[Epidemiological characteristics of norovirus acute gastroenteritis outbreaks and influencing factors in China, 2007-2021]

Objective: To analyze the epidemiological characteristics of norovirus-caused acute gastroenteritis outbreaks in China, identify the factors influencing the scale of outbreaks, and provide scientific evidences for early control of norovirus infection outbreaks. Methods: The descriptive epidemiological analysis approach was applied to analyze the incidence of national norovirus infection outbreaks by using the data from the Public Health Emergency Event Surveillance System in China from January 1, 2007 to December 31, 2021. The unconditional logistic regression model was applied to analyze the risk factors that affected the outbreaks' scale. Results: A total of 1 725 norovirus infection outbreaks were recorded in China from 2007 to 2021, with an upward trend in the number of the reported outbreaks. The southern provinces had their annual outbreak peaks from October to March; the northern provinces had two outbreak peaks from October to December and from March to June annually. The outbreaks occurred mainly in southeastern coastal provinces with a trend of gradual spread to central, northeastern and western provinces. The outbreaks mainly occurred in schools and childcare setting (1 539 cases, 89.22%), followed by enterprises and institutions (67 cases, 3.88%) and community households (55 cases, 3.19%). Human to human transmission was the main infection route (73.16%), and norovirus GⅡ genotype was the predominate pathogen causing the outbreaks (899 cases, 81.58%). The time interval between the onset of the primary case and the outbreak reporting M (Q₁, Q₃) was 3 (2, 6) days and the case number of the outbreak M (Q₁, Q₃) was 38 (28, 62). The timeliness of outbreak reporting was improved in recent years and the scale of the outbreaks showed a decreasing trend over the years, the differences in reporting timeliness and outbreak scale among different settings were significant (P<0.001). The factors that affected outbreaks' scale included the outbreak setting, transmission route, outbreak reporting timeliness and type of living areas (P<0.05). Conclusions: From 2007 to 2021, the number of the norovirus-caused acute gastroenteritis outbreaks increased in China and the more areas were affected. However, the outbreak scale showed a decreasing trend and the outbreak reporting timeliness was improved. It is important to further improve the surveillance sensitivity and reporting timeliness for the effective control of the outbreak scale.

[Epidemiological characteristics of typhoid fever and paratyphoid fever in China, 2004-2020]

Objective: To analyze the incidence trend and epidemiological characteristics of typhoid fever and paratyphoid fever in China from 2004 to 2020, understand the high-incidence population and hotspot areas, and provide evidences to develop more targeted prevention and control measures. Methods: The descriptive epidemiological method and spatial analysis method were applied to analyze the epidemiological characteristics of typhoid fever and paratyphoid fever in China during this period by using the surveillance data collected from the National Notifiable Infectious Disease Reporting System of Chinese Center for Disease Control and Prevention. Results: A total of 202 991 cases of typhoid fever were reported in China from 2004 to 2020. More cases occurred in men than in women (sex ratio: 1.18∶1). Most cases were reported in adults aged 20-59 years (53.60%). The incidence rate of typhoid fever decreased from 2.54/100 000 in 2004 to 0.38/100 000 in 2020. The highest incidence rate was reported in young children aged <3 years after 2011, ranging from 1.13/100 000 to 2.78/100 000, and during this period the proportion of cases in this age group increased from 3.48% to 15.59%. The proportion of the cases in the elderly aged ≥60 years increased from 6.46% in 2004 to 19.34% in 2020. The hotspot areas existed in Yunnan, Guizhou, Guangxi and Sichuan Provinces and expanded to Guangdong, Hunan, Jiangxi, and Fujian Provinces. A total of 86 226 paratyphoid fever cases were reported from 2004 to 2020, the male to female ratio of the cases was 1.21∶1. Most cases were reported in adults aged 20-59 years (59.80%). The incidence rate of paratyphoid fever decreased from 1.26/100 000 in 2004 to 0.12/100 000 in 2020. The highest incidence rate of paratyphoid fever was in young children aged <3 years after 2007, ranging from 0.57/100 000 to 1.19/100 000, and during this period the proportion of the cases in this age group increased from 1.48% to 30.92%. The proportion of the cases in the elderly aged ≥60 years increased from 4.52% in 2004 to 22.28% in 2020. The hotspot areas expanded to the east, including Guangdong, Hunan and Jiangxi Provinces, from Yunnan, Guizhou, Sichuan, and Guangxi Provinces. Conclusions: The results showed a low level of incidence of typhoid fever and paratyphoid fever in China with a trend of decreasing per year. The hotspots were mainly in the of Yunnan, Guizhou, Guangxi and Sichuan Provinces, with an expanding trend to eastern China. It is necessary to strengthen the typhoid fever and paratyphoid fever prevention and control in southwestern China, among young children aged <3 years and the elderly aged ≥60 years.

[Incidence and risk factors of thromboembolism in patients with lung cancer receiving immunotherapy]

Objective: To evaluate the incidence of thromboembolism in a cohort of patients with lung cancer who received immune checkpoint inhibitors (ICIs), and explore relevant clinical risk factors. Methods: We retrospectively collected and analyzed the clinical data of patients with confirmed primary lung cancer and treated with ICIs between March 2018 and June 2021 at three hospitals in China (Tongji Hospital of Tongji Medical College of Huazhong University of Science and Technology, Fudan University Shanghai Cancer Center and Zhongshan Hospital of Fudan University). The cumulative incidence and risk factors of thromboembolism in these patients were analyzed using a competitive risk model. Results: A total of 804 patients were enrolled, there were 623 males and 181 females, with a median age of 59 years (ranged 28-86 years). Of these, 62 patients encountered 65 thromboembolic events, including 51 venous thromboembolism events (VTE) and 14 arterial thromboembolism events. The cumulative incidence of thromboembolism events at 3, 6, 12 and 24 months were 4.3%, 6.1%, 10.1% and 16.8%, respectively. And the cumulative incidence of venous thromboembolism events at 3, 6, 12 and 24 months were 3.4%, 4.7%, 9.0% and 13.3%, respectively. Multivariate analysis showed that history of thromboembolism (HR=6.345, 95%CI: 2.917-13.802,P<0.001),liver metastasis (HR=2.249, 95%CI: 1.123-4.502,P=0.022) and peripherally inserted central venous catheter (HR=3.674, 95%CI: 1.751-7.712, P<0.001) were independent risk factors for venous thromboembolism during ICIs therapy in patients with lung cancer. Conclusions: Patients with lung cancer under ICIs therapy are at high risk of thromboembolism. And history of thromboembolism, liver metastasis and peripherally inserted central venous catheter are risk factors of venous thromboembolism.

Research Progress on Pathological Fibrosis of Sinoatrial Node

Abstract

Human heart rhythm is mainly regulated and controlled by the sinoatrial node. Fibrosis plays an important regulating role in adjusting the structural and functional integrity of the sinoatrial node pacemaker complex. In physiological state, the fibrosis degree of sinoatrial node is negatively correlated with heart rate, positively correlated with age and heart size, and can maintain a relatively stable heart rate. Pathological fibrosis of sinoatrial node can induce various types of arrhythmias which can result in sudden death. Determination of the mechanisms related to sinoatrial node pathological fibrosis could provide a target for clinical treatment of sinoatrial node fibrosis and diagnosis basis for forensic pathologists. This paper reviews the main mechanism of sinoatrial node pathological fibrosis, including abnormal activation of cardiac fibroblast cells in sinoatrial node, hyperplasia of epicardial adipose tissue, calcium clock disorder, artery stenosis, etc., introduces the test methods, diagnostic criteria as well as its role in sudden cardiac death and discusses the potential application, to provide reference for relevant research and application.

[Epidemiological characteristics of severe cases of hand, foot, and mouth disease in China, 2008-2018]

Objective: To characterize the epidemiology of severe hand, foot and mouth disease (HFMD) in China from 2008 to 2018 and provide evidence for the prevention and control of severe HFMD. Methods: The incidence data of severe HFMD cases from 2008 to 2018 were collected from the National Notifiable Infectious Diseases Reporting System of Chinese Center for Disease Control and Prevention. Descriptive epidemiological methods were used to analyze distributions, pathogen constituent and change of severe HFMD. Joinpoint regression model was used to analyze the trends of severity rate, proportion of severe cases and severe fatality rate. Results: From 2008 to 2018, a total of 157 065 cases of severe HFMD were reported in China, with an average annual case-severity rate of 1.05/100 000, a severe case proportion of 0.76% and a severity-fatality rate of 2.34%. The severity rate and the proportion of severe cases showed a downward trend after 2010, and severe fatality rate decreased significantly after 2014. The severe cases mainly occurred in infants aged ≤3 years (91.47%), more boys were affected than girls (1.78∶1). The median age of severe HFMD cases caused by EV-A71 was highest (1.99 years) and increased year by year, other enterovirus infection cases accounted for a higher proportion in infants aged ≤1 year (66.56%). The incidence peak occurred during April-July, other enteroviruses replaced EV-A71 as the predominant serotype in 2018 (61.97%). The incidence of severe HFMD were high in some provinces in southwestern, central and eastern China. Conclusion: The overall severity rate, proportion of severe cases and severe fatality rate of HFMD in the mainland of China have shown a downward trend. The predominant pathogen in some provinces has changed from EV-A71 to other enteroviruses. It is necessary to strengthen the prevention and control of HFMD in key population, high incidence seasons and areas and carry out the surveillance of various pathogens of HFMD.

[Clinical efficacy of cyberknife in patients with primary large hepatocellular carcinoma over 70 years old]

Objective: To analyze the clinical efficacy and safety of cyberknife in the treatment of patients with primary large hepatocellular carcinoma over 70 years old. Methods: A total of 82 patients (58 males and 24 females) with large hepatocellular carcinoma aged over 70 years (70 to 85 years, (75±4) years) with a median tumor diameter of 6.7 cm (5.0~10.0 cm) were retrospectively collected. All patients were diagnosed by pathology or radiography in the Cancer Radiotherapy Center of the Fifth Medical Center of the PLA General Hospital from March 2014 to December 2018, and treated with cyberknife stereotactic radiotherapy. Progression free survival rate (PFS), local control rate (LC), overall survival rate (OS) and adverse reactions were observed at 1, 2 and 3 years. Kaplan-Meier was used for survival analysis, and Cox regression model was used to analyze survival-related factors. Results: All 82 patients successfully completed radiation therapy with a median survival time of 20 months, a median PFS of 10 months, an objective response rate of 64.63% (53/82), and a disease control rate of 85.37% (70/82). After treatment, the PFS at 1, 2, and 3 years were 39.0% (32/82), 22.1% (18/82), and 17.1% (14/82), respectively; the LC at 1, 2, and 3 years were 95.1% (78/82), 92.3% (76/82), and 92.3% (76/82), respectively; and the OS at 1, 2, and 3 years were 68.3% (56/82), 48.8% (40/82) and 31.7% (26/82), respectively. Nine patients suffered from radiation-induced liver disease (RILD), and there were no deaths due to RILD. Cox regression analysis showed that alpha-fetoprotein (AFP) was an independent risk factor for OS (HR=2.304, 95%CI 1.118-4.747;P<0.05). Conclusion: Cyberknife treatment for patients with primary large hepatocellular cancer over 70 years old has higher LC and OS, better curative effect, and less treatment-related adverse reactions.

[Application of moving epidemic method in establishing epidemic intensity threshold of hand, foot, and mouth disease in southern China]

Objective: To evaluate the incidence intensity of hand, foot, and mouth disease (HFMD) in 2018/2019 season in southern China by Moving Epidemic Method (MEM), and compare the intensity among provinces, so as to provide basis for optimizing the allocation of public health resources. Methods: The weekly incidence data of HFMD of children under 5 years old in 15 provinces of southern China from March 1, 2012 to February 28, 2019 were collected from Disease Surveillance Reporting System of Chinese Center for Disease Control and Prevention, and the epidemic intensity threshold of each province in southern China during this period was calculated and evaluated by MEM. Results: In the first incidence peak of 2018/2019 HFMD season, in 15 provinces in the south China, 6 provinces (Jiangsu, Zhejiang, Jiangxi, Chongqing, Sichuan and Yunnan) reported very high incidence rates in children under 5 years old while Guangdong, Guangxi and Hainan provinces had low incidence level. In the second incidence peak, the incidences in 6 provinces (Shanghai, Jiangsu, Zhejiang, Chongqing, Sichuan and Yunnan) reached very high levels. The incidences in remaining provinces also reached medium or high levels. In most provinces, the thresholds in the first incidence peak were higher than those in the second incidence peak, but Chongqing and Sichuan were different. The results of model validation showed that the sensitivity and specificity of MEM were higher than 70% except for Hainan, Chongqing and Yunnan. Conclusions: For southern provinces with two incidence peaks in HFMD season, MEM can be used to determine the epidemic intensity thresholds of different incidence peaks by dividing the disease season to analyze the incidence intensity of HFMD in different stages. The epidemic intensity threshold established by MEM integrates the historical data, and the province (city) with extremely high epidemic level identified represents that the province (city) has an abnormal increase compared with the historical incidence level, which requires more attention from all areas and timely implementation of prevention and control measures.

[Significance of micropapillary histopathological subtype of thyroid carcinoma]

Objective: To study the clinical and pathologic factors of papillary thyroid microcarcinoma (PTMC) and its significance as a histopathologic subtype of papillary thyroid carcinoma (PTC). Methods: A retrospective study of 719 patients with non-high-risk PTMC who underwent surgery for the first time in the Peking University People's Hospital from January 2007 to June 2019 was conducted, the relationship between clinicopathologic factors and lymph node metastasis, and the expression of four tumor markers CK19, HMBE1, Galectin-3 and CD56 by immunohistochemistry were evaluated. Some comparisons were made with PTC. Results: The peak patients' age was 40-49 years for both non-high-risk PTMC and PTC; the lymph node metastasis rate was higher in the 30-39 years age group than the 50-59 years age group (P<0.05); the lymph nodes metastasis rate was significantly higher for multiple lesions than for single lesion (P<0.05). Lymph node metastasis rate of PTMC with capsular invasion was significantly higher than those without (P<0.05). There was no significant correlation between lymph node metastasis of PTMC and patients' gender, tumor location, tumor size, and lymphocytic thyroiditis. The expression rates of CK19, HMBE1 and Galectin-3 both in PTMC and PTC were 100%, and the expression rates of CD56 were 25.6% (85/332) and 20.0% (70/350) respectively. Conclusion: As the main pathologic subtype of PTC, a variety of clinicopathologic factors of PTMC are related to lymph node metastasis, and it is highly recommended to pay close attention to PTMC. The expression of tumor marker CD56 alone cannot be used as a basis to exclude PTMC and PTC.

[Epidemiological characteristics of fatal cases of hand, foot, and mouth disease in children under 5 years old in China, 2008-2018]

Objective: To understand the epidemiological characteristics and risk factors of fatal cases of hand, foot, and mouth disease (HFMD) in children under 5 years old in China from 2008 to 2018, and provide evidence for the development of targeted prevention and control measures and reduction of the incidence of fatal HFMD cases. Methods: The incidence data of reported HFMD cases in China during 2008-2018 were collected from the National Notifiable Disease Surveillance Reporting System of China for the analyses on the demographic characteristics, spatial distribution, diagnosis or reporting and pathogen spectrum of the HFMD cases. Then the risk factors causing deaths were analyzed by using logistic regression model. Results: From 2008 to 2018, a total of 3 646 fatal cases of HFMD in children under 5 years old were reported in China. There were more fatal HFMD cases in boys than in girls (1.82∶1), the death mainly occurred in age group 0 to 2 years (87.71%). Adjusted mortality rate of HFMD in children under 5 years old in China declined from 0.87 per 100 000 in 2010 to 0.11 per 100 000 in 2018 (APC=-23.20%). In the 2 523 laboratory-confirmed deaths, 2 323 (92.07%) were EV-A71 infections, but the constituents of CV-A16 and other enterovirus infections increased. The interval from onset to diagnosis M=2(P(25)-P(75):2-4)d. The interval from onset to death M=3(P(25)-P(75):2-4)d. Age between 0 and 1 years, EV-A71 infection, longer interval between onset and diagnosis, and living in rural area were the risk factors causing fatal HFMD cases. Conclusions: The number of the fatal cases, the rate of mortality and case fatality HFMD in China had shown downward trends since 2010. EV-A71 is still the main pathogen causing fatal cases, but we should pay more attention to gene pattern of the other enteroviruses except EV-A71 and CV-A16. To reduce the risk of the fatal cases we should strengthen the health education about the immunization of EV-A71 inactivated vaccines and reduce the interval from onset to diagnosis in young children in western provinces and rural areas.

[A screening system for anti-metastatic small-molecule compounds based on perinucleolar compartment prevalence in liver cancer cells]

Objective: To establish a screening system for anti-metastatic small-molecule compounds based on perinucleolar compartment (PNC) prevalence in liver cancer cells and to investigate its validity. Methods: Polypyrimidine tract-binding protein (PTB) monoclonal antibody was used to measure the PNC prevalence in HepG2, HepG2M, and Huh7 cells, and wound healing assay and transwell assay were used to analyze the migration and invasion abilities of hepatoma cells. HepG2M cells were used as the model for the screening of anti-metastatic small-molecule compounds, and after the treatment with the compounds A1, A4, and E696, qPCR was used to measure the expression of metastasis-related miRNAs (miR-141 and miR-200c). A one-way analysis of variance was used for comparison of data between multiple groups. Results: PTB immunofluorescence assay showed that HepG2M cells had the highest PNC prevalence, followed by Huh7 and HepG2 cells, and PNC prevalence was positively correlated with the metastasis and invasion abilities of hepatoma cells. The PNC prevalence of HepG2M cells was reduced to 22.88% ±4.61% by A1, 14.22% ± 3.05% by A4, and 26.12% ± 4.94% by E696. Wound healing assay showed that the 48-hour scratch ratio increased from 17.70% ± 3.34% to 64.50% ± 2.65%, 83.40% ± 5.10%, and 57.20% ± 3.06% (F = 171.1, P < 0.01), respectively. Transwell assay showed that the number of invasive cells was reduced from 264.33 ± 30.50 to 104.33 ± 13.50, 58.00 ± 11.00, and 111.33 ± 19.50 (F = 59.87, P < 0.01), respectively. The anti-metastatic effect of these three compounds was positively correlated with their ability to destroy PNC. A4 upregulated the expression of miR-141 and miR-200c in a dose-dependent manner, and after HepG2M cells were treated with A4 at a concentration of 5 μM, 10 μM, or 20 μM, the level of miR-141 was increased to 3.61 ± 0.78, 8.12 ± 1.15, and 18.24 ± 2.44 folds (F = 88.01, P < 0.01), respectively, and that of miR-200c was increased to 2.82 ± 0.43, 4.82 ± 0.89, and 10.74 ± 1.22 folds (F = 87.94, P < 0.01), respectively. Conclusion: The screening system for anti-metastatic small-molecule compounds based on PNC prevalence can provide an effective technical platform for research and development of anti-metastatic drugs for liver cancer.

[Hospitalization burden of hand, foot and mouth disease in Anhua county of Hunan province, 2013-2016]

Objective: To estimate the serotype and age-specific hospitalization burden associated with hand, foot and mouth disease (HFMD) in Anhua county of Hunan province, between October 2013 and September 2016. Methods: We collected hospitalization records of HFMD patients from 6 virological surveillance hospitals, and reimbursement records through new rural cooperative medical system from 23 township health centers to estimate the age-specific hospitalization burden of HFMD in Anhua. Combined with the results of virological surveillance, the serotype-specific hospitalization burden of HFMD in Anhua, was estimated. Results: During the three years, it was estimated that 3 541 clinical diagnosed HFMD cases, including 3 146 laboratory-confirmed HFMD cases, were hospitalized in Anhua, but only one was diaguosed as being severe. The estimated average hospitalization rate was 723/100 000(95%CI: 699/100 000-747/100 000) for clinical diagnosed HFMD and 642/100 000 (95%CI: 620/100 000-665/100 000) for laboratory-confirmed HFMD between October 2013 and September 2016. The cases caused by Cox A16 (208/100 000) and Cox A6 (202/100 000) had higher hospitalization rates compared with the cases caused by EV71 (130/100 000), Cox A10 (38/100 000) and other enterovirus (64/100 000), and the difference was statistically significant (P<0.001). HFMD-associated hospitalization rates peaked in children aged 1 year (3 845/100 000), and then decreased with age. Compared with the hospitalized HFMD caused by EV71 and Cox A16, Cox A6-associated hospitalizations mainly occurred in younger age groups (P<0.001). Conclusion: Our study revealed a substantial hospitalization burden associated with mild HFMD caused by EV71, Cox A16, Cox A6 and Cox A10, especially in young children, in Anhua.

Evaluating Radiation in Combination with Hyperthermia Trials: The Importance of Clinical and Technical Parameters

A proper evaluation of hyperthermia and irradiation trials Is necessary to correctly interpret clinical results and to define limitations and properties of this new therapeutic approach. A better understanding of the « weight » of different technologic and clinical parameters that influence clinical response is thus clearly needed, particularly if future advances in hyperthermia technology and clinical results are to be expected. Patient variables, tumor variables, and treatment characteristics have been analyzed, and the difficulties of properly evaluating the « weight » of single parameters have been stressed. At the current state of knowledge, the Karnofsky index, site of disease (for regional heating), tumor status (recurrent versus metastatic disease) and XRT dose per fraction (for melanomas) seem to correlate with response. Tumor dimension, XRT total dose and thermal parameters reflecting the lowest tumor temperatures appear to statistically influence complete response rates of heated and irradiated tumors. In addition, a critical method of presenting results should be followed to enable comparison of data from different trials.

Strategic planning in an academic radiation medicine program

Background

In this paper, we report on the process of strategic planning in the Radiation Medicine Program (rmp) at the Princess Margaret Cancer Centre. The rmp conducted a strategic planning exercise to ensure that program priorities reflect the current health care environment, enable nimble responses to the increasing burden of cancer, and guide program operations until 2020.

Methods

Data collection was guided by a project charter that outlined the project goal and the roles and responsibilities of all participants. The process was managed by a multidisciplinary steering committee under the guidance of an external consultant and consisted of reviewing strategic planning documents from close collaborators and institutional partners, conducting interviews with key stakeholders, deploying a program-wide survey, facilitating an anonymous and confidential e-mail feedback box, and collecting information from group deliberations.

Results

The process of strategic planning took place from December 2014 to December 2015. Mission and vision statements were developed, and core values were defined. A final document, Strategic Roadmap to 2020, was established to guide programmatic pursuits during the ensuing 5 years, and an implementation plan was developed to guide the first year of operations.

Conclusions

The strategic planning process provided an opportunity to mobilize staff talents and identify environmental opportunities, and helped to enable more effective use of resources in a rapidly changing health care environment. The process was valuable in allowing staff to consider and discuss the future, and in identifying strategic issues of the greatest importance to the program. Academic programs with similar mandates might find our report useful in guiding similar processes in their own organizations.

[Surveillance data on typhoid fever and paratyphoid fever in 2015, China]

Objective: Through analyzing the surveillance data on typhoid fever and paratyphoid fever in 2015 to understand the related epidemiological features and most possible clustering areas of high incidence. Methods: Individual data was collected from the passive surveillance program and analyzed by descriptive statistic method. Characteristics on seasonal, regional and distribution of the diseases were described. Spatial-temporal clustering characteristics were estimated, under the retrospective space-time method. Results: A total of 8 850 typhoid fever cases were reported from the surveillance system, with incidence rate as 0.65/100 000. The number of paratyphoid fever cases was 2 794, with incidence rate as 0.21/100 000. Both cases of typhoid fever and paratyphoid fever occurred all year round, with high epidemic season from May to October. Most cases involved farmers (39.68%), children (15.89%) and students (12.01%). Children under 5 years showed the highest incidence rate. Retrospective space-time analysis for provinces with high incidence rates would include Yunnan, Guangxi, Guizhou, Hunan and Guangdong, indicating the first and second class clusters were mainly distributed near the bordering adjacent districts and counties among the provinces. Conclusion: In 2015, the prevalence rates of typhoid fever and paratyphoid fever were low, however with regional high prevalence areas. Cross regional transmission existed among provinces with high incidence rates which might be responsible for the clusters to appear in these areas.

[Recent studies on corneal epithelial barrier function]

Corneal epithelium, the outermost layer of eyeball, is the main route for foreign materials to enter the eye. Under physiological conditions, the corneal epithelial superficial cells form a functionally selective permeability barrier. Integral corneal epithelial barrier function not only ensures the enrolling of nutrients which is required for regular metabolism, but also prevents foreign bodies, or disease-causing microorganism invasion. Recently, a large number of clinical and experimental studies have shown that abnormal corneal epithelial barrier function is the pathological basis for many ocular diseases. In addition, some study found that corneal epithelial barrier constitutes a variety of proteins involved in cell proliferation, differentiation, apoptosis, and a series of physiological and pathological processes. This paper reviewed recent studies specifically on the corneal epithelial barrier, highlights of its structure, function and influence factors. (Chin J Ophthalmol, 2016, 52: 631-635).

Nickel oxide nanoparticles induced pulmonary fibrosis via TGF-β1 activation in rats

Nano nickel oxide (NiO), widely used in industry, has recently been discovered to have pulmonary toxicity. However, no subchronic exposure studies about nano NiO-induced pulmonary fibrosis have been reported. The objective of this study was to investigate pulmonary fibrosis induced by nano NiO and its potential mechanism in rats. Male Wistar rats ( n = 40, 200–240 g) were randomized into control group, nano NiO groups (0.015, 0.06, and 0.24 mg/kg), and micro NiO group (0.024 mg/kg). All rats were killed to collect lung tissue after intratracheal instillation of NiO particles twice a week for 6 weeks. To identify pulmonary fibrosis, Masson trichrome staining, hydroxyproline content, and collagen protein expression were performed. The results showed widespread lung fibrotic injury in histological examination and increased content of hydroxyproline, collagen types I and III in rat lung tissue exposed to nano NiO. To explore the potential pulmonary fibrosis mechanism, transforming growth factor beta 1 (TGF- β1) content was measured by enzyme-linked immunosorbent assay, and the messenger RNA expression of key indicators was detected by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The TGF- β1 content was increased in nano NiO exposure groups, as well as the upregulated gene expression of TGF- β1, Smad2, Smad4, matrix metalloproteinase, and tissue inhibitor of metalloproteinase. The findings indicated that nano NiO could induce pulmonary fibrosis, which may be related to TGF- β1 activation.

Building a New Model of Care for Rapid Breast Radiotherapy Treatment Planning: Evaluation of the Advanced Practice Radiation Therapist in Cavity Delineation

AIMS

Breast radiotherapy treatment is commonly managed by a multidisciplinary team to ensure optimal delivery of care. We sought a new model of care whereby a clinical specialist radiation therapist (CSRT) delineates the cavity target for whole breast radiotherapy treatment planning and the radiation oncologist validates the contour during final plan review. This study evaluated the radiation oncologist's acceptance of these contours and identified characteristics of cavities suitable for CSRT-directed contouring.

MATERIALS AND METHODS

Following specialised breast oncology education and training by the radiation oncologist, the CSRT prospectively delineated cavities in 30 tangential breast radiotherapy cases and consulted the radiation oncologist in 'complex' cases but directed 'non-complex' cases for treatment planning. Changes to CSRT contours were evaluated using the conformity index. Breast density, time since surgery and cavity location, size and visualisation score [CVS: range 1 (no visible cavity) to 5 (homogenous cavity)] were captured.

RESULTS

Of the 30 CSRT delineated cavities contours, the CSRT directed 20 (66.7%) cases for planning without radiation oncology review; 19 were accepted (without changes) by the radiation oncologist upon final plan review and one was changed by the radiation oncologist (conformity index = 0.93) for boost treatment and did not affect the tangential treatment plan. Ten (33.3%) cases, all CVS ≤ 3, were reviewed with the radiation oncologist before planning (conformity index = 0.88 ± 0.12). CVS was inversely correlated with breast density and cavity size (P < 0.01).

CONCLUSIONS

The CSRT delineated cavities appropriate for clinical radiotherapy treatment planning in women with well-visualised cavities, whereas 'complex' cases with dense breast parenchyma, CVS ≤ 3, and/or cases needing boost radiotherapy treatment required review with the radiation oncologist before planning.

Omission of Breast Radiotherapy in Low-risk Luminal A Breast Cancer: Impact on Health Care Costs

AIMS

The economic burden of cancer care is substantial, including steep increases in costs for breast cancer management. There is mounting evidence that women age ≥ 60 years with grade I/II T1N0 luminal A (ER/PR+, HER2- and Ki67 ≤ 13%) breast cancer have such low local recurrence rates that adjuvant breast radiotherapy might offer limited value. We aimed to determine the total savings to a publicly funded health care system should omission of radiotherapy become standard of care for these patients.

MATERIALS AND METHODS

The number of women aged ≥ 60 years who received adjuvant radiotherapy for T1N0 ER+ HER2- breast cancer in Ontario was obtained from the provincial cancer agency. The cost of adjuvant breast radiotherapy was estimated through activity-based costing from a public payer perspective. The total saving was calculated by multiplying the estimated number of luminal A cases that received radiotherapy by the cost of radiotherapy minus Ki-67 testing.

RESULTS

In 2010, 748 women age ≥ 60 years underwent surgery for pT1N0 ER+ HER2- breast cancer; 539 (72%) underwent adjuvant radiotherapy, of whom 329 were estimated to be grade I/II luminal A subtype. The cost of adjuvant breast radiotherapy per case was estimated at $6135.85; the cost of Ki-67 at $114.71. This translated into an annual saving of about $2.0million if radiotherapy was omitted for all low-risk luminal A breast cancer patients in Ontario and $5.1million across Canada.

CONCLUSION

There will be significant savings to the health care system should omission of radiotherapy become standard practice for women with low-risk luminal A breast cancer.

BTEX in vitro exposure tool using human lung cells: trips and gains

Cytotoxicity of benzene, toluene, ethylbenzene and xylenes (BTEX) to human lung cells was explored using three different exposure methods: Method 1 - in normal 96-well plates using DMSO as a carrier vehicle, we exposed (a) human lung carcinoma A549 cells, (b) A549 cells over-expressed with cytochrome P450 2E1 cells, and (c) normal lung fibroblast LL-24 cells to benzene, toluene, ethylbenzene and xylene individually and in a mixture which models car exhaust gases for between 1-88 h. We found that the order of the BTEX potency is benzene<toluene<ethylbenzene=m-xylene with acute BTEX toxicity to A549≈LL-24>CYP2E1 over-expressed A549 cells. A significant difference was found between inter-assay responses for all 24h exposures (P<0.005) suggesting a poor assay repeatability. No sign of potency increase was found from 6 to 72 h exposures. Method 2 - Using sealed vials to expose A549 cells to benzene, toluene and ethylbenzene, we observed a twenty-fold increase in their cytotoxicity, but also with no time-course effect. Method 3 - Using air exposed hanging-drop cell culture, we were able to see both an increase of demonstration of toxicity and a time-course effect from 1 to 12h exposure. We conclude that exposing cells in sealed and unsealed media using DMSO as a carrier vehicle was not suitable for BTEX exposure studies. Hanging-drop air exposure has more potential. It should be noted that if there are any changes in their exposure matrixes, its exposure mass distribution in cells could differ.

Biomarkers for the evaluation of population health status 16 years after the intervention of arsenic-contaminated groundwater in Xinjiang, China

The arsenicosis endemic area in the region of Kuitun and Chepaizi, Dzungaria district, Xinjiang, People Republic of China was the first identified arsenic endemic area in China where arsenic concentration of up to 850 μg/L in the groundwater was reported. An intervention was put in place in 1985 by government to provide an alternative water source at a centralized community level. Sixteen years on since the intervention, we evaluated the health status of 178 villagers from endemic and 179 villagers from control sites. Biomarkers in their urine, included arsenic, porphyrins and malondialdehyde (MDA) were measured and the prevalence of skin lesions was also assessed. The average urinary arsenic (117 ± 8.3 μg/g of creatinine) from the endemic-villages was significantly higher (p<0.001) than that of the controls (73.6 ± 3.2 μg/g of creatinine) while no significant difference was found in urinary porphyrins and malondialdehyde concentrations in the overall studies subjects from these two areas. However when the urinary arsenic was higher than 150 μg/g of creatinine, MDA and porphyrins were higher in the endemic-villagers compared to the controls. Fifty-one out of 178 people from the arsenic endemic area showed skin lesions related to arsenicosis but these were absent among villagers from the control site. Of particular concern, skin lesions related to arsenicosis were observed in 4 out of 9 subjects 16 years of age or younger who were from different villages and born after the completion of water intervention. Although sporadic exposure and/or voluntary drinking contaminated water were thought to be a contributor of arsenicosis after the water intervention, the contribution from other dietary arsenic intakes remain unclear.

Hanging drop: an in vitro air toxic exposure model using human lung cells in 2D and 3D structures

Using benzene as a candidate air toxicant and A549 cells as an in vitro cell model, we have developed and validated a hanging drop (HD) air exposure system that mimics an air liquid interface exposure to the lung for periods of 1h to over 20 days. Dose response curves were highly reproducible for 2D cultures but more variable for 3D cultures. By comparing the HD exposure method with other classically used air exposure systems, we found that the HD exposure method is more sensitive, more reliable and cheaper to run than medium diffusion methods and the CULTEX(®) system. The concentration causing 50% of reduction of cell viability (EC50) for benzene, toluene, p-xylene, m-xylene and o-xylene to A549 cells for 1h exposure in the HD system were similar to previous in vitro static air exposure. Not only cell viability could be assessed but also sub lethal biological endpoints such as DNA damage and interleukin expressions. An advantage of the HD exposure system is that bioavailability and cell concentrations can be derived from published physicochemical properties using a four compartment mass balance model. The modelled cellular effect concentrations EC50cell for 1h exposure were very similar for benzene, toluene and three xylenes and ranged from 5 to 15 mmol/kgdry weight, which corresponds to the intracellular concentration of narcotic chemicals in many aquatic species, confirming the high sensitivity of this exposure method.

Regional assessment of ambient volatile organic compounds from biopharmaceutical R&D complex

Biopharmaceutical R&D complexes are major emission sources of volatile organic compounds (VOCs), which may pose potential health risks for staff on site and residents nearby. In this paper health risk assessments were performed for the VOCs in the ambient air of a typical biopharmaceutical R&D complex in China. Results showed halogenated and alkyl compounds were dominant components among 24 major VOCs from 9 selected sampling sites, inside or around the complex. The principal component analysis (PCA) indicated VOCs were generated predominantly from the biopharmaceutical research activities (factor 1 (F1), 71.6%) and traffic vehicles (factor 2 (F2), 15.4%), which were confirmed by contour maps of five selected VOCs (benzene, toluene, chlorobenzene, methylene chloride and n-hexane) simulated by Golden Software Surfer. The cumulative cancer risks for the staff on site and residents nearby were investigated and results showed the risk value were 1.01E--5 and 2.03E--5, respectively, higher than the threshold value of 1.0E--6. These results indicated that elevated VOCs from biopharmaceutical R&D complex are potential risks to the public health. Furthermore, the human health risk assessment revealed that 1,2-dichloroethane, methylene chloride, carbon tetrachloride and benzene were the dominant risk contributors for staff on site, while methyl chloride, carbon tetrachloride, 1,2-dichloroethane and tetrahydrofuran for residents nearby. As a conclusion, this work suggests that proper control strategy should be taken for VOCs releasing to minimize the public health risks, especially for the halogenated compounds.

Overexpression of TNF-alpha and TNFRII in invasive micropapillary carcinoma of the breast: clinicopathological correlations

AIMS

Angiogenesis is essential for tumour growth and metastasis and tumour necrosis factor (TNF)-alpha is a potent angiogenic factor. Invasive micropapillary carcinoma of the breast (IMPC), a rare subtype of breast cancer, possesses a lymphotropic nature with a high incidence of lymph node metastasis and poor prognosis. The aim was to evaluate the role of TNF-alpha and its receptor TNFRII in the vascular development and metastasis of IMPC.

METHODS AND RESULTS

One hundred cases of IMPC and 97 cases of invasive ductal carcinoma, not otherwise specified (IDC) were studied in parallel by immunohistochemistry for TNF-alpha and TNFRII, and microvessel density (MVD) of the tumours was measured. The results showed that the expression of TNF-alpha and TNFRII and the MVD were higher in IMPC than in IDC (P < 0.05). In IMPC, MVD was significantly increased in those with lymph node metastasis compared with those without nodal metastasis (P = 0.001). TNF-alpha expression showed a significant positive correlation with the rate of proliferation, histological grade, lymph node metastasis and MVD (P < 0.05), whereas expression of TNFRII was correlated with TNF-alpha expression and the proliferation of tumour cells in IMPC (P < 0.05).

CONCLUSIONS

Expression of TNF-alpha and TNFRII might play an important role in the angiogenesis, tumour cell proliferation and metastasis of IMPC. These markers could represent new targets for therapeutic intervention, i.e. blocking of TNF-alpha and its signal transduction could be a promising tool for treatment.

Adenovirus-p53 gene therapy in human nasopharyngeal carcinoma xenografts

BACKGROUND

One major challenge to human cancer gene therapy, is efficient delivery of the gene-vector complex.

METHODS AND RESULTS

Using two distinct human nasopharyngeal carcinoma (NPC) models, we demonstrate that intra-tumoural (IT) administration of adenoviral-mediated wild-type p53 gene therapy (Ad-p53) caused no greater inhibition of tumour growth as compared to ionizing radiation (XRT) alone. Detailed histologic examination of tumour sections demonstrated that <15% of tumour cells were transduced by IT adv-beta-gal.

CONCLUSIONS

This report underscores the importance of developing gene transfer vectors, which can provide therapeutic levels of transgene expression efficiently in solid tumours.

[Application of wide-bore capillary gas chromatography in the synthesis of special esters of methacrylic acid]

A simple, rapid and accurate method for separating and analysing components in the synthesis of special esters of methacrylic acid by gas chromatography is reported. An SE-54 wide-bore capillary column of 50 m x 0.53 mm i.d. x 0.6 microns was used. The esters include dimethylaminoethyl methacrylate(DMAM), n-butyl methacrylate(BMA) and ethylene glycol dimethacrylate(EGDMA). Crude materials such as methyl methacrylate(MMA) and N, N-dimethyl ethanol amine (DMEA) were also analysed. The recoveries were 99.71%-102.89%, and the RSDs of the main components were below 0.1%. The method can be used to control the production of the esters.

Outcome of curative management of malignant tumours of the parotid gland

PURPOSE

The optimal management of malignant parotid gland tumours remains to be defined precisely. Specifically, a further understanding of the tumour features that influence treatment outcome is needed.

MATERIALS AND METHODS

A retrospective review was conducted on 184 patients who were registered at the Princess Margaret Hospital with a diagnosis of a primary malignant parotid gland tumour.

RESULTS

All patients were initially managed with a parotidectomy, and postoperative x-ray radiation therapy (XRT) was administered to 159 patients. The actuarial 5-year cause-specific survival and locoregional control rates were 76% and 81%, respectively. The survival and locoregional control rates for patients treated with surgery alone versus surgery plus postoperative XRT were not statistically different. A multiple regression analysis identified only age and tumour category to be independently significant prognostic factors for both survival and locoregional control.

CONCLUSION

We would recommend that patients with malignant parotid gland tumours be managed with parotidectomy, followed by postoperative XRT for tumours with residual disease, aggressive histology, and/or positive lymph nodes.

The benefits and pitfalls of ipsilateral radiotherapy in carcinoma of the tonsillar region

PURPOSE

Ipsilateral techniques designed to restrict treatment to the primary tumor and neck on the same side have been used in selected cases of cases of carcinoma of the tonsillar region at our institution for many years. The primary purpose of this study is to evaluate the risk of failure in the opposite neck in cases selected for unilateral radiotherapy over a 21-year period.

METHODS AND MATERIALS

Ipsilateral radiotherapy techniques were used in 228 of 642 patients with carcinoma of the tonsillar region from 1970 to 1991. Local control, regional lymph-node control (including contralateral failure), and survival were calculated for different degrees of tumor extent treated with these techniques.

RESULTS

Mean follow-up was 7 years. Cases tended to be T1 and T2, with N0 disease. The 3-year actuarial local control rate was 77% and cause-specific survival was 76%. Opposite neck failure was seen in 8 patients (crude rate of 3.5%). In the earlier period of the study, primary coverage was problematic in a proportion of cases and resulted in higher rates of local failure.

CONCLUSION

Appropriately selected cases of carcinoma of the tonsil show minimal risk of failure in the opposite neck with ipsilateral techniques. Patients should undergo computed tomography planning to ensure adequate target coverage.

A comparison of published head and neck stage groupings in carcinomas of the tonsillar region

BACKGROUND

The combination of T, N, and M classifications into stage groupings was designed to facilitate a number of activities including: the estimation of prognosis and the comparison of therapeutic interventions among similar groups of cases. The authors tested the UICC/AJCC 5th edition stage grouping and seven other TNM-based groupings proposed for head and neck cancer to determine their ability to meet these expectations in a specific site: carcinoma of the tonsillar region.

METHODS

The authors defined four criteria to assess each stage grouping scheme: 1) The subgroups defined by T and N comprising a given group within a grouping scheme have similar survival rates (hazard consistency); 2) The survival rates differ across the groups (hazard discrimination); 3) The prediction of cure is high (outcome prediction); and 4) The distribution of patients among the groups is balanced. The authors identified or derived a measure for each criterion and the findings were summarized using a scoring system. The range of scores was from 0 (best) to 7 (worst). Data were from a retrospective chart review on 642 cases of carcinoma of the tonsillar region treated with radiotherapy for cure at the Princess Margaret Hospital from 1970-1991. None of the patients had distant metastases.

RESULTS

The scheme proposed by Synderman and Wagner, which was published in Otolaryngology Head and Neck Surgery in 1995 (vol.112, pages 691-4), scored best at 1.2. The UICC/AJCC scheme scored worst at 6.1. The hazard consistency ranged from a 3.1% average survival difference to 6.7% across the 8 schemes. The hazard discrimination measure varied by 28% from the best to worst scheme. Prediction varied by up to almost twofold across the schemes assessed. The distribution of patients varied from expected by between 0.13% and 0.57%.

CONCLUSION

UICC/AJCC stage groupings were defined without empirical investigation. When tested, this scheme did not perform as well as any of seven empirically-derived schemes the authors evaluated. The results of the current study suggest that the usefulness of the TNM system can be enhanced by optimizing the design of stage groupings through empirical investigation.

The role of protein kinase B (PKB) in modulating heat sensitivity in a human breast cancer cell line

PURPOSE

Protein kinase B (PKB) is a critical mediator of phosphoinositide 3-kinase-dependent survival signals in mammalian cells. Its activity is induced after heat shock, and is inhibited in cells undergoing apoptosis. We hypothesized that PKB may be an important modulator for heat-induced apoptosis in human cancer cells.

METHODS AND MATERIALS

MCF-7 cells were transfected using four different plasmids, encoding a kinase-dead mutant PKB-AAA, a constitutively activated mutant PKB-DD, wild-type PKB, and the neomycin-resistant selection gene. These stable transfectants were subjected to heat shock, and assessed for PKB phosphorylation, PKB activity, and likelihood of undergoing apoptosis.

RESULTS

After heating to 45 degrees C x 30 mins, 25% of MCF-7/neo transfectants underwent apoptosis, which increased to 38% in the presence of wortmannin (WT), an inhibitor of phosphoinositide 3-kinase. In contrast, 23% of the constitutively activated MCF-7/DD transfectants underwent apoptosis, minimally affected by WT. Heat-induced apoptosis occurred in 34% of the kinase-dead MCF-7/AAA transfectants, which increased further to 58% with the addition of WT. This in turn was associated with a two-fold reduction in clonogenic survival compared to the MCF-7/neo transfectants.

CONCLUSION

Heat shock activation of PKB in human MCF-7 cells appears to be a significant modulator of heat-induced apoptosis and survival. Further understanding of this important pathway may offer potential in developing novel strategies in cancer therapy.

Cisplatin chemotherapy plus adenoviral p53 gene therapy in EBV-positive and -negative nasopharyngeal carcinoma

We have previously shown that the introduction of human recombinant wild-type p53 mediated by an adenoviral vector (Ad5CMV-p53), either alone or delivered in combination with ionizing radiation, was cytotoxic to two nasopharyngeal carcinoma (NPC) cell lines. To further explore the potential therapeutic role for gene therapy, the combination of Ad5CMV-p53 and cisplatin was examined in two NPC cell lines, CNE-1 and C666-1. The C666-1 cells are particularly relevant because they express Epstein-Barr virus latent gene products analogous to human NPC in situ. Cells were infected with 5 pfu/cell of Ad5CMV-p53 or Ad5CMV-beta-gal, followed by exposure to increasing doses of cisplatin. Clonogenic and MTT assays were used to assess the sensitivity of cells to these treatments, and apoptosis was also quantified. The combination of Ad5CMV-p53 and cisplatin resulted in approximately 25% greater cytotoxicity compared to that observed with cisplatin alone in either cell line. Apoptosis was induced in approximately 50% of cells following administration of both Ad5CMV-p53 and cisplatin, but was induced in considerably fewer cells following either treatment alone. The two modalities appeared to interact in an additive manner. Ad5CMV-p53 gene therapy resulted in the expression of biologically active p53 protein, shown by induction of p21(WAF1/CIP1). Cisplatin treatment showed little effect on either p53 or p21(WAF1/CIP1) expression. Therefore, both p53 gene therapy and cisplatin chemotherapy demonstrated cytotoxicity mediated by apoptosis despite the presence of EBV gene products in the C666-1 cells, but it appears that the two modalities induce cytotoxicity by independent pathways.

Carcinoma-in-situ of the glottic larynx: results of treatment with radiation therapy

PURPOSE

Carcinoma-in-situ (CIS) of the vocal cords frequently progresses to invasive disease if untreated. Treatment approaches include vocal cord stripping, radiation therapy (RT), and laser excision. The purpose of this analysis was to assess the efficacy and safety of a standard RT regimen in the treatment of this condition.

METHODS AND MATERIALS

Between January 1980 and December 1994, 67 patients (52 men, 15 women; median age, 65 years) with glottic CIS were treated with RT. The standard RT regimen was 51 Gy in 20 fractions given over 4 weeks (99% of patients). Prior to receiving RT, 21 patients (31%) had undergone 1 or 2 vocal cord stripping procedures, and 1 had been treated with laser.

RESULTS

With a median follow-up of 6.5 years, 1 patient developed invasive glottic cancer, giving a 5-year actuarial local control rate of 98%. This patient recurred 14 months after treatment and was salvaged with laryngectomy. He is currently free of disease 2 years after surgery. There were no serious acute or late treatment complications. Sixteen patients (24%) developed subsequent malignancies, 8 of these being in the upper aerodigestive tract, although none were in the radiation field.

CONCLUSIONS

Moderate-dose radiation therapy is an effective treatment for glottic CIS. It is well tolerated, produces no serious acute or long-term side effects, with an excellent cure rate.

Potential molecular prognostic markers in head and neck squamous cell carcinomas

BACKGROUND

Current management strategies for squamous cell carcinoma of the head and neck (HNSCC) rely on an understanding of the natural history of the disease, along with the use of prognostic factors to guide selection of appropriate treatment. However, it is recognized that tumor heterogeneity limits the reliable use of currently available prognostic markers. With the evolving understanding of the genetic and molecular basis of human malignancies, there has been much interest in determining whether specific molecular changes in HNSCC might guide treatment decisions.

METHODS

A literature review of potential molecular markers relevant to HNSCC was undertaken and evaluated. It is evident that the published information is promising but, oftentimes, limited by a scarcity of large, uniformly staged and treated patients, from which the value of novel molecular markers can be assessed.

RESULTS

On the basis of the review of more than 100 articles, some of the emerging molecular markers that might provide independent prognostic information include epidermal growth factor receptor (EGFR), transforming growth factor-alpha (TGF-alpha), cyclin D1, and p53. This review will discuss the current status of these molecular factors and consequent implications for novel therapeutic approaches for patients with HNSCC.

CONCLUSION

With the evolving understanding that human malignancies have developed and progressed on the basis of accumulated molecular abnormalities, there is an existing body of work trying to determine whether such abnormalities can predict clinical behavior of HNSCC. Such studies have to be conducted rigorously to derive useful information. Nevertheless, the role of such molecular markers, and the possibility to exploit them for therapeutic gain, is already at the horizon.

Adenoviral p53 gene therapy promotes heat-induced apoptosis in a nasopharyngeal carcinoma cell line

BACKGROUND

It has previously been demonstrated that Ad5CMV-p53 gene transfer, either used alone or delivered concomitantly with ionizing radiation, resulted in cytotoxicity mediated by apoptosis in nasopharyngeal carcinoma (NPC) cell lines. In this study, a novel approach was evaluated of combining Ad5CMV-p53 gene therapy with hyperthermia (HT), in the CNE-1 NPC cell line, which harbours a mutation in codon 249 of the p53 gene.

MATERIALS AND METHODS

CNE-1 cells were infected using either Ad5CMV-p53 or Ad5CMV-B-gal, followed, 24 h later, by HT (43 degrees C x 0-2 h). Protein was extracted for Western blot analysis, and apoptosis was evaluated using acridine-orange ethidium bromide staining, followed immediately by fluorescent microscopy examination for the proportion of cells displaying morphologic features of apoptosis.

RESULTS

Ad5CMV-p53 gene therapy combined with HT resulted in a dose-dependent cytotoxicity with less than 1% clonogenic survival when 10 pfu/cell of Ad5CMV-p53 was combined with 2 h heating at 43 degrees C. Western blotting demonstrated that treatment with Ad5CMV-p53 resulted in the rapid expression of p53, which was minimally affected by HT. The inducible form of hsp70 was maximally expressed at 48 h post-HT, with minimal effect when cells were additionally treated with Ad5CMV-p53. Clonogenic cytotoxicity was associated with the development of apoptosis, with up to 70% of CNE-1 cells displaying morphologic features of apoptosis after the combination treatments.

CONCLUSION

Based on the shapes of the clonogenic survival curves, Ad5CMV-p53 gene therapy and HT appear to interact in an additive manner, suggesting the therapeutic potential of this combined treatment approach for patients with NPC.

Heat-directed gene targeting of adenoviral vectors to tumor cells

Targeting therapeutic gene expression to tumor cells represents a major challenge for cancer gene therapy. The strong transcriptional response exhibited by heat shock genes, along with the beneficial therapeutic effects of hyperthermia have led us to develop a heat-directed gene-targeting strategy for cancer treatment. Heat shock gene expression is mediated in large part by the interaction of heat shock factor 1 with specific binding sites (heat shock elements; HSE) found in the promoters of heat-inducible genes. Here we present a quantitative analysis of heat-inducible gene expression mediated by the wild-type hsp70b gene promoter, as well as a modified hsp70b promoter containing additional HSE sequences. Beta-galactosidase (beta-gal) expression was induced between 50- and 800-fold in a panel of human breast cancer cell lines infected with an adenoviral vector containing the wild-type hsp70b promoter (Ad.70b.betag) following treatment at 43 degrees C for 30 minutes. Infection with an adenoviral vector containing the modified hsp70b promoter (Ad.HSE.70b.betag) resulted in a 200- to 950-fold increase in beta-gal expression under the same conditions, and also provided a 1-2 degrees C decrease in the threshold of activation. Significant increases in the heat responsiveness of the Ad.HSE.70b.betag construct were observed in five of six tumor cell lines tested, as well as under thermotolerant conditions. Finally, we demonstrate that localized heating of a HeLa cell xenograft can effectively target beta-gal gene expression following intratumoral injection of Ad.70b.betag. Adenoviral vectors incorporating heat-inducible therapeutic genes may provide useful adjuncts for clinical hyperthermia.

Carcinoma of the maxillary antrum: a retrospective analysis of 110 cases

BACKGROUND AND PURPOSE

Cancer of the maxillary antrum is a rare disease with a variety of treatment options. The present study was undertaken to review the outcome of patients with carcinoma of the maxillary antrum managed at a single institution.

MATERIALS AND METHODS

A retrospective analysis of 110 cases of carcinoma of the maxillary antrum managed with curative intent during the time period 1976-1993 was performed. There were 33 females and 77 males; the median age was 64 years (range 38-89). The median follow-up time was 4 years (range from 2 months to 17 years). The majority of patients presented with locally advanced disease (78 T4 tumours); nodal involvement was observed in 17/110 cases. Histologic subtypes included in the analysis were limited to squamous cell carcinoma (95 cases) and undifferentiated carcinoma (15 cases). Patients were managed with either primary radiation therapy with surgery reserved for salvage (83/110) or with a planned combined approach with surgery and either pre or postoperative radiation (27/110).

RESULTS

The actuarial 5-year cause-specific survival rate was 43%. The 5-year local control rate was 42%. Of 63 patients with local failure, 25 underwent salvage surgery with a subsequent 5-year cause-specific survival of 31%. Multiple regression analysis of patient, disease and treatment related variables identified local disease extent and nodal disease at presentation as the only variables independently associated with cause-specific survival.

CONCLUSIONS

This analysis indicates that survival from carcinoma of the maxillary antrum is poor with outcome strongly related to local disease extent. The best treatment strategy for this disease remains undefined. Salvage surgery can result in prolonged survival in selected patients experiencing local failure.

Evaluation of major active components in St. John's Wort dietary supplements by high-performance liquid chromatography with photodiode array detection and electrospray mass spectrometric confirmation

A RP-HPLC method with photodiode array detection and LC-electrospray ionization (ESI) MS confirmation was established for the determination of major active components in St. John's Wort dietary supplement capsules. The samples alternatively were extracted with ethanol-acetone (2:3) using a 55 degrees C water-bath shaker or an ambient temperature ultrasonic bath. Extracts were separated by RP-C18 chromatography using a 95-min water-methanol-acetonitrile-trifluoroacetic acid gradient. The major components were identified by photodiode array detection and then confirmed by LC-ESI-MS. The quantification of components was performed using an internal standard (luteolin). This method may serve as a valuable tool for the quality evaluation of St. John's Wort dietary supplement products.

Optimization of extraction conditions for active components in Hypericum perforatum using response surface methodology

Optimal conditions for extraction of Hypericum perforatum were determined using response surface methodology. A 3 x 4 x 4 full factorial design representing three extraction temperatures, four extraction times, and four solvent concentrations was executed. The overall extraction efficiency was defined by comparing either the total extractable material weight or the individual component peak area to the peak area of luteolin as internal standard. Of the tested variables, the extraction temperature most significantly affected extraction efficiency. Higher temperatures gave better extraction efficiencies, but high temperature also caused decomposition of hypericin. Within the test range, responses for most variables had local maxima. Optimum ranges of time and concentration for individual variables were overlaid. Considering all variables, optimum ranges for extraction time and extraction solvent concentration (percent ethanol in acetone) were 5.0-6.7 h and 44-74% at 23 degrees C, 5.4-6.9 h and 45-72% at 40 degrees C, and 5.3-5.9 h and 44-69% ethanol in acetone at 55 degrees C, respectively.

Liquid chromatographic analysis of incurred amoxicillin residues in catfish muscle following oral administration of the drug

Improper application of antibiotic chemicals to livestock and aquaculture species may lead to the occurrence of residues in food supplies. An appropriate depletion period is needed after the administration of drugs to animals for ensuring that residues in edible tissues are below established tolerance levels. This study was conducted to determine incurred amoxicillin residues in catfish muscle following oral administration. Dosed fish were harvested after four depletion periods, and muscle fillets were analyzed for amoxicillin residues using an HPLC method with precolumn derivatization and fluorescence detection. The residue levels in fish after a 6-h depletion ranged from 40 to 64 ng/g with one exception at 297 ng/g. Average residue levels decreased to 5.4 and 2. 8 ng/g after 24- and 48-h depletions, respectively. Residue levels after a 72-h depletion decreased to below the method's limit of quantitation (1.2 ng/g). An LC-MS/MS confirmatory method was developed. Confirmation of the presence of amoxicillin was demonstrated in incurred fish samples containing residues at approximately 50-300 ng/g.

A phase II study of Biotene in the treatment of postradiation xerostomia in patients with head and neck cancer

One of the major side effects of radical radiation therapy for head and neck malignancies is xerostomia, or dryness of the mouth. There is no clearly effective treatment for this condition, but we have observed that patients in our practice believe that their symptoms improve significantly when using two "over-the-counter" oral comfort products - Biotene (toothpaste, mouthwash and chewing gum) and Oralbalance gel. We decided to study these agents in a formal phase II study to evaluate their usefulness in patients with postirradiation xerostomia. Twenty-eight patients with post-irradiation xerostomia were entered on the study. All had biopsy-proven carcinoma of the nasopharynx, oropharynx, oral cavity, hypopharynx or larynx, and had received primary radiotherapy with curative intent (> or =50 Gy in 20 fractions) more than 4 months before study entry. More than 75% of both parotid glands were included in the primary radiation field. There was no clinical evidence of recurrent disease. Patients were provided with a 2-month supply of Biotene mouthwash, toothpaste, chewing gum and Oralbalance gel. Response was evaluated 1 and 2 months after study entry using a patient-completed visual analogue scale to assess the severity of xerostomia and its effects on quality of life. For analysis, the scored baseline was subtracted from the later scores to assess change. Patients with an increase of 10 mm from their baseline score on the visual analogue scale were classified as having responded to the treatment intervention, and those with an increase of > or =25 mm from their baseline score were classified as having experienced a major improvement in their symptoms. After 2 months of treatment, 15 patients (54%) reported an improvement in intraoral dryness and 10 of these patients (36%) reported a major improvement. Similar proportions of patients (46% some improvement, 25% major improvement) reported an improvement in their ability to eat normally. Seventeen patients (61%) reported an improvement in oral discomfort, and 12 of these (43%) had a major improvement in their symptoms. The results of this study suggest that the use of Biotene (mouthwash, toothpaste and chewing gum) and Oralbalance gel can improve many of the symptoms of radiation-induced xerostomia. A placebo effect could account for many of the observed improvements in symptoms, and in order to assess the role of these agents in the management of patients with postirradiation xerostomia a randomised phase III study is needed.

Inhibition of protein kinase C activity promotes heat-induced apoptosis in RIF-1 but not in TR-4 cells

PURPOSE

Inhibition of protein kinase C (PKC) activity has been demonstrated to reduce thermotolerance (TT), presumably by decreasing heat shock protein (HSP) production. Therefore, the interest was in evaluating this relationship further in two isogenic murine tumour cell lines: RIF-1 and its thermoresistant TR-4 selectant.

MATERIALS AND METHODS

TT was induced in RIF-1 and TR-4 cells (45 degrees C for 15 min, then 37 degrees C for 6 h) with or without Ro31-8220, a specific inhibitor of PKC. PKC activity was assayed by determining the catalytic transfer of ATP to a specific substrate peptide. Survival was determined using the clonogenic assay. Apoptosis was quantitated by counting the number of cells demonstrating apoptosis after staining with acridine-orange/ ethidium bromide. Production of the inducible form of HSP70 was assessed using Western blot.

RESULTS

At 2 microM Ro31-8220, >80% of PKC activity was inhibited in both cell lines, which was associated with no cytotoxicity at 37 degrees C. Basal HSP70 level was approximately 10-fold higher in the TR-4 compared with the RIF-1 cells. Upon TT induction, HSP70 level increased significantly in both cell lines, which was suppressed in the presence of Ro31-8220, but the relative amount of HSP70 remained high in the TR-4 cells. At 24 h, heat-induced apoptosis increased from 4 to 38% in RIF-1 cells in the presence of Ro31-8220, which was associated with a 26% reduction in clonogenic survival after thermotolerant heating. In contrast, <1% of TR-4 cells demonstrated apoptosis even with the highest dose of Ro31-8220, and no effect on survival was observed.

CONCLUSION

Inhibition of PKC activity reduces HSP70 induction, which in turn is associated with promotion of heat-induced apoptosis in RIF-1 cells. However, the survival signals in the TR-4 cells are so strong, that even 80% inhibition of PKC activity has minimal impact on heat-induced apoptosis and survival in this thermoresistant cell line.

The effects of combining ionizing radiation and adenoviral p53 therapy in nasopharyngeal carcinoma

PURPOSE

Nasopharyngeal carcinoma (NPC) is a malignant disease of the head/neck region, with a 5-year survival level of approximately 65%. To explore gene therapy as a novel approach which might improve outcome, we have shown previously that introduction of human recombinant wild-type p53 mediated by the adenoviral vector (Ad5CMV-p53) was cytotoxic in two human nasopharyngeal carcinoma (NPC) cell lines (CNE-1 and CNE-2Z). The current work was designed to determine whether this strategy, combined with ionizing radiation (XRT), was more effective than either treatment alone.

METHODS AND MATERIALS

CNE-1, CNE-2Z, and a normal human nasopharyngeal fibroblast strain, KS1, were infected with 2- and 6-plaque-forming units (pfu)/cell of Ad5CMV-p53, respectively. These doses were isoeffective for beta-galactosidase activity in the CNE-1 and CNE-2Z cells. XRT was administered 24 h post-infection, and Western blot analyses were conducted for p53, p21WAF1/CIP1, bax, and bcl-2 2 days after XRT. Cell survival was assessed using a clonogenic assay. Presence of DNA ladders reflecting apoptosis was detected using DNA agarose gel electrophoresis, and cell cycle was analyzed using flow cytometry.

RESULTS

The combination of Ad5CMV-p53 plus XRT (2, 4, and 6 Gy) resulted in an approximately 1-log greater level of cytotoxicity compared to that observed with XRT alone for both NPC cell lines. The two modalities appear to be interacting in a synergistic manner in cancer cells, but not in KS1 fibroblasts. XRT alone stimulated minimal p53 expression in control cells; Ad5CMV-p53 alone induced significant recombinant p53 expression, which was not further enhanced by the addition of XRT. Similar observations were made for p21WAF1/CIP1 expression. No changes were observed for bax or bcl-2 expression with any of these treatments. Apoptosis was induced following 4 Gy of XRT alone, but was observed after only 2 Gy when combined with Ad5CMV-p53. Cell cycle analysis indicated that Ad5CMV-p53 infection did not perturb the cell cycle beyond that observed with XRT alone.

CONCLUSION

p53 gene therapy and XRT appears to interact in a synergistic manner; underscoring the significant potential of this novel strategy in the treatment of NPC.