THAP9-AS1 promotes nasopharyngeal carcinoma progression through targeted regulation of the miR-185-5p/SOX13 axis

Background

It has been reported that long non-coding RNA THAP9-AS1 exerts carcinogenic role by mediating miRNAs and target genes in various human cancers. However, whether THAP9-AS1 influences the progression of nasopharyngeal carcinoma (NPC) remains unknown.

Methods

The transcriptional levels of THAP9-AS1 and miR-185-5p were estimated via quantitative real time polymerase chain reaction (qRT-PCR) assay. The protein level of SOX13 was detected with western blotting assay. Additionally, methyl thiazolyl tetrazolium (MTT) assay as well as colony formation assay were utilized to measure cell growth. The apoptotic cells were observed by employing Terminal-deoxynucleoitidyl Transferase Mediated Nick End Labeling (TUNEL) staining analysis, and transwell assay was introduced to test cell migration in addition to invasion. Moreover, the relationship between miR-185-5p and THAP9-AS1 or SOX13 was estimated through dual-luciferase reporter gene assay.

Results

THAP9-AS1 was overexpressed in head and neck squamous cell carcinoma (HNSCC) tissues and NPC cells. Besides, silencing of THAP9-AS1 depressed the life processes of NPC cells including cell growth, migration as well as invasion but facilitated cell apoptosis. Further investigation proved that miR-185-5p was the direct target of THAP9-AS1. Besides, the knockdown of THAP9-AS1 notably reduced the transcriptional level of miR-185-5p. Furthermore, THAP9-AS1 served as a sponge of miR-185-5p to modulate the expression of SOX13, which regulated the development of NPC cells.

Conclusion

This work verified that THAP9-AS1 promoted NPC cell progression at least partly by mediating the miR-185-5p/SOX13 axis.

CT-based radiomics for prediction of pulmonary haemorrhage after percutaneous CT-guided transthoracic lung biopsy of pulmonary nodules

AIM

To evaluate the feasibility of intranodular and perinodular computed tomography (CT) radiomics features for predicting the occurrence of pulmonary haemorrhage after percutaneous CT-guided transthoracic lung biopsy (PCTLB) in pulmonary nodules.

MATERIALS AND METHODS

The data for 332 patients with pulmonary nodules who underwent PCTLB were reviewed retrospectively. Pulmonary haemorrhage after PCTLB was evaluated using CT (144 cases occurred). Radiomics features based on gross nodular (GNV) and perinodular volumes (PNV) were extracted from pre-biopsy CT images and features selection using least absolute shrinkage and selection operator (LASSO) regression, and three radiomics scores (rad-scores) were built. Rad-scores, clinical, and clinical-radiomic models were developed and evaluated to predict the occurrence of pulmonary haemorrhage.

RESULTS

Five, five, and six significant features were selected for prediction of pulmonary haemorrhage based on GNV, PNV, and GNV + PNV, respectively. Lesion depth was the only clinical characteristics related to pulmonary haemorrhage. Lesion depth and rad-score based on GNV, PNV, and GNV + PNV for predicting the pulmonary haemorrhage achieved areas under the curves (AUCs) of 0.656, 0.645, 0.651, and 0.635 in the validation group, respectively. Three clinical-radiomic models improved the AUCs to 0.743, 0.723, and 0.748. The performance of rad-score_GNV + PNV combined with lesion depth outperformed the clinical model (p=0.024) and the radiomics signature (p=0.038). In addition, the radiomics signatures were significantly associated with higher-grade pulmonary haemorrhage (p<0.05).

CONCLUSIONS

Radiomics features from intranodular and perinodular regions of pulmonary nodules have good predictive ability for pulmonary haemorrhage after PCTLB, which may provide additional predictive value for clinical practice.

AB0596 AORTIC MANIFESTATIONS IN GIANT CELL ARTERITIS: SINGLE CENTRE 10-YEAR EXPERIENCE

Background

Disease stratification in GCA is an urgent need, with patients categorised into cranial and large-vessel GCA (LV-GCA) subgroups. LV-GCA may have worse outcomes with regards relapsing disease, poor response to glucocorticoids (GC) and aortic involvement.

Objectives

We report a single centre experience using clinical, imaging and treatment outcomes from a specialist clinic.

Methods

134 patients with LV-GCA were identified over a 10-year period at Southend University Hospital (2012-2022). Medical records were reviewed retrospectively for baseline demographics, clinical presentation, inflammatory markers, imaging (vascular ultrasound, PET-CT, echocardiography), vascular damage and treatment.

Results

There was a female predominance (female n=91). Age at presentation ranged from 46 to 86 years (median 70 years). Co-morbidities implicated in aortic disease included hypertension (n=60), hypercholestrolaemia (n=29), diabetes (n=14), aortic valvular disease (n=5) and atherosclerotic disease including coronary and carotid artery disease (n=19). Constitutional disturbance was most frequently observed presentation (70%, n=94), and the only feature for 11 patients. This was followed by cranial symptoms (62%, n=83), polymyalgia (53%, n=71), ischaemic symptoms i.e., visual disturbance or tongue/jaw claudication (24%, n=32) and cardiovascular presentations (7%, n=9). The latter included limb claudication, stroke, and aortic aneurysm. Although LV-GCA refers to extra-cranial disease, 12 patients (9%) had isolated cranial and/or ischaemic symptoms at initial presentation.

Inflammatory markers were typically elevated at presentation, C-reactive protein ranged from 1-425mg/L and ESR 1-130mm. Vascular ultrasound was used at diagnosis in 93 patients, with positive temporal artery findings in 50% (n=38) and positive axillary findings in 75% (n=57). PET-CT data was available for 125 patients, of which 113 were positive for LV-GCA. Thoracic aorta FDG-uptake was seen in 77%, with 7 ascending and 1 abdominal aortic aneurysm observed. Transthoracic echocardiogram was available for 46% (n=62). Four (6.5%) patients had a dilated aortic root when indexed to height as per British Society of Echocardiography (BSE) guidelines1 (SOV (mm/m) > 21.8mm in males and > 20.7mm in females). Values for our patients were 22.6 and 21.2 mm/m for the female patients and 29.2 and 25.2 mm/m for the male patients. Furthermore, 32 patients showed some extent of diastolic dysfunction as per BSE criteria (52%).

All patients received GC as part of their treatment, 60% (n=82) needing one or more DMARDs and 17% (n=23) Tocilizumab for relapsing disease. DMARDs used included Leflunomide (n=63), Methotrexate (n=18), Mycophenolate mofetil (n=3) and Azathioprine (n=1). One patient received cyclophosphamide.

Conclusion

By combined imaging modalities, 11 patients (8%) had evidence of ascending aortic damage. Grade 1 diastolic dysfunction can be age related, so this may be association rather than causation2,3. Over half of patients had not undergone echocardiogram evaluation, so there may be a hidden burden of disease. Many patients required GC-sparing therapy, showing GC alone are often not enough to halt disease progression, and vascular damage was relatively reduced compared to historical reports. The authors feel GCA services should include standardised protocols for early DMARDs, continuing thorough assessment for LV-GCA and vascular damage, including echocardiography, progressing to cross-sectional imaging if indicated.

References

[1]Harkness A. et al. Normal reference intervals for cardiac dimensions and function for use in echocardiographic practice: a guideline from the British Society of Echocardiography”. Echo Research and Practice 7.1 (2020): G1-G18.

[2]Sanders, D et al. Diastolic dysfunction, cardiovascular aging, and the anesthesiologist. Anesthesiology clinics vol. 27,3 (2009): 497-517.

[3]Jakovljevic and Djordje G. Physical activity and cardiovascular aging: Physiological and molecular insights. Experimental gerontology vol. 109 (2018): 67-74.

Disclosure of Interests

None declared

Comparative Outcomes for Trauma Patients in Prison and the General Population

BACKGROUND

Prisoners are a vulnerable population, and there are few contemporary studies that consider trauma patient outcomes within the prisoner population. Therefore, we sought to provide a descriptive analysis of prisoners involved in trauma and evaluate whether a healthcare disparity exists. We hypothesized that prisoners and non-prisoners have a similar risk of mortality and in-hospital complications after trauma.

METHODS

The Trauma Quality Improvement Program (2015-2016) was queried for trauma patients based upon location inside or outside of prison at the time of injury. A multivariable logistic regression analysis was performed to compare these groups for risk of mortality-the primary outcome.

RESULTS

From 593,818 trauma patients, 1115 were located in prison. Compared to non-prisoners, prisoner trauma patients had no significant difference in mortality (5.1 vs 6.0%, P = .204). However, after adjusting for covariates, prisoners had a shorter length of stay (LOS) (mean days, 6.3 vs 7.8, P < .001), shorter intensive care unit (ICU) LOS (mean days, 5.44 vs 5.89, P = .004), and fewer complications, including lower rates of drug/alcohol withdrawal (.4% vs 1.1%, P = .030), pneumonia (.5 vs 1.6%, P = .004), and urinary tract infections (.0 vs 1.1%, P < .001). Upon performing a multivariable logistic regression model, prisoner trauma patients had a similar associated risk of mortality compared to non-prisoners (OR 1.61, CI .52-4.94, P = .409).

DISCUSSION

Our results suggest that prisoner trauma patients at least receive equivalent treatment in terms of mortality and may have better outcomes when considering some complications. Future prospective studies are needed to confirm these results and explore other factors, which impact prisoner patient outcomes.

Regional variations in discrete collagen fibre mechanics within intact intervertebral disc resolved using synchrotron computed tomography and digital volume correlation

Many soft tissues, such as the intervertebral disc (IVD), have a hierarchical fibrous composite structure which suffers from regional damage. We hypothesise that these tissue regions have distinct, inherent fibre structure and structural response upon loading. Here we used synchrotron computed tomography (sCT) to resolve collagen fibre bundles (∼5μm width) in 3D throughout an intact native rat lumbar IVD under increasing compressive load. Using intact samples meant that tissue boundaries (such as endplate-disc or nucleus-annulus) and residual strain were preserved; this is vital for characterising both the inherent structure and structural changes upon loading in tissue regions functioning in a near-native environment. Nano-scale displacement measurements along >10,000 individual fibres were tracked, and fibre orientation, curvature and strain changes were compared between the posterior-lateral region and the anterior region. These methods can be widely applied to other soft tissues, to identify fibre structures which cause tissue regions to be more susceptible to injury and degeneration. Our results demonstrate for the first time that highly-localised changes in fibre orientation, curvature and strain indicate differences in regional strain transfer and mechanical function (e.g. tissue compliance). This included decreased fibre reorientation at higher loads, specific tissue morphology which reduced capacity for flexibility and high strain at the disc-endplate boundary.

Statement of significance

The analyses presented here are applicable to many collagenous soft tissues which suffer from regional damage. We aimed to investigate regional intervertebral disc (IVD) structural and functional differences by characterising collagen fibre architecture and linking specific fibre- and tissue-level deformation behaviours. Synchrotron CT provided the first demonstration of tracking discrete fibres in 3D within an intact IVD. Detailed analysis of regions was performed using over 200k points, spaced every 8 μm along 10k individual fibres. Such comprehensive structural characterisation is significant in informing future computational models. Morphological indicators of tissue compliance (change in fibre curvature and orientation) and fibre strain measurements revealed localised and regional differences in tissue behaviour.

[Chaihu Guizhi decoction produces antidepressant-like effects via sirt1-p53 signaling pathway]

OBJECTIVE

To investigate the mechanism of the antidepressant-like effects of Chaihu Guizhi decoction (CGD).

OBJECTIVE

Chaihu Guizhi decoction at the daily dose of 17 g/kg and solvent vehicle were administered by gavage in 12 and 14 male C57BL/6J mice for 7 consecutive days, respectively. Forced swimming test (FST), elevated plus maze (EPM) test, open field test (OFT) and novelty-suppressed feeding test (NSF) were performed to assess the depression- and anxiety-like behaviors and motor ability of the mice. We further used chronic social defeat stress (CSDS) and social interaction test to evaluate the antidepressant-like effects of CGD in comparison with the solvent vehicle. Western blotting and RT-qPCR were performed to detect the expressions of sirt1, p53, acetylated p53, and the neuron plasticity-related genes including synapsin I (Syn1), Rab4B, SNAP25 and tubulin beta4b in the hippocampus of the mice.

OBJECTIVE

In FST, the immobility time of CGDtreated mice was decreased significantly (P < 0.05); no significant differences were found in the performances in EPM, NSF and OFT tests between the two groups. In social interaction test, the mouse models of CSDS treated with CGD showed significantly increased time in the interaction zone (P < 0.05). Compared with those in the vehicle group, the CGD-treated mouse models exhibited significantly increased protein level of SIRT1 and decreased p53 acetylation (P < 0.05) with up-regulated synapsin I mRNA expression in the hippocampus (P < 0.05); no significant difference were found in Rab (P=0.813), SNAP (P=0.820), or Tubb mRNA expressions (P=0.864) between the two groups.

OBJECTIVE

CGD produces antidepressant-like effects in mice possibly through the sirt1-p53 signaling pathway and synaptic plasticity.

Second-order QCD corrections to event shape distributions in deep inelastic scattering

We compute the next-to-next-to-leading order (NNLO) QCD corrections to event shape distributions and their mean values in deep inelastic lepton-nucleon scattering. The magnitude and shape of the corrections varies considerably between different variables. The corrections reduce the renormalization and factorization scale uncertainty of the predictions. Using a dispersive model to describe non-perturbative power corrections, we compare the NNLO QCD predictions with data from the H1 and ZEUS experiments. The newly derived corrections improve the theory description of the distributions and of their mean values.

[Moxibustion combined with highly active antiretroviral therapy for CD4+ and γ chain cytokines of HIV infected patients]

OBJECTIVE

To compare the effects of moxibustion combined with highly active antiretroviral therapy (HAART) and simple HAART for human immunodeficiency virus (HIV) infected patients.

METHODS

A total of 100 patients with HIV receiving HAART were randomized into an observation group and a control group, 50 cases in each one. In the observation group, moxibustion was used at Zusanli (ST 36), Guanyuan (CV 4) and Sanyinjiao (SP 6), etc. combined with HAART of zidovudine, lamivudine, nevirapine and efavirenzone, etc. Simple HAART was used in the control group. The patients were observed for 18 months. The indexes were CD₄⁺, CD₄⁺/CD₈⁺, interleukin 2 (IL-2), interleukin 7 (IL-7), the incidence of side effects and the score of quality of life.

RESULTS

After treatment, CD₄⁺, CD₄⁺/CD₈⁺, serum IL-2 and the scores of quality of life (physiological, psychological, social relation fields and comprehensive score) increased and serum IL-7 decreased compared with those before treatment in the two groups (P<0.01, P<0.05), with better results except CD₄⁺ in the observation group (P<0.01, P<0.05). The incidences of gastrointestinal side effects and total side effects in the observation group were lower than those in the control group (14% (7/50) vs 32% (16/50), 58% (29/50) vs 80% (40/50), both P<0.05).

CONCLUSION

Moxibustion combined with HAART for HIV infected patients could reduce the incidence of side effects, improve medication compliance, CD₄⁺/CD₈⁺, IL-2, IL-7 and the quality of life.

An in-situ thermally regenerated air purifier for indoor formaldehyde removal

Formaldehyde is a common indoor pollutant that is an irritant and has been classified as carcinogen to humans. Adsorption technology is safe and stable and removes formaldehyde efficiently, but its short life span and low adsorption capacity limit its indoor application. To overcome these limitations, we propose an in-situ thermally regenerated air purifier (TRAP) which self-regenerates as needed. This purifier has four working modes: cleaning mode, regeneration mode, exhaust mode, and outdoor air in-take mode, all of which are operated by valve switching. We developed a real-scale TRAP prototype with activated carbon as adsorbent. The experimental testing showed that the regeneration ratios for formaldehyde of TRAP were greater than 90% during 5 cycles of adsorption-regeneration and that through the 5 cycles, there was no damage to the adsorption material as confirmed by scanning electron microscope (SEM) and Brunauer-Emmett-Teller (BET) tests. The total energy consumption by the prototype for purifying 1000 m³ indoor air was 0.26 kWh. This in-situ thermal-regeneration method can recover the purifier's adsorption ability through at least five cycles.

Voriconazole and squamous cell carcinoma after lung transplantation: A multicenter study

This study evaluated the independent contribution of voriconazole to the development of squamous cell carcinoma (SCC) in lung transplant recipients, by attempting to account for important confounding factors, particularly immunosuppression. This international, multicenter, retrospective, cohort study included adult patients who underwent lung transplantation during 2005-2008. Cox regression analysis was used to assess the effects of voriconazole and other azoles, analyzed as time-dependent variables, on the risk of developing biopsy-confirmed SCC. Nine hundred lung transplant recipients were included. Median follow-up time from transplantation to end of follow-up was 3.51 years. In a Cox regression model, exposure to voriconazole alone (adjusted hazard ratio 2.39, 95% confidence interval 1.31-4.37) and exposure to voriconazole and other azole(s) (adjusted hazard ratio 3.45, 95% confidence interval 1.07-11.06) were associated with SCC compared with those unexposed after controlling for important confounders including immunosuppressants. Exposure to voriconazole was associated with increased risk of SCC of the skin in lung transplant recipients. Residual confounding could not be ruled out because of the use of proxy variables to control for some confounders. Benefits of voriconazole use when prescribed to lung transplant recipients should be carefully weighed versus the potential risk of SCC. EU PAS registration number: EUPAS5269.

Application of the amniotic fluid metabolome to the study of fetal malformations, using Down syndrome as a specific model

Although monitoring and diagnosis of fetal diseases in utero remains a challenge, metabolomics may provide an additional tool to study the etiology and pathophysiology of fetal diseases at a functional level. In order to explore specific markers of fetal disease, metabolites were analyzed in two separate sets of experiments using amniotic fluid from fetuses with Down syndrome (DS) as a model. Both sets included 10–15 pairs of controls and cases, and amniotic fluid samples were processed separately; metabolomic fingerprinting was then conducted using UPLC-MS. Significantly altered metabolites involved in respective metabolic pathways were compared in the two experimental sets. In addition, significantly altered metabolic pathways were further compared with the genomic characters of the DS fetuses. The data suggested that metabolic profiles varied across different experiments, however alterations in the 4 metabolic pathways of the porphyrin metabolism, bile acid metabolism, hormone metabolism and amino acid metabolism, were validated for the two experimental sets. Significant changes in metabolites of coproporphyrin III, glycocholic acid, taurochenodeoxycholate, taurocholate, hydrocortisone, pregnenolone sulfate, L-histidine, L-arginine, L-glutamate and L-glutamine were further confirmed. Analysis of these metabolic alterations was linked to aberrant gene expression at chromosome 21 of the DS fetus. The decrease in coproporphyrin III in the DS fetus may portend abnormal erythropoiesis, and unbalanced glutamine-glutamate concentration was observed to be closely associated with abnormal brain development in the DS fetus. Therefore, alterations in amniotic fluid metabolites may provide important clues to understanding the etiology of fetal disease and help to develop diagnostic testing for clinical applications.

Antiviral Activities of Peptides with Sequences Related to the Cytoplasmic Domain of the Respiratory Syncytial Virus Glycoproteins

A set of peptides from 6–10 amino acids in length with sequences corresponding to the respiratory syncytial virus (RSV) attachment glycoprotein, G, has been found to inhibit secretion of virus particles from two human cell lines infected with RSV. Peptides of similar lengths with sequences related to the fusion (F) protein were not effective. A modified assay for syncytia formation was used to measure infectious particles and we found that cell-free infectious RSV was inhibited by those same peptides that blocked particle release. However, only about 5–20% of the total infectious virus formed in the cultured cells was released from the cells – the remaining was assayable only after lysis of the infected cells. Formation of this major fraction of infectious, cell-associated RSV was not affected by the peptides. The inhibitory peptides were ineffective in blocking release of infectious virus from cells infected with influenza, vesicular stomatitis and Semliki Forest viruses. Only a set of specific amino acids in these peptides were inhibitory and they consisted of a very hydrophobic sequence that also required a cysteine residue.

Understanding and controlling airborne organic compounds in the indoor environment: mass transfer analysis and applications

Mass transfer is key to understanding and controlling indoor airborne organic chemical contaminants (e.g., VVOCs, VOCs, and SVOCs). In this study, we first introduce the fundamentals of mass transfer and then present a series of representative works from the past two decades, focusing on the most recent years. These works cover: (i) predicting and controlling emissions from indoor sources, (ii) determining concentrations of indoor air pollutants, (iii) estimating dermal exposure for some indoor gas-phase SVOCs, and (iv) optimizing air-purifying approaches. The mass transfer analysis spans the micro-, meso-, and macroscales and includes normal mass transfer modeling, inverse problem solving, and dimensionless analysis. These representative works have reported some novel approaches to mass transfer. Additionally, new dimensionless parameters such as the Little number and the normalized volume of clean air being completely cleaned in a given time period were proposed to better describe the general process characteristics in emissions and control of airborne organic compounds in the indoor environment. Finally, important problems that need further study are presented, reflecting the authors' perspective on the research opportunities in this area.

Depth-resolved model-based reconstruction of attenuation coefficients in optical coherence tomography

We present a method, based on a single scattering model, to calculate the attenuation coefficient of each pixel in optical coherence tomography (OCT) depth profiles. Numerical simulations were used to determine the model's response to different depths and attenuation coefficients. Experiments were performed on uniform and layered phantoms with varying attenuation coefficients. They were measured by a 1300 nm OCT system and their attenuation coefficients were evaluated by our proposed method and by fitting the OCT slope as the gold standard. Both methods showed largely consistent results for the uniform phantoms. On the layered phantom, only our proposed method accurately estimated the attenuation coefficients. For all phantoms, the proposed method largely reduced the variability of the estimated attenuation coefficients. The method was illustrated on an in-vivo retinal OCT scan, effectively removing common imaging artifacts such as shadowing. By providing localized, per-pixel attenuation coefficients, this method enables tissue characterization based on attenuation coefficient estimates from OCT data.

Expression of interleukin-18 in a rat model of deep vein thrombosis

AIM

Interleukin-18 (IL-18) is an important proinflammatory cytokine. However, little is known about the roles of IL-18 in the process of venous thrombosis. This study aimed to investigate the roles of IL-18 during deep vein thrombosis (DVT).

METHODS

Fifty rats were randomly divided into 0 (control group), 12, 24, 36 and 48 h groups (10 rats in each group) by observation time. The inferior vena cava (IVC) was ligated to establish the DVT model. Serum samples were extracted to determine the levels of IL-18, tumor necrosis factor-alpha (TNF-α), thromboxane B2 (TXB2) and 6-keto-prostaglandin Fl alpha (6-keto-PG Flα) by enzyme-linked immunosorbent assay (ELISA). The weight and length of IVC was also measured.

RESULTS

The DVT model was successfully established by ligating IVC. The injury of vein endothelium was observed in the model groups. IL-18, TNF-α, TXB2, TXB2/6-keto-PG Flα levels and thrombus weight were significantly increased in the model groups as compared with the control group, and peaked at 24 h after IVC ligation. 6-keto-PG F1α slightly decreased in the model groups comparing with the control group. IL-18 was positively correlated with TNF-α, TXB2, TXB2/6-keto-PG Flα ratio and thrombus weight. However, IL-18 was negatively correlated with 6-keto-PG Flα. There was a positive correlation between TXB2/6-keto-PG Flα ratio and thrombus weight.

CONCLUSION

Serum IL-18 level increased in the process of DVT, which might impair venous endothelial cells and result in venous thrombosis. IL-18 might be a new potential therapeutic target of DVT prevention.

Developmental expression and subcellular distribution of synaptotagmin 11 in rat hippocampus

Synaptotagmins are required for Ca(2+)-dependent membrane-trafficking in either neuronal synaptic vesicles or cellular membranes. Previous reports suggested that the synaptotagmin 11 (syt11) gene is involved in the development of schizophrenia based on the genomic analysis of patients. Parkin protein binds to the C2 domains of Syt11 which leads to the polyubiquitination of Syt11. However, where and how Syt11 performs its role in the brain is largely unknown. Here, we report that Syt11 is expressed mainly in the brain. In addition, exogenously expressed Syt11 in HEK293 cells can form higher molecular weight complex via its transmembrane domain. Also, Syt11 is targeted to both dendrite and axon compartments. Immunocytochemistry showed that Syt11 is juxtaposed to postsynaptic markers in both excitatory and inhibitory synapses. Both neuroligin 1 and 2, which are postsynaptic cell adhesion molecules and differentially induce excitatory and inhibitory presynapses, respectively, recruit Syt11 in neuron coculture. Immunogold electron microscopy analysis revealed that Syt11 exists mainly in presynaptic neurotransmitter vesicles and plasma membrane, and rarely in postsynaptic sites. These results suggest that Syt11 may contribute to the regulation of neurotransmitter release in the excitatory and inhibitory presynapses, and postsynapse-targeted membrane trafficking in dendrites.

Delta15N of soil N and plants in a N-saturated, subtropical forest of southern China

We investigated the delta(15)N profile of N (extractable NH(4)(+), NO(3)(-), and organic N (EON)) in the soil of a N-saturated subtropical forest. The order of delta(15)N in the soil was EON > NH(4)(+) > NO(3)(-). Although the delta(15)N of EON had been expected to be similar to that of bulk soil N, it was higher than that of bulk soil N by 5 per thousand. The difference in delta(15)N between bulk soil N and EON (Delta(15)N(bulk-EON)) was correlated significantly with the soil C/N ratio. This correlation implies that carbon availability, which determines the balance between N assimilation and dissimilation of soil microbes, is responsible for the high delta(15)N of EON, as in the case of soil microbial biomass delta(15)N. A thorough delta(15)N survey of available N (NH(4)(+), NO(3)(-), and EON) in the soil profiles from the organic layer to 100 cm depth revealed that the delta(15)N of the available N forms did not fully overlap with the delta(15)N of plants. This mismatch in delta(15)N between that of available N and that of plants reflects apparent isotopic fractionation during N uptake by plants, emphasizing the high N availability in this N-saturated forest.

5-HT 3 receptors mediate the time-dependent vagal afferent modulation of nociception during chronic food allergen-sensitized visceral hyperalgesia in rats

Converging lines of evidence demonstrate a vagally mediated antinociceptive pathway in animals undergoing acute visceral insults, the contribution of this system to visceral pain following chronic noxious stimuli is unknown. 5-HT(3) receptor (5-HT(3)Rs) on spinal afferents are crucially involved in nociceptive processing, the role of 5-HT(3)Rs on vagal afferents is unclear. The aim of the present study was to determine the contribution of vagal afferents to visceral nociception in rats undergoing chronic luminal allergen stimulation and whether it involves vagal 5-HT(3)Rs. Sensitized rats received chicken egg albumin (EA, 1 mg mL(-1)) in drinking water for 2 weeks (day 1-14). Visceromotor response (VMR) to colorectal distension [colorectal distension (CRD), 60 mmHg] and the levels of mRNA encoding 5-HT(3)R (including 3A and 3B subunits) in the nodose ganglia (NG) were evaluated on day 2, 4, 8 and 15. Chronic EA challenge induced gradually increased visceral nociception, with a peak on day 15. Subdiaphragmatic vagotomy or functional deafferentation with capsaicin abolished this time-dependent manner, inducing hyperalgesia from day 2, lasting to day 15. Intraluminal infusion of a 5-HT(3)R antagonist (granisetron), whether alone or infused after local mucosa anaesthetic with 1% lidocaine, mimicked the effects of vagotomy. The mRNA levels for 5-HT(3B) or 5-HT(3A) subunit in the NG showed an opposite time-course to that of visceral pain, which increased from day 2, then decreased gradually to levels lower than those of controls. Our results demonstrate a time-dependent vagal afferent modulation of chronic allergen-sensitized visceral hyperalgesia, which may involve a 5-HT(3)R pathway.

A simple method for fixation and microdissection of frozen fresh tissue sections for molecular cytogenetic analysis of cancers

Microdissection has been widely used for procuring DNA from specific microscopic regions of formalin fixed, paraffin embedded tissue sections. We have developed a method for fixation and microdissection of frozen fresh biopsy tissue sections. Five micrometer frozen fresh tissue sections were fixed with ethanol and stored at room temperature. Well defined regions from hematoxylin and eosin (H & E) stained or unstained sections were briefly steamed and microdissected using a needle. The dissected tissue was digested with proteinase K and DNA was isolated. Whole genome amplifications were obtained by degenerate oligonucleotide primed polymerase chain reaction (DOP-PCR) from these samples. The reliability of this technique was demonstrated by comparing conventional comparative genomic hybridization (CGH) with DOP-PCR-CGH. The advantages of this method are that frozen fresh sections can be fixed easily and stored for more than 4 years, it is easy to microdissect and pick-up very minute regions (0.1 mm(2)), and it is rapid; microdissection and purification can be accomplished within 3 h. Using DNA from microdissected sections, DOP-PCR-CGH revealed genetic abnormalities more accurately than conventional CGH. Although this novel method was demonstrated using DOP-PCR-CGH, we believe that it will be useful for other genetic analyses of specific small regions and cell populations. We also observed whether storage time, H & E staining and crude DNA extracts affected the quality of amplified DNA. DNA integrity was maintained for at least 49 months in ethanol fixed sections that were stored at room temperature, but DNA was gradually degraded after one month if the ethanol fixed sections had been H & E stained and stored. When crude DNA extracts from H & E stained sections were used, the size of the DOP-PCR product was reduced. Our study suggests that ethanol fixed tissue sections may be stored at room temperature for at least 4 years without DNA degradation, the H & E stains may not affect the quality of amplified DNA, but H & E or other components in the staining process may reduce the size of DOP-PCR product, which is critical for the quality of CGH hybridization.

The Frequency of Proliferative Stromal Cells in Adipose Tissue Varies Between Inbred Mouse Strains

Stromal cells derived from adipose tissue (ASCs) can proliferate as undifferentiated cells with a fibroblast-like morphology in cell culture, or can be induced to differentiate into a variety of cell types including, adipipogenic, myogenic, neurogenic, osteogenic, chondrogenic and hepatic cells. There is increasing interest to understand the factors controlling the proliferation of ASCs since these cells might provide a readily available source of autologous stem/progenitor cells for cell therapy applications. To explore potential genetic factors that modify the properties of ASCs, we tried to identify relevant properties of ASCs that differ between inbred mouse strains. Plating cells in a modified colony forming assay indicates that the percentage of high proliferative cells among ASCs differs more than 2-fold between 129x1/svj and C57Bl/6J mice. The identification of genetic factors affecting the proliferative capacity of stem cell populations could improve the efficacy of cell therapy.

Modification of an effector strain for replacement therapy of dental caries to enable clinical safety trials

AIMS

To construct a genetically modified strain of Streptococcus mutans for dental caries prevention. The strain has significantly reduced cariogenicity owing to a deletion of the entire open reading frame for lactate dehydrogenase, and has excellent colonization potential through the production of a natural antibiotic called mutacin 1140. For use in human clinical trials, additional mutations were introduced to enable rapid elimination of the strain in case of adverse side effects and to increase genetic stability.

METHODS

Deletion mutations were introduced into the dal gene for d-alanine biosynthesis and the comE gene for genetic transformation. The resulting strain, A2JM, was tested for dependence on exogenous d-alanine and its ability to be eradicated from colonized rats. The strain was also tested for its ability to exchange DNA with another strain of S. mutans in in vitro and in vivo models.

CONCLUSIONS

A2JM was completely dependent on exogenous d-alanine, but could colonize the oral cavity of rats in low numbers in the absence of dietary d-alanine. Results indicated that A2JM can scavenge d-alanine from other plaque bacteria. Lowering of the total oral bacterial load through daily application of chlorhexidine enabled virtually complete eradication of A2JM. The introduction of the comE gene did not significantly decrease the transformability of A2JM in in vitro or in vivo models. The addition of a deletion in the comE gene does, nonetheless, provide additional safety as it has a very low reversion frequency.

SIGNIFICANCE AND IMPACT OF THE STUDY

Based on the safety and efficacy profiles established in vitro and in animal models, A2JM appears suitable for safe use in human clinical trials.

Metabolic syndrome, its preeminent clusters, incident coronary heart disease and all-cause mortality--results of prospective analysis for the Atherosclerosis Risk in Communities study

OBJECTIVE

To investigate the prospective association between Metabolic Syndrome (MetS) and coronary heart disease (CHD) and all-cause mortality.

SUBJECTS AND DESIGN

A bi-racial cohort of 14 699 middle-aged Americans from the Atherosclerosis Risk in Communities study were followed for the development of new CHD and death over a period of 9 years. MetS, using the original ATP-III criteria, was defined as having at least three of the following components: elevated blood pressure (BP), elevated plasma glucose, elevated blood triglyceride (TG), increased waist circumference, and low HDL cholesterol (HDL-c). Incident CHD cases included hospitalized myocardial infarction (MI), fatal CHD, revascularization procedures, and silent MI as detected by EKG.

RESULTS

The prevalence of the MetS at baseline was 29%, 30%, 40% and 26% among CHD-free white women, white men, black women, and black men, respectively. There were 1018 incident CHD cases and 1039 deaths. The relative risk (RR) and 95% confidence interval (CI) of incident CHD associated with MetS was 2.46 (1.99, 3.03) for women and 1.86 (1.59, 2.18) for men. Clear dose-response relationship between the number of MetS components and incidence of CHD was found (P for linear trend <0.001). The following three clusters of MetS components posed the highest risk for CHD: (i) the elevated BP and glucose and low HDL-c group [RR = 5.68 (3.44, 9.37)]; (ii) the elevated BP and glucose and TG group [RR = 5.08 (2.96, 8.70)]; and (iii) the elevated BP and TG and low HDL-c group [RR = 3.98 (2.75, 5.77)]. When all five components co-existed, the risk was the highest [RR = 6.24 (4.65, 8.36)]. Similar results with attenuated RR were found for all-cause mortality.

CONCLUSIONS

Individuals, especially women, with the MetS have significantly higher risk of developing CHD. The riskiest combination is high-BP and glucose clustered with low HDL-c or high TG. These data highlight the importance of targeting MetS in the prevention of CHD and premature death.

Headache, cerebrovascular symptoms, and stroke: the Atherosclerosis Risk in Communities Study

OBJECTIVE

To evaluate the occurrence of stroke/TIA symptoms and ischemic stroke events among those with a lifetime history of migraine or other headaches with some migraine features in a biracial cohort of older adults.

METHODS

Participants were 12,750 African-American and white men and women from the Atherosclerosis Risk in Communities Study (1993 to 1995). The participants were queried about their lifetime headache history and characterized using modified International Headache Society diagnostic criteria. Stroke/TIA symptoms were classified using a computerized diagnostic algorithm, and ischemic stroke events were identified and validated using medical records. Multivariate logistic regression was used to assess the relationship between headache types and stroke/TIA symptoms and ischemic stroke events.

RESULTS

Migraine with aura was strongly associated with stroke symptoms (odds ratio [OR] 5.46, 95% CI: 3.64 to 8.18), TIA symptoms (OR 4.28, 95% CI: 3.02 to 6.08), and verified ischemic stroke events (OR 2.81, 95% CI: 1.60 to 4.92). Similarly, other headaches with aura were significantly associated with stroke symptoms (OR 3.68, 95% CI: 2.26 to 5.99) and TIA symptoms (OR 4.53, 95% CI: 3.08 to 6.67). In contrast, the associations for migraine without aura and other headaches without aura were not as consistent or robust.

CONCLUSIONS

Migraines and other headaches, particularly those accompanied by aura, were associated with an increased occurrence of stroke/TIA symptoms and ischemic stroke events.

Novel insight into VOC removal performance of photocatalytic oxidation reactors

A general model has been developed for analyzing the removal of volatile organic compounds (VOCs) by photocatalytic oxidation (PCO) reactors, taking into consideration of the photocatalytic (surface) reaction and the convective mass transfer coefficients including allowance for their spatial dependence. On this basis, a novel insight into VOC removal performance of PCO reactors is presented. The key parameter for evaluating PCO reactor VOC removal performance is the number of the mass transfer unit (NTU(m)), which is shown to be a simple linear product of three dimensionless parameters: the ratio of the reaction area to the cross-sectional area of the flow channel (A*), the Stanton number of mass transfer (St(m)), and the reaction effectiveness (eta). The A* represents the geometric and structural characteristic of a PCO reactor. The St(m) shows the synergistic degree of alignment between the fluid and mass flow fields, and reflects the convective mass transfer rate of the reactor. The eta, describes the relative intensity between the PCO reaction rate and the mass transfer rate. By using the relationship and the parameters, the influence of various factors on the VOC removal performance, the bottleneck for improving the performance and design of a PCO reactor can be determined. Three examples are used to illustrate the application of our proposed model. It is found that the VOC removal bottleneck is the reaction rate for honeycomb type reactor, while mass transfer rate for light-in-tube type reactor. With six fins the fractional conversion of a light-in-tube reactor increases about 70% relative to the one without any fins.

PRACTICAL IMPLICATIONS

Indoor air quality problem caused by volatile organic compounds (VOCs) have annoyed people for many years. Photocatalytic oxidation (PCO) appears to be a promising technique for destroying VOCs in indoor air. With the model and the novel insight presented in this paper, the influence of various factors on the VOC removal performance can be determined. And the bottleneck for improving the performance of a PCO reactor can be easily identified. These are helpful for designing high performance PCO reactors and optimizing their operative performance.

Fine mapping of 10q and 18q for familial Alzheimer's disease in Caribbean Hispanics

Familial Alzheimer's disease (AD [MIM 104300]) has been a focus of intense investigation, primarily in Caucasian families from Europe and North America families. Although the late-onset form of familial AD, beginning after age 65 years, has been linked to regions on chromosomes 10q and 12p, the specific genetic variants have not yet been consistently identified. Using a unique cohort of families of Caribbean Hispanics ancestry, we screened the genome using 340 markers on 490 family members from 96 families with predominantly late-onset AD. We observed the strongest support for linkage on 18q (LOD=3.14). However, 17 additional markers (chromosomes 1-6, 8, 10, 12, and 14) exceeded a two-point LOD score of 1.0 under the affecteds-only autosomal dominant model or affected sibpair model. As we previously reported the fine-mapping effort on 12p showing modest evidence of linkage, we focused our fine-mapping efforts on two other candidate regions in the current report, namely 10q and 18q. We added 31 family members and eight additional Caribbean Hispanic families to fine map 10q and 18q. With additional microsatellite markers, the evidence for linkage for 18q strengthened near 112 cM, where the two-point LOD score for D18S541 was 3.37 and the highest NPL score in that region was 3.65 (P=0.000177). This narrow region contains a small number of genes expressed in the brain. However, at 10q (134-138 cM), the NPL score decreased from 3.15 (P=0.000486) to 2.1 (P=0.0218), but two broad peaks remained overlapping with previously reported peaks. Our results provide modest support for linkage on 10q and 12p in this cohort of Caribbean Hispanic families with familial Alzheimer's disease, and strong evidence for a new locus on 18q.

Prevalence of diabetes and impaired fasting glucose in the Chinese adult population: International Collaborative Study of Cardiovascular Disease in Asia (InterASIA)

AIMS/HYPOTHESIS

To estimate the prevalence of diagnosed and undiagnosed diabetes and impaired fasting glucose in the general adult population of China.

METHODS

The International Collaborative Study of Cardiovascular Disease in ASIA, conducted from 2000 to 2001, included a nationally representative sample of 15 540 adults, aged 35 to 74 years. An overnight fasting blood specimen was collected to measure serum glucose and information on history of diabetes and use of hypoglycaemic medications was obtained by a standard questionnaire. Undiagnosed diabetes (fasting glucose > or =7.0 mmol/l) and impaired fasting glucose (6.1-6.9 mmol/l) were defined using the American Diabetes Association criteria.

RESULTS

Prevalence of self-reported diagnosed diabetes, undiagnosed diabetes, and impaired fasting glucose in Chinese adults were 1.3%, 4.2%, and 7.3%, respectively. Overall, 5.2% or 12.7 million men and 5.8% or 13.3 million women in China aged 35 to 74 years had diabetes (self-reported diagnosis plus undiagnosed diabetes). The age-standardized prevalence of diabetes was higher in residents of northern compared to southern China (7.4% vs 5.4%, p<0.001) and in those living in urban compared to rural areas (7.8% vs 5.1%, p<0.001).

CONCLUSIONS/INTERPRETATION

Our results show that the prevalence of diabetes in the adult population in China is much higher than previously reported. Three out of every four diabetes patients are undiagnosed, indicative of a lack of population-based screening programmmes and a relatively rapid and recent increase in incidence of diabetes. These results indicate that diabetes has become a major public health problem in China and underscore the need for national strategies aimed at prevention and treatment of diabetes.

Nesidioblastosis coexisting with islet cell tumor and intraductal papillary mucinous hyperplasia

A coexisting of intraductal papillary mucinous hyperplasia (IPMH) and islet cell tumor with nesidioblastosis of the pancreas in a 51-year-old man is reported. All of the clinical data indicated an insulinoma. A distal pancreatectomy was performed. A discrete mass measuring 1.9 x 2.0 cm was grossly identified in the tail of the pancreas. There were no other gross lesions. An islet cell tumor with nesidioblastosis was confirmed by immunostains and ultrastructural study. In addition, an IPMH was found that involved mainly branches of the pancreatic duct. The islet cell tumor and IPMH were topographically separated; however, there was a histologically intimate relationship between the nesidioblastosis and the IPMH. These findings indicate that the IPMH may have derived from autocrine and paracrine influences on the existing duct epithelial cells. To the best of our knowledge, this is the first report of nesidioblastosis coexisting with islet cell tumor and IPMH.

[Process of recovery of peristaltic function at anastomotic stoma after dismembering pyeloplasty in rabbits]

OBJECTIVE

To study the process of recovery of peristaltic function at anastomotic stoma after dismembering pyeloplasty in rabbits.

METHODS

An animal model of obstructive hydronephrosis was made with 32 New Zealand rabbits. These rabbits were divided into four groups to be examined within the first, second, third, and fourth week respectively after a dismembering pyeloplasty was performed on them, eight rabbits in each group. Thirty-two normal New Zealand rabbits were divided into four corresponding control groups as controls. Pressures of the renal pelvis and upper ureter were measured, electromyogram was recorded, and histological examination was made to the tissue of anastomotic stoma before and after the operation.

RESULTS

In the normal control rabbits, the resting pressure was (10.8 +/- 1.3) mm Hg, contraction amplitude was (1.6 +/- 0.4) mm Hg, pulse amplitude of EMG was (0.39 +/- 0.10) mV, and pulse frequency was (5.4 +/- 1.0)/min in the renal pelvis; and the resting pressure was (11.7 +/- 1.7) mm Hg, contraction amplitude was (1.8 +/- 0.5) mm Hg, pulse amplitude of EMG was (0.38 +/- 0.08) mV, pulse frequency was (5.3 +/- 0.9)/min in the upper ureter. Within the first week after operation, the resting pressure of renal pelvis was (14.4 +/- 1.3) mm Hg, significant higher than normal (P < 0.05), the contraction amplitude of renal pelvis was (1.1 +/- 0.4) mm Hg, lower than normal (P < 0.05); the pulse amplitudes of EMG in renal pelvis (0.19 +/- 0.05) mV and in upper ureter (0.26 +/- 0.04) mV were lower than normal (P < 0.05). A thin layer of mucosa was seen covering the anastomotic stoma. In the second week after operation, no statistical difference was observed in resting pressure, contraction amplitude, amplitude of EMG, and frequency of EMG in renal pelvis between the experimental rabbits and the controls (P > 0.05). Newborn smooth muscle cells were seen running through the anastomotic stoma, and close contact was observed among the cells. Within the third week after operation, the pressures and EMG in renal pelvis and in upper ureter were not significantly different from those in normal rabbits (P > 0.05). Nerve endings could be seen near the anastomotic stoma. Within the fourth week after operation, newborn muscle cells became mature and arranged regularly, and contacted each other closely.

CONCLUSION

Within the first week after the dismembering pyeloplasty, no peristalsis runs through the anastomotic stoma, and the renal pelvic resting pressure increases. Within the second week after the operation, the newborn smooth muscle cells at the anastomotic stoma begin to exercise their contractive and conductive functions. Peristalsis begins to run through the anastomotic stoma. Within the third after the operation, the peristaltic function basically recovers to normal.

DNA damage in the nucleosome core is refractory to repair by human excision nuclease

To investigate the effect of nucleosomes on nucleotide excision repair in humans, we prepared a mononucleosome containing a (6-4) photoproduct in the nucleosome core and examined its repair with the reconstituted human excision nuclease system and with cell extracts. Nucleosomal DNA is repaired at a rate of about 10% of that for naked DNA in both systems. These results are in agreement with in vivo data showing a considerably slower rate of repair of overall genomic DNA relative to that for transcriptionally active DNA. Furthermore, our results indicate that the first-order packing of DNA in nucleosomes is a primary determinant of slow repair of DNA in chromatin.

Improving degenerate oligonucleotide primed PCR-comparative genomic hybridization for analysis of DNA copy number changes in tumors

Combining degenerate oligonucleotide-primed PCR (DOP-PCR) with comparative genomic hybridization (CGH) has made it possible to analyze genomic changes in single cells. Although DOP-PCR-CGH methodology has been reported, the reproducibility of the method has been uncertain. We have developed a reproducible DOP-PCR-CGH protocol by systematically evaluating different labeling methods (including nick translation, PCR incorporation, and random-primed labeling) and different hybridization mixtures (including amplified test DNA vs. amplified reference DNA, termed homo-hybridization; and amplified test DNA vs. unamplified reference DNA or vice versa, termed hetero-hybridization). We have analyzed DNA samples obtained from 16 tissue sources including fresh/frozen normal and tumor samples, formalin fixed and paraffin embedded tumor tissue, and tumor cell lines by using differently labeled probes and hybridization combinations, and we calculated the corresponding rate (CR) of DOP-PCR-CGH with standard CGH. We found that homo-hybridization produced reproducible results with high CRs as compared to standard CGH (91-100% CR, mean 97%); In contrast, hetero-hybridization failed to generate reproducible hybridization with low CRs (57-97% CR, mean 80%; chi(2) = 1245.8, P<0.0001), high background, uneven hybridization, and false deletions or amplifications. In addition, our improved DOP-PCR protocol raised the amplification efficiency at least five times as compared to previously reported protocols, allowing for the detection of genomic imbalances in as little as 12.5 pg of starting DNA. In conclusion, the DOP-PCR-CHG homo-hybridization method, especially when combined with labeling by nick translation, is reliable and reproducible. The method can be used in screening for genomic imbalances using minute amounts of tumor DNA, thereby facilitating CGH application. Genes Chromosomes Cancer 28:395-403, 2000.

Identification of a fourth subunit of mammalian DNA polymerase delta

A 12-kDa and two 25-kDa polypeptides were isolated with highly purified calf thymus DNA polymerase delta by conventional chromatography. A 16-mer peptide sequence was obtained from the 12-kDa polypeptide which matched a new open reading frame from a human EST () encoding a hypothetical protein of unknown function. The protein was designated as p12. Human EST was identified as the putative human homologue of Schizosaccharomyces pombe Cdm1 by a tBlastn search of the EST data base using S. pombe Cdm1. The open reading frame of human EST encoded a polypeptide of 107 amino acids with a predicted molecular mass of 12.4 kDa, consistent with the experimental findings. p12 is 25% identical to S pombe Cdm1. Both of the 25-kDa polypeptide sequences matched the hypothetical KIAA0039 protein sequence, recently identified as the third subunit of pol delta. Western blotting of immunoaffinity purified calf thymus pol delta revealed the presence of p125, p50, p68 (the KIAA0039 product), and p12. With the identification of p12 mammalian pol delta can now be shown to consist of four subunits. These studies pave the way for more detailed analysis of the possible functions of the mammalian subunits of pol delta.

Evidence that DNA polymerase delta isolated by immunoaffinity chromatography exhibits high-molecular weight characteristics and is associated with the KIAA0039 protein and RPA

DNA polymerase delta, the key enzyme for eukaryotic chromosomal replication, has been well characterized as consisting of a core enzyme of a 125 kDa catalytic subunit and a smaller 50 kDa subunit. However, less is known about the other proteins that may comprise additional subunits or participate in the macromolecular protein complex that is involved in chromosomal DNA replication. In this study, the properties of calf thymus pol delta preparations isolated by immunoaffinity chromatography were investigated. It is demonstrated for the first time using highly purified preparations that the pol delta heterodimer is associated with other polypeptides in high-molecular weight species that range from 260000 to >500000 in size, as determined by FPLC gel filtration. These preparations are associated with polypeptides of ca. 68-70, 34, 32, and 25 kDa. Similar findings were revealed with glycerol gradient ultracentrifugation. The p68 polypeptide was shown to be a PCNA binding protein by overlay methods with biotinylated PCNA. Protein sequencing of the p68, p34, and p25 polypeptide bands revealed sequences that correspond to the hypothetical protein KIAA0039. KIAA0039 displays a small but significant degree of homology to Schizosaccharomyces pombe Cdc27, which, like Saccharomyces cerevisiae Pol32p, has been described as the third subunit of yeast pol delta. These studies provide evidence that p68 is a subunit of pol delta. In addition, the p68-70 and p32 polypeptides were found to be derived from the 70 and 32 kDa subunits of RPA, respectively.

[Separation and determination of the ingredients of cold medicines by capillary electrophoresis with amperometric detection]

Determination and separation of three ingredients--chlorphenamine maleate, acetaminophen and vitamin C in cold medicines by capillary electrophoresis with amperometric detection were carried out. The effects of detection potential and organic modifier were extensively investigated. Separation efficiency could be improved by adding 1, 2-propanediol into buffer. On optimizing condition, chlorphenamine maleate, acetaminophen and vitamin C were separated satisfactorily and eluted within 12 min. The detection limits were 0.02, 0.08 and 0.01 mg/L respectively. The ingredients in several cold medicines were detected successfully. The recoveries of the samples were 94.2%-102.8%. The method is simple, rapid and highly reliable for routine analysis.

[Determination of epinephrine, chlorpromazine and promethazine by capillary electrophoresis with scanning voltammetric detector]

With a self-constructed electrochemical detection system, the determination of epinephrine, chlorpromazine and promethazine has been studied by using capillary electrophoresis with scanning voltammetric detector. Scanning potential generation and data acquisition were carried out with D/A and A/D converter board that mounted on a 486DX66 computer. A complex software, which was written by authors in BORLAND C++, was serve to data acquisition, abstraction of three-dimension data, display and print of the electrophorograms. Using a 25 microns x 70 cm fused-silica capillary, the optimum conditions for separation and detection of titled drugs are 10 mmol/L K2HPO4 + H3PO4 (pH 3.0) running electrolyte, 20 kV separation voltage, hydrodynamic injection 10 s at 20 cm height, scanning potential from +0.4 to +1.0 V vs. SCE. With the optimizing condition, the separation of titled drugs is satisfactory, and good reproducibility and low limit are obtained. In this study, all experiments are carried out under air-conditioning (18 degrees C) and constant humidity (relative humidity 50%). In comparison to amperometric detection, scanning voltammetric detection has the advantages of minimizing fouling of the working electrode surface, and direct identification of unknown chemicals by voltammetric curves.