Identification and Automated Delineation of Radioresistant Biological Tumor Volume in Nasopharyngeal Carcinoma Based on Magnetic Resonance Imaging Radiomics

PURPOSE/OBJECTIVE(S)

Widespread use of intensity modulated radiotherapy (IMRT) has improved the tumor control rate of nasopharyngeal carcinoma (NPC). However, nearly 20% of the patients with local-advanced NPC would relapse after precise irradiation and 80% of the recurrent lesions occur within the high dose field, suggesting that there are radiation-resistant cancer cell subsets within the tumor. In this context, identification and contouring of radiation resistance region of NPC for dose escalation at primary IMRT could be advantageous. In this work, we proposed a two-step radiomics workflow to predict local relapse and the recurrent region of NPC before primary IMRT.

MATERIALS/METHODS

In this single-center, retrospective study, pre-treatment magnetic resonance (MR) sequences of T1-weighted imaging (T1-w) and contrast-enhanced T1-weighted imaging (CET1-w) were collected from 800 patients of newly diagnosed and non-metastatic NPC between April 2009 and December 2015. The primary gross tumor volume (GTVp) of all patients and the actual recurrent lesion (GTVr) of patients who suffered from local recurrence were manually contoured for further analysis. A two-step complete radiomics workflow was designed to predict tumor recurrence and segment the region. First, least absolute shrinkage and selection operator (LASSO) was utilized for radiomics features selection of GTVp and support vector machine (SVM) was adopted to predict the recurrence. If the model predicts a recurrence, then the workflow utilizes an improved 3D U-Net to segment the recurrent region. Area under receiver operating characteristic curve (ROC-AUC) was used to evaluate the performance of tumor recurrence prediction, and Dice similarity coefficient (DSC) was used to assess the consistence between the actual and predicted GTVr.

RESULTS

Of 800 NPC patients, 95 (11.9%) patients developed in-field local recurrence. For recurrence risk prediction, the SVM ensemble model (T1-w+CET1-w) was selected for further application with higher sensitivity. The average ROC-AUC, specificity, sensitivity of the SVM ensemble model in a 5-fold cross-validation and in the independent test set of 160 patients were 0.922, 0.922, 0.777 and 0.928, 0.915, 0.737, respectively. Moreover, for recurrent region segmentation, the multi-modality (T1-w+CET1-w) model was superior to the single-modality (T1-w or CET1-w) model. In an independent test set of 15 patients, the DSC, sensitivity and 95% Hausdorff Distance between actual and predicted GTVr was 0.549±0.176, 0.696±0.118 and 9.813±4.788 which was superior to 0.444±0.188, 0.497±0.218 and 12.047±5.361 of original 3D U-Net.

CONCLUSION

The proposed two-step radiomics workflow showed a good performance in predicting tumor recurrence of NPC. The predicted location of the recurrence lesion was all accurate, but there was still a certain difference between the volume of the automated delineated and actual GTVr, which needed to be further optimized to be used as biological tumor volume.

Corrigendum: Comparative proteomics analysis of Schistosoma japonicum developed in different Oncomelania snails as intermediate hosts

[This corrects the article DOI: 10.3389/fcimb.2022.959766.].

Comparative proteomics analysis of Schistosoma japonicum developed in different Oncomelania snails as intermediate hosts

Schistosomiasis is a tropical parasitic disease that seriously endangers humans and animals. In this study, two Oncomelania snails, Oncomelania hupensis (O. hupensis) and Oncomelania weishan (O. weishan), were infected with Schistosoma japonicum (S. japonicum) cercariae during the early period, and ICR mice were subsequently infected with two kinds of miracidia that developed in male and female adult worms. In this study, isobaric tags for relative and absolute quantification (iTRAQ) were used to identify four channels: 113, 115, 117, and 119. A total of 2364 adult schistosome proteins were identified, and 1901 proteins were quantitative. Our results revealed 68 differentially expressed proteins (DEPs) in female adult worms, including 24 upregulated proteins and 44 downregulated proteins, and 55 DEPs in male adult worms, including 25 upregulated proteins and 30 downregulated proteins. LC-MS/MS and bioinformatics analysis indicated that these DEPs are mainly concentrated in cellular composition, molecular function, biological function and catabolism pathways. In summary, this proteomics analysis of adult schistosomes that hatched in two intermediate hosts helps to improve our understanding of the growth and developmental mechanisms of S. japonicum.

Analysis of Epidemiological Changes and Prevention Effects for Malaria in Weifang, Shandong Province, China from 1957 to 2017

Background

We aimed to conduct a retrospective analysis of the epidemiological changes and prevention effects for malaria in Weifang, Shandong Peninsula, China from 1957 to 2017.

Methods

The malaria data from a web-based reporting system were analyzed to explore malaria epidemiological characteristics and prevention effects in Weifang.

Results

Overall, 1, 704, 890 malaria cases were reported in Weifang from 1957 to 2017, of which two major malaria epidemics occurred in 1961 (827.28/10, 000) and 1971 (366.14/10, 000). Prior to 1997, all malaria patients (1, 704, 829) were infected with Plasmodium vivax (P. vivax). After 2007, the cases of Plasmodium falciparum (P. falciparum) showed an upward trend (76.8%). The reported cases after the 21st century were mainly imported cases, and the last indigenous case was a patient that infected with P. vivax in 2006. Overall, 36 imported cases were reported from 2010 to 2017, of which 88.9% were acquired in Africa. Except for one 32-year-old woman, the rest were male (97.2%), in which laborers and farmers represented the vast majority (66.6%). From 1987 to 2017, there were 1, 224, 474 cases of fever with blood tests, and the average blood test rate was 4.9%. From 1957 to 2017, a total of 1, 704, 890 malaria patients were treated, 96 cases were treated during resting phase from 1987 to 2017.

Conclusion

Weifang should continue to strengthen the management of the migrant population, making blood tests for fever patients and patient treatment as important means of malaria control and monitoring.

Hierarchical Construction of Higher-Order Exceptional Points

The realization of higher-order exceptional points (HOEPs) can lead to orders of magnitude enhancement in light-matter interactions beyond the current fundamental limits. Unfortunately, implementing HOEPs in the existing schemes is a rather difficult task, due to the complexity and sensitivity to fabrication imperfections. Here we introduce a hierarchical approach for engineering photonic structures having HOEPs that are easier to build and more resilient to experimental uncertainties. We demonstrate our technique by an example that involves parity-time symmetric optical microring resonators with chiral coupling among the internal optical modes of each resonator. Interestingly, we find that the uniform coupling profile is not required to achieve HOEPs in this system-a feature that implies the emergence of HOEPs from disorder and provides resilience against some fabrication errors. Our results are confirmed by using full-wave simulations based on Maxwell's equation in realistic optical material systems.

Elimination of Lymphatic Filariasis in Shandong Province, China, 1957-2015

China used to be one of the most heavily endemic countries for lymphatic filariasis (LF) in the world. Bancroftian filariasis, which is caused by the filarioid nematode Wuchereria bancrofti, is the only filariasis in Shandong Province. A total of 864 endemic counties (cities) in 16 provinces/autonomous regions/municipalities with a total population of 330 million people were at risk of infection. Shandong Province was a highly LF-endemic area in the 1950s, the epidemiological investigation of LF conducted in 1957 indicated that the disease was endemic in 74 counties and the highest microfilaria rate was up to 26%. There were ∼5 million people in the province infected with LF; among which almost 2.5 million people had lymphedema, elephantiasis, or hydrocele. Through vigorous prevention and scientific research, Shandong Province was the first to propose to treat LF with fortified diethylcarbamazine salt, more than 25 million people in the province had taken the salt, and more than 3 million people took intermittent medication. After more than 50 years of unremitting efforts, Shandong Province basically eliminated LF in 1983 and became the first province in China that successfully eradicated LF in 2004, which has played an important role in accelerating the elimination of filariasis in the country in 2007 and has made tremendous contributions to social and economic development of China. Since 1980, Shandong Province has carried out extensive international cooperation as the WHO Collaborating Center for Lymphatic Filariasis. This article is intended to share the experience in eliminating LF to other parts of the world and improve public health capacity in regions such as Africa and Oceania where the disease is still endemic for interest.

Toward the Elimination of Malaria in China: A Retrospective Analysis of Malaria-Endemic Characteristics and Prevention Effects in Yantai, Shandong Province, 1951 to 2017

Objectives: To study the epidemiological characteristics of malaria and the effects of comprehensive malaria control implementation in Yantai, as well as to provide a scientific basis for future malaria elimination. Materials and Methods: A retrospective analysis was conducted to explore the epidemiological changes and prevention effects in Yantai from 1951 to 2017. The malaria data before 2004 were collected from paper-based annual reports, and data after 2004 came from the Infectious Diseases Information Reporting Management System. Results: A total of 81,286 malaria cases were identified in Yantai from 1957 to 2017, with two peaks occurring in 1966 (120.93/100,000) and 1970-1972 (366.12/100,000). From 1951 to 2003, the case classification was mainly Plasmodium vivax (99.80%); the first case attributed to Plasmodium falciparum occurred in 2004, and P. falciparum became the main cause of malaria after 2011. All cases reported since 2010 have been imported cases, and the last indigenous case was caused by P. vivax in 2008. A total of 129 imported cases were reported from 2010 to 2017, most of which originated in Africa (93.80%), mainly in men aged 30-49 years (68.28%). From 1951 to 1973, 73,868 cases of malaria were diagnosed with clinical symptoms, and from 1974 to 2017, 818,943 cases in fever patients were diagnosed with blood tests. Conclusions: To achieve the goal of eliminating malaria by 2020, Yantai should continue to strengthen the management of migrant population, including improving malaria surveillance for returnees and immigrants from overseas endemic areas, and continue to increase the training of medical personnel to improve their diagnostic ability.

Potential Risks Associated with Japanese Encephalitis Prevalence in Shandong Province, China

Japanese encephalitis (JE), which is caused by the Japanese encephalitis virus (JEV), is a zoonotic, vector-borne neurotropic disease that remains a major cause of viral encephalitis in Asia. JEV is spread to humans through mosquitoes, and its primary transmission vector is Culex tritaeniorhynchus. Mosquitoes were sampled from three collection sites: Hanzhuang town in Weishan County, Taibai Lake in Jining city, and Dongping Lake in Shandong Province, China. Pyrethroid insecticide resistance bioassays were conducted using adult mosquitoes. Cx. tritaeniorhynchus and C. pipiens pallens populations in Hanzhuang town and Dongping Lake showed resistance to pyrethroid insecticides, and populations in Taibai Lake showed incipient resistance. Coquillettidia ochracea populations in Hanzhuang town presented resistance as well, while in Taibai Lake, resistance was incipient. A total of 16,711 mosquitoes were collected, identified, and divided into 346 pools for JEV testing. Cx. tritaeniorhynchus had the advantage of being a local mosquito species. Overall, 31 (22.96) of the 135 pools of Cx. Tritaeniorhynchus were positive for JEV. The overall maximum likelihood estimates of Cx. tritaeniorhynchus, C. pipiens pallens, and Cq. ochracea indicated pooled infection rates of 5.29/1000 mosquitoes (95% confidence interval [CI] = 3.67-7.42), 1.60/1000 mosquitoes (95% CI = 0.82-2.85), and 6.39/1000 mosquitoes (95% CI = 0.39-32.23), respectively. There were no significant differences in the pooled infection rates between the districts. The resistance to pyrethroids has increased the difficulty in controlling the mosquito vectors, especially JEV-positive mosquitoes. Given the changes in the JEV transmission vectors, the spatial and temporal diversity and the dynamic variety of mosquito species, insecticide resistance and global warming have the potential to facilitate the transmission of JE to humans.

A Large Cohort of Neurocysticercosis in Shandong Province, Eastern China, 1997-2015

Neurocysticercosis (NCC) has a wide spectrum of neurologic and psychiatric manifestations, including epileptic seizures, high intracranial pressure, cognitive dysfunction, and meningoencephalitis. This study presents the clinical diagnosis of 2539 NCC patients in Shandong Province, Eastern China, from 1997 to 2015. The diagnosis was based primarily on clinical features, neuroimaging, immunology, and electroencephalogramy studies. In all age groups, seizures were found to be the most common manifestation, followed by headaches, memory loss, and limb numbness, and disability. After antiparasitic treatment, computed tomography and magnetic resonance imaging showed that most of the lesions had been completely absorbed in 2106 (82.95%) patients, most of the lesions had been absorbed and a small proportion was converted into calcifications in 433 (17.05%) cases. Indirect hemagglutination (IHA), enzyme-linked immunosorbent assay (ELISA), and circulating antigen (CAg) serum tests initially gave 76.45%, 86.37%, and 80.66% positive results, respectively. After antiparasitic therapy, the positive rates of the IHA, ELISA, and CAg tests were 74.77%, 84.70%, and 3.75%, respectively, showing no significant difference in antibody levels (p > 0.05), but a significant difference in CAg levels (p < 0.01). The clinical antiparasitic treatment of NCC with three to four courses of a combination of albendazole and praziquantel achieved satisfactory therapeutic efficacy.

Trends in insecticide resistance in Culex pipiens pallens over 20 years in Shandong, China

Background

Culex pipiens pallens is the most abundant Culex mosquito species in northern China and is an important vector of bancroftian filariasis and, potentially, West Nile virus. Insecticides, particularly pyrethroids, are widely used for adult mosquito control. Insecticide resistance has become common in several mosquito species, and vector control is the main method currently available to prevent disease transmission. The voltage-gated sodium channel (Vgsc) gene is the target site of pyrethroids, and mutations in this gene cause knockdown resistance (kdr).

Methods

Culex pipiens pallens larvae were collected from May to November over two decades, from 1992 to 2018, in four cities in Shandong Province, China. The World Health Organization (WHO) standard resistance bioassay was applied to test the resistance levels of Cx. p. pallens larvae to five different insecticides and to test deltamethrin resistance in adults, using the F1 generation. Mutations at Vgsc codon 1014 were also screened in 471 adult samples collected in 2014 to determine the association between kdr mutations and phenotypic resistance.

Results

Larval resistance against deltamethrin showed an increasing trend from the 1990s until 2018, which was statistically significant in all populations; resistance to cypermethrin increased significantly in mosquitoes from the Zaozhuang population. However, larval resistance to other insecticides remained relatively stable. Larval resistance against deltamethrin was consistent with adult bioassays in 2014, in which all tested populations were highly resistant, with mortality rates ranging from 39.4 to 55.23%. The L1014S and L1014F mutations were both observed in five Cx. p. pallens populations, with L1014F significantly associated with deltamethrin resistance.

Conclusions

The long-term dataset from Shandong demonstrates major increases in pyrethroid resistance over a 20-year period. The L1014F kdr mutation may be considered a viable molecular marker for monitoring pyrethroid resistance in Cx. p. pallens.

Electronic supplementary material

The online version of this article (10.1186/s13071-019-3416-9) contains supplementary material, which is available to authorized users.

Cysticercosis in Shandong Province, Eastern China

We analyzed demographic and clinical data and estimated the incidence of cysticercosis in Shandong Province, China, during 1975–2014. Our analyses showed that a cysticercosis-endemic area is present in Shandong Province, especially in its western regions. Improved surveillance and control are needed to address the elevated risk for cysticercosis in this region.

Malaria control and prevention towards elimination: data from an eleven-year surveillance in Shandong Province, China

BACKGROUND

Shandong Province experienced a declining malaria trend of local-acquired transmission, but the increasing imported malaria remains a challenge. Therefore, understanding the epidemiological characteristics of malaria and the control and elimination strategy and interventions is needed for better planning to achieve the overall elimination goal in Shandong Province.

METHODS

A retrospective study was conducted and all individual cases from a web-based reporting system were reviewed and analysed to explore malaria-endemic characteristics in Shandong from 2005 to 2015. Annual malaria incidence reported in 2005-2015 were geo-coded and matched to the county-level. Spatial cluster analysis was performed to evaluate any identified spatial disease clusters for statistical significance. The space-time cluster was detected with high rates through the retrospective space-time analysis scanning using the discrete Poisson model.

RESULTS

The overall malaria incidence decreased to a low level during 2005-2015. In total, 1564 confirmed malaria cases were reported, 27.1% of which (n = 424) were indigenous cases. Most of the indigenous case (n = 339, 80.0%) occurred from June to October. However, the number and scale of imported cases have been increased but no significant difference was observed during months. Shandong is endemic for both Plasmodium vivax (n = 730) and Plasmodium falciparum (n = 674). The disease is mainly distributed in Southern (n = 710) and Eastern region (n = 424) of Shandong, such as Jinning (n = 214 [13.7%]), Weihai (n = 151 [9.7%]), and Yantai (n = 107 [6.8%]). Furthermore, the spatial cluster analysis of malaria cases from 2005 to 2015 indicated that the diseased was not randomly distributed. For indigenous cases, a total of 15 and 2 high-risk counties were determined from 2005 to 2009 (control phase) and from 2010 to 2015 (elimination phase), respectively. For imported cases, a total of 26 and 29 high-risk counties were determined from 2005 to 2009 (control phase) and from 2010 to 2015 (elimination phase), respectively. The method of spatial scan statistics identified different 13 significant spatial clusters between 2005 and 2015. The space-time clustering analysis determined that the most likely cluster included 14 and 19 counties for indigenous and imported, respectively.

CONCLUSIONS

In order to cope with the requirements of malaria elimination phase, the surveillance system should be strengthened particularity on the frequent migration regions as well as the effective multisectoral cooperation and coordination mechanisms. Specific response packages should be tailored among different types of cities and capacity building should also be improved mainly focus on the emergence response and case management. Fund guarantees for scientific research should be maintained both during the elimination and post-elimination phase to consolidate the achievements of malaria elimination.

Extrication process of chlorogenic acid in Crofton weed and antibacterial mechanism of chlorogenic acid on Escherichia coli

Crofton weed is a perennial herb and a biological intruding species. The present study firstly used the orthogonal test to compare the differences in extraction of chlorogenic acid in leaves and stems of Crofton weed by using three kinds of solvents, namely water, ethanol and ethyl acetate. The best effect was found by using ethonolic extraction of chlorogenic acid in Crofton weed. Further, by choosing Escherichia coli as test object, in-vitro antibacterial test was conducted to study the antimicrobial activities of chlorogenic acid by testing a series of indexes before and after the interaction between chlorogenic acid and Escherichia coli, to clarify the antibacterial mechanism of chlorogenic acid on Escherichia coli. Finally, by comparing the antibacterial activities of isochlorogenic acid A on Escherichia coli, it was concluded that both chlorogenic acid and isochlorogenic acid A showed antibacterial activities against Escherichia coli, wherein chlorogenic acid had a better antibacterial effect on Escherichia coli than isochlorogenic acid A.

Extracellular DNA traps released by acute promyelocytic leukemia cells through autophagy

Acute promyelocytic leukemia (APL) cells exhibit disrupted regulation of cell death and differentiation, and therefore the fate of these leukemic cells is unclear. Here, we provide the first evidence that a small percentage of APL cells undergo a novel cell death pathway by releasing extracellular DNA traps (ETs) in untreated patients. Both APL and NB4 cells stimulated with APL serum had nuclear budding of vesicles filled with chromatin that leaked to the extracellular space when nuclear and cell membranes ruptured. Using immunofluorescence, we found that NB4 cells undergoing ETosis extruded lattice-like structures with a DNA-histone backbone. During all-trans retinoic acid (ATRA)-induced cell differentiation, a subset of NB4 cells underwent ETosis at days 1 and 3 of treatment. The levels of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) were significantly elevated at 3 days, and combined treatment with TNF-α and IL-6 stimulated NB4 cells to release ETs. Furthermore, inhibition of autophagy by pharmacological inhibitors or by small interfering RNA against Atg7 attenuated LC3 autophagy formation and significantly decreased ET generation. Our results identify a previously unrecognized mechanism for death in promyelocytes and suggest that ATRA may accelerate ET release through increased cytokines and autophagosome formation. Targeting this cellular death pathway in addition to conventional chemotherapy may provide new therapeutic modalities for APL.

C35 is overexpressed in colorectal cancer and is associated tumor invasion and metastasis

The aim of this study was to investigate the expression of C35, an oncogene previously found in breast and prostate cancers, and its clinicopathological significance in colorectal cancer (CRC). Qualitative and quantitative detection of C35 mRNA expression was performed using reverse transcription-PCR (RT-PCR) and real-time PCR. C35 protein expression was determined using immunohistochemistry. C35 mRNA was detected in none of 10 normal colorectal tissue samples, 55 of 65 (84.6%) CRC tissue samples, and 43 of 55 (78.2%) adjacent non-cancerous tissue samples. In addition, the level of C35 mRNA in CRC tissue samples was markedly higher than that in tumor adjacent non-cancerous tissue samples. C35 protein expression was detected in 58 of 80 (72.5%) CRC tissue samples and was closely associated with tumor serosal invasion, lymphnode metastasis, and an advanced Dukes stage. These results suggest that C35 might serve as a biomarker or therapeutic target for management of CRC.

Development of insecticide resistance in malaria vector Anopheles sinensis populations from Shandong province in China

BACKGROUND

Anopheles sinensis is a major vector of malaria and among the dominant species in Shandong province of China. Insecticide resistance is an important threat to vector-borne disease control. However, there are only few reports about insecticide resistance of An. sinensis populations from Shandong province.

METHODS

From 2003 to 2012, six districts in Shandong province were selected as the study areas. Insecticide susceptibility bioassay were tested on F1 progeny of An. sinensis to 4% DDT, 0.05% deltamethrin, 0.15% cyfluthrin, and 5% malathion, using the standard WHO resistance tube assay.

RESULTS

The resistance status of An. sinensis showed a significant decrease in the mortality rates in DDT, deltamethrin and cyfluthrin during the past ten years. Whereas obvious increase of mortality to malathion was observed throughout the assay, ranging from 47.37% to 86.62%.

Expression profile of insulin-like growth factor system genes in muscle tissues during the postnatal development growth stage in ducks

Insulin-like growth factors (IGFs) are regulators that modulate the proliferation and differentiation of muscle tissues. We quantified the messenger RNA (mRNA) expression of IGF-I, IGF-II, and type I and II IGF receptors (IGF-IR and IGF-IIR) in muscle tissues including the breast, leg, and myocardium during an early postnatal development growth stage (post-hatching weeks 1-8) in ducks. The results showed a significant age-related change in mRNA in these muscle tissues. In breast muscle, the developmental expression of IGF-I and IGF-II was highest during week 1 but decreased quickly and maintained a relatively lower level. Leg muscle had the highest mRNA expression of IGF-I and IGF-II genes at week 3. In myocardial tissues, the expression level of IGF-IR and IGF-IIR genes exhibited a "rise-decline" developmental trend. The expression patterns of IGF-I/IGF-IR and IGF-II/IGF-IIR were different between weeks 4 and 6. The same expression pattern was observed for IGF-I and IGF-IR; however, it was different from that observed for IGF-II and IGF-IIR. Our results showed a negative correlation between IGF-II mRNA expression and leg muscle weight at week 4 (P < 0.05). A negative correlation was also found between IGF-II mRNA expression and breast muscle weight (P < 0.01), and a positive correlation was found between IGF-IR expression and breast muscle weight. At week 6, a positive correlation was found between IGF-IR expression and breast muscle weight. However, at week 8, a negative correlation was found between IGF-IR expression and breast muscle weight. The results showed that the expression of IGF mRNA in duck tissues exhibits a specific developmental trend and an age-related pattern, suggesting that the regulation mechanism of these 4 genes in proliferation and differentiation of muscle tissues differed.

A method for the temperature calibration of an infrared camera using water as a radiative source

Presented here is an effective low-cost method for the temperature calibration of infrared cameras, for applications in the 0-100 degrees C range. The calibration of image gray level intensity to temperature is achieved by imaging an upwelling flow of water, the temperature of which is measured with a thermistor probe. The upwelling flow is created by a diffuser located below the water surface of a constant temperature water bath. The thermistor probe is kept immediately below the surface, and the distance from the diffuser outlet to the surface is adjusted so that the deformation of the water surface on account of the flow is small, yet the difference between the surface temperature seen by the camera and the bulk temperature measured by the thermistor is also small. The benefit of this method compared to typical calibration procedures is that, without sacrificing the quality of the calibration, relatively expensive commercial blackbodies are replaced by water as the radiative source (epsilon approximately 0.98 for the wavelengths considered here). A heat transfer analysis is provided, which improves the accuracy of the calibration method and also provides the user with guidance to further increases in accuracy of the method.

A method for removing surfactants from an air/water interface

The study of heat, mass, and momentum transport across an air/water interface is an aspect of fluid mechanics where the presence of surfactant monolayers can play a significant role. Experimental studies of air/water transport typically require a method for cleaning the air/water interface so that it is free from any contaminating surfactant monolayer. This may be for the sake of running an experiment under clean surface conditions, or to clean the surface prior to deposition of a known surfactant. Herein a method is described for maintaining a clean air/water interface during conditions of finite air flow over the water surface. The unique aspect of this method is its ability to maintain clean surfaces while experiments are conducted.

Anti-inflammatory activities of triterpenoid saponins from Polygala japonica

Bioassay-guided investigation was performed to identify the active constituents from a methanol extract of Polygala japonica, a folk medicinal plant widely used in China to treat inflammatory diseases. The n-BuOH and EtOAc fractions of the P. japonica methanol extract, which show significant anti-inflammatory activity in in vivo test, were further subjected to column chromatography to afford six triterpene glycosides, marked here as saponins 1-6. All compounds were evaluated for their anti-inflammatory activity in the carageenan-induced mouse paw edema test, and saponins 1, 4 and 5 showed significantly anti-inflammatory effects on both phases of carageenan-induced acute paw edema in mice. Saponin 5 was also found to significantly inhibit the production of inflammatory mediators - nitric oxide (NO) in LPS-stimulated RAW264.7 macrophages, with no obvious effects on macrophage viability.

Lot Consistency as an Equivalence Problem

One requirement for licensure of a vaccine in the United States is demonstration by the manufacturer of consistently produced lots of vaccine. Demonstration of consistency of manufacturing can be viewed as a multigroup equivalence problem. The standard statistical procedures for evaluating equivalence assume normally distributed data and define equivalence margins with respect to group means. As an alternative approach, we define a measure of the similarity among group distributions and their nonparametric estimators. Through computer simulations we explore the statistical properties of an equivalence test based on this estimator and compare them to the standard methods. Preliminary work suggests that a test of similarity can be useful in demonstrating equivalence when distributions are not normal or when there are differences in scale or shape. It appears to detect departures from equivalence that are not reflected by differences among group means.

Double photoionization of C(60) and C(70) in the valence region

Photoion yields from gaseous fullerenes, C(60) and C(70), for production of singly and doubly charged ions are measured by mass spectrometry combined with tunable synchrotron radiation at hnu=25-150 eV. Since the signal of triply or highly charged ions is very weak, the total photoionization yield curve can be estimated from the sum of the yields of the singly and doubly charged ions. A distinct feature appears in the resultant curve of C(60) which is absent in the calculated total photoabsorption cross section previously reported. This difference is attributed to C(60) (2+) ions chiefly produced by spectator Auger ionization of the shape resonance states followed by tunneling of the trapped electron or by cascade Auger ionization. Ratios between the yields of doubly and singly charged ions for C(60) and C(70) are larger than unity at hnu>50 eV. These ratios are quite different from those reported in the experiments using electron impact ionization.

Risk factors for spinal epidural hematoma after spinal surgery

STUDY DESIGN

A case-control retrospective analysis comparing patients who developed a postoperative spinal epidural hematoma with patients who did not develop this complication.

OBJECTIVES

To identify risk factors for the development of an epidural hematoma following spinal surgery.

SUMMARY OF BACKGROUND DATA

Neurologic deterioration following spinal surgery is a rare but devastating complication. Epidural hematomas should be suspected in the patient who demonstrates a new postoperative neurologic deficit. The risk factors that predispose a patient to a postoperative spinal epidural hematoma have not been identified.

METHODS

Patients who underwent spinal surgery at a single institution over a 10-year period were retrospectively reviewed. Twelve patients who demonstrated neurologic deterioration after surgery and required surgical decompression because of an epidural hematoma were identified. All cases involved lumber laminectomies. A total of 404 consecutive patients that underwent lumbar decompression and did not develop an epidural hematoma formed the control group. Factors postulated to increase the risk of postoperative spinal epidural hematoma were compared between the two groups using logistic regression.

RESULTS

Multilevel procedures (P = 0.037) and the presence of a preoperative coagulopathy (P < 0.001) were significant risk factors. Age, body mass index, perioperative durotomies, and postoperative drains were not statistically significant risk factors.

CONCLUSIONS

Patients who require multilevel lumbar procedures and/or have a preoperative coagulopathy are at a significantly higher risk for developing a postoperative epidural hematoma.

Study on the transmission threshold value of bancroftian filariasis

OBJECTIVE

To elucidate the transmission dynamic and epidemic trend of bancroftian filariasis occurred under the condition with no control measure taken 5 years after elimination of filariasis.

METHODS

A 10-year longitudinal observation (from 1984 to 1994) was made in Huayuan Village in Shengli Township of Tancheng County, which used to be a high bancroftian filariasis-endemic area in southern part of Shandong Province.

RESULTS

The microfilarial rate decreased from 0.56% before the study to 0.12% after the study and 8 out of the 9 previous microfilaria-positive cases became negative gradually. During the study period, 6 new microfilaremia cases were detected, 5 of which became negative naturally within 3 to 4 years. Eighty-eight point eight nine per cent of the detected patients with microfilaremia converted into IgG4-negative after 10 years. The natural infective rate of vectors decreased year by year and became zero by the tenth year of the study, the annual transmission potency decreased also from 3.47 to zero by the tenth year.

CONCLUSIONS

It showed that under the local natural environment the biting rate representing the vector density which was obtained by capture method was from 24.1 to 52.5 person/night among the residents who did not use mosquito nets, and 13.5 to 21 person/night among the residents who used mosquito nets. The microfilarial rate of 0.56% in population with the average microfilarial density of 6.6 to 20.7 capita/60 microliters ear blood of residual microfilaria-positive patients might be considered as the terminal threshold of transmission.

[Effects of yizhi pills on memory, superoxide dismutase and malondialdehyde of brain and immunity in mice]

Passive avoidance tests have shown that Yizhi Pills (YZ) markedly improve the memory of normal mice at a dose of 100 mg/kg after oral administration for fifteen days, and significantly reverse the scopolamine, NaNO2 and EtOH-induced disruptions of memory retention in mice at doses of 100, 200, 500 mg/kg after oral administration for five days. In aged mice induced by D-galactose, YZ also significantly improve the impaired memory, increase the activity of SOD and decrease the content of MDA in brain. All these effects were observed at doses of 200, 500 mg/kg after oral administration for forty-one days. YZ significantly promote blood carbon particle clearance, enhance hemolysin antibody in immunodepressed mice induced by cyclophosphamide, and increase earswelling in immunodepressed mice induced by prednisolonum.

[Pharmacological study on the compatibility of cortex Cinnamomi with Halloysitum Rubrum]

The decoction of Cortex Cinnamomi (CC, 1 g/kg p.o.) and Halloysitum Rubrum (HR, 3 g/kg p.o.) or the combination of the two drugs (4 g/kg p.o., CC 1 g/kg, HR 3 g/kg) could antagonize the diarrhea caused by p.o. water ex tract of Radix et Rhizoma Rhei in mice; and inhibit the platelet aggregation induced by ADP in vitro. Meanwhile, the effect of the combination of the two drugs was not different from that of each single one. In addition, CC was able to inhibit the spontaneous movement of intestine in situ and showed an analgesic effect (hot-plate method) in mice; HR was ineffective in these aspects and did not reduce the effect of CC. CC(20 g/kg p.o., i.p. or i.v.) exhibited very strong toxicity in mice, while HR(60 g/kg p.o., i.p. or i.v.) was nontoxic. When the two drugs were used together, the toxicity was markedly reduced.

Teaching safety: evaluation of a children's village in Maryland

OBJECTIVES

The purpose of this study was to evaluate Children's Village, a life safety education facility for children.

SETTING

The study took place in Washington County, Maryland, a rural county.

METHODS

Eight elementary schools with 20 second grade classrooms (410 students aged 7 and 8) were selected to participate. Using a quasiexperimental design, tests were administered to two cohorts of children before (pretest) and after (post-test) they attended the Children's Village during 1993-4. Parent and teacher surveys were also completed after the program.

RESULTS

Among children who attended in December 1993-January 1994, there was a significant improvement in average test scores between the pretest (58% correct) and post-test (78%). Among children who attended in April 1994, there also was a significant improvement in test scores between pretest (74%) and post-test (85%). Among parents, 70% reported that their child learned a great deal at Children's Village and 33% reported having made changes in their home as a result. The parent survey also revealed that 25% of children and 35% of adults did not always wear their seat belts, and 74% of children did not always wear bicycle helmets. Teachers' responses to the program were generally positive.

CONCLUSIONS

Children's Village brought together an extensive network of community leaders, parents, and teachers dedicated to safety education of children. The curriculum had a positive impact on children's knowledge and, to a lesser extent, on parents' safety practices. Program impact could be enhanced by more emphasis on automobile restraints and helmets (behaviors that parents reported were not consistently practiced) and by expanding the village services to parents as well as children. Others considering creating similar programs need to identify community leaders willing to commit the time, effort, and resources required to develop and sustain such programs.

Effect of ibudilast on ciliary activity of human paranasal sinus mucosa in vitro

The effect of ibudilast (CAS 50847-11-5, 3-isobutyryl-2-isopropylpyrazolo[1,5-a]pyridine, KC-404), an anti-asthmatic drug, on ciliary beat frequency (CBF) of human paranasal sinus mucosa was examined in vitro. Ciliary activation was observed after a 10-min exposure to 4.6 x 10(-6) mol/l ibudilast. Ibudilast dose-dependently increase CBF at the concentrations ranging from 4.6 x 10(-7) mol/l to 4.6 x 10(-5) mol/l. Propranolol inhibited ciliary activity induced by ibudilast; however, neither indometacin nor verapamil affected the activation of ibudilast on CBF. Platelet activating factor (PAF) and Leukotriene D4 (LTD4) are chemical mediators inducing mucosal dysfunction and damage. Ibudilast prevented ciliary inhibition induced by PAF and LTD4. These findings indicated that ibudilast activates CBF and inhibits the effect of PAF and LTD4 on ciliated cells, and consequently improves the pathogenesis of allergic disorders such as the inhibited mucociliary transport system and airway hyperresponsiveness.

Analysis of models for determining intestinal wall permeabilities

In determining intestinal wall permeabilities, several mass transport models may be applied to analyze the results from external perfusion experiments. The appropriateness of any given model depends on the applicability of the model assumptions to the experimental system. This report compares several mass transport models with respect to their assumptions and applicability to a particular experimental design. The models are shown to differ in their assumptions regarding convection and diffusion in the perfusing fluid. However, since the wall permeability is an unknown parameter in each model and is estimated from the data, all of the models fit the mass transfer results reasonably well, despite fundamentally different assumptions. However, the determined permeabilities differ. Residence time distribution analysis of the experimental system is more sensitive to the model assumptions. It is shown that, in a particular experimental system, laminar flow in a cylindrical tube is the most appropriate model. The model also has the advantage of implicitly accounting for the convection-diffusion problem in the perfusing fluid. Hence, the diffusion layer thickness is not estimated from the data. With the hydrodynamics defined, the relative permeabilities resulting from the application of the several models to the data can be interpreted. The wall permeability determined in the suggested manner provides an estimate of the limiting assistance under perfect mixing conditions.