expressed in a distinct population of neurons. Overall, there were distinct expression profiles of closely related MmedOR genes from the same cluster in M. mediator. These data provide a basic understanding of the olfactory coding in parasitoid wasps.

[Metformin's effect on 5-fluorouracil,cisplatin,paclitaxel in laryngocarcinoma Hep-2 cells]

Objective:To investigate metformin's effect on chemosensitivity of chemotherapeutic drug 5-fluorouracil in laryngocarcinoma Hep-2 cells. Investigate the variation trend of protein expression of AMPK pathway in the combined effect.Method:Laryngocarcinoma Hep-2 cells were treated with different concentrations of 5-fluorouracil in vitro together with or without metformin for 72 h. Use MTT assay to investigate the influence on the inhibition rate to Hep-2 cells. Hep-2 cells were treated with cisplatin, 5-fluorouracil or paclitaxel with or without metformin. Use Western blot assay to investigate the expression level of AMPKα, P21 or Cyclin D1 protein. Result:5-fluorouracil and metformin could inhibit the proliferation of Hep-2 cells. 5-fluorouracil in low concentration combined with metformin could increase the proliferation inhibition rate of Hep-2 cells. In the circumstances of using 5-fluorouracil in high concentration with metformin , the cell proliferation inhibition rate of combining group makes no differences with the single-drug group. The combination of metformin and 5-fluorouracil produced an antagonism action in Hep-2 cells.Western blot assay showed that metformin, cisplatin, 5-fluorouracil could have caused the increase of expression level of AMPK-α, P21 and Cyclin D1 in Hep-2 cells while Paclitaxel could have cause the decrease of expression level of Cyclin D1. Using combined drug could cause the change of protein expression. Conclusion:5-fluorouracil has been found to inhibit the proliferation of Hep-2 cells. Metformin has an antagonism on the anticancer effect to 5-fluorouracil in Hep-2 cells, and this antagonistic effect occurred partially through molecular signal pathways of AMPK-α, P21 and Cyclin D1 and it's significantly related to the cell cycle arrest.

[LB100 reverses the acquired resistance to gefitinib in lung adenocarcinoma cells with EGFR mutation]

Objective: To investigate the possibility of the Protein Phosphatase 2A (PP2A) inhibitor, LB100, in reversing acquired resistance to gefitinib in lung adenocarcinoma with epidermal growth factor receptor (EGFR) gene mutation. Methods: Cell line NCI-H1975 and established primary culture cell line 44-1 with gefitinib resistance were sequenced to determine the mutation type of EGFR gene. Cells were treated with gefitinib alone or combined with LB100 to determine the half maximal inhibitory concentration (IC50), and sensitivity of 44-1 and NCI-1975 to gefitinib alone or combined with LB100 was compared. The volume of NCI-H1975 xenografts with different drug treatments was observed to determine the efficiency of gefitinib with or without LB100 in tumor growth inhibition. Results: Both 44-1 and NCI-1975 cells had double EGFR mutation (sensitive L858R mutation and resistant T790M mutation). Both cells showed significant gefitinib resistance (IC50: 23.0 μmol/L in 44-1, 16.7 μmol/L in NCI-1975). When combined with LB100, IC50 of gefitinib decreased to 6.9 μmol/L in 44-1 cell and decreased to 3.4 μmol/L in NCI-H1975 cells. In NCI-1975 xenografts experiments, LB100 enhanced the ability of gefitinib in tumor growth inhibition (P<0.05). Conclusion: LB100 reverses acquired resistance to gefitinib in lung adenocarcinoma cell lines.

[Impact of auditory deprivation on rats and plasticity expressionof growth associated protein-43 in auditory cortex]

Objective:To explore the molecular mechanism of neural plasticity in the reconstitution following impairment of auditory system,we studied the changing levels of GAP-43 expression in the auditory cortex(AC) in the developing rats and in ototoxicity deafened rats before and after electrical intracochlear stimulation.Method:Auditory brain stem response(ABR) measurements were performed to rats of OAD,NC1,CAD and NC2 group to evaluate hearing function.We studied the changing levels of GAP-43-positive neurons expression in the auditory cortex of the OAD,NC1,EIS1 and EIS2 group and RT-PCR was performed to do semiquantitative analysis.Result:The early electrical intracochlear stimulation elevated GAP-43 level(EIS1,120.00±5.59/HP) in ipsilateral AC instead of in the contralateral AC compared with the non-stimulation group (OAD4W,93.25±4.30/HP),and the two groups had statistical difference(EIS1/OAD4W,129.17%±3.33%,P<0.05).After the late electrical intracochlear stimulation,similar to the early group,the staining level of GAP-43(EIS2,102.50±4.02/HP) in the AC was also higher than the unaffected group(OAD8W,81.67±3.76/HP),and the two groups also had statistical difference(EIS2/OAD8W,123.74%±2.70%,P<0.05).Similarly,the expression of GAP-43 mRNA had the synchronous change with the GAP-43 in the AC.Conclusion:GAP-43 has close correlation with the growth and plasticity of the AC,which can be a significant marker for auditory plasticity.

Comparison of clinical and cone beam computed tomography measurements to diagnose furcation involvement

AIM

This study aimed to determine the degree of discrepancy between clinical measurement of furcation involvement (FI) and cone beam computed tomography image analysis of multirooted teeth.

METHODS

FI measurements obtained from clinical records were compared to CBCT images of the same teeth to determine the degree of discrepancy between CBCT FI grading and clinical FI grading.

RESULTS

Of the hundred and fifty-four sites analysed, 22% of FI measurements from probing and CBCT were in agreement. Fifty-eight percent of clinical FI recordings were overestimated, and 20% were underestimated when compared to CBCT analysis.

CONCLUSION

Clinical recording of FI is both over and underestimated compared to CBCT analysis. This was highest for probing recording grade I furcation involvement where it was highly overestimated. The occurrence of over and under estimation of FI will affect the assignment of prognosis to multirooted teeth, which can influence treatment planning for periodontal therapy and may result in inappropriate treatment.

Gene-gene interactions of IRF5, STAT4, IKZF1 and ETS1 in systemic lupus erythematosus

Interferon (IFN) activation signaling and T helper 17 (Th17)-cell/B-cell regulation play a critical role in the pathogenesis of systemic lupus erythematosus (SLE). Several studies have provided convincing evidence that polymorphisms in IRF5, STAT4, IKZF1 and ETS1 from these pathways may be involved in SLE by affecting gene expression or epistasis. We analyzed the genetic interaction in known SLE susceptibility loci from the four genes in northern Han Chinese. A total of 946 northern Han Chinese participated in this study (370 unrelated SLE patients and 576 healthy controls). Subjects underwent genotyping for the single-nucleotide polymorphisms (SNPs) rs2004640 in IRF5, rs7574865 in STAT4, rs4917014 in IKZF1 and rs1128334 in ETS1 by use of a TaqMan SNP genotyping assay and direct sequencing. Gene-gene interaction analysis involved direct counting, multifactor dimensionality reduction (MDR) and linear regression analysis. SLE patients and controls differed in allele frequencies of rs7574865, rs1128334 (P < 0.001) and rs4917014 (P < 0.01). Direct counting revealed that the frequency of risk homozygote combinations was higher for SLE patients than controls (P < 0.01). Furthermore, 2-, 3- and 4-way gene-gene epistasis in SLE was confirmed by parametric methods and MDR analysis. Gene expression analysis partially supported the findings. Our study confirmed the association of the IFN pathway or Th17/B-cells and the pathogenesis of SLE, and gene-gene interaction in this pathway may increase the risk of SLE.

Effects of tetra-arsenic tetra-sulfide on BXSB lupus-prone mice: a pilot study

Systemic lupus erythematosus (SLE) is an autoimmune disease of uncertain etiology that affects multiple tissues and organs. Arsenic trioxide (ATO) has been used in lupus-prone mice with a regulatory effect on immune abnormality. Tetra-arsenic tetra-sulfide (As4S4), a traditional Chinese medicine, is effective on acute promyelocytic leukemia with mild side effects than ATO. In this study, a pilot study was performed to investigate the effects and the mechanism of As4S4 on the lupus-prone BXSB mice. Improvement of monocytosis (p<0.05) in spleen and decreased serum interleukin-6 (IL-6) (p=0.0277) were observed with As4S4 treatment. As4S4-treated mice exhibited amelioration of skin, liver and renal disease with mild side effects. Histological analysis revealed that As4S4 suppressed immune complex deposition, mesangial proliferation and inflammatory cell infiltration in kidney and liver. Our study support that As4S4 selectively suppresses cutaneous lupus and nephritis in BXSB mice and might be a potential treatment for SLE.

Reactive gas environment induced structural modification of noble-transition metal alloy nanoparticles

Noble-transition metal (noble=Pt,Au; transition=Co,Ni,Cu) alloy particles with sizes of about 5 nm have been studied by in situ high-energy x-ray diffraction while subjected to oxidizing (O(2)) and reducing (H(2)) gas atmospheres at elevated temperatures. The different gas atmospheres do not affect substantially the random alloy, face-centered-cubic structure type of the particles but do affect the way the metal atoms pack together. In an O(2) atmosphere, atoms get extra separated from each other, whereas, in an H(2) atmosphere, they come closer together. The effect is substantial, amounting to 0.1 Å difference in the first neighbor atomic distances, and concurs with a dramatic change of the particle catalytic properties. It is argued that such reactive gas induced "expansion shrinking" is a common phenomenon that may be employed for the engineering of "smart" nanoparticles responding advantageously to envisaged gas environments.

An intronic variant associated with systemic lupus erythematosus changes the binding affinity of Yinyang1 to downregulate WDFY4

Two recent genome-wide association studies of East Asian populations revealed three genetic variants in WDFY4/LRRC18 associated with systemic lupus erythematosus (SLE). To identify the gene contributing to this disease susceptibility, we examined the mRNA expression of WDFY4 and LRRC18 in patients with SLE and healthy controls. WDFY4 was significantly downregulated in SLE patients as compared with controls. We used allelic expression and dual-luciferase assays to identify the functional variant. Transcriptional activity was lower for the rs877819A than -G allele. Electrophoretic mobility shift and supershift assays revealed that the transcription factor Yinyang1 (YY1) binds to rs877819, with lower affinity to the A allele, which explained the reduced transcriptional activity. This effect was further confirmed by YY1 small interfering RNA knockdown, overexpression and chromatin immunoprecipitation experiments. rs877819 in WDFY4 might be the functional site associated with SLE by reduced binding of YY1 and downregulating WDFY4 expression.

Effects of islet neogenesis-associated protein pentadecapeptide on cell mass and insulin secretion of pancreatic β-cells

OBJECTIVE

To explore the effects of islet neogenesis- associated protein pentadecapeptide (INGAP-PP) on proliferation and secretion function of β-cells.

METHODS

Islets of adult Sprague Dawley rats were isolated by collagenase digestion and treated with 10 μg/ml INGAP-PP, after 12, 24, 48 h, glucose-stimulated insulin secretion (GSIS) and acridine orange/pro pidium iodide (AO/PI) staining were used to detect the secretion function and cell viability. The INS-1 cells were treated with 0, 1, 10, 25, 50, 100, 250, and 500 μg/ml INGAP-PP for 24 or 48 h, MTT cell proliferation assay was adopted to survey the dose-response relationship between INGAP-PP and cell proliferation. The mRNA expression of roliferating cell nuclear antigen (PCNA), Cyclin D1, Cdk4, P27, p38MAPK, and JNK in INS-1 cells were examined by RT-PCR, and the protein expression of PCNA was examined by Western blot. The statistical significance was determined by Student's t-test or one-way analysis of variance.

RESULTS

The insulin secreted by islets and the cell viability were increased by INGAP-PP. MTT indicated a dose-response relationship between INGAP-PP and quantity of INS-1 cells, and treatment for 48 h had a stronger effect on cell proliferation than the 24 h. INGAP-PP up-regulated the mRNA expression of PCNA, Cyclin D1, Cdk4 and downregulated P27, p38MAPK, and JNK. Moreover, the protein expression of PCNA was up-regulated by 45% after INGAPPP exposure for 48 h.

CONCLUSIONS

INGAP-PP increased the insulin secretion, enhanced the proliferation and might reduce apop tosis of β-cells. The mechanism may contribute to the changed expression of some genes related to cell cycle.

Compaction through buckling in 2D periodic, soft and porous structures: effect of pore shape

Soft cellular structures that comprise a solid matrix with a square array of holes open avenues for the design of novel soft and foldable structures. Our results demonstrate that by simply changing the shape of the holes the response of porous structure can be easily tuned and soft structures with optimal compaction can be designed.

Down-regulation of prostate specific antigen in LNCaP cells by flavonoids from the pollen of Brassica napus L

The pollen of Brassica napus L. has been used in China to treat benign prostatic hyperplasia (BPH) for over decades. In this study, the pollen of Brassica napus L. was extracted successively with chloroform, ethyl acetate and ethanol. The ethyl acetate extract showed strong activity in decreasing the secretion of prostate specific antigen (PSA) in LNCaP cells as compared to two other extracts, measured by ELISA with finasteride as positive control in the assay. Five flavonoids were subsequently isolated from the active extract using bioassay-guided fractionation. They were Naringenin (1); Luteolin (2); Kaempferol (3); Kaempferol 3-(3-E-p-coumaroyl-alpha-L-rhamnopyranoside) (4); and Kaempferol 3-(2,3-di-E-p-coumaroyl-alpha-L-rhamnopyranoside) (5). All these compounds inhibited PSA secretion significantly, with IC50 values in the range of 5-50 microM. Compounds 2, 4 and 5 showed moderate cytotoxicity to LNCaP cells within the active concentration range, while compounds 1 and 3 showed no cytotoxicity. Further studies on the mechanism action of these compounds were performed by evaluating their activation of estrogen receptor (ER) and antagonistic activities on androgen receptor (AR) in cell-based reporter gene assays. All compounds described here were first isolated from the pollen of Brassica napus L.

Human recombinant erythropoietin (rEpo) has no effect on tumour growth or angiogenesis

Tumour hypoxia has been shown to increase mutation rate, angiogenesis, and metastatic potential, and decrease response to conventional therapeutics. Improved tumour oxygenation should translate into increased treatment response. Exogenous recombinant erythropoietin (rEpo) has been recently shown to increase tumour oxygenation in a mammary carcinoma model. The mechanism of this action is not yet understood completely. The presence of Epo and its receptor (EpoR) have been demonstrated on several normal and neoplastic tissues, including blood vessels and various solid tumours. In addition, rEpo has been shown in two recent prospective, randomized clinical trials to negatively impact treatment outcome. In this study, we attempt to characterize the direct effects of rEpo on tumour growth and angiogenesis in two separate rodent carcinomas. The effect of rEpo on R3230 rat mammary adenocarcinomas, CT-26 mouse colon carcinomas, HCT-116 human colon carcinomas, and FaDu human head and neck tumours, all of which express EpoR, was examined. There were no differences in tumour growth or proliferation (measured by Ki-67) between placebo-treated and rEpo-treated tumours. In the mammary window chamber, vascular length density (VLD) measurements in serial images of both placebo-treated and Epo-treated rats revealed no difference in angiogenesis between the Epo-treated tumours and placebo-treated tumours at any time point. These experiments are important because they suggest that the recent clinical detriment seen with the use of Epo is not due to its tumour growth effects or angiogenesis. These studies also suggest that further preclinical studies need to examine rEpo's direct tumour effects in efforts to improve the therapeutic benefits of Epo in solid tumour patients.

Additive Effects of Leflunomide and Tacrolimus in Prevention of Islet Xenograft Rejection

Leflunomide is a low molecular weight immunosuppressive drug which inhibits the enzymes dehydroorotate dehydrogenase and protein tyrosine kinase, both of which are important components in the immune response. As the mechanisms of action of leflunomide and tacrolimus are different, we postulated an additive or synergistic effect of the two drugs and investigated the effects of leflunomide alone, or in combination with a suboptimal dose of tacrolimus, on xenogeneic islet transplantation in a rat-to-mouse model. A total of 1200-1500 rat islets were transplanted under the left kidney capsule of streptozotocin-induced diabetic BALB/c mice. The median survival time (MST) of the untreated group was 6 days. Leflunomide at 5, 10 and 20 mg/kg/d administrated for 10 days significantly prolonged MST to 10, 16 and 20 days. A dose of tacrolimus (2 mg/kg/d) was associated with a graft survival of 9 (range 6-12) days; most grafts rejected during ongoing therapy. When tacrolimus (2 mg/kg/d) was combined with leflunomide (10 mg/kg/d), the survival time of the islet xenografts was increased further to 22 days, significantly longer than with leflunomide or tacrolimus alone. In summary, our findings demonstrate that leflunomide prolonged xenogeneic islet graft survival, and that its immunosuppressive effect was improved when combined with tacrolimus.

Intravital fluorescence facilitates measurement of multiple physiologic functions and gene expression in tumors of live animals

The purpose of this report is to present an overview of the use of fluorescence imaging in vivo, with particular emphasis on oncology. It is important to note, however, that many of the methods described herein have been applied to the study of non-malignant tissues as well. Modern medicine and biology research has benefited greatly from an ever-expanding assortment of fluorescent markers and labels. These markers and labels have allowed investigators to observe the behavior and properties of cell and molecular entities of interest in the context of complicated biological systems such as a mammalian cell or a whole mouse. Methods developed to image fluorescence in whole mice have been valuable in studying patterns of tumor growth and metastases. Alternatively, more detailed information and a wide variety of endpoints can be obtained using "intravital" preparations. This review focuses on use of fluorescence imaging for intravital preparations. For detail on fluorescence imaging of whole animals, refer to reviews on this subject [1,2]. For oncologic applications, studies have focused primarily on window chamber preparations that allow for real-time visualization of tumor growth, vascularity, vascular responses to stimulation, vascular permeability, vascular orientation, flow instability, and the like. These endpoints have been used to show that there are functional differences between tumor and normal tissues with respect to these functions under baseline conditions and after therapeutic manipulation. Examples of some of these differences are provided in this review as a means to illustrate how they can be used.

Enzyme-linked immunosorbent assay for glycyrrhizin using anti-glycyrrhizin monoclonal antibody and an eastern blotting technique for glucuronides of glycyrrhetic acid

Hybridomas secreting a monoclonal antibody against glycyrrhizin were produced by fusing splenocytes from a mouse immunized against a glycyrrhizin-bovine serum albumin conjugate with the hypoxanthine-aminopterin-thymidine-sensitive mouse myeloma cell line, P3-X63-Ag8-653. A very weak cross-reaction with glycyrrhetinic acid monoglucuronide and glycyrrhetic acid occurred. An enzyme-linked immunosorbent assay (ELISA) that had an effective measuring range of 20 -200 ng/mL of glycyrrhizin was established using this monoclonal antibody. In addition, a method named eastern blotting for the detection of glycyrrhizin was investigated. In this method, we developed a new way to separate the glycyrrhizin molecule into two functional parts using a simple and well-known chemical reaction. The sugar parts were oxidized by sodium periodate to give dialdehydes, which reacted with amino groups on the protein and covalently bound to the adsorbent membrane. The monoclonal antibody bound to the aglycone part of the glycyrrhizin molecule for immunostaining. This method was validated by immunocytolocalization of glycyrrhizin in fresh Glycyrrhiza root.

Mechanisms associated with tumor vascular shut-down induced by combretastatin A-4 phosphate: intravital microscopy and measurement of vascular permeability

The tumor vascular effects of the tubulin destabilizing agent disodium combretastatinA-4 3-O-phosphate (CA-4-P) were investigated in the rat P22 tumor growing in a dorsal skin flap window chamber implanted into BD9 rats. CA-4-P is in clinical trial as a tumor vascular targeting agent. In animal tumors, it can cause the shut-down of blood flow, leading to extensive tumor cell necrosis. However, the mechanisms leading to vascular shut-down are still unknown. Tumor vascular effects were visualized and monitored on-line before and after the administration of two doses of CA-4-P (30 and 100 mg/kg) using intravital microscopy. The combined effect of CA-4-P and systemic nitric oxide synthase (NOS) inhibition using N(omega)-nitro-L-arginine (L-NNA) was also assessed, because this combination has been shown previously to have a potentiating effect. The early effect of CA-4-P on tumor vascular permeability to albumin was determined to assess whether this could be involved in the mechanism of action of the drug. Tumor blood flow reduction was extremely rapid after CA-4-P treatment, with red cell velocity decreasing throughout the observation period and dropping to <5% of the starting value by 1 h. NOS inhibition alone caused a 50% decrease in red cell velocity, and the combined treatment of CA-4-P and NOS inhibition was approximately additive. The mechanism of blood flow reduction was very different for NOS inhibition and CA-4-P. That of NOS inhibition could be explained by a decrease in vessel diameter, which was most profound on the arteriolar side of the tumor circulation. In contrast, the effects of CA-4-P resembled an acute inflammatory reaction resulting in a visible loss of a large proportion of the smallest blood vessels. There was some return of visible vasculature at 1 h after treatment, but the blood in these vessels was static or nearly so, and many of the vessels were distended. The hematocrit within larger draining tumor venules tended to increase at early times after CA-4-P, suggesting fluid loss from the blood. The stacking of red cells to form rouleaux was also a common feature, coincident with slowing of blood flow; and these two factors would lead to an increase in viscous resistance to blood flow. Tumor vascular permeability to albumin was increased to approximately 160% of control values at 1 and 10 min after treatment. This could lead to an early decrease in tumor blood flow via an imbalance between intravascular and tissue pressures and/or an increase in blood viscosity as a result of increased hematocrit. These results suggest a mechanism of action of CA-4-P in vivo. Combination of CA-4-P with a NOS inhibitor has an additive effect, which it may be possible to exploit therapeutically.

The novel tubulin-binding drug BTO-956 inhibits R3230AC mammary carcinoma growth and angiogenesis in Fischer 344 rats

BTO-956 [methyl-3,5-diiodo-4-(4'-methoxyphenoxy)benzoate], a novel tubulin-binding drug and thyroid hormone analogue, was originally found to inhibit human carcinoma cell proliferation in vitro and to have potent growth delay activity in human breast and ovarian carcinoma xenografts in nude mice. Here we report that BTO-956 given to Fischer 344 rats also inhibits corneal angiogenesis and the growth and neovascularization of the R3230Ac rat mammary carcinoma tumor implanted in skin-fold window chambers. Hydron pellets containing recombinant human basic fibroblast growth factor (50 ng) and Sucralfate (20 microg) were implanted into surgically created corneal micropockets (day 0). BTO-956 was administrated by oral gavage (500 mg/kg, twice a day for 6 days) on days 1-6 (controls received vehicle alone). On day 7, rats received retrograde infusions of India ink via the thoracic aorta to visualize the corneal vasculature. Digitized images of slide-mounted corneas from control and treated animals were taken with a microscope. For the tumor growth and angiogenesis study, small pieces of R3230Ac tumor from a donor rat were implanted into surgically prepared window chambers (day 0). BTO-956 was given during days 5-11, and images of the tumors and their vasculature were recorded on day 12. No body weight loss was observed in either study. BTO-956 significantly inhibited corneal angiogenesis (by 50-80%), as assessed by measurements of limbal circumference displaying neovascularization, vessel length, vascularized area, and vascular area density. In the window chamber assay, tumors from treated animals were >50% smaller than tumors in control animals. In addition, vascular length densities in peripheral tumor zones were 30% less in treated compared with control animals. Together, these findings demonstrate that BTO-956 can inhibit angiogenesis induced by a growth factor in the rat cornea and in the peripheral area of implanted tumors, where tumor angiogenesis is most active.

Role of incipient angiogenesis in cancer metastasis

Metastasis is the primary cause of mortality in cancer patients. Angiogenesis is intimately involved in metastasis at the site of entry of tumor cells into the vasculature and at the site of eventual metastasis growth. In this commentary, we review current paradigms regarding angiogenesis in metastatic sites. Recent discoveries challenge some of the existing paradigms. Significant prior data suggest that successful formation of metastases requires: 1) angiogenesis in the primary tumor site; 2) downregulation of cohesive molecules and tumor cell increased motility, resulting in invasion into neovessels; 3) tumor cell embolism; 4) arrest and attachment in capillary beds of distant organs; 5) extravasation and proliferation in the organ parenchyma; and 6) re-establishment of angiogenesis when the tumor reaches > 1-2 mm in size [1]. While most recent data largely confirm the aforementioned sequence of events, a few reports have revealed new knowledge about the earliest phases of angiogenesis of metastases. Of particular importance has been the ability to create tumor cell lines that are stably transfected with reporter genes, such as green fluorescence protein. With these tools it is now literally possible to monitor tumor formation from a single cell [2-7].

Tamoxifen inhibits angiogenesis in estrogen receptor-negative animal models

Inhibition of tumor angiogenesis is a therapeutic strategy that can inhibit tumor growth and metastases. The aim of this study was to determine whether the estrogen receptor (ER) ligand drug tamoxifen has antiangiogenic effects. We used three different models of angiogenesis, including measurement of microvessel densities in murine tumors, ex vivo aortic ring assays, and corneal pocket assays. ER-negative fibrosarcoma tumors in tamoxifen-treated ovariectomized rats had significantly less vessel formation compared with untreated animals (median microvessel density, 53.6 versus 94.3 counts/per x 200 field; P = 0.002). Rat aortic rings treated with tamoxifen at several different concentrations demonstrated significantly less vascular sprouting than control rings (P = 0.0001). Corneal pocket assays performed in tamoxifen-treated rats compared with control and estrogen-treated rats demonstrated decreased vascular length (0.88 mm versus 1.26 mm versus 1.47 mm; P = 0.022) and vessel area (21% versus 34% versus 47%; P = 0.018). These three animal models all showed significant inhibition of angiogenesis by tamoxifen and suggest a possible contributory mechanism of ER-independent manipulation by tamoxifen in the treatment and prevention of breast cancer. These studies raise the question as to whether or not newer ER ligand drugs might possess even more potent antiangiogenic effects, which in turn could lead to the broadening of the clinical usefulness of these compounds in a number of diseases. More importantly, these studies suggest that the antiangiogenic effects of tamoxifen are due, in part, to ER-independent mechanisms.