Endogenous H2O2 Self-Replenishment and Sustainable Cascades Enhance the Efficacy of Sonodynamic Therapy

Purpose

Sonodynamic therapy (SDT), with its high tissue penetration and noninvasive advantages, represents an emerging approach to eradicating solid tumors. However, the outcomes of SDT are typically hampered by the low oxygen content and immunosuppression in the tumor microenvironment (TME). Accordingly, we constructed a cascade nanoplatform to regulate the TME and improve the anti-tumor efficiency of SDT.

Methods

In this study, we rationally design cascade nanoplatform by incorporating immunostimulant hyaluronic acid (HA) and sonosensitizer chlorin e6 (Ce6) on the polydopamine nanocarrier that is pre-doped with platinum nanozymes (designated Ce6/Pt@PDA-HA, PPCH).

Results

The cascade reactions of PPCH are evidenced by the results that HA exhibits reversing immunosuppressive that converts M2 macrophages into M1 macrophages in situ, while producing H2O2, and then platinum nanozymes further catalyze the H2O2 to produce O2, and O2 produces abundant singlet oxygen (1O2) under the action of Ce6 and low-intensity focused ultrasound (LIFU), resulting in a domino effect and further amplifying the efficacy of SDT. Due to its pH responsiveness and mitochondrial targeting, PPCH effectively accumulates in tumor cells. Under LIFU irradiation, PPCH effectively reverses immunosuppression, alleviates hypoxia in the TME, enhances reactive oxygen species (ROS) generation, and enhances SDT efficacy for eliminating tumor cells in vivo and in vitro. Meanwhile, an in vivo dual-modal imaging including fluorescence and photoacoustic imaging achieves precise tumor diagnosis.

Conclusion

This cascade nanoplatform will provide a promising strategy for enhancing SDT eradication against tumors by modulating immunosuppression and relieving hypoxia.

[Association between sedentary behavior and force expiratory volume in 1 second reduction in middle-aged and elderly adults in communities]

Objective: To analyze the relationship between sedentary behavior and the force expiratory volume in 1 second (FEV₁) reduction in middle-aged and elderly people in communities. Methods: The participants aged ≥40 years were randomly selected from a natural population cohort in Songjiang District, Shanghai, for pulmonary function tests and survey by using international physical activity questionnaire, a generalized additive model was used to analyze the association between sedentary behavior and FEV₁ reduction in the study population and different sex-age subgroups. Results: A total of 3 121 study subjects aged ≥40 years were included. The prevalence of FEV₁ reduction was 14.8%, which was higher in men than in women. There were 24.8% participants were completely sedentary. The prevalence of FEV₁ reduction in women aged <60 years in complete sedentary group was 2.04 (95%CI: 1.11-3.72) times higher than that in non-complete sedentary group. In men aged <60 years, the prevalence of FEV₁ reduction increased with daily sedentary time (OR=1.16, 95%CI: 1.04-1.29), and the prevalence of FEV₁ reduction was also higher in those with sedentary time >5 hours/day than those with sedentary time ≤5 hours/day (OR=3.02, 95%CI: 1.28-7.16). The sensitivity analysis also found such associations. Conclusions: FEV₁ reduction rate in age group <60 years was associated with sedentary behavior. Complete sedentary behavior or absence of moderate to vigorous physical activity played important roles in FEV₁ reduction in women, while men were more likely to be affected by increased sedentary time, which had no association with physical activity. Reducing sedentary time to avoid complete sedentary behavior, along with increased physical activity, should be encouraged in middle-aged and elderly adults in communities to improve their pulmonary function.

Recent advances in sonodynamic immunotherapy

Tumor immunotherapy has become an important means of tumor therapy by enhancing the immune response and triggering the activation of immune cells. However, currently, only a small number of patients respond to immunotherapy alone, and patients may experience immune-related adverse events (irAEs) during the course of treatment. Sonodynamic therapy (SDT) can produce cytotoxic substances to tumor tissue, induce apoptosis and enhance immunity. SDT combined with immunotherapy is considered a promising strategy for cancer treatment. In this mini review, we summarize the role of SDT in immunotherapy in recent years, including the application of SDT-triggered immunotherapy and the combination of SDT and immunotherapy.

Ultrasonographic Diagnosis of Intussusception in Children: A Systematic Review and Meta-Analysis

Ultrasonography offers a unique advantage in the clinical diagnosis of intussusception. We aimed to evaluate the diagnostic accuracy of ultrasonography in pediatric intussusception. The PubMed, Embase, Web of Science, Cochrane Library databases, and African Journals Online database were searched for studies pertaining to ultrasonographic diagnosis of intussusception in children. Finally, 14 studies (combined n = 2367) were found eligible for inclusion. Pooled sensitivity and specificity were 0.94 (95% confidence interval: 0.91-0.96) and 0.96 (95% confidence interval: 0.93-0.98), respectively. In conclusion, ultrasonography has high sensitivity and specificity in the diagnosis of intussusception.

Conventional Ultrasound and Contrast-Enhanced Ultrasound in the Diagnosis of Splenic Diseases: A Systematic Review and Meta-analysis

Accurate diagnosis of splenic diseases is important for timely and accurate treatment. The objective of this study was to compare the accuracy of contrast-enhanced ultrasound (CEUS) and conventional ultrasound (US) in detecting splenic lesions. A systematic literature search was undertaken, and 8 studies met the inclusion criteria. The sensitivity and specificity of the consolidated results of CEUS were 0.95 (95% confidence interval [CI], 0.92-0.97) and 0.97 (95% CI, 0.90-0.99), respectively (I² = 27.4%; area under the curve [AUC] from a summary receiver operating characteristic curve = 0.97). The sensitivity and specificity of the consolidated results of conventional US were 0.70 (95% CI, 0.56-0.80) and 0.96 (95% CI, 0.76-0.99; I² = 83.4%; AUC = 0.84). In this systematic review and meta-analysis, the sensitivity and specificity of CEUS were higher than those of conventional US in diagnosing splenic lesions. Contrast-enhanced US is a promising method for accurately diagnosing splenic lesions.

Two new combinations in Oreocharis (Gesneriaceae) based on morphological, molecular and cytological evidence

The newly-circumscribed genus Oreocharis is recently enlarged by incorporating ten other genera with high floral diversity. In this study, our morphological, molecular and cytological evidence supports our adding two species from other two different genera (Boeica and Beccarinda) to Oreocharis. The special corolla shape (campanulate or flat-faced) and related short filament of these two new combinations, Oreocharis guileana and O. baolianis, further enrich the diversity of floral characters of the enlarged Oreocharis. Meanwhile, some supplementary and amended descriptions of these two species are made here. Our morphological, molecular and geographical data indicate that O. guileana is related to O. pilosopetiolata to a certain extent. For O. baolianis, however, our current dataset does not allow conclusions on the species relationship within Oreocharis.

[Mental health sataus and influencing factors of medical staff after blood-borne occupational exposure]

Objective: To explore the mental health status and influencing factors of medical staff after blood-borne occupational exposure, and to provide scientific basis for effective psychological intervention. Methods: From January 2017 to December 2018, 178 medical staff with blood-borne occupational exposure in three hospitals of Shandong Province were collected as the contact group, and 100 routine medical staff as the control group during the same period. Questionnaires were conducted among medical staff in the two groups, including general information questionnaire, symptom checklist 90 (SCL-90) , post-traumatic stress disorder self-rating scale (PCL-C) , coping style scale (CPS) , social support scale (SSRS) . The basic situation and mental health level of medical staff in the two groups, as well as the coping and social support status of medical staff exposed to hematogenous occupational exposure were analyzed. Relevant influencing factors. Results: The total score of SCL-90 was 1.66+0.33, 45 (38.14%) were positive, and 21 (21.00%) were positive in the control group. The difference was statistically significant (χ(2)=7.529, P<0.05) . Compared with the control group, the scores of SCL-90 somatization, obsessive-compulsive symptoms, depression, anxiety, hostility, paranoia and total scores of medical staff in the exposure group increased significantly (P<0.05) . The total PCL-C score of exposure group was 36.84+9.50, PTSD positive 47 (39.83%) and control group 13 (13.00%) . The difference was statistically significant (χ(2)=19.534, P<0.05) . Compared with the control group, PCL-C re-experience, avoidance, vigilance factor scores and total scores of medical staff in the contact group increased significantly (P<0.05) . The problem solving, help seeking and subjective support of the medical staff in the positive mental health group with blood-borne occupational exposure were significantly lower than those in the negative group, while self-blame, fantasy and withdrawal were significantly higher than those in the negative group (P<0.05) . The mental health level of medical staff with occupational exposure was negatively correlated with problem solving, help seeking and subjective support, and positively correlated with self-blame, fantasy and withdrawal (P<0.05) . Problem solving, help seeking and subjective support were protective factors of mental health (OR=2.121, 1.616, 1.371) , and self-blame and withdrawal were risk factors of mental health (OR=0.160, 0.484) . Conclusion: Medical personnel exposed to blood-borne occupational exposure are prone to psychological problems and PTSD. Solving problems, seeking help and subjective support are protective factors for mental health, while self-blame and withdrawal are risk factors for mental health.

Abnormal methylation of spermatozoa induced by benzo(a)pyrene in rats

Epigenetic mutations caused by pollutants are possibly linked to many diseases. Benzo(a)pyrene (BaP) is one of the most representative air pollutants and has aroused wide concern because of its strong carcinogenicity. The reproductive toxicity induced by BaP has been identified, but little is known about the characteristics of the methylation changes induced by BaP. In this study, a methylated DNA immunoprecipitation sequencing method was used to detect the methylation of sperm DNA of rats exposed to BaP. Compared with the respective genes in normal rats, there were 3227 hypomethylated genes and 828 hypermethylated genes after BaP exposure. Gene ontology enrichment analysis reported that differentially methylated genes (DMGs) were enriched in the localization, single-multicellular organism process and plasma membrane. Kyoto Encyclopedia of Genes and Genomes pathway analysis showed that the DMGs were significantly enriched in the Ras signalling pathway, Rap1 signalling pathway, pancreatic secretion and neuroactive ligand-receptor interaction. DisGeNET disease spectrum analysis showed that DMGs were associated with infertility and certain genetic diseases. Further research needs to be done to explore whether these abnormal methylation are transgenerational.

[Efficacy and safety of anti-interleukin-5 therapy in patients with asthma: systematic reviews]

Objective: To evaluate the efficacy and safety of anti-Interleukin-5 therapy in patients with asthma. Methods: Data were collected from PubMed, E-Mbase, Springer, Ovid, Cochrane Library, ClinicalTrials.gov, CNKI and Wanfang database (-Feb 2017). Bibliographies of the retrieved articles were checked and analyzed. Results: Twenty publications involving a total of 6 406 patients were used in the analysis, including 23 randomly controlled trials (RCTs) which compared anti-interleukin 5 monoclonal antibody with placebo. Pooled analyses showed that anti-interleukin 5 monoclonal antibody significantly reduced exacerbation risk [RR=0.66, 95%CI(0.59, 0.73)], increased FEV(1)[MD=0.10, 95%CI(0.07, 0.13)] and FEV(1)% predicted [MD=3.90, 95%CI(1.86, 5.95)], and improved the scores on the Asthma Quality of Life Questionnaire (AQLQ) [MD=0.24, 95%CI(0.16, 0.32)]. Anti-interleukin 5 monoclonal antibody was also associated with significantly decreased risk of adverse events than placebo[OR=0.71, 95%CI(0.58, 0.87)]. Conclusion: Anti-interleukin 5 monoclonal antibody reduces the risk of exacerbations and improves quality of life in patients with asthma, and is tolerated well.

[Constituent and workload of service providers engaged in cancer screening: findings and suggestions from a multi-center survey in China]

Objective: To understand the constituent and workload of service providers engaged in cancer screening in China and provide evidence for the assessment of the sustainability of national cancer screening project. Methods: Using either questionnaire or online approach, the survey was conducted in 16 provinces, where Cancer Screening Program in Urban China (CanSPUC) was conducted, from 2014 to 2015. The medical institutes surveyed included hospitals [71.1% were class Ⅲ(A) hospitals], centers for disease control and prevention (CDCs) and community centers where cancer screening was undertaken during 2013-2015. The questionnaire survey was conducted among the staffs responsible for the overall coordination, management and implementation of the screening project to collect the information about the allocation, workload and compensation of the service providers from different specialties. Results: A total of 4 626 staffs were surveyed in this study, their average age was (37.7±9.5) years, and males accounted for 31.0%. Human resources allocated differed with province. The number of senior staff ranged from 6 (Chongqing) to 43 (Beijing) among the 8 comparable provinces. Among the staffs surveyed, 2 192 were from hospitals, 431 were from CDCs and 1 990 were from community centers, and the staffs who complained heavy workload accounted for 19.9%, 24.6% and 34.1% respectively (P<0.001). Among 227 staffs for overall coordination, 376 management staffs and 3 908 staffs for implementation, those who complained heavy workload accounted for 23.6%, 22.3% and 28.2% respectively (P<0.001). A total of 3 244 staffs (73.8%) got compensations for heavy workload. The compensation types were manly labor fee linked with workload (67.5%) and labor fee regardless workload (26.6%). Conclusion: The province specific differences in human resources allocation indicated the differences in screening project's organizing pattern and capability. It is suggested to conduct routine cancer screening (using specialized staffs), reduce the workload of the first line and community staffs and increase the compensation for the service providers for the sustainability of cancer screening project in China.

[Willingness of potential service suppliers to provide cancer screening in urban China]

Objective: Based on the investment for potential suppliers of cancer screening services, we assessed the reasons that affecting their participation motivation related to the long-term sustainability of cancer screening in China. Methods: Hospitals that had never been involved in any national level cancer screening project were selected by using the convenient sampling method within the 16 project cities of Cancer Screening Program in Urban China (CanSPUC) with 1 or 2 hospitals for each city. All the managers from the institutional/department level and professional staff working and providing screening services in these hospitals, were interviewed by paper-based questionnaire. SAS 9.4 was used for logical verification and data analysis. Results: A total of 31 hospitals (18 hospitals at the third level and, 13 hospitals at the second level) and 2 201 staff (508 hospital and clinic unit managers, 1 693 professional staff) completed the interview. All the hospitals guaranteed their potential capacity in service providing. 92.5% hospital managers showed strong willingness in providing cancer screening services, while 68.3% of them declared that the project fund-raising function was the responsibility of the government. For professional staff, their prospect gains from providing screening service would include development on professional skills (72.4%) and material rewards (46.8%). Their main worries would include extra work for CanSPUC might interfere their routine work (42.1%) plus inadequate compensation (41.8%). Medians of the prospect compensation for extra work ran between 20 to 90 Chinese Yuan per screening item respectively. For all the screening items, workers from the third-level hospitals expected their compensation to be twice as much of those working at the second level hospitals. Conclusion: Professional capacity building and feasible material incentive seemed to be the two key factors that influenced the sustainability and development of the programs.

[Potential demand on cancer screening service in urban populations in China: a cross-sectional survey]

Objective: To understand the acceptance and personal demand for cancer screening service among the urban residents who had never been involved in any national level cancer screening programs in China and identify the key factors influencing the sustainability of cancer screening. Methods: A questionnaire survey was conducted among the local people aged 40-69 years selected through convenience sampling in 16 provinces of China to collect the general information about their demands for the screening service and others. Results: A total of 16 394 qualified questionnaires were completed. The average age of the people surveyed was (53.8±8.0) years, and men accounted for 44.6%. Without concerning the cost, 4 831 people (29.5%) had no demands for cancer screening services, the reasons are as follow: they would like to go to see doctors only when they were ill (61.8%); they had already received similar medical examinations (36.8%) and they would like to receive cancer screening directly without pre-health risk assessment (33.0%). Among the people surveyed, 10 795 (65.8%) had demands for cancer screening services, but they had choice on the screening settings, 43.7% wanted to receive the service in a general hospitals, while 36.5% would like to go to cancer-specialized hospitals. As for the level of medical institutes providing cancer screening service, 61.4% of the people surveyed would choose a higher level one, while 36.4% would choose an ordinary one. On screening procedures, 61.5% of the people surveyed would accept the mode of "clinical examination after questionnaire-assessment" . Conclusion: Most people surveyed had demands for cancer screening services and they would like to receive the screening services in higher level medical institutes. It is suggested to spread cancer screening know ledge, and strengthen the capability building of screening in grass root medical institutes to attract more people to receive cancer screening.

[Preference on screening frequency and willingness-to-pay for multiple-cancer packaging screening programs in urban populations in China]

Objective: From an actual cancer screening service demanders' perspective, we tried to understand the preference on screening frequency and willingness-to-pay for the packaging screening program on common cancers and to evaluate its long-term sustainability in urban populations in China. Methods: From 2012 to 2014, a multi-center cross-sectional survey was conducted among the actual screening participants from 13 provinces covered by the Cancer Screening Program in Urban China (CanSPUC). By face-to-face interview, information regarding to preference to screening frequency, willingness-to-pay for packaging screening program, maximum amount on payment and related reasons for unwillingness were investigated. Results: A total of 31 029 participants were included in this survey, with an average age as (55.2±7.5) years and median annual income per family as 25 000 Chinese Yuan. People's preference to screening frequency varied under different assumptions ( " totally free" and "self-paid" ). When the packaging screening was assumed totally free, 93.9% of residents would prefer to take the screening program every 1 to 3 years. However, the corresponding proportion dropped to 67.3% when assuming a self-paid pattern. 76.7% of the participants had the willingness-to-pay for the packaging screening, but only 11.2% of them would like to pay more than 500 Chinese Yuan (the expenditure of the particular packaging screening were about 1 500 Chinese Yuan). The remaining 23.3% of residents showed no willingness-to-pay, and the main reasons were unaffordable expenditure (71.7%) and feeling'no need'(40.4%). Conclusions: People who participated in the CanSPUC program generally tended to choose high-frequency packaging screening program, indicating the high potential acceptance for scale-up packaging screening, while it needs cautious assessments and rational guidance to the public. Although about seven in ten of the residents were willing to pay, the payment amount was limited, revealing the necessity of strengthening individual's awareness of his or her key role in health self-management, and a reasonable payment proportion should be considered when establishing co-compensation mechanism.

[Willingness and preferences of actual service suppliers regarding cancer screening programs: a multi-center survey in urban China]

Objective: From the perspective of actual service suppliers regarding cancer screening, this study aimed to assess the long-term sustainability of cancer screening programs in China. Methods: Based on a Cancer Screening Program in Urban China (CanSPUC), our survey focused on all the hospitals, centers for disease control and prevention (CDC) and community service centers across 16 provinces in China which participated in the programs between 2013 and 2015. All the managers (institutional/department level) and professional staff involved in the program were interviewed using either paper-based questionnaire or online approach. Results: A total of 4 626 participants completed the interview. It showed that the main gains from providing screening service emphasized promotion in social value (63.6%), local reputation (35.9%), and professional skills (30.6%), whereas difficulties encountered included inadequate compensation (30.9%) and discordance among information systems (28.3%). When the service remuneration amounts to about 50 Chinese Yuan per screening item, those professional staff self-reported that they would like to work overtime. More than half (63.7%) of the staff expressed willingness to provide routine screening service, the main expectations were to promote their reputation to the local residents (48.7%) and to promote professional skills (43.1%). Those who were not willing to provide screening services were worried about the potential heavy workload (59.8%) or being interfered with their routine work (49.8%). Further detailed results regarding the different organization types and program roles were presented in the following detailed report. Conclusions: Findings of gains and difficulties showed that if cancer screening is expected to become a long-term running, incentive mechanism from the program, external promotion and advocacy as well as capacity building should be strengthened; furthermore, rewards to staff's screening services should be raised according to the local situations. Results regarding the "willingness to provide service" showed that management of the program should also be strengthened, including information system building and inter-agency and inter-department coordination at the government levels.

[The application value of contrast-enhanced ultrasound in the surgery of renal masses]

Objective: To investigate the clinical value of contrast-enhanced ultrasound in the diagnosis of renal masses. Methods: A total of 50 patients with renal masses who underwent partial nephrectomy were analyzed from January 2014 to October 2016 in the Department of Urology of China-Japan Union Hospital of Jilin University.In the intraoperative contrast-enhanced ultrasound, the characteristics of ultrasound imaging were recorded including location, size, boundary, echo, real-time internal and peripheral blood and renal pelvis distance, artery, guidance on the selection of surgical methods, intraoperative real-time estimation of the extent of tumor resection. Results: In the 50 patients, there were 49 cases enhancement in the imaging of the cystic masses, 1 case had no enhancement.Contrast-enhanced ultrasound assisted clinical accurate positioning 34 masses which were in the renal contour and not convex.And 15 patients were found main arteries of renal occupied lesions.There were 38 cases whose distance from occupying to pelvis was more than 0.5 cm, and maintained the original operation scheme for partial nephrectomy.There were 12 cases whose distance from occupying to pelvis was less than 0.5 cm, and proceeded radical resection. Conclusions: Intraoperative contrast-enhanced ultrasound can provide a more accurate imaging basis for the surgeon in partial nephrectomy.It's of great significance for the correct choice of surgical procedures, and can reduce or avoid the occurrence of postoperative complications.

Development of microsatellite markers for Sargentodoxa cuneata (Lardizabalaceae) using next-generation sequencing technology

PREMISE OF THE STUDY

Microsatellite loci were developed for a woody deciduous liana, Sargentodoxa cuneata (Lardizabalaceae), to help infer the evolutionary histories of ancient monotypic genera in subtropical China.

METHODS AND RESULTS

Using next-generation sequencing (Illumina MiSeq) technology, 21 polymorphic primer sets were identified in three wild populations. The number of alleles per locus ranged from one to seven. The expected and observed heterozygosities varied from 0 to 0.788 and 0 to 0.917, respectively. Transferability analyses were performed in Stauntonia chinensis, Akebia trifoliata, and A. quinata. Eighteen (85.7%), 18 (85.7%), and 17 (81.0%) markers were successfully amplified, respectively.

CONCLUSIONS

The newly developed markers will facilitate further studies on genetic diversity and phylogeographic patterns throughout the distributional range of S. cuneata. This set of microsatellite primers represents the second report on molecular markers in Lardizabalaceae.

Assembly of cyanometalate-functionalized phosphotungstates with magnetic properties and bifunctional electrocatalytic activities

Two cyanometalate-functionalized Dawson type phosphotungstates with a “Netherlands windmills” shape have been prepared under conventional reaction conditions. Their magnetic properties and electrocatalytic activity were investigated.

Separation properties of aluminium-plastic laminates in post-consumer Tetra Pak with mixed organic solvent

The separation properties of the aluminium-plastic laminates in postconsumer Tetra Pak structure were studied in this present work. The organic solvent blend of benzene-ethyl alcohol-water was used as the separation reagent. Then triangle coordinate figure analysis was taken to optimize the volume proportion of various components in the separating agent and separation process. And the separation temperature of aluminium-plastic laminates was determined by the separation time, efficiency, and total mass loss of products. The results show that cost-efficient separations perform best with low usage of solvents at certain temperatures, for certain times, and within a certain range of volume proportions of the three components in the solvent agent. It is also found that similar solubility parameters of solvents and polyethylene adhesives (range 26.06-34.85) are a key factor for the separation of the aluminium-plastic laminates. Such multisolvent processes based on the combined-system concept will be vital to applications in the recycling industry.

Neopterin concentrations in synovial fluid may reflect disease severity in patients with osteoarthritis

We aimed to detect neopterin concentrations in serum and synovial fluid (SF) of knee osteoarthritis (OA) patients and to clarify their relationship with clinical severity of the disease. We cross-sectionally enrolled 176 knee OA patients and 63 age- and sex-matched controls. We measured neopterin concentrations by enzyme-linked immunosorbent assay (ELISA) and investigated the correlation between serum/SF neopterin concentrations and Kellgren-Lawrence (KL) grades as well as Western Ontario and McMaster Universities Arthritis Index (WOMAC) scores in OA patients. Our results demonstrated that increased SF neopterin concentrations were independently correlated with greater symptomatic and radiographic severity in OA patients. These results suggested a crucial role of neopterin activation in the development and progression of knee OA. Assessment of neopterin levels in SF is a potential biomarker to evaluate disease severity in OA patients.

[Identification of a protein interacting with apoptin from human leucocyte cDNA library by using yeast two-hybrid screening]

To screen the protein interacting with apoptin from human leucocyte cDNA library by using yeast two-hybrid system, four clones interacting with apoptin were identified. One of them was homologous with Nmi (N-Myc interaction protein). Cell co-immunoprecipitation showed that apoptin could bind to Nmi in mammalian cells. Apoptin mutants T1, T2 and T3 lacked the C-terminal 11 AA,33-46 AA and both,respectively. Apoptin mutants T2 and T3 failed to interact with Nmi, suggesting that its 33-46 AA was pivotal for the interaction. Apoptin mutant T1 still interacted with Nmi, suggesting that its C-terminal 11 AA was not essential for the interaction.

[Construction of transgenic rice populations by inserting the maize transponson Ac/Ds and genetic analysis for several mutants]

An efficient and rapid gene transformation system of rice mediated by Agrobacterium tumefaciens was used. Calli induced from immature and mature embryos of Zhonghua No. 11, a japonic rice variety, were cultured with the A. tumefaciens strain EHA105 harboring the superbinary plasmid pDsBar1300 or pUBITs separately, and more than 400 independent transgenic lines inserted Ds element or Ac fragment were obtained. Some visible mutants in T0 or T1 generation were found, consisting of disease resistance, albino, dwarf, male sterile, chlorosis, early heading, late heading, stripe, etc. From the phenotype analysis, a few mutants such as dwarf and male sterile seemed to be linked to the Basta resistance and the transposon.

[Cloning of E. coli mtl-D gene and its expression in transgenic Balizhuangyang (Populus)]

E. coli 1-phosphate mannitol dehydrogenase gene (mtl-D) was cloned using PCR method. Sequence analysis showed that the gene was the same as the published one except that codon CAT at position 416 was replaced by AAA and resulted in a Lys residue instead of His. This gene (mtl-D) was inserted in a binary vector and transformed into populas via agrobacteria. Several transgenic plants grow very well in 0.6% NaCl while controls can not survive even in 0.4% NaCl. PCR analysis and Northern blotting indicated that foreign gene was integrated into the genome of transgenic plant and transcribed successfully.

Effect of smoking on semen quality of infertile men in Shandong, China

AIM

To study the effect of smoking on the semen quality in infertile men in Shandong Province, China.

METHODS

Adult non-drinker males attending the infertility clinic, including 110 non-smokers and 191 smokers, were recruited for the study. Sixty-one fertile, non-smoker and non-drinker males, who had one or more children, served as the controls. The smokers were divided into subgroups according to the amount and duration of smoking. Semen parameters (semen volume and sperm density, viability, motility, and morphology) were examined and seminal plasma contents of Zn , Cu and superoxide dismutase (SOD) determined.

RESULTS

The semen volume and acidity, and the sperm density, viability and forward progression, as well as the seminal plasma contents of Zn, Cu and SOD were much lower in the medium, heavy and long-term smokers than in the non-smokers (P < 0.01). The sperm density, viability and forward progression, and the seminal plasma Zn, Cu and SOD levels were negatively correlated with the amount and duration of cigarette smoking (P < 0.01).

CONCLUSION

Medium, heavy and long-term smoking adversely affected the semen quality in a population of men visiting the infertility clinic in Shandong, China.

Surface Characteristics of Magnetite in Aqueous Suspension

Surface characteristics of magnetite at 25degreesC in aqueous suspensions are systematically studied. The measured specific surface area and concentration of proton binding sites correspond well to the calculated values. Zeta potential of magnetite in the absence of multivalent cations exhibits positive values in acidic solution and becomes negative with increasing pH. pHpzc is about 6. In the presence of excess cations such as Fe2+ or Fe3+, specific adsorption takes place at the surface of magnetite, which dramatically influences the value of zeta potential. The concentrations of soluble Fe ions at pH about 4.5 increase with solid concentrations of magnetite indicating some surface-related reaction mechanisms. Copyright 1998 Academic Press. Copyright 1998Academic Press

[The effects of gossypol on rat luteal cells, human decidual cells and cytotrophoblasts]

The direct effects of gossypol on the serum-free primary cultures of rat luteal cells and cytotrophoblasts were observed. The results indicate that: (1) Gossypol affected the viability of the cultured rat luteal cells, LD50: 1.6 (0.4-2.9) micrograms.ml-1. (2) The basal secretions of progesterone were significantly inhibited at low and high concentrations. The activities of 3 beta-HSD, adenyl cyclase and hCG-stimulated progesterone production were inhibited by higher concentrations of gossypol. (3) Gossypol damaged cultured human decidual cells and cytotrophoblasts, the LD50 were 3.5(0.4-6.6) micrograms.ml-1 and 4.1(0.6-7.6) micrograms.ml-1, respectively. These results suggest that the luteolytic effect is the main mechanism of action for the termination of early pregnancy by gossypol, while the direct damaging effects on decidual cells and cytotrophoblasts may also play a role in the termination of early pregnancy.

[The application of halo assay in analysis of cell chromatin structure]

Halo assay, a method for quantitative analysis of chromatin structure in cell, was developed recently. Due to visualization, feasibility, rapidity, and sensitivity of the method, it has been applied in radiobiology and cancer research. According to previous reports, with some improvement, this method has been established in our laboratory. Employing halo assay, the chromatin structure of two kinds of cell strain with similar genetic background and different radiosensitivity was analyzed and the results show that radiosensitive strain has looser chromatin structure than radioresistant one. It is possible that this difference is related to their different radiosensitivity, thus it's a proof for the relation of chromatin structure and radiosensitivity.

[Computed multifactorial analysis influencing long-term survival of gastric cancer radically resected]

During 1960 to 1982, 1,110 patients with gastric cancer were treated in our hospital. Four hundred and one patients were given radical operation and were followed with a rate of 100%. Basing on the multivariant analysis with Apple-plus minicomputer, a mathematical model was developed from joint affect (13 items, 34 factors) to predict the survival after radical operation. Two equations evaluating the prognosis were obtained according to two different methods: I. characteristic vector and stepwise regressive analysis; II. stepwise regressive analysis. The sensitivity of I and II methods was 0.84 and 0.82 in the intra-group check-up, 0.88 and 0.88 in the extra-group check-up, respectively. Their specificity was 0.81 and 0.77 in the intra-group check-up, 0.71 and 0.57 in the extra-group. I is better than II. According to the results of screening and operating, it is shown that there are five factors influencing the five year survival rate of gastric cancer patients, that is, invasion depth, growth fashion, gross type, lymph node metastasis and location of cancer. The five factors are very important in selecting the reasonable radical operation model and judging the prognosis.

Induction of gastric adenocarcinoma in rats by N-methyl-N-nitro-N-nitroso-guanidine and ultrastructural changes of epithelial cells of the pyloric gland region

Rats of non-pure strain were allowed to drink N-Methyl-N-Nitro-N-Nitroso-guanidine (MNNG) solution (200-250 micrograms per milliliter) ad libitum. After 14 months, in addition to MNNG, each of them was fed with 1 ml of saturated NaCl solution once a week. During a period of 18 months, there were 5 cases of gastric adenocarcinoma and 2 cases of adenocarcinoma of the duodenum among 18 experimental rats. Besides, there were a few cases of papilloma of the fore-stomach and carcinoma of the lung. In 17 control rats, no tumors of the gastro-intestinal tract were seen. Microscopic examination of the mucosa of the pyloric gland region of the stomach in the experimental rats showed that the deep epithelial cells of the gastric pit exhibited a marked degree of proliferation and a malignant change had started in these cells. Electron microscopic observation of these epithelial cells revealed that the the proliferating cells showed only increased nucleocytoplasmic ratio, while those with atypical hyperplasia showed that the form of the nucleus and the changes in the basement membrane and intercellular junctions were somewhat similar to those of malignant cells. It is believed that increase in concentration of the carcinogens and prolongation of the time of contact with them may induce malignant tumors in the insensitive animal.