[The cases of tracing the source of patients infected with Omicron variant of SARS-CoV-2 based on wastewater-based epidemiology in Shenzhen]

Wastewater-based epidemiology (WBE) is an emerging discipline, which has been applied to drug abuse tracking and infectious disease pathogen surveillance. During the COVID-19 epidemic, WBE has been applied to monitor the epidemic trend and SARS-CoV-2 variants etc. In order to detect hidden COVID-19 cases and prevent transmission in the community, wastewater surveillance system for monitoring SARS-CoV-2 RNA was developed in Shenzhen. The sewage sampling sites were set up in key places such as the port areas, urban villages and residential communities of Futian, Nanshan, Luohu and Yantian districts. From July 26 to November 30, 2022, a total of 369 sewage sampling sites were set up, covering 1.93 million people. Continuous sampling was carried out for 3 hours in the peak period of water use every day. Sewage virus enrichment and SARS-CoV-2 nucleic acid detection were carried out by polyethylene glycol precipitation method and RT-qPCR, and a positive water sample disposal process was molded. This article aims to introduce the case of source tracing of COVID-19 infected patients based on urban sewage in Shenzhen. The sewage monitoring of Honghu water treatment plant in Luohu District played an early warning role, and the source of infection was traced. In the disposal of positive water samples in Futian South Road, Futian District, the important experience of monitoring point layout was obtained. In the sewage monitoring of Nanshan village, Nanshan District, the existence of occult infection was revealed. Sharing the experience of tracing the source of COVID-19 patients to avoid the spread of COVID-19 in the community based on wastewater surveillance of SARS-CoV-2 RNA in Shenzhen, and summarizing the advantages and application prospects of sewage surveillance can provide new ideas for monitoring emerging or re-emerging pathogens that are known to exhibit gastrointestinal excretion in the future.

Worldwide trends in mortality for hypertensive heart disease from 1990 to 2019 with projection to 2034: data from the Global Burden of Disease 2019 study

AIMS

This study aims to analyse the worldwide trends in hypertensive heart disease (HHD) mortality and associations with age, period, and birth cohort and predict the future burden of HHD deaths.

METHODS AND RESULTS

Mortality estimates were obtained from Global Burden of Disease 2019 study. We used age-period-cohort (APC) model to examine the age, period, and cohort effects on HHD mortality between 1990 and 2019. Bayesian APC model was utilized to predict HHD deaths to 2034. The global HHD deaths were 1.16 million in 2019 and were projected to increase to 1.57 million in 2034, with the largest increment in low- and middle-income countries (LMICs). Between 1990 and 2019, middle/high-middle socio-demographic index (SDI) countries had the largest mortality reductions (annual percentage change = -2.06%), whereas low SDI countries saw a lagging performance (annual percentage change = -1.09%). There was a prominent transition in the age distribution of deaths towards old-age population in middle/high-middle SDI countries, while the proportion of premature deaths (aged under 60 years) remained at 24% in low SDI countries in 2019. Amongst LMICs, Brazil, China, and Ethiopia showed typically improving trends both over time and in recent birth cohorts, whereas 63 countries including Indonesia, the Philippines, and Pakistan had unfavourable or worsening risks for recent periods and birth cohorts.

CONCLUSION

The HHD death burden in 2019 is vast and is expected to increase rapidly in the next decade, particularly for LMICs. Limited progress in HHD management together with high premature mortality would exact huge human and medical costs in low SDI countries. The examples from Brazil, China, and Ethiopia suggest that efficient health systems with action on improving hypertension care can reduce HHD mortality effectively in LMICs.

[Predictive value of neutrophil-to-lymphocyte ratio and platelet-to-lymphocyte ratio for 28-day death in patients treated with extracorporeal membrane oxygenation]

The study aimed to evaluate the predictive value of the neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) for 28-day mortality in patients treated with extracorporeal membrane oxygenation (ECMO). Patients receiving ECMO treatment were selected from the Department of Intensive Care Medicine of Zhejiang Hospital from January 2019 to February 2022. The moment when patients started receiving ECMO treatment was set as the starting point, and death at 28 days was set as the endpoint. The patients were divided into survivors and deaths. Laboratory tests, such as neutrophil, lymphocyte, and platelet counts, using the peripheral blood of all patients were collected within 24 h after ECMO treatment. NLR and PLR were calculated. The risk factors influencing prognosis were analyzed by logistic regression. The correlation between NLR, PLR, acute physiology, and chronic health score Ⅱ (APACHE Ⅱ) was investigated. Receiver operating characteristic (ROC) curve analysis was used to analyze the value of NLR and PLR in predicting the 28-day mortality of patients treated with ECMO. Kaplan-Meier method was used to analyze the cumulative survival of patients at 28 days. The results showed that of 53 patients, 20 survived, and 33 died. The NLR and PLR of the deceased were higher than those of the survivors (NLR: 30.67±14.48 vs. 17.41±7.06;PLR: 303.34±159.23 vs. 191.54±106.03;P<0.001). NLR and PLR were positively correlated with APACHE Ⅱ (r=0.296, r=0.284, P<0.05). ROC curve analysis showed that the area under the curve (AUC) of NLR and PLR to predict the 28 d death of ECMO-treated patients was 0.805 and 0.714, respectively, and the optimal cutoff values of NLR and PLR were 18.93 and 253.0, respectively. The 28-day fatality rate in patients with NLR≥18.93 was higher than that in patients with NLR<18.93 [86.20%(25/29) vs. 33.33%(8/24), χ²=15.625, P<0.01],that in patients with a PLR≥253.0 was higher than that in patients with PLR<253.0 [82.61%(19/23) vs. 46.67%(14/30), χ²=7.158, P<0.01]. Kaplan-Meier survival curve showed that the 28-day cumulative survival rate of NLR≥18.93 was lower than that of NLR<18.93 [9.00 (2.00, 19.50) d vs. 28.00 (10.75, 28.00) d, Z=-3.124, P<0.01], and that of PLR≥253.0 was lower than that of PLR<253.0 [6.00 (2.00, 19.00) d vs. 28.00 (6.25, 28.00) d, Z=-2.673, P<0.01]. Thus, NLR and PLR have good predictive value for 28-day mortality in patients treated with ECMO.

[Scalp-nape acupuncture as adjuvant therapy for pharyngeal dysphagia of stroke at recovery stage: a randomized controlled trial]

OBJECTIVE

To observe the therapeutic effect of scalp-nape acupuncture for pharyngeal dysphagia of stroke at recovery stage on the basis of neuromuscular electrical stimulation (NMES) and rehabilitation training.

METHODS

A total of 42 patients with pharyngeal dysphagia of stroke at recovery stage were randomized into an observation group and a control group, 21 cases in each group. Conventional medical symptomatic treatment was given in both groups. NMES and rehabilitation training were adopted in the control group, 30 min for each one. On the basis of the treatment in the control group, scalp-nape acupuncture was given in the observation group, scalp acupuncture was applied at lower 2/5 of anterior and posterior oblique lines of parietal and temporal, nape acupuncture was applied at Fengchi (GB 20), Yiming (EX-HN 14), Gongxue (Extra), Zhiqiang (Extra), Tunyan (Extra), etc. The treatment was given once a day, 5 days a week for 3 weeks in both groups. Before and after treatment, the videofluoroscopic dysphagia scale (VDS) score, the Kubota water swallowing test grade, the functional oral intake scale (FOIS) grade and the swallowing quality of life (SWAL-QOL) score were observed in both groups.

RESULTS

After treatment, the VDS scores were decreased and the SWAL-QOL scores were increased compared before treatment (P<0.05), the Kubota water swallowing test grade and FOIS grade were improved compared before treatment (P<0.05) in both groups. The changes of VDS score and SWAL-QOL score, Kubota water swallowing test grade and FOIS grade in the observation group were superior to those in the control group (P<0.05).

CONCLUSION

Based on NMES and rehabilitation training, scalp-nape acupuncture can enhance the therapeutic effect on pharyngeal dysphagia of stroke at recovery stage, and improve the patients' swallowing function and quality of life.

Effectiveness of a Multifaceted Intervention for Prevention of Obesity in Primary School Children in China: A Cluster Randomized Clinical Trial

IMPORTANCE

A rapid nutritional transition has caused greater childhood obesity prevalence in many countries, but the repertoire of effective preventive interventions remains limited.

OBJECTIVE

To determine the effectiveness of a novel multifaceted intervention for obesity prevention in primary school children.

DESIGN, SETTING, AND PARTICIPANTS

A cluster randomized clinical trial was conducted during a single school year (from September 11, 2018, to June 30, 2019) across 3 socioeconomically distinct regions in China according to a prespecified trial protocol. Twenty-four schools were randomly allocated (1:1) to the intervention or the control group, with 1392 eligible children aged 8 to 10 years participating. Data from the intent-to-treat population were analyzed from October 1 to December 31, 2019.

INTERVENTIONS

A multifaceted intervention targeted both children (promoting healthy diet and physical activity) and their environment (engaging schools and families to support children's behavioral changes). The intervention was novel in its strengthening of family involvement with the assistance of a smartphone app. The control schools engaged in their usual practices.

MAIN OUTCOMES AND MEASURES

The primary outcome was the change in body mass index (BMI; calculated as weight in kilograms divided by height in square meters) from baseline to the end of the trial. Secondary outcomes included changes in adiposity outcomes (eg, BMI z score, prevalence of obesity), blood pressure, physical activity and dietary behaviors, obesity-related knowledge, and physical fitness. Generalized linear mixed models were used in the analyses.

RESULTS

Among the 1392 participants (mean [SD] age, 9.6 [0.4] years; 717 boys [51.5%]; mean [SD] BMI, 18.6 [3.7]), 1362 (97.8%) with follow-up data were included in the analyses. From baseline to the end of the trial, the mean BMI decreased in the intervention group, whereas it increased in the control group; the mean between-group difference in BMI change was -0.46 (95% CI, -0.67 to -0.25; P < .001), which showed no evidence of difference across different regions, sexes, maternal education levels, and primary caregivers (parents vs nonparents). The prevalence of obesity decreased by 27.0% of the baseline figure (a relative decrease) in the intervention group, compared with 5.6% in the control group. The intervention also improved other adiposity outcomes, dietary, sedentary, and physical activity behaviors, and obesity-related knowledge, but it did not change moderate- to vigorous-intensity physical activity, physical fitness, or blood pressure. No adverse events were observed during the intervention.

CONCLUSIONS AND RELEVANCE

The multifaceted intervention effectively reduced the mean BMI and obesity prevalence in primary school children across socioeconomically distinct regions in China, suggesting its potential for national scaling.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03665857.

[Early reduction of serum RANTES can predict HBsAg clearance in patients with chronic hepatitis B treated with nucleos(t)ide analogues combined with peginterferon alpha]

Objective: To observe the dynamic changes of serum RANTES during the treatment with nucleos(t)ide analogues combined with pegylated interferon alpha (peginterferon-α), and further analyze the predictive effect of RANTES on HBsAg clearance in patients with chronic hepatitis B. Methods: 98 cases of chronic hepatitis B with quantitative HBsAg < 3 000 IU/ml and HBV DNA < 20 IU/ml after≥1 year NAs treatment were enrolled. Among them, 26 cases continued to receive NAs monotherapy, 72 cases received NAs combined with pegylated interferon alpha therapy. The changes in RANTES during treatment were observed. The receiver operating characteristic curve was used to analyze the early changes of RANTES to predict the HBsAg clearance during 48 weeks. Results: During 48 weeks, 15 cases (20.83%) had achieved HBsAg clearance in combination group, while no patient had achieved HBsAg clearance in NAs group. The overall serum RANTES level had decreased from baseline in NAs and combination group. At week 48, in the combination group, the serum RANTES level was decreased more significantly in patients with HBsAg clearance than patients without. Further analysis showed that, in combination group, HBsAg clearance rate of patients with serum RANTES decreased at week 12 and 24 was higher than patients with elevated (29.17% vs. 4.17%, P = 0.014; 28.00% vs. 4.55%, P = 0.052), and quantitative HBsAg reduction was larger significantly [(1.49 ± 1.26) log(10)IU/ml vs. (0.73 ± 0.81) log(10)IU/ml, P = 0.017; (1.54 ± 1.27) log(10)IU/ml vs. (0.57 ± 0.56) log(10)IU/ml, P = 0.004]. Receiver operating characteristic curve analysis showed that the baseline quantitative HBsAg and the reduction in quantitative HBsAg and serum RANTES during the early period were predictors of HBsAg clearance after 48-week combination therapy. Furthermore, the combination of baseline quantitative HBsAg and 12 - or 24-week reduction of serum RANTES were better predictors of HBsAg clearance than that of baseline quantitative HBsAg combined with HBsAg decrease at week 12 or 24. The area under the receiver operating characteristic curve of the former was 0.925 and 0.939, while that of the latter was 0.909 and 0.929, respectively. Conclusion: Early reduction of serum RANTES at week 12 and 24 can predict HBsAg loss in CHB patients receiving addition of peginterferon-α to ongoing NAs Therapy, so serum RANTES could be one of the key immunological markers for predicting HBsAg clearance.

Upregulation of SNHG12 accelerates cell proliferation, migration, invasion and restrain cell apoptosis in breast cancer by enhancing regulating SALL4 expression via sponging miR-15a-5p

Breast cancer (BC) is malignant cancer that threatens the health of millions of females worldwide. Long non-coding RNA (lncRNA) small nucleolar RNA host gene 12 (SNHG12) has been identified as an oncogene in multiple cancers. However, the regulatory role of SNHG12 in BC cell progression is still obscured. The levels of SNHG12, miR-15a-5p, and Sal-like 4 (SALL4) in BC tumor tissues and cells were measured by qRT-PCR. Cell viability, apoptosis, migration, and invasion were examined by CCK8, flow cytometry, and transwell assay, respectively. The interaction between miR-15a-5p and SNHG12 or SALL4 was evaluated by dual-luciferase reporter assay. Protein expression of SALL4 was analyzed by western blot. Xenograft mice were established by subcutaneously injecting BC cells stably transfected with sh-SNHG12 and sh-NC. SNHG12 and SALL4 expressions were upregulated whereas miR-15a-5p was downregulated in BC tumors compared with normal tissues. Besides, miR-15a-5p was correlated with SNHG12 and SALL4 inversely as calculated by Pearson's correlation coefficient. More importantly, SNHG12 knockdown attenuated BC tumor growth in vitro and in vivo. Subsequently, dual-luciferase reporter assay confirmed the interaction between miR-15a-5p and SNHG12 or SALL4. The rescue experiments revealed that miR-15a-5p inhibitor restored SNHG12 silencing induced inhibition on BC cell proliferation, migration, invasion, and promotion of apoptosis. Additionally, SNHG12 was found to accelerate BC cell progression by absorbing miR-15a-5p to enhance SALL4 expression. SNHG12 promotes cell proliferation, migration, and invasion but suppresses apoptosis in BC by upregulating SALL4 expression via sponging miR-15a-5p, representing potential targets for the development of novel diagnosis and treatment methods.

Effect of Conduction Band Non-Parabolicity on the Nonlinear Optical Properties in GaAs/Ga1-xAlxAs Double Semi-V-shaped Quantum Wells

In this paper, we investigate the effect of conduction band non-parabolicity (NPBE) on the third harmonic generation(THG), the linear and nonlinear intersub-band optical absorption coefficients (OACs) related with electronic states of double semi-V-shaped GaAs/Ga_1−xAl_xAs quantum wells(QWs) by using the compact-density-matrix approach. Simultaneously, the work is performed in the position dependent effective mass in order to compute the electronic structure for the system by the finite difference and self-consistent techniques. We also compare the results with and without considering NPBE. It is found that: (1) the NPBE has a significant influence on the sub-band energy levels of double semi-V-shaped QWs, and (2) the amplitude and position of the resonant peaks of the THG and nonlinear OACs in the case of considering NPBE show complicated behavior due to the energy dependent effective mass m*(E) where the energy value was chosen self-consistently.

[Trichloroethylene-induced abnormal methylation on promoter region of SET in hepatic L-02 cells]

Objective: To explore the trichloroethylene-induced alteration of methylation on the promoter region of SET and related mechanisms in hepatic L-02 cells. Methods: L-02 cells were treated with different concentrations of TCE(0 mmol/L, 1 mmol/L, 2 mmol/L, 4 mmol/L, 8 mmol/L) for 24 h. The genomic DNA were then extracted and modified by bisulfite sodium. The DNA methylation was then analyzed using bisulfite sequencing PCR (BSP). Results: The overall methylation on promoter region of SET was decreased along with the increased concentrations of TCE in hepatic L-02 cells. Moreover, 73 CpG islands were found abnormally altered, among which 9 were predicted in transcriptional factor binding regions. Conclusion: The decreased levels of CpG islands in the transcriptional factor binding region may contribute to the elevation of SET in TCE-induced hepatotoxicity.

[Analysis on the gender-specific risk factors of new-onset cerebral hemorrhage]

Objective: To explore the gender-specific risk factors of new-onset cerebral hemorrhage. Methods: In this prospective cohort study,a total of 98 961 participants((51.1±12.6)years old), who underwent the 2006 to 2007 physical examination and met the inclusion criteria, were enrolled from the Kailuanstudy cohort. There were 78 908 (79.7%) male,and 20 053 (20.3%) female.The incidence of cerebral hemorrhage was observed once per year until December 31, 2016.The difference on the incidence of cerebral hemorrhage between male and female was compared. Multivariate Cox regression analysis was applied to analyze therisk factors of cerebral hemorrhage events among different genders. Results: The participants were followed up for(10.00±0.73) years,and 860 cerebral hemorrhage events were recorded during follow up. The incidence of cerebral hemorrhage in the population was 86.90/10 million person years (standardized incidence rate of 47.85/10 million person years). The incidence of cerebral hemorrhage was significantly higher in male (49.61/10 million person years) than in female (34.07/10 million person years, P<0.05). Multivariate Cox regression analysis showed that 45-59 years old, ≥ 60 years old, diabetes,and waist-hip ratio were more strongly related to new-onset of cerebral hemorrhage events in female than in male, and the hazard ratios(95%CI) were 2.33 (1.23-4.43) ,2.71 (1.30-5.66) ,2.16 (1.24-3.74) and 8.79 (1.42-54.32) in female versus 1.55 (1.21-1.97) ,2.16 (1.68-2.78) ,1.19 (0.93-1.53) and 3.21 (1.09-9.41) in male, respectively. The risk of male cerebral hemorrhage increased by 29% (HR=1.29, 95%CI 1.19-1.40) in male and 24% (HR=1.24, 95%CI 1.20-1.28) in female,when the systolic blood pressure increased 10 mmHg (1 mmHg=0.133 kPa). Conclusions: The incidence of cerebral hemorrhage is higher in male than in female in this cohort.The association between systolic blood pressure and cerebral hemorrhage is stronger in male than that in female.The associations between age, waist-hip ratio, diabetes and cerebral hemorrhage are stronger in female than in male. Trial Registration: Chinese Clinical Trail Registry, ChiCTR-TNC-11001489.

Design of Stretchable Electronics Against Impact

Stretchable electronics offer soft, biocompatible mechanical properties; these same properties make them susceptible to device failure associated with physical impact. This paper studies designs for stretchable electronics that resist failure from impacts due to incorporation of a viscoelastic encapsulation layer. Results indicate that the impact resistance depends on the thickness and viscoelastic properties of the encapsulation layer, as well as the duration of impact. An analytic model for the critical thickness of the encapsulation layer is established. It is shown that a commercially available, low modulus silicone material offers viscous properties that make it a good candidate as the encapsulation layer for stretchable electronics.

A Mechanics Model for Sensors Imperfectly Bonded to the Skin for Determination of the Young's Moduli of Epidermis and Dermis

A mechanics model is developed for the encapsulated piezoelectric thin-film actuators/sensors system imperfectly bonded to the human skin to simultaneously determine the Young's moduli of the epidermis and dermis as well as the thickness of epidermis.

[A comparation of efficacy between unilateral laminectomy approach bilateral decompression and traditional total laminectomy decompression in the treatment of lumbar spinal stenosis]

OBJECTIVES

To compare the efficacy between unilateral laminectomy approach bilateral decompression and traditional total laminectomy decompression in the treatment of graft bone fusion and internal fixation for degenerative lumbar spinal stenosis with the unilateral symptoms.

METHOD

From January 2013 to December 2014, a total of 40 patients with unilateral symptoms of lumbar spinal stenosis were treated in Department of Spinal Surgery Bozhou People's Hospital of Anhui Province. Twenty patients(group A ) were treated by severe symptoms unilateral facetectomy and resection of superior articular and laminectomy and lateral recess decompression, interbody fusion, pedicle screw fixation.Twenty patients(group B ) were treated by total laminectomy interbody fusion and pedicle screw fixation.The time of operation, blood loss of the two groups were recorded.At the same time the visual analog scale (VAS), Oswestry disability index(ODI), Japanese Orthopaedic Association Scores(JOA) before and after operation (3, 6 , 12months) were recorded retrospectively. The effect of surgery were evaluated and compared.

RESULT

The VAS, JOA, and ODI of group A preoperation is respectively have no significant differences with the group B (P>0.05). The operation time, blood loss in operation of group A was respectively(133.2±25.3) min, (415.0±42.1) ml, significant differences with the group B[(491.0±46.3)ml; (156.2±28.5) min, P<0.05)]. The VAS, JOA, ODI of group A had no significant differences with the group B (P>0.05) at 3, 6 months after operation.The VAS, JOA, ODI of group A was respectively (3.0±0.6), (25.3±5.1), (16.5±1.5)scores, had significant differences with the group B and preoperation (P<0.05) at 12 months after operation. The radiographic data showed that the interbody fusion rate of group A was 100%, and group B was 95%, had significant differences by statistical analysis (P<0.05) at 12 months afer operation.

CONCLUSION

The improved unilateral laminectomy approach and bilateral decompression have less operation time and blood loss, more satisfactory for the lumbar spinal stenosis patients with the unilateral severe symptoms, the other side moderate stenosis and mild symptoms.The efficacy of lumbar stability and bilateral decompression is better by operation of improved unilateral approach.

Doubly Q-switched Ho:LuAG laser with acoustic-optic modulator and Cr²⁺:ZnS saturable absorber

A doubly Q-switched (DQS) Ho:LuAG laser resonantly pumped by a 1.91-μm laser was first presented with an acoustic-optic modulator (AOM) and a Cr2+:ZnS saturable absorber. A comparison among the active Q-switched (AQS), passively Q-switched (PQS), and DQS laser performances was carried out. The maximum continuous wave (CW) output power of 6 W with the central wavelength of 2100.65 nm was obtained at an incident pump power of 35.2 W. Compared with CW laser, the AQS, PQS, and DQS lasers shared the same central wavelength of 2098.34 nm under the same incident pump power. The central wavelength of the AQS and DQS lasers remained constant with the change of AOM repetition frequency (RF). When the incident pump power was 35.2 W and the AOM RF was 15 kHz, the DQS Ho:LuAG laser at a maximum RF of 2.13 kHz achieved the maximum average output power of 4.95 W. At the AOM RF of 10 kHz, the DQS Ho:LuAG laser achieved the shortest pulse width of 40.4 ns with the highest peak power of 61.5 kW. At an incident pump power of 35.2 W, the PQS Ho:LuAG laser obtained the shortest pulse width of 46.1 ns, corresponding to the RF of 2.25 kHz. Experiment results showed that the pulse width could be compressed effectively with a significant increase of peak power for a 2-μm DQS laser.

Polymorphism and haplotype analyses of swine leukocyte antigen DQA exons 2, 3, 4, and their associations with piglet diarrhea in Chinese native pig

In this study, 290 Chinese native Yantai black pig piglets were investigated to identify gene polymorphisms, for haplotype reconstruction, and to determine the association between piglet diarrhea and swine leukocyte antigen (SLA) class II DQA exons 2, 3, and 4 by polymerase chain reaction-single stranded conformational polymorphism and cloning sequencing. The results showed that the 5, 8, and 7 genotypes were identified from SLA-DQA exon 2, 3, and 4, respectively, based on the single-stranded conformational polymorphism banding patterns and found a novel allele D in exon 2 and 2 novel mutational sites of allele C (c.4828T>C) and allele F (c.4617T>C) in exon 3. Polymorphism information content testing showed that exon 2 was moderately polymorphic and that exons-3 and -4 loci were highly polymorphic. The piglet diarrhea scores for genotypes AB (1.40 ± 0.14) and AC (1.54 ± 0.17) in exon 2, AA (1.22 ± 0.32), BC (1.72 ± 0.13), DD (1.67 ± 0.35), and CF (1.22 ± 0.45) in exon 3, and AD (2.35 ± 0.25) in exon 4 were significantly higher than those for the other genotypes (P ≤ 0.05) in DQA exons. There were 14 reconstructed haplotypes in the 3 exons from 290 individuals and Hap12 may be the diarrhea-resistant gene. Haplotype distribution was extremely uneven, and the SLA-DQA gene showed genetic linkage. In this study, we identified molecular genetic markers and provided a theoretical foundation for future pig anti-disease resistance breeding.

Output characteristics of actively Q-switched Ho:LuVO₄ laser at room temperature

A compact continuous wave (CW) and actively Q-switched (AQS) Ho:LuVO4 laser pumped by a 1.94 μm Tm: YAP laser is demonstrated. The performance of the laser was investigated by changing the output coupler. The maximum output power of 4.1 W at 2058.43 nm in CW regime is obtained at the maximum absorbed pump power of 12.3 W. The minimum pulse width of 29.3 ns was obtained at Pulse Repetition Frequency (PRF) of 20 kHz with the same output coupler corresponding to a peak power of 6.9 kW. The maximal output power is 4.1 W with center wavelength of 2058.43 nm at PRF of 40 kHz, corresponding to slope efficiency of 43.0% with respect to absorbed pump power. The M2 factors measured by the traveling knife-edge method are 1.04 in parallel a-axis and 1.08 in parallel c-axis with diffraction limited beam quality.

Study on the application of Raman spectroscopy on detecting water hardness

Laser Raman spectrum method was used to study the hardness index of four water samples. The ratio of bending vibration peak intensity to stretching vibration peak intensity of these water samples was measured. The results showed that as the total hardness of water decreases, so does the ratio. This offers a possible new approach to water quality analysis that is both simple and effective.

Chromium(VI) causes down regulation of biotinidase in human bronchial epithelial cells by modifications of histone acetylation

Hexavalent chromium (Cr(VI)), a commonly used industrial metal, is a well-known mutagen and carcinogen, and occupational exposure can induce a broad spectrum of adverse health effects, including cancers. Although Cr(VI)-induced DNA damage is thought to be the primary mechanism of chromate genotoxicity and mutagenicity, there is an increasing number of reports showing that epigenetic mechanisms of gene regulation might be a central target of Cr(VI) toxicity. Epigenetic changes, such as changes in phosphorylation, altered DNA methylation status, histone acetylation and signaling pathways, have been observed after chromium exposure. Nevertheless, to better demonstrate the roles of epigenetic modifications in Cr(VI)-induced carcinogenesis, more work needs to be carried out. This study is aimed to investigate changes in biotinidase (BTD) and holocarboxylase synthetase (HCS), two major proteins which maintain homeostasis of the newfound epigenetic modification: histone biotinylation, in cells exposed to Cr(VI). The data showed that Cr(VI) decreased BTD expression at the transcriptional level in human bronchial epithelial cells (16HBE). In addition, using the epigenetic modifiers, 5-Aza-2'-deoxycytidine (Aza) and Trichostatin A (TSA), we found that modifications of histone acetylation reversed the inhibition of BTD, suggesting that Cr(VI) may cause down regulation of BTD by modifications of histone acetylation.

3 T MR cholangiopancreatography appearances of biliary ascariasis

AIM

To evaluate the 3 T MR cholangiopancreatography (MRCP) appearances of biliary ascariasis.

MATERIALS AND METHODS

Nine patients with a MRCP diagnosis of biliary ascariasis were reviewed. All patients had endoscopic retrograde cholangiopancreatography (ERCP) or surgical confirmation of the disease.

RESULTS

On thin-slab MRCP imaging, Ascaris worms are clearly demarcated within the biliary tree. All the identified worms demonstrated a characteristic three-parallel-lines appearance. The middle high-signal intensity line is sandwiched between two low-signal intensity lines and they are in turn surrounded by high signal bile. On thick-slab MRCP the worms also show the three-line sign but with less clarity. However, thick-slab MRCP has the advantage of providing three-dimensional ERCP-like images of the pancreaticobiliary system.

CONCLUSION

The "three-line" sign appears to be a characteristic sign of biliary ascariasis on 3 T MRCP.

[Effect of cadmium chloride on the expression and phosphorylation of mitogen-activated protein kinase in normal rat kidney epithelial cells]

OBJECTIVE

To explore the effect of cadmium chloride on the expression and phosphorylation of mitogen-activated protein kinase (MAPK) in normal rat kidney epithelial (NRK) cells.

METHODS

The NRK cells were incubated with cadmium chloride either at respective dose (0, 1, 5, 10, 20, 40 µmol/L) for 24 h or at same dose (10 µmol/L) for respective time (0, 0.5, 1.0, 2.0, 4.0, 8.0 h). Western blotting was applied to test the expression of MAPK in NRK cells (ERK1/2, p38, JNK); and phosphor-specific antibody to detect the phosphorylated MAPK (p-ERK1/2, p-p38, p-JNK).

RESULTS

There was no significant difference in the MAPK expression among the groups either treated with different doses or for different time; however, the level of phosphorylated MAPK was comparatively higher than it in control group. There was an obvious expression of p-ERK1/2 at 1.00 ± 0.06 in the group incubated with 10 µmol/L CdCl(2); and the expression in the 20 µmol/L and 40 µmol/L CdCl(2) group was 2.58 ± 0.11, 2.76 ± 0.23 respectively, which was 1.58 and 1.76 times more than it in 10 µmol/L CdCl(2) group. The differences were statistically significant (F = 827.70, P < 0.01). The respective expression of p-p38MAPK in the 20 µmol/L (2.47 ± 0.20)and 40 µmol/L CdCl(2) group (3.73 ± 0.25)was 1.47 and 2.73 times more than it in control group (1.00 ± 0.02), and the differences were also statistically significant (F = 280.06, P < 0.01). There was a dose-effect relationship of the concentration of cadmium in the expression of p-ERK1/2 (r = 0.919, t = 4.69, P = 0.009) and p-p38MAPK (r = 0.945, t = 5.79, P = 0.004). Additionally, phosphorylated MAPK expressed in a time-dependent manner. The expression of p-ERK1/2 was obvious in the group incubated for 1 h (1.26 ± 0.11), and the respective expression in the 4 h group (1.51 ± 0.07) and 8 h group (3.53 ± 0.23) was 1.5 and 3.5 times of it in the control group (1.00 ± 0.02). The differences were statistically significant (F = 427.82, P < 0.001). The expression of p-p38MAPK increased significantly in 1 h group (1.31 ± 0.07); while the respective expression in 4 h group (3.53 ± 0.32) and 8 h group (4.41 ± 0.38) was 3.5 and 4.4 times of it in control group (1.00 ± 0.03). The differences were also statistically significant (F = 280.06, P < 0.001).

CONCLUSION

Cadmium chloride could significantly enhance the phosphorylation of MAPK in NRK cells; and it is probably associated with the activation of MAPK.

Breast cancer resistance protein expression and 5-fluorouracil resistance

OBJECTIVE

To filtrate breast cancer resistance protein (BCRP)-mediated resistant agents and to investigate clinical relationship between BCRP expression and drug resistance.

METHODS

MTT assay was performed to filtrate BCRP-mediated resistant agents with BCRP expression cell model and to detect chemosensitivity of breast cancer tissue specimens to these agents. A high performance liquid chromatography (HPLC) assay was established, and was used to measure the relative dose of intracellular retention resistant agents. RT-PCR and immunohistochemistry (IHC) were employed to investigate the BCRP expression in breast cancer tissue specimens.

RESULTS

MTT assay showed that the expression of BCRP increased with the increasing resistance of 5-fluorouracil (5-Fu) (P<0.05, n=3) in the cell model, while HPLC assay indicated that the intracellular retention dose of 5-Fu was significantly correlated with the expression of BCRP (r=-0.897, P<0.05, n=3). A total of 140 breast cancer tissue specimens were collected. BCRP-positive expression was detected in forty-seven specimens by both RT-PCR and IHC. As shown by MTT assay subsequently, the resistance index (RI) of 47 BCRP-positive breast cancer tissue specimens to 5-Fu was 7-12 times as high as that of adjacent normal tissue samples. BCRP expression was related to 5-Fu resistance (R2=0.8124, P<0.01).

CONCLUSION

Resistance to 5-Fu can be mediated by BCRP. Clinical chemotherapy for breast cancer patients can be optimized based on BCRP-positive expression.

[Study on the relationship between breast cancer resistance protein expression and 5-fluorouracil resistance]

OBJECTIVE

To screen breast cancer resistance protein BCRP-mediated resistance agents and to investigate the relations between BCRP expression and drug resistance.

METHODS

MT assay was performed to screen BCRP-mediated resistant agents with established BCRP expression cell model. While, the high performance liquid chromatography (HPLC) assay was administrated to measure the related dosage of intracellular retention resistant agents. The BCRP expression was investigated by both real-time RT-PCR and immunohistochemistry (IHC) assay in 140 clinical breast cancer tissue specimens. Chemosensitivity to resistant agents for clinical breast cancer tissue specimens was analyzed by MT assay. The Nonparametric variance statistics method was used to analyze the correlations between clinical breast cancer tissue of BCRP expression and drug resistance.

RESULTS

MT assay showed that increasing resistance of 5-fluorouracil (5-Fu) climbed with the increases of the BCRP expressions by 10.58 times (P < 0.05, n = 3) in cell model. HPLC assay also proved that a significant negative correlation between the intracellular retention dose of 5-Fu with different expression of BCRP (r = -0.897, P < 0.05, n = 3). Forty-seven tissue specimens of BCRP-positive expression were rapidly determined by using both real-time RT-PCR and IHC in 140 clinical breast cancer tissue specimens. Subsequently, the resistance index (RI) for 47 BCRP-positive clinical breast cancer tissues to 5-Fu was shown from 7 to 12 times compared with normal cancer-side tissues through MT assay. The statistical correlation between BCRP expression and 5-Fu resistance was observed in clinical breast cancer tissue specimens (R2 = 0.8124, P < 0.01).

CONCLUSION

This study results showed that there is a significant relationship between BCRP expression and 5-Fu resistance. Moreover, the results suggest that the chemotherapy scheme could be optimized on BCRP-positive expression breast cancer patients.

Possible role of DNA polymerase beta in protecting human bronchial epithelial cells against cytotoxicity of hydroquinone

OBJECTIVE

To explore the toxicological mechanism of hydroquinone in human bronchial epithelial cells and to investigate whether DNA polymerase beta is involved in protecting cells from damage caused by hydroquinone.

METHODS

DNA polymerase beta knock-down cell line was established via RNA interference as an experimental group. Normal human bronchial epithelial cells and cells transfected with the empty vector of pEGFP-C1 were used as controls. Cells were treated with different concentrations of hydroquinone (ranged from 10 micromol/L to 120 micromol/L) for 4 hours. MTT assay and Comet assay [single-cell gel electrophoresis (SCGE)] were performed respectively to detect the toxicity of hydroquinone.

RESULTS

MTT assay showed that DNA polymerase beta knock-down cells treated with different concentrations of hydroquinone had a lower absorbance value at 490 nm than the control cells in a dose-dependant manner. Comet assay revealed that different concentrations of hydroquinone caused more severe DNA damage in DNA polymerase beta knock-down cell line than in control cells and there was no significant difference in the two control groups.

CONCLUSIONS

Hydroquinone has significant toxicity to human bronchial epithelial cells and causes DNA damage. DNA polymerase beta knock-down cell line appears more sensitive to hydroquinone than the control cells. The results suggest that DNA polymerase beta is involved in protecting cells from damage caused by hydroquinone.

[Research on differential display genes of tolerant-damage induced by trichloroethylene]

OBJECTIVE

To observe the differentially expressed genes of the human normal liver cell (L-02) induced by low concentration of trichloroethylene (TCE).

METHODS

The dose-effect relation of TCE toxicity was analyzed by means of MTT. 5 micromol/L was chosen as low concentration while 40 micromol/L as high concentration. Then L-02 were treated with low concentration, high concentration, pretreated with low concentration then attacked with high concentration of TCE respectively. Fluorescence differential display polymerase chain reaction (Fluoro DD-PCR) was used to search differentially expressed genes of the different treatment groups of TCE. Results 51 differential expressed strap were found, 11 differential straps have been cloned and sequenced. 9 of them were known gene, while 2 of them were new genes.

CONCLUSION

The differential straps would be identified to provide scientific base for research deeply the mechanism of low concentration TCE inducing adaptive response of L-02.

[Study on differential display genes of tolerant-damage of MRC-5 induced by formaldehyde of low dose]

OBJECTIVE

To observe the differentially expressed genes of the human embryo lung fibroblast (MRC-5) induced by formaldehyde (FA) of low dose using fluoro DD-PCR.

METHODS

The dose-effect relation of FA toxicity to MRC-5 was acquired, No observed damage effect or proliferation concentration was used as low dose, and obvious damage concentration was used as high dose. MRC-5 was treated with low and high dose, and treated with high dose after pretreated with low dose for some time. Then Fluoro differential display polymerase chain reaction (Fluoro DD-PCR) was used to search differentially expressed genes of the differently treated groups of FA. 61 differential display straps were acquired and 11 of them were reamplified, cloned, sequenced and blasted.

RESULTS

According to the dose-effect relation of FA toxicity to MRC-5, 100 micromol/L was choosed as low dose and 10 mmol/L was choosed as high dose. Samples of differently treated groups were amplified by means of fluro-DD-PCR, 61 differentially expressed straps were acquired. 11 differential display straps have been cloned, sequenced and blasted. Two of them were known genes: one was highly homologous to nuclear factor of activated T-cells 5 (NFAT5) and the other was highly homologous to tetratricopeptide repeat domain 3(TPRD-3). Nine of them were new genes.

CONCLUSION

It seemed that FA of low dose could promote MRC-5 proliferation and find 61 differentially expressed genes of differently treated groups, and the result of clone could provide scientific base for mechanism of FA toxicity research.

[Expression establishment and functional analysis of breast cancer resistance protein with doxycycline induced tet regulating system in mouse fibroblast cell line PA317]

BACKGROUND & OBJECTIVE

Breast cancer resistance protein (BCRP), discovered in 1998, is a novel member of ATP-binding cassette (ABC) membrane transporters superfamily. This study was to establish the functional expression of BCRP with doxycycline (Dox) induced Tet regulating system in mouse fibroblast cell line PA317, provide an ideal experimental platform for understanding the mechanism of BCRP-mediated drug resistance, and develop effective methods to reverse the drug-resistance.

METHODS

Tet-on regulating plasmid was transferred into PA317 cells under the Dox induced Tet-on regulating system, and stable expression of Tet-on was established in PA317 cells through G418 selection. The response plasmid of recombinant pTRE-BCRP was transferred into positive PA317/Tet-on cells, and stable expression of BCRP was established through hygromycin selection. Six single cellular clones were taken and cultivated in amplification. Positive PA317/Tet-on/TRE-BCRP cells, which showed well dose-response in expression of BCRP with different concentration of Dox induction, were selected by both reverse transcriptase-polymerase chain reaction (RT-PCR) and Western blot. The inhibitory effects of mitoxantrone on positive PA317/Tet-on/TRE-BCRP cells with various concentrations of Dox induction were detected by MTT method. Ko143, a specific inhibitor of BCRP, was used to detect the drug sensitivity of positive PA317/Tet-on/TRE-BCRP cells to mitoxantrone. Fluorescence intensity of remaining intracellular mitoxantrone in positive PA317/Tet-on/TRE-BCRP cells with different expression of BCRP was analyzed by flow cytometry (FCM).

RESULTS

The positive No.5 PA317/Tet-on /TRE-BCRP cell clone showed well dose-response in expression of BCRP with different concentration of Dox induction; its drug-resistance against mitoxantrone has positive correlation with BCRP expression (r=0.995, P=0.002); its drug sensitivity to mitoxantrone was significantly enhanced by Ko143 (P< 0.05). Furthermore, different expression of BCRP induced by various concentrations of Dox caused different intracellular mitoxantrone retention in this cell clone.

CONCLUSION

Functional expression of BCRP under Dox induced Tet regulating system was successfully established in PA317 cells, which provided an ideal experimental platform for further study of BCRP.

Stage-specific expression of leukaemia inhibitory factor and its receptor in rabbit pre-implantation embryo and uterine epithelium during early pregnancy

Leukaemia inhibitory factor (LIF) has been shown to play an important role in the development and implantation of blastocysts in mice. In the current study, the reverse transcription-polymerase chain reaction (RT-PCR) was employed to examine the expression patterns of LIF and its receptor (LIFR) genes in rabbit embryos during pre-implantation development, and the uterine expression of LIF and LIFR was also evaluated by Western blotting. Transcripts for LIFR were detected within morula and blastocyst-stage embryos, while the LIF mRNA was only found in blastocysts (from early to fully expanded blastocoel cavities), indicating that embryo-derived LIF can act in an autocrine manner on the process of blastocyst formation. The expression levels of LIF and LIFR in uterine epithelium were gradually increased during pre-implantation period and reached their highest levels on days 6.5 of pregnancy, just before the time of blastocyst implantation, suggest that paracrine LIF circuit should exist between the endometrium and the early embryos, which may be involved in the embryo-maternal dialogue and important for the blastocyst implantation. The data present here show the stage-specific and dynamic expression patterns of LIF and LIFR, both in embryos and endometrium, during early pregnancy in rabbits, which indicated that LIF might play an important role in the pre-implantation development and subsequent implantation of rabbit embryos.

[Identification of down-regulated expressed sequence tag at chromosome 3p21 in nasopharyngeal carcinoma]

BACKGROUND & OBJECTIVE

It was reported that a locus of high frequency loss of heterozygosity was found at 3p14-25 of nasopharyngeal carcinoma (NPC) cells. This study was designed to identify the expressed sequence tags (ESTs) associated with NPC at chromosome 3p21 in order to clone new candidate NPC-associated genes at the locus.

METHODS

The expression of relative ESTs at 3p21 was determined in nasopharyngeal carcinoma tissues and normal nasopharyngeal epithelia using ESTs homology analysis with bioinformatics in computer network combined with reverse transcription-polymerase chain reaction (RT-PCR). The expression of EST was detected in other normal tissues and tumor cell lines using Northern blot analysis.

RESULTS

Comparing with expression of normal nasopharyngeal epithelia, EST (N31985) was down-regulated in 60.00% (3/5) nasopharyngeal carcinoma cell lines and 47.06% (16/34) nasopharyngeal carcinoma tissues (P < 0.05).

CONCLUSION

N31985 is down-regulated in NPC, suggesting it may play a role in NPC carcinogenesis.

[RFLP analysis of wheat-L. racemosus translocation lines]

A number of wheat-L. racemosus translocation lines were developed by irradiation, pollen culture and gametocidal chromosome methods. In order to identify homozygous translocation lines and determine the exact location of the breakpoints involved in the translocations, 67 probes genetically or physically mapped previously on wheat chromosomes belonging to seven homoeologous groups were used for RFLP analysis. Three homozygous translocation lines were identified: T1BL.7Lr # 1S, T4BS.4BL-7Lr # 1 and T6AL.7Lr # 1S. In lines T1BL.7Lr # 1S and T6AL.7Lr # 1S, the breakpoint of chromosome 7Lr # 1 was located in the short arm between the area marked by clone MWG808 and that of ABG476.1, and the breakpoints of chromosomes 1B and 6A were both located near the centromere. In line T4BS.4BL-7Lr # 1S, the breakpoint of chromosome 7Lr # 1 was located in the short arm between the area marked by clone BCD349 and that of CDO595, the breakpoint of chromosome 4B was located in the long arm between the area marked by clone CDO541 and that of PSR164.

The effect of dietary protein level on threonine dehydrogenase activity in chickens

An experiment was carried out to determine the effect of dietary protein level on the specific activity of hepatic L-threonine dehydrogenase in young growing chicks. Six replicate pens of seven Leghorn chicks were fed semipurified diets containing 23, 27, or 32% CP with identical relative proportions of amino acids in each protein group. Body weights and feed consumption were measured for 3 d, and hepatic mitochondria were isolated for assay of threonine dehydrogenase (TDH) activity. Weight gains and feed efficiency increased at each level of protein supplementation, but feed consumption was not affected by protein level. The specific activity of threonine dehydrogenase in isolated liver mitochondria was significantly (P < 0.05) higher in the 32% CP group than in the 23% CP group, and the activity in the 27% CP group was intermediate. We conclude that moderate increases in dietary protein level result in elevated hepatic threonine dehydrogenase activity in growing chicks.

Characterization of hepatic L-threonine dehydrogenase of chicken

The L-threonine dehydrogenase (TDH) was purified approximately 1300-fold to a specific activity of approximately 18000 unit mg(-1) from chicken (Gallus domesticus) liver mitochondria. Purification was obtained by sequential chromatography on DEAE Cellulose, Phenyl Sepharose High Performance hydrophobic interaction, Affi-Gel Blue affinity and Matrex Gel Red A columns. The molecular weight of the subunit was estimated to be 36 kDa by sodium dodecyl-polyacrylamide gel electrophoresis. An apparent molecular mass of native protein between 62 and 74 kDa was obtained by gel filtration chromatography, suggesting a dimeric structure of TDH. The isoelectric point of TDH was determined by isoelectric focusing to be 5.3. Partial amino-terminal sequence analyses, carried out on two purified preparations of TDH, revealed a high degree of homology to the reported sequence of porcine TDH. The Michaelis constants for L-threonine and NAD for partially purified chicken hepatic TDH are 5.38 and 0.19 mM, respectively.

Antihepatoma effect of alpha-fetoprotein antisense phosphorothioate oligodeoxyribonucleotides in vitro and in mice

AIM: To evaluate antihepatoma effect of antisense phosphorothioate oligodeoxyribonucleotides (S-ODNs) targeted to alpha-fetoprotein (AFP) genes in vitro and in nude mice.

METHODS: AFP gene expression was examined by immunocytochemical method or enzyme-linked immunosorbent assay. Effect of S-ODNs on SMMC-7721 human hepatoma cell growth in vitro was determined using microculture tetrazolium assay. In vivo antitumor activities of S-ODNs were monitored by measuring tumor weight differences in treated and control mice bearing SMMC-7721 xenografts. Induction of cell apoptosis was evaluated by fluorescence-activated cell sorter (FACS) analysis.

RESULTS: Antisense S-ODN treatment led to reduced AFP gene expression. Specific antisense S-ODNs, but not control S-ODNs, inhibited the growth of heaptoma cells in vitro. In vivo, only antisense S-ODNs exhibited obvious antitumor activities. FACS analysis revealed that the growth inhibition by antisense S-ODNs was associated with their cell apoptosis induction.

CONCLUSION: Antisense S-ODNs targeted to AFP genes inhibit the growth of human hepatoma cells and solid hepatoma, which is related to their cell apoptosis induction.

Temporal response of hepatic threonine dehydrogenase in chickens to the initial consumption of a threonine-imbalanced diet

Amino acid imbalances contribute to higher requirements of amino acids than would occur if the dietary profile of amino acids perfectly matched the requirements. The mechanisms of imbalances have not been fully elucidated. Because threonine dehydrogenase (TDH) activity in liver mitochondria increases in chicks and rats subjected to threonine imbalance, the current study was carried out to determine whether the change in TDH activity occurs rapidly enough after the consumption of an imbalanced diet to be considered a possible primary metabolic response. In a series of experiments, Leghorn chicks were allowed free access to a semipurified basal diet marginally limited in threonine or the same diet containing a mixture of indispensable amino acids (IAA) lacking threonine to cause a threonine imbalance. In the first experiment, dietary supplements of 5.5 and 11.1% IAA were used to determine a level of supplement that would cause a robust response in the specific activity of TDH. Feed intake, body weight gains and efficiency of feed utilization were lower and specific activities of TDH were higher in chicks fed 11.1% IAA than in those fed 5.5% IAA. In subsequent experiments, hepatic TDH activities and plasma amino acid profiles of the control and experimental groups were determined at 1. 5, 3, 6, 12 and 24 h after the first offering of the diet containing 11.1% IAA. The specific activities of TDH in chicks fed the IAA supplement were 40-150% higher (P < 0.05) and plasma threonine concentrations were 42-53% lower (P < 0.05) than in chicks fed the basal diet at all times except 1.5 h. These results indicate that changes in the capacity for threonine degradation via TDH may occur in the liver within a few hours after the consumption of a threonine-imbalanced diet and suggest the possibility that altered TDH activity may contribute to the increased threonine requirement associated with threonine imbalance.

Human hepatoma cell telomerase activity inhibition and cell cycle modulation by its RNA component antisense oligodeoxyribonucleotides

AIM

To investigate the effects of human telomerase RNA component antisense oligodeoxyribonucleotides on telomerase activity of human hepatoma cells and their effects on cell cycle distribution.

METHODS

Modified telomeric repeat amplification protocol was used to detect telomerase activity. Cell cycle was analyzed by flow cytometer.

RESULTS

Telomerase activity was detected in all of four human hepatoma cell lines but absent in normal liver cells. Antisense oligomers to human telomerase RNA component (hTR) inhibited telomerase activity of BEL-7404 human hepatoma cells markedly in vitro. After in vitro treatment with antisense oligomers for 96 h, cell cycle of BEL-7404 human hepatoma cells was mainly arrested at G2/M phase.

CONCLUSION

Antisense oligomers to hTR inhibited telomerase activity of BEL-7404 human hepatoma cells in vitro and resulted in cell cycle arrest at G2/M phase.

Anti-hepatoma activity of taxol in vitro

AIM

To investigate the in vitro anti-hepatoma activity of taxol against SMMC-7721 human hepatoma cells.

METHODS

The hepatoma cell growth was measured by MTT-microculture tetrazolium assay. Cell-cycle kinetics and apoptosis were analyzed by flow cytometry and microscopic examination.

RESULTS

Taxol inhibited the hepatoma cell growth in concentration- and time-dependent manners with IC50 of 18.96 nmol.L-1. Marked cell accumulation in G2/M phase and multinucleated cells were also observed after treatment with taxol 10 nmol.L-1. In addition, taxol at 10 nmol.L-1 could induce the apoptosis of hepatoma cells.

CONCLUSION

Taxol suppresses the growth of SMMC-7721 human hepatoma cells in vitro by causing cell-cycle arrest, aberrant mitosis, and apoptosis of the human hepatoma cells.

Using a non-radioisotopic, quantitative TRAP-based method detecting telomerase activities in human hepatoma cells

A non-radioisotopic, quantitative TRAP-based telomerase activity assay was established mainly by using SYBR Green-I staining instead of radioisotope. Comparing with conventional radioisotope based method, it was better in reproducibility and accuracy. Using this method, we found telomerase activities were absent in normal human liver cells, while detected in all of four human hepatoma cell lines (BEL-7404, SMMC-7721, QGY-7903 and HCCM) without significant differences.

Developmental pattern of phenylalanine hydroxylase activity in the chicken

Experiments were conducted to determine the conditions for assay of hepatic phenylalanine hydroxylase (PAH) activity in the chicken and to determine the developmental pattern of PAH activity in liver 25,000 x g supernatant. PAH activity was detected in liver supernatant and (postnuclear) 25,000 x g particulate fraction. Optimum assay conditions differed for the two cell fractions, the most notable difference being a broad pH optimum of 7.7 to 9.2 for the supernatant and 4.7 and 5.6 for the particulate fraction. The PAH activity in the supernatant increased to a maximum as L-phenylalanine concentration in the assay medium increased from 0.02 to 0.5 mM and 1.0 mM. Activity increased in the particulate fraction as the Phe concentration increased to 0.5 mM. Substrate inhibition of PAH activity occurred at Phe concentrations of 3 to 5 mM in the supernatant but not in the particulate fraction. Concentrations of the cofactor, 6(R)-5,6,7,8-tetrahydrobiopterin, ranging from 0.09 to 0.75 mM, resulted in maximal PAH activity. The developmental pattern of PAH in supernatant was determined using a modified assay in which substrate and cofactor concentrations and pH were optimum. The PAH activity in liver supernatant was present at a low level in 11 d chick embryos and increased several fold between Days 15 and 17 to a maximum at Days 17 to 21. Activity declined at hatching to levels that were present in 11 to 15 d embryos and remained at this level in male chicks through 4 wk of age. Mature males had higher PAH activity than mature laying females.

A survey of social nutrition status of the elderly in the urban area of Chengdu, Sichuan Province

The social nutrition status was investigated among 246 subjects aged 60-90 living at three urban communities in Chengdu of Sichuan Province. The questionnaire was designed to evaluate socio-demographic background, the subjects' nutrition knowledge, and the support systems for geriatric nutrition. Fasting venous blood was collected for the analysis of biochemical parameters. Blood pressure, bone mineral contents (BMC), body weight (BW) and body height (BH) were measured at the same time. Only 49.7% of the subjects correctly answered four basic questions on nutrition. Food patterns for the elderly were simple and modest. Several nutrition-related disorders for the elderly were including high systolic blood pressure (44.6%), hypertriglyceridemia (25.9%), high diastolic blood pressure (25.1%), obesity (24.5%), high PBG (20.6%), emaciation (19.9%), high FBG (17.9%) and osteoporosis (16.8%). These data indicate that the support systems for the geriatric nutrition will have to be improved.

Preliminary evidence for an association of Epstein-Barr virus with pre-ulcerative oral lesions in patients with recurrent aphthous ulcers or Behçet's disease

In this study we used the polymerase chain reaction (PCR), slot blot and Southern blot hybridization, direct sequencing and in situ hybridization (ISH) to show the possible presence of EBV-DNA in pre-ulcerative oral aphthous lesions of patients with recurrent aphthous ulcers (RAU) or Behçet's disease (BD). For this purpose, formalin-fixed biopsy specimens were obtained from 13 pre-ulcerative oral aphthous lesions of nine RAU and four BD patients. Five specimens of normal oral mucosa (NOM) from five normal control subjects and 10 specimens of oral erosive or ulcerative lesions from 10 patients with erosive lichen planus (ELP) were also included. EBV-DNA was detected by PCR in 5 of the 13 (38.5%) pre-ulcerative oral aphthous lesions, two from RAU patients and three from BD patients. However, no EBV-DNA was demonstrated in five NOM specimens from normal control subjects and in 10 specimens of oral lesions from ELP patients. EBV-DNA was also demonstrated in patients' peripheral blood lymphocytes and/or plasma, suggesting that the lymphocytes may be the reservoir of latent EBV infection and there is EBV shedding in the plasma. EBV-DNA was detected by ISH in only one PCR-positive case; the reaction product was found to deposit on the nuclei of some of the epithelial cells and lymphocytes. By immunohistochemistry, expression of Epstein-Barr nuclear antigen and EBV/C3d receptors was also noted in some of the epithelial cells and lymphocytes in this ISH-positive case. Therefore, we suggest that the epithelial cells of pre-ulcerative oral aphthous lesions may be infected by EBV through EBV-infected lymphocytes; also, the cytotoxic T lymphocyte-induced lysis of the EBV-infected epithelial cells, but not the virus-induced cytolysis, may be the main mechanism causing oral ulcer formation. Our data provide preliminary evidence for an association of EBV with pre-ulcerative oral aphthous lesions in RAU and BD patients.

Improvement of bioavailability of the HIV protease inhibitor SC-52151 in the beagle dog by coadministration of the CYP3A4 inhibitor, ketoconazole

1. SC-52151, an HIV protease inhibitor, is mainly metabolized by CYP3A4 and is poorly bioavailable after oral administration. After i.v. administration of SC-52151 to the female beagle dog (2.5 mg/kg), SC-52151 was rapidly eliminated in plasma with an elimination half-life of about 1 h, a plasma clearance of 44 ml/min/kg and an apparent steady-state volume distribution of 2.2 litre/kg. The high value of plasma clearance of SC-52151 suggests an extensive hepatic first-pass metabolism since SC-52151 is highly protein bound and does not partition itself into red blood cells. 2. The extensive hepatic first-pass metabolism was reduced by coadministration of a CYP3A4 inhibitor, ketoconazole. 3. Dogs were dosed daily with ketoconazole at dose of 100 mg ketoconazole per dog (approximately 10 mg/kg) for 5 days prior to the initiation of coadministration of SC-52151 for 15 days. The doses used for SC-52151 was 0, 60 and 120 mg SC-52151/kg/day (divided t.i.d., 8-h dosing interval). Coadministration of ketoconazole improved the bioavailability of SC-52151 from 4.1 to 9.6% and also improved the Cmax of SC-52151 from 0.41 to 0.83 microgram/ml. 4. Although the absolute bioavailability of SC-52151 was still low (approximately 10%), the Cmax and AUC achieved in this study were satisfactory for conducting chronic toxicology studies. No toxicity associated with the coadministration of ketoconazole was evident. Results from this study suggest that coadministration of ketoconazole might be a practical approach to increase the exposure of SC-52151 in both preclinical and clinical studies.

Isolation and identification of metabolites of leukotriene A4 hydrolase inhibitor SC-57461 in rats

The metabolic fate of SC-57461, N-methyl-N-[3-[4-(phenylmethyl)-phenoxy]propyl]-beta-alanine, a potent and specific inhibitor of the leukotriene A4 hydrolase, was determined by LC/MS/MS, NMR and GC/MS in male Sprague-Dawley rats. The major metabolites of SC-57461 in rats were the desmethyl metabolite, the hydroxylated metabolite, the N-oxide metabolite, the hydroxylamine metabolite, and the propionic acid metabolite. The N-oxide metabolite was found to be stable in the rat plasma and urine, but was unstable in most organic solvents (methanol, acetonitrile, and methylene chloride, etc.) because of the classic Cope reaction of the N-oxide, which led to the formation of the corresponding hydroxylamine product and acrylic acid. The hydroxylamine metabolite and acrylic acid were reactive in the biomatrix and could not be isolated in the in vivo samples. However, formation of the hydroxylamine metabolite and acrylic acid from the N-oxide metabolite in methylene chloride was verified by NMR. The propionic acid metabolite was found to be the common metabolite shared by SC-57461, N-oxide metabolite, as well as the hydroxylamine metabolite, which suggested a sequential metabolism of SC-57461 in rats. The ultimate fate of the propionic acid metabolite was incorporation into rat glycerolipid metabolism as a result of its structural similarity to aryl-substituted propionic acid, a known class of compounds that can be incorporated into rat glycerolipid metabolism. Finally, the isolated hydroxylated metabolite and the N-desmethyl metabolite were found to have excellent inhibitory effects toward leukotriene A4 hydrolase and therefore were the major active metabolites of SC-57461 in rats.

Effects of D&C yellow no. 11 ingestion on F344/N rats and B6C3F1 mice

D&C yellow no. 11 (CAS no. 8003-22-3) was administered in the feed at concentrations of 500-50,000 ppm to groups of F344/N rats and B6C3F1 mice of each sex for 13 wk to determine the toxicity. In addition, a perinatal study was conducted to determine the effects of feeding diets containing D&C yellow no. 11 to female rats during reproduction and to their offspring. Although the estimated intake (g/kg) of D&C yellow no. 11 of mice was more than twice that of rats, the results were generally similar for both rats and mice. In both species, D&C yellow no. 11 caused no mortality, but it did reduce body weight gain slightly in both sexes of rats exposed to 17,000 and 50,000 ppm. Absolute and relative liver weights were significantly increased in all groups of rats and mice administered D&C yellow no. 11 in the feed. There was minimal to mild degeneration of the periportal hepatocytes in rats at doses of 1700 ppm and higher and in mice at 5000 ppm and above. A dose-related yellow-brown pigment was observed in hepatocytes, Kupffer cells, and biliary epithelium of the liver of both sexes of both species and in the renal tubule epithelium in both sexes of rats. In male rats, all treated groups had increased number and size of hyaline droplets in the renal tubule epithelium of the cortex and outer medulla. To determine if these renal and hepatic lesions were reversible, male rats were administered 5000 ppm dietary D&C yellow no. 11 for 70 d and then examined at 3, 14, and 28 d after the chemical was removed from the diet. Pigment persisted in the kidney and liver for as long as 28 d following removal of D&C yellow no. 11 from the diet, but hepatocellular degeneration and cytoplasmic alteration in the kidney completely resolved by d 3 and 14, respectively. In the perinatal toxicity study, body weight gain in rat dams given diets containing as much as 50,000 ppm D&C yellow no. 11 for 4 wk before mating to untreated males was similar to that of controls at the time of mating but was lower at parturition and weaning. However, fertility, gestation length, litter size, and pup birth weights were unaffected by treatment. At weaning, there was a significant dose-related decrease in pup body weights from the 5000, 17,000, and 50,000 ppm groups. At 8 wk of age, pups fed the same dosed-feed concentrations as the dams had depressed body weights in the 17,000 and 50,000 ppm treated groups. Microscopic lesions in the liver and kidney of the pups in all dose groups were similar to those described in the 13-wk study. The results of these studies indicate that compound-related effects occurred at all dietary concentrations of D&C yellow no. 11. Liver weights were increased in dosed rats and mice, minimal to mild hepatocellular degeneration was seen in rats receiving dietary concentrations of 1700 ppm and above and in mice at 5000 ppm and above, and there was an increase in the number and size of hyaline droplets in all dosed groups of male rats. Similar compound-related effects were also seen in all dosed rats in the perinatal toxicity study. With the exception of pigment accumulation, the treatment-related kidney and liver lesions in male rats were reversible by 14 d after chemical was withdrawn from the diet.

Human cytomegalovirus as a potential etiologic agent in recurrent aphthous ulcers and Behçet's disease

In a preliminary study on anti-human cytomegalovirus (HCMV) antibody (Ab) by ELISA, the serum anti-HCMV/IgG Ab concentrations in 22 patients with recurrent aphthous ulcers (RAU) in the remission stage were found to be significantly higher than in 22 control subjects (121 +/- 42 vs 100 +/- 27, P < 0.05) and in 39 patients with RAU in the active stage (121 +/- 42 vs 88 +/- 45, P < 0.01). Therefore, the potential of HCMV as an etiologic agent in RAU was proposed and studies using the polymerase chain reaction (PCR) and in situ hybridization (ISH) have been performed to investigate the possible presence of HCMV DNA in pre-ulcerative oral aphthous lesions in patients with RAU or Behçet's disease (BD) of the mucocutaneous type. For this purpose, formalin-fixed biopsy specimens were obtained from 13 pre-ulcerative oral aphthous lesions, 2 samples of normal oral mucosa and 1 ileal mucosal lesion from 9 RAU patients and 4 BD patients. Five specimens of normal oral mucosa from 5 normal control subjects and 12 specimens of oral erosive or ulcerative lesions from 12 patients with erosive lichen planus (ELP) were also included. By PCR, HCMV DNA was detected in 5 of the 13 (38.5%) pre-ulcerative oral aphthous lesions, 3 from RAU patients and 2 from BD patients. The ileal mucosa specimen was also HCMV DNA-positive, whereas HCMV DNA was not demonstrated in any of the 7 specimens of normal oral mucosa from RAU patients and normal control subjects; 12 specimens of oral lesions from ELP patients were similarly negative. ISH did not detect HCMV DNA in any of the biopsy specimens from RAU patients and control subjects. Our findings suggest that HCMV may be an etiologic agent in some cases of RAU and BD.

Toxicokinetics of 4-methylimidazole in the male F344 rat

The toxicokinetics and metabolism of 4-methylimidazole (4-MZ) have been studied in the male F344 rat using 14C radiolabelled compound. Radioactivity in plasma and urine was profiled by hplc. After gavage administration of 50 mg/kg, about 85% of the administered radioactivity was recovered in urine within 48 h. The majority of the radioactivity in urine or plasma was associated with the parent compound and only one minor hydrophilic metabolite was present in urine and in plasma. Elimination of radioactivity via fecal, biliary or respiration was negligible. Elimination of 4-MZ after an i.v. dose of 5 mg/kg can be described by a two-compartment process with an estimated half-life of 1.8 h and an estimated apparent volume of distribution of 2.3 litre/kg. After gavage at doses of 5, 50 and 150 mg/kg, 4-MZ was readily absorbed with a estimated bioavailability of 60-70%. Urinary excretion data indicated that renal clearance of 4-MZ accounted for about 80% of total body plasma clearance. Based on the estimated AUC of metabolite and the estimated renal clearance of 4-MZ, the formation of metabolite and the renal clearance of 4-MZ appeared to be a saturable process.

Effects of gavage versus dosed feed administration on the toxicokinetics of benzyl acetate in rats and mice

Effects of gavage versus dosed feed administration on the toxicokinetics of benzyl acetate were studied in male F344 rats and B6C3F1 mice. Benzyl acetate was rapidly hydrolysed to benzyl alcohol and then oxidized to benzoic acid. After gavage administration of benzyl acetate in corn oil at 500 mg/kg (rats) and 1000 mg/kg (mice), high benzoic acid plasma concentrations were observed. In contrast, much lower benzoic acid plasma concentrations were found after dosed feed administration at about 615 mg/kg/day for rats and about 850 mg/kg/day for mice. Results show that although the daily doses of benzyl acetate are comparable, bolus gavage administration effectively saturated the benzoic acid elimination pathway whereas dosed feed administration did not. In contrast, hippuric acid plasma concentrations were similar after both gavage and dosed feed administration due to the depletion of the glycine supply pool. Study results could explain the different toxicity and carcinogenicity responses of benzyl acetate observed in 2-yr chronic gavage and dosed feed studies.

Toxicokinetics of pentachlorophenol in the F344 rat. Gavage and dosed feed studies

1. The toxicokinetics of pentachlorophenol (PCP) were studied in the Fischer 344 rat using i.v. and oral (gavage, dosed feed) routes of exposure. 2. Only minor sex differences were observed in the elimination kinetics of PCP after i.v. administration at 5 mg/kg. 3. Absorption of PCP from the gastrointestinal tract after gavage doses of 9.5 and 38 mg/kg in aqueous methylcellulose vehicles was first order with an absorption half-life of about 1.3 h. 4. The absorption rate constant of PCP from doses feed was comparable with that obtained from aqueous methylcellulose gavage formulations. 5. Bioavailability of PCP administered in dosed feed was significantly lower than the bioavailability of PCP administered by gavage. 6. Dose proportionality was established to a dosage of at least 38 mg/kg. 7. Daily fluctuation of PCP plasma concentrations was observed during the dosed feed study with peak and trough concentrations occurring in early morning and late afternoon, respectively. 8. The time course of PCP plasma concentrations during the dosed feed study were simulated using a computer model based on linear theory. The simulations were comparable with the experimentally determined concentrations.

Comparison of the toxicity of citral in F344 rats and B6C3F1 mice when administrated by microencapsulation in feed or by corn-oil gavage

A study of the potential effects of microencapsulation on the toxicity of citral was conducted in 14-day continuous feeding studies with both sexes of F344 rats and B6C3F1 mice. Toxicity by the feeding route was compared with that from bolus doses of the neat chemical in corn oil administrated by gavage. Both sexes of rats and mice were given diet containing 0, 0.63, 1.25, 2.5, 5 and 10% citral microcapsules. These feed formulations were equivalent to daily doses of 0, 142, 285, 570, 1140 and 2280 mg citral/kg body weight for rats and 0, 534, 1068, 2137, 4275 and 8550 mg citral/kg body weight for mice. The daily gavage doses were 0, 570, 1140 and 2280 mg citral/kg body weight for both sexes of rats, and 0, 534, 1068 and 2137 mg citral/kg body weight for both sexes of mice. Citral microcapsules administered in the diet did not cause mortality in mice or rats. Toxicity was confined to decreases in body weight at the 10% concentration in mice, at the 5 and 10% concentrations in rats, and decreases in absolute weights of the liver, kidney and spleen at the 10% concentration in rats. The only histopathological change observed was minimal to mild hyperplasia and/or squamous metaplasia of the respiratory epithelium in the anterior portion of the nasal passages of rats fed 5 or 10% citral microcapsules. By contrast, citral gavage caused mortality in five out of five male and female mice at 2137 mg/kg body weight, and in two out of five male mice at 1068 mg/kg body weight. There were dose-related increases in absolute liver weights of male and female mice. Cytoplasmic vacuolization of hepatocytes occurred in all female mice gavaged with 1068 and 2137 mg citral/kg body weight, and in male mice from the 2137 mg/kg dose group. Necrosis, ulceration and/or acute inflammation of the forestomach occurred in the high-dose mice of both sexes. Inflammation and/or hyperplasia of the forestomach occurred in about half of the male and female mice dosed with 1068 mg citral/kg. Citral gavage at doses that were equivalent to up to 10% in the diet (2280 mg/kg body weight) did not cause toxicity in rats, except for minimal hyperplasia of the squamous epithelium of the forestomach in high-dose males.(ABSTRACT TRUNCATED AT 400 WORDS)