[Research progress in the performance of clear aligner attachment materials]

For most patients undergoing clear aligner treatment, it could be necessary to bond multiple attachments on their tooth surfaces. The clear aligner attachment is designed to enhance aligner retention, transmit orthodontic forces, and make the programmed tooth movement more predictable. Materials such as restorative resin, orthodontic bonding adhesive, flowable resin, and resin-modified glass ionomer cement are currently used for attachment bonding. But there is currently no conclusion as to which material suits most. The objective of this review is to look into the studies published in recent years, in order to explore the optimal material option for making clear aligner attachments.

A Wohlfahrtiimonas chitiniclastica with a novel type of blaVEB-1-carrying plasmid isolated from a zebra in China

Background

Wohlfahrtiimonas chitiniclastica is an emerging fly-borne zoonotic pathogen, which causes infections in immunocompromised patients and some animals. Herein, we reported a W. chitiniclastica BM-Y from a dead zebra in China.

Methods

The complete genome sequencing of BM-Y showed that this isolate carried one chromosome and one novel type of blaVEB-1-carrying plasmid. Detailed genetic dissection was applied to this plasmid to display the genetic environment of blaVEB-1.

Results

Three novel insertion sequence (IS) elements, namely ISWoch1, ISWoch2, and ISWoch3, were found in this plasmid. aadB, aacA1, and gcuG were located downstream of blaVEB-1, composing a gene cassette array blaVEB-1-aadB-aacA1-gcuG bracketed by an intact ISWoch1 and a truncated one, which was named the blaVEB-1 region. The 5'-RACE experiments revealed that the transcription start site of the blaVEB-1 region was located in the intact ISWoch1 and this IS provided a strong promoter for the blaVEB-1 region.

Conclusion

The spread of the blaVEB-1-carrying plasmid might enhance the ability of W. chitiniclastica to survive under drug selection pressure and aggravate the difficulty in treating infections caused by blaVEB-1-carrying W. chitiniclastica. To the best of our knowledge, this is the first report of the genetic characterization of a novel blaVEB-1-carrying plasmid with new ISs from W. chitiniclastica.

Spin in the Abstracts of Randomized Controlled Trials in Operative Dentistry: A Cross-sectional Analysis

OBJECTIVE

To assess the presence and characteristics of spin in recently published RCT abstracts in operative dentistry and to investigate potential factors associated with the presence of spin.

METHODS AND MATERIALS

The PubMed database was searched to identify parallel-group RCTs published between 2015 and 2019 in the field of operative dentistry, which compared two or more groups and had nonsignificant results for the primary outcome. Two authors evaluated independently the presence and characteristics of spin among these abstracts. Multivariable logistic regression analyses were conducted to identify factors associated with the presence of spin in the Results and the Conclusions sections, respectively.

RESULTS

A total of 77 RCT abstracts were included, among which 58 (75.3%) showed at least one type of spin. Spin was identified in the Results and Conclusions sections of 32 (41.6%) and 45 (58.4%) abstracts, respectively. 19 RCTs (24.7%) presented spin in both the Results and the Conclusions section of abstracts. The presence of spin in the Results section of abstracts was significantly associated with source of funding (OR=8.10; p=0.025) and number of treatment arms was associated with the presence of spin in the Conclusions section of abstracts (OR=5.66; p=0.005).

CONCLUSION

The occurrence rate of spin in the sample of operative dentistry RCTs abstracts is high.

[Percentage of tonsil hypertrophy in orthodontic patients with different sagittal skeletal relationship]

Objective: To investigate the prevalence of tonsil hypertrophy in patients with different sagittal skeletal craniofacial patterns, as well as the correlation between tonsil hypertrophy and the type of skeletal pattern. Methods: Lateral cephalograms of patients who visited the Department of Orthodontics Division 1, School of Stomatology, Wuhan University during January to August, 2019 were retrospectively collected. Patients (children: age≥6 and ≤12 year; adults: age≥18 year) were divided into three groups according to the ANB (subspinale-nasion-supramental) angle: the skeletal class Ⅰ group (0°≤ANB≤4°), skeletal class Ⅱ group (ANB>4°) and skeletal class Ⅲ group (ANB<0°). Tonsil hypertrophy was diagnosed with lateral cephalogram by two specifically trained orthodontists independently, according to the Baroni's method. The between-group differences in tonsil hypertrophy prevalence were analyzed using chi-square tests with Bonferroni correction (α=0.017). Results: A total of 1 776 patients (593 children and 1 183 adults) were included, among which 672 (37.8%) were with class Ⅰ, 849 (47.8%) with class Ⅱ, and 255 (14.4%) with class Ⅲ skeletal pattern. The prevalence of tonsil hypertrophy in children was 66.3% (393/593). The proportion of children with tonsil hypertrophy in class Ⅲ group [87.0% (60/69)] were significantly higher than that in class Ⅰ [65.6% (145/221), χ²=11.56, P<0.017] and class Ⅱ [62.0% (188/303), χ²=15.69, P<0.017] groups. The prevalence of tonsil hypertrophy in adults was 23.2% (275/1 183). The proportion of adults with tonsil hypertrophy in class Ⅲ group [42.5% (79/186)] was significantly higher than that in class Ⅰ [19.1% (86/451), χ²=36.50, P<0.017] and class Ⅱ [20.2% (110/546), χ²=35.00, P<0.017] groups. However, there was no significant difference in the prevalence of tonsil hypertrophy between class Ⅰ and class Ⅱ groups for both children (χ²=0.70, P>0.017) and adults (χ²=0.18, P>0.017). Conclusions: The prevalence of tonsil hypertrophy in skeletal class Ⅲ patients was significantly higher than that in patients with skeletal class Ⅰ and Ⅱmalocclusion. Tonsil hypertrophy could be an important risk factor for skeletal class Ⅲ patients.

[Comparison of early outcome between one-stage hybrid technique and frozen elephant thunk technique in the treatment of Stanford A aortic dissection involving the arch]

Objective: To analyze the early outcome of one-stage hybrid technique in the treatment of Stanford type-A aortic dissection involving the arch and compare its therapeutic efficacy with the classical frozen elephant trunk technique (FET). Methods: A total of 106 patients with Stanford type-A aortic dissection involving the arch in Department of Cardiac and Vascular Surgery, 1st Affiliated Hospital of Soochow University from October 2015 to October 2019 was collected. All patients in this group were treated with one-stage hybrid technique (modified arch debranching technique) without deep hypothermia circulation. Meanwhile, 30 patients with Stanford type A dissection involving the arch who underwent FET from January 2014 to September 2015 were collected. The therapeutic effects of the two surgical methods were analyzed and compared. Results: The age [M (Q₁, Q₃)] of 106 patients in hybrid group was 49.0 (40.0, 55.0) years, including 89 males and 17 females. The age [M(Q₁, Q₃)] of 30 patients in FET group was 49.5 (41.5, 65.3) years, including 24 males and 6 females. The time [M(Q₁, Q₃)] of using ventilator in hybrid group was 56.0 (38.0, 72.0) h, which was shorter than 127.0 (92.0, 145.0) h in FET group (P<0.001). The incidence of cerebral infarction in hybrid group was 2.8% (3 cases), which was lower than 13.3% (4 cases) in FET group (P=0.042); the incidence of postoperative renal insufficiency in hybrid group was 7.5% (8 cases), which was lower than 23.3% (7 cases) in FET group (P=0.023); the ICU time [M (Q₁, Q₃)] in hybrid group was 8.0 (6.0, 10.0) d, which was shorter than 14.0 (8.3, 24.0) d in FET group (P<0.001). Conclusion: Compared with FET, one-stage hybrid technology is safer and more effective in the treatment of Stanford type A aortic dissection involving the arch. Its short-term therapeutic efficacy appears good.

[Diagnostic value of FNDC5 in patients with subclinical diabetic cardiomyopathy]

Objective: To estimate the diagnostic value of fibronectin type Ⅲ-domain containing protein 5 (FNDC5) in subclinical diabetic cardiomyopathy. Methods: A total of 94 patients with type 2 diabetes (T2DM), who were hospitalized from April 2018 to June 2019 in the Third Affiliated Hospital of Soochow University, were enrolled in this study. Patients were divided into T2DM with cardiac dysfunction (subclinical DCM) group (n=47) and T2DM without cardiac dysfunction (non-DCM) group (n=47) according to echocardiography and gated myocardial perfusion imaging results. Basic clinical data and serum FNDC5 level were compared between the two groups. Logistic regression analysis was used to establish predicting models and the diagnostic efficiency of established models was compared by ROC curve analysis. Results: Compared to non-DCM group, patients in subclinical DCM group were older, with longer duration of diabetes, and had higher levels of glycosylated hemoglobin A1c (HbA1c), total cholesterol (TC), triglyceride (TG) and low-density lipoprotein cholesterol (LDL-C) (all P<0.05). Serum FNDC5 level was significantly lower in subclinical DCM group than in non-DCM group (P<0.001). FNDC5 level was positively correlated with ventricular septal e'(r=0.451,P=0.005), mitral valve e'(r=0.291,P<0.001), the ratio of peak early diastolic trans-mitral flow velocity (E) to peak late diastolic trans-mitral flow velocity (A)(r=0.490,P=0.002), while negatively correlated with A(r=-0.399,P<0.001), the average ratio of E/e'(r=-0.490,P<0.001), tricuspid regurgitation velocity(r=-0.567,P<0.001), left atrial volume index(r=-0.491,P<0.001). Univariate ROC analysis showed that the diagnostic efficacy of FNDC5(AUC=0.940,95%CI 0.897-0.982)was superior to age(AUC=0.639,95%CI 0.523-0.752), diabetic duration(AUC=0.663,95%CI 0.555-0.772), HbA1c(AUC=0.740,95%CI 0.638-0.839), TG(AUC=0.661,95%CI 0.547-0.776), TC(AUC=0.675,95%CI 0.563-0.788)and LDL-C(AUC=0.644,95%CI 0.532-0.756). Model 1 was established with subclinical DCM as dependent variable, age, diabetic duration, TG, TC, LDL-C and HbA1c as independent variables. Model 2 was established by adding FNDC5 as independent variable on the basis of model 1. Diagnostic efficacy for subclinical DCM was compared between the two models by ROC analysis. The diagnostic efficiency was better with model 2 (AUC=0.980) than with model 1 (AUC=0.879, P<0.001). When sensitivity was set at 0.617, the specificity of model 2 was higher than that of model 1(0.979 vs. 0.936). When sensitivity was set at 0.532, the sensitivity of model 2 was higher than that of model 1 (1.000 vs. 0.915). Conclusions: Our findings suggest that serum FNDC5 could be used as a novel biomarker for the diagnosis of subclinical DCM.

LncRNA UCA1 inhibits proliferation and promotes apoptosis of cervical cancer cells by regulating β-catenin/TCF-4

OBJECTIVE

The aim of this study was to explore the regulatory effect of long non-coding ribonucleic acid (lncRNA) urothelial carcinoma antigen 1 (UCA1) on the proliferation and apoptosis of HeLa cells and to elucidate its potential regulatory mechanism.

MATERIALS AND METHODS

HeLa cells were cultured in vitro and randomly divided into three groups, including blank control group (Control group), lncRNA UCA1 negative control (NC) group, and lncRNA UCA1 interference group [lncRNA UCA1 small interfering RNA (siRNA) group]. The expression level of lncRNA UCA1 in HeLa cells was detected by quantitative reverse transcription-polymerase chain reaction (qRT-PCR). Methyl thiazolyl tetrazolium (MTT) assay was performed to determine the effect of lncRNA UCA1 on the proliferation of HeLa cells. The effect of lncRNA UCA1 on the apoptosis of HeLa cells was determined via Hoechst 33258 staining assay and flow cytometry. In addition, qRT-PCR and Western blotting were employed to measure the messenger RNA (mRNA) and protein expression levels of β-catenin and TCF-4 in HeLa cells, respectively.

RESULTS

There were no statistically significant differences in the proliferation and apoptosis of HeLa cells as well as the mRNA and protein levels of β-catenin and TCF-4 in HeLa cells between Control group and lncRNA UCA1 NC group (p>0.05). In comparison with lncRNA UCA1 NC group, lncRNA UCA1 siRNA group exhibited overtly reduced proliferation, enhanced apoptosis rate of HeLa cells and down-regulated mRNA and protein levels of β-catenin and TCF-4 in HeLa cells (p<0.05).

CONCLUSIONS

LncRNA UCA1 inhibits proliferation and promotes the apoptosis of HeLa cells. Furthermore, its mechanism of action may be related to the inhibition on the β-catenin/TCF-4 signaling pathway.

Muscone alleviates myocardial ischemia-reperfusion injury via inhibition of oxidative stress and enhancement of SIRT3

This study aimed at probing into the function of muscone in ameliorating myocardial ischemiareperfusion (I/R) injury and exploring the underlying mechanism. To analyze the function of muscone, H9c2 cardiomyocytes were treated with hypoxia/reoxygenation (H/R) and Sprague-Dawley (SD) rats were treated with left anterior descending (LAD) of the coronary artery ligation for 30 min and reperfusion for 2 h to induce myocardial I/R injury. Quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot were used to detect the expression of SIRT3. MTT assay and TUNEL assay were performed to investigate H9c2 viability and apoptosis, respectively. ELISA was employed to determine the expressions of inflammatory cytokines TNF-α, IL-6 and IL-1β, and myocardial injury markers CK and LDH. Oxidative stress markers MDA and SOD, and ROS expression levels were also detected. SIRT3 inhibitor 3-TYP was used to further confirm whether muscone worked via the augmentation of SIRT3. Herein, we found that muscone significantly inhibited inflammation and oxidative stress in H9c2 cardiomyocytes in a dose-dependent manner. H9c2 viability was promoted by muscone while apoptosis was inhibited. In SD rats, pre-treatment of muscone alleviated I/R injury-induced cardiac function dysregulation and left ventricle remolding. Furthermore, muscone increased SIRT3 expression at both mRNA and protein levels. With 3-TYP inhibiting SIRT3, the protective effects of muscone in H9c2 cardiomyocytes and SD rats were all significantly alleviated. In summary, muscone can attenuate inflammation, oxidative stress and cardiomyocytes injury in H9c2 cells treated with H/R and alleviate myocardial I/R injury of SD rats, which are dependent on SIRT3.

Quality of Split-Mouth Trials in Dentistry: 1998, 2008, and 2018

The objectives of this study were to assess the reporting quality and methodological quality of split-mouth trials (SMTs) published during the past 2 decades and to determine whether there has been an improvement in their quality over time. We searched the MEDLINE database via PubMed to identify SMTs published in 1998, 2008, and 2018. For each included SMT, we used the CONsolidated Standards Of Reporting Trials (CONSORT) 2010 guideline, CONSORT for within-person trial (WPT) extension, and a new 3-item checklist to assess its trial reporting quality (TRQ), WPT-specific reporting quality (WRQ), and SMT-specific methodological quality (SMQ), respectively. Multivariable generalized linear models were performed to analyze the quality of SMTs over time, adjusting for potential confounding factors. A total of 119 SMTs were included. The mean overall score for the TRQ (score range, 0 to 32), WRQ (0 to 15), and SMQ (0 to 3) was 15.77 (SD 4.51), 6.06 (2.06), and 1.12 (0.70), respectively. The primary outcome was clearly defined in only 28 SMTs (23.5%), and only 27 (22.7%) presented a replicable sample size calculation. Only 45 SMTs (37.8%) provided the rationale for using a split-mouth design. The correlation between body sites was reported in only 5 studies (4.2%) for sample size calculation and 4 studies (3.4%) for statistical results. Only 2 studies (1.7%) performed an appropriate sample size calculation, and 46 (38.7%) chose appropriate statistical methods, both accounting for the correlation among treatment groups and the clustering/multiplicity of measurements within an individual. Results of regression analyses suggested that the TRQ of SMTs improved significantly with time ( P < 0.001), while there was no evidence of improvement in WRQ or SMQ. Both the reporting quality and methodological quality of SMTs still have much room for improvement. Concerted efforts are needed to improve the execution and reporting of SMTs.

Abstracts of published randomised controlled trials in Endodontics: Reporting quality and spin

AIMS

To assess the reporting quality of recently published randomised controlled trial (RCT) abstracts in Endodontics, to investigate factors associated with reporting quality, and to evaluate the existence and characteristics of spin. Spin refers to reporting strategies that distort study results and misguide readers.

METHODOLOGY

The PubMed database was searched to identify abstracts of RCTs in the field of Endodontics published during 2017 to 2018. Two authors assessed the reporting quality of each included abstract using the original 16-item CONSORT for Abstracts checklist, with the overall quality score (OQS, range: 0 to 16) being the primary outcome measure. For each individual item, a score of '1' was given if it was described adequately, and '0' if the description was inadequate. Linear regression analyses were conducted to identify factors associated with reporting quality. For the evaluation of spin, two authors selected parallel-group RCTs with a nonsignificant primary outcome from the included abstracts, and evaluated independently the existence and characteristics of spin among these abstracts.

RESULTS

A total of 162 abstracts were included for assessment of reporting, for which the mean OQS was 3.97 (SD, 1.30; 95 % CI, 3.77 to 4.17). According to multivariable analysis, origin from Europe (P=0.001) and reporting of the exact P value (P=0.020) were significantly associated with better reporting. Forty abstracts with statistically nonsignificant results for their primary outcome were included for spin evaluation, among which 34 (85.0%) had at least one type of spin. Thirty-two abstracts (94.1%) had spin in their conclusions section, and six abstracts (17.6%) had spin in the results section.

CONCLUSIONS

The reporting quality of RCT abstracts in Endodontics needs to be improved. The occurrence rate of spin in the sample of abstracts of RCTs in the field of Endodontics was high. Relevant stakeholders are recommended to be familiar with the CONSORT for Abstracts guideline and develop active strategies to ensure its implementation.

Coronavirus Disease 2019 (COVID-19): Emerging and Future Challenges for Dental and Oral Medicine

The epidemic of coronavirus disease 2019 (COVID-19), originating in Wuhan, China, has become a major public health challenge for not only China but also countries around the world. The World Health Organization announced that the outbreaks of the novel coronavirus have constituted a public health emergency of international concern. As of February 26, 2020, COVID-19 has been recognized in 34 countries, with a total of 80,239 laboratory-confirmed cases and 2,700 deaths. Infection control measures are necessary to prevent the virus from further spreading and to help control the epidemic situation. Due to the characteristics of dental settings, the risk of cross infection can be high between patients and dental practitioners. For dental practices and hospitals in areas that are (potentially) affected with COVID-19, strict and effective infection control protocols are urgently needed. This article, based on our experience and relevant guidelines and research, introduces essential knowledge about COVID-19 and nosocomial infection in dental settings and provides recommended management protocols for dental practitioners and students in (potentially) affected areas.

GluR1 protects hypoxic ischemic brain damage via activating Akt signaling pathway in neonatal rats

OBJECTIVE

To investigate the role of glutamic acid receptor 1 (GluR1) in hypoxic-ischemic brain damage (HIBD) in neonatal rats and its underlying mechanism.

MATERIALS AND METHODS

7-day-old neonatal rats received right common carotid artery (CCA) ligation for the establishment of HIBD. After the operation, rats were sacrificed at different time points (0, 4, 6, 12, 24, 48, and 72 h), respectively. Meanwhile, rats in Sham group underwent similar procedures without ligation. Lentivirus-GLUR1-shRNA (LV-GLUR1 shRNA group) was constructed and then transfected into the right lateral ventricles of rats to inhibit GluR1 in vivo. Rats received LV-control injection were selected in the control group (LV-control group). After injection of Lentivirus-GLUR1-shRNA, CCA ligation was performed in rats for HIBD construction. Western blot was performed to detect the protein levels of GLUR1, Akt, p-Akt, and vascular endothelial growth factor (VEGF) in brain tissues. Cell apoptosis was measured by TUNEL staining assay.

RESULTS

After hypoxic ischemia (HI), GLUR1 expression increased gradually and reached a peak at 24 h. Meanwhile, p-Akt expression increased immediately and then gradually decreased. 24 h later, p-Akt expression increased again and peaked at 48 h. VEGF expression increased at 4 h after HI and reached a peak at 12 h. The expression levels of GLUR1, p-Akt, and VEGF in the brain tissues derived from rats transfected with LV-GLUR1 shRNA significantly decreased at both 4 h and 24 h after HI. In addition, results indicated that cell apoptosis was enhanced after LV-GLUR1 shRNA administration, suggesting the role of GLUR1 in protecting against HIBD.

CONCLUSIONS

GLUR1 exhibits a remarkable protective role in HIBD, which may be related to the activation of the Akt signaling pathway and the upregulation of VEGF after HI.

Phase 1, single-dose escalating study of marzeptacog alfa (activated), a recombinant factor VIIa variant, in patients with severe hemophilia

Essentials Marzeptacog alfa (activated) [MarzAA] is a novel variant of activated human factor VII. A phase 1 dose escalation trial of MarzAA was conducted in subjects with severe hemophilia. MarzAA was safe and tolerated at intravenous doses up to 30 μg kg-1 Data observed support further trials for hemophilia patients with inhibitors to factors VIII/IX.

SUMMARY

Background Marzeptacog alfa (activated) (MarzAA), a new recombinant activated human factor VII (rFVIIa) variant with four amino acid substitutions, was developed to provide increased procoagulant activity and a longer duration of action in people with hemophilia. Objectives To investigate the safety, tolerability, immunogenicity, pharmacokinetics (PK) and pharmacodynamics (PD) of single ascending intravenous bolus doses of MarzAA in non-bleeding patients with congenital hemophilia A or B with or without inhibitors. Methods This international, phase 1, open-label study (NCT01439971) enrolled males aged 18-64 years with severe hemophilia A or B, with or without FVIII or FIX inhibitors. Subjects were assigned to single-dose MarzAA cohorts (0.5, 4.5, 9, 18 or 30 μg kg-1 ). Blood sampling was performed predose and postdose, and subjects were monitored for 60 days postdose. Safety endpoints included adverse events, vital sign changes, electrocardiograms, laboratory abnormalities, and immunogenicity; secondary endpoints included evaluation of PK and PD. Results Overall, in 25 patients, MarzAA was well tolerated at all dose levels tested, and was not associated with dose-limiting toxicity. No treatment-emergent severe or serious adverse events occurred. MarzAA showed linear dose-response PK across the 4.5-30 μg kg-1 dose range, with a terminal half-life of ⁓ 3.5 h. Dose-dependent shortening of the activated partial thromboplastin time and prothrombin time, and evidence of an increase in peak thrombin as determined with a thrombin generation assay, were observed at all doses. Conclusions MarzAA was tolerated at doses up to 30 μg kg-1 . The safety profile and pharmacological effects observed support further clinical trials for the treatment of hemophilic patients with inhibitors.

Open access to journal articles in oncology: current situation and citation impact

Background

Recent years have seen numerous efforts and resources devoted to the development of open access (OA), but the current OA situation of the oncology literature remains unknown. We conducted this cross-sectional study to determine the current share and provision methods of OA in the field of oncology, identify predictors of OA status (OA versus non-OA), and study the association between OA and citation counts.

Materials and methods

PubMed was searched for oncology-related, peer-reviewed journal articles published in December 2014. Google, Google Scholar, PubMed, ResearchGate, OpenDOAR and OAIster were manually checked to assess the OA status of each included article. Citation data were extracted from Web of Science, Scopus and Google Scholar. Descriptive statistics were used to summarize the OA proportion (primary outcome) and OA provision methods. Multivariable logistic regression and multilevel generalized linear model analyses were performed to study predictors of OA status and the association between OA and citation counts, respectively.

Results

In a random sample of 1000 articles, 912 were deemed eligible and therefore included. Of these, the full-texts of 530 articles (58.1%; 95% CI: 54.9-61.3) were freely available online: 314 (34.4%) were available from publishers ('Gold road' to OA), 424 (46.5%) were available via self-archiving ('Green road' to OA). According to multivariable regression analyses, impact factor, publisher type, language, research type, number of authors, continent of origin, and country income were significant predictors of articles' OA status; OA articles received a citation rate 1.24 times the incidence rate for non-OA articles (95% CI: 1.05-1.47; P = 0.012).

Conclusions

Based on our sample, in the field of oncology, 42% of recent journal articles are behind the pay-wall (non-OA) 1 year after publication; the 'Green road' of providing OA is more common than the 'Gold road'; OA is associated with higher citation counts.

Phase 1 dose-escalating study to evaluate the safety, pharmacokinetics, and pharmacodynamics of a recombinant factor Xa variant (FXaI16L )

Essentials FXaI16L is a recombinant zymogen-like variant of activated coagulation factor X (FXa). A phase 1 dose escalation clinical trial of FXaI16L was conducted in healthy adults. FXaI16L was safe and tolerated at doses up to 5 μg/kg; no dose-limiting toxicity was observed. Data support further development of FXaI16L for patients with acute hemorrhagic conditions.

SUMMARY

Background FXaI16L (PF-05230907) is a zymogen-like variant of activated factor X (FXa). It shows enhanced resistance to inactivation by endogenous inhibitors as compared with wild-type FXa, and restores hemostatic activity in non-clinical models of various bleeding conditions. Objectives To evaluate the safety, pharmacokinetics and pharmacodynamics of FXaI16L by performing a phase 1, first-in-human, dose-escalation clinical trial in healthy adult volunteers. Methods Participants were assigned to one of six ascending single-dose cohorts (0.1, 0.3, 1, 2, 3 or 5 μg kg-1 ), each planned to comprise six volunteers treated with FXaI16L and two treated with placebo. Assessments included safety monitoring, pharmacokinetic and pharmacodynamic (PD) analyses, and immunogenicity testing. Results The trial enrolled 49 male volunteers. Administration of a single intravenous bolus dose of FXaI16L was safe and tolerated at all dose levels tested, with no dose-limiting toxicity or serious adverse events. FXaI16L plasma levels appeared to increase dose-proportionally, with a half-life of ~ 4 min. Treatment-related PD changes were observed for activated partial thromboplastin time, thrombin generation assay, thrombin-antithrombin complexes, prothrombin fragment 1 + 2, and D-dimer. One volunteer had a weak and transient non-neutralizing antidrug antibody response, which did not cross-react with native FX or native FXa. Conclusions FXaI16L was safe and tolerated, and showed a pharmacologic effect in healthy adults when administered at doses up to 5 μg kg-1 . The safety profile, pharmacokinetics and pharmacodynamics observed in this clinical trial support the further development of FXaI16L for hemostatic treatment in individuals with acute hemorrhagic conditions.

A quantitative systems pharmacology model of blood coagulation network describes in vivo biomarker changes in non-bleeding subjects

Essentials Baseline coagulation activity can be detected in non-bleeding state by in vivo biomarker levels. A detailed mathematical model of coagulation was developed to describe the non-bleeding state. Optimized model described in vivo biomarkers with recombinant activated factor VII treatment. Sensitivity analysis predicted prothrombin fragment 1 + 2 and D-dimer are regulated differently.

SUMMARY

Background Prothrombin fragment 1 + 2 (F1 + 2 ), thrombin-antithrombin III complex (TAT) and D-dimer can be detected in plasma from non-bleeding hemostatically normal subjects or hemophilic patients. They are often used as safety or pharmacodynamic biomarkers for hemostatis-modulating therapies in the clinic, and provide insights into in vivo coagulation activity. Objectives To develop a quantitative systems pharmacology (QSP) model of the blood coagulation network to describe in vivo biomarkers, including F1 + 2 , TAT, and D-dimer, under non-bleeding conditions. Methods The QSP model included intrinsic and extrinsic coagulation pathways, platelet activation state-dependent kinetics, and a two-compartment pharmacokinetics model for recombinant activated factor VII (rFVIIa). Literature data on F1 + 2 and D-dimer at baseline and changes with rFVIIa treatment were used for parameter optimization. Multiparametric sensitivity analysis (MPSA) was used to understand key proteins that regulate F1 + 2 , TAT and D-dimer levels. Results The model was able to describe tissue factor (TF)-dependent baseline levels of F1 + 2 , TAT and D-dimer in a non-bleeding state, and their increases in hemostatically normal subjects and hemophilic patients treated with different doses of rFVIIa. The amount of TF required is predicted to be very low in a non-bleeding state. The model also predicts that these biomarker levels will be similar in hemostatically normal subjects and hemophilic patients. MPSA revealed that F1 + 2 and TAT levels are highly correlated, and that D-dimer is more sensitive to the perturbation of coagulation protein concentrations. Conclusions A QSP model for non-bleeding baseline coagulation activity was established with data from clinically relevant in vivo biomarkers at baseline and changes in response to rFVIIa treatment. This model will provide future mechanistic insights into this system.

Elevation of Vδ1 T cells in peripheral blood and livers of patients with primary biliary cholangitis

Primary biliary cholangitis (PBC), hitherto called primary biliary cirrhosis, is a cholestatic liver disease of unclear aetiology with autoimmune features. Accumulating evidence revealed that γδ T cells were involved in the development of autoimmune diseases. As one of γδ T cells subsets, however, the role of Vδ1 T cells in the immunopathogenesis of PBC is poorly understood. We analysed peripheral blood Vδ1 T cells in PBC patients in active stage (ASP, n = 18), adequate responders (AR, n = 10) and inadequate responders (IAR, n = 4) to ursodeoxycholic acid (UDCA) and an age-matched healthy control group (n = 16) by flow cytometric analysis. The ASP group exhibited a significantly higher proportion and absolute number of Vδ1 T cells, which were also observed in immunofluorescence staining of liver biopsy specimens of PBC patients. Moreover, these Vδ1 T cells expressed a series of activation markers and intracellular cytokines, which may contribute to the immunopathogenesis of PBC. Our study will help to clarify the role of Vδ1 T cells in the development of PBC.

Surveys on Reporting Guideline Usage in Dental Journals

The objectives of this study were 1) to find out if and how authors and peer reviewers for dental journals are encouraged to use reporting guidelines (RGs); 2) to identify factors related to RG endorsement; and 3) to assess the knowledge, opinions, and future plans of dental journal editors in chief (EICs) on RGs. A total of 109 peer-reviewed and original research-oriented dental journals that were indexed in the MEDLINE and/or SCIE database in 2015 were included. The "instructions to authors" and "instructions to reviewers" of these journals were identified and retrieved from journals' official websites. Any mention of RGs or other related policies were sought and extracted. In addition, an anonymous survey of the EICs of the included journals was conducted with a validated questionnaire. All 109 journals provided "instructions to authors," among which 55 (50.5%) mentioned RGs. Only the CONSORT (45.0%), PRISMA (13.8%), and STROBE (12.8%) guidelines were mentioned by >10% of the included journals. Statistical analyses suggest that RGs were more frequently mentioned by SCIE-indexed journals (P < 0.001), higher-impact journals (P = 0.002), and journals that endorsed the ICMJE recommendations (P < 0.001). "Instructions to reviewers" were available online for only 9 journals (8.3%), 3 of which mentioned RGs. For the EIC survey, the response rate was 32.1% (35 of 109). Twenty-six editors (74.3%) stated that they knew what RGs were before receiving our questionnaire. Twenty-four editors (68.6%) believed that RGs should be adopted by all refereed dental journals where appropriate. RGs are important tools for enhancing research reporting and reducing avoidable research waste, but currently they are not widely endorsed by dental journals. Joint efforts by all stakeholders to further promote RG usage in dentistry are needed.

Bone marrow stromal cells inhibits HMGB1-mediated inflammation after stroke in type 2 diabetic rats

High-mobility group box 1 (HMGB1), a ligand of receptor for advanced glycation endproducts (RAGE), functions as a proinflammatory factor. It is mainly involved in inflammatory activation and contributes to the initiation and progression of stroke. By using a model of transient middle cerebral artery occlusion (MCAo) in type 2 diabetic rats, we investigated the changes of pro-inflammation mediators, blood-brain barrier (BBB) leakage and functional outcome after stroke. Type 2 diabetic rats did not show an increased lesion volume, but exhibited significantly increased expression of HMGB1 and RAGE, BBB leakage, as well as decreased functional outcome after stroke compared with control rats. Injection of bone marrow stromal cells (BMSCs) into type 2 diabetic rats significantly reduced the expression of HMGB1 and RAGE, attenuated BBB leakage, and improved functional outcome after stroke. BMSCs-treated type 2 diabetic rats inhibited inflammation and improved functional outcome after stroke. Furthermore, in vitro data support the hypothesis that BMSCs-induced reduction of HMGB1 and RAGE in T2DM-MCAo rats contributed to attenuated inflammatory response in the ischemic brain, which may lead to the beneficial effects of BMSCs treatment. Further investigation of BMSCs treatment in type 2 diabetic stroke is warranted.

Risk factors associated with aortic remodeling in patients with Stanford type B aortic dissection after thoracic endovascular aortic repair

To determine the risk factors associated with adverse aortic remodeling after thoracic endovascular aortic repair (TEVAR) in patients with Stanford type B aortic dissection, we performed a retrospective analysis of 54 patients between January 2009 and June 2012 at the First Affiliated Hospital of Soochow University. All patients underwent TEVAR of the descending thoracic aorta. Multiple-logistic regression analyses were performed to identify risk factors associated with aortic remodeling. True-lumen and false-lumen volumes were increased (P < 0.001) and decreased (P < 0.001) after surgery, respectively. Therefore, the remodeling index increased after surgery (1.04 ± 0.6 to 2.06 ± 1.12, P < 0.001). Remodeling index and true-lumen volume were higher in the favorable aortic remodeling group compared to the adverse aortic remodeling group (P < 0.001), while the false-lumen volume was lower in the favorable aortic remodeling group (P < 0.001). Multivariate analyses revealed a branch originating from the false lumen (OR = 39.9, P < 0.01) and multiple tears (OR = 27.4, P < 0.01) to be independent risk factors for adverse aortic remodeling. Therefore, a branch originating from the false lumen and multiple tears were determined to be independent risk factors for adverse aortic remodeling after TEVAR in patients with Stanford type B aortic dissection.

Using a Systems Pharmacology Model of the Blood Coagulation Network to Predict the Effects of Various Therapies on Biomarkers

A number of therapeutics have been developed or are under development aiming to modulate the coagulation network to treat various diseases. We used a systems model to better understand the effect of modulating various components on blood coagulation. A computational model of the coagulation network was built to match in-house in vitro thrombin generation and activated Partial Thromboplastin Time (aPTT) data with various concentrations of recombinant factor VIIa (FVIIa) or factor Xa added to normal human plasma or factor VIII-deficient plasma. Sensitivity analysis applied to the model revealed that lag time, peak thrombin concentration, area under the curve (AUC) of the thrombin generation profile, and aPTT show different sensitivity to changes in coagulation factors' concentrations and type of plasma used (normal or factor VIII-deficient). We also used the model to explore how variability in concentrations of the proteins in coagulation network can impact the response to FVIIa treatment.

Isolation and identification of feline herpesvirus type 1 from a South China tiger in China

In 2012, an FHV-1-like virus was isolated from a tiger that presented with clinical signs of sialorrhea, sneezing and purulent rhinorrhea. Isolation was performed with the FK81 cell line, and the virus was identified by PCR, transmission electron microscopy (TEM), and the phylogenetic analysis of the partial thymidine kinase (TK) and glycoprotein B (gB) genes. A total of 253 bp of the TK gene and 566 bp of the gB gene were amplified from the trachea of the tiger by PCR/RT-PCR method. Phylogenetic analysis showed that the isolate belonged to the same cluster with other FHV-1 strains obtained from GenBank. Herpes-like viruses with an envelope and diameters of approximately 200 nm were observed in the culture supernatants of FK81 cells inoculated with samples from the tiger. The FHV-1 infection was confirmed by an animal challenge experiment in a cat model. Our finding extends the host range of FHV-1 and has implications for FHV-1 infection and South China tiger conservation.

Increased percentages of PD-1 on CD4+ T cells is associated with higher INF-γ production and altered IL-17 production in patients with systemic lupus erythematosus

OBJECTIVES

Programmed death (PD)-1 is a cell death receptor that, upon stimulation, leads to apoptosis. Previous studies have shown alteration of PD-1 expression on T cells and PD-1 genes in patients with systemic lupus erythematosus (SLE). The aim of this study was to assess the expression of this receptor on effector T cells in patients with SLE.

METHOD

In this study we enrolled 32 SLE patients and 31 healthy controls. T cells from peripheral blood were analysed by flow cytometry for the expression of PD-1. Interferon (IFN)-γ and interleukin (IL)-17-producing cells were investigated for the expression of this co-stimulatory marker.

RESULTS

Percentages of CD4(+) T cells expressing PD-1 were significantly increased in patients with SLE compared to healthy controls. The percentage of PD-1 expression was correlated with the production of INF-γ (r = 0.83, p < 0.0001). We also investigated the production of IL-17 by PD-1(+) CD3(+) T cells. Inactive patients (3.2 ± 1.2% vs. 5.9 ± 3.5%, p = 0.002) and patients without lupus nephritis (LN) (3.2 ± 1.5% vs. 5.9 ± 3.5%, p = 0.005) showed lower levels of IL-17 compared to healthy controls.

CONCLUSION

We have demonstrated increased expression of PD-1 on CD4(+) T cells in SLE patients and an association between PD-1 expression on CD4(+) T cells and IFN-γ expression on CD3(+) T cells. We have also shown that there is an altered subset of PD-1(+) T cells in inactive patients and patients without LN producing lower amounts of IL-17.

Identification of forensically important beetles (Coleoptera: Histeridae) in China based on 16S rRNA and Cyt b

Exact identification of an insect sample is usually the first essential step in a forensic entomological analysis. However, the morphological similarity of beetles in the level of species usually poses a challenge for forensic scientists within their routine work. As a supplementary to traditional morphological method, molecular genetics identification turns out to be simple and time-saving. A molecular identification method involving a 288-bp segment of the 16S ribosomal RNA (16S rRNA) gene and a 334-bp segment of the cytochrome b (Cyt b) gene from 23 histerid beetles specimens, collected from 7 locations in 6 Chinese provinces, was evaluated. The 16S rRNA and Cyt b genes are sequenced to examine the ability of the region, resolve species identities and enrich the local databases. The monophyletic branches of the phylogenetic tree showed the potential of the markers in identifying beetles within families. Combined analysis is a more accurate approach for species identication than independent analysis.

Progesterone is neuroprotective against ischemic brain injury through its effects on the phosphoinositide 3-kinase/protein kinase B signaling pathway

We tested the hypothesis that the phosphoinositide 3-kinase/protein kinase B (PI3K/Akt) pathway mediates some of the neuroprotective effects of progesterone (PROG) after ischemic stroke. We examined whether PROG acting through the PI3K/Akt pathway could affect the expression of vascular endothelial growth factor (VEGF) and brain-derived neurotrophic factor (BDNF). Rats underwent permanent focal cerebral ischemia by electrocoagulation and received intraperitoneal injections of PROG (8 mg/kg) or vehicle at 1 h post-occlusion and subcutaneous injections at 6, 24, and 48 h. PAkt/Akt levels, apoptosis and apoptosis-related proteins (phosphorylated Bcl-2-associated death promoter (pBAD), BAD, caspase-3, and cleaved caspase-3) were analyzed by TUNEL assays, Western blotting and immunohistochemistry at 24 h post-pMCAO. VEGF and BDNF were analyzed at 24, 72 h and 14 days post-pMCAO with Western blots. Following pMCAO, PROG treatment significantly (P<0.05) reduced ischemic lesion size and edema. Treatment with PROG significantly (P<0.05) decreased VEGF at 24 and 72 h but increased VEGF expression 14 days after injury. The treatment also increased BDNF, and attenuated apoptosis by increasing Akt phosphorylation compared with vehicle alone. The selective PI3K inhibitor wortmannin compromised PROG-induced neuroprotective effects and reduced the elevation of pAkt levels in the ischemic penumbra. Our findings lead us to suggest that the PI3K/Akt pathway can play a role in mediating the neuroprotective effects of PROG after stroke by altering the expression of trophic factors in the brain.

Organization of NMDA receptors at extrasynaptic locations

NMDA receptors are found in neurons both at synapses and in extrasynaptic locations. Extrasynaptic locations are poorly characterized. Here we used preembedding immunoperoxidase and postembedding immunogold electron microscopy and fluorescence light microscopy to characterize extrasynaptic NMDA receptor locations in dissociated hippocampal neurons in vitro and in the adult and postnatal hippocampus in vivo. We found that extrasynaptic NMDA receptors on neurons in vivo and in vitro were usually concentrated at points of contact with adjacent processes, which were mainly axons, axon terminals, or glia. Many of these contacts were shown to contain adhesion factors such as cadherin and catenin. We also found associations of extrasynaptic NMDA receptors with the membrane associated guanylate kinase (MAGUKs), postsynaptic density (PSD)-95 and SAP102. Developmental differences were also observed. At postnatal day 2 in vivo, extrasynaptic NMDA receptors could often be found at sites with distinct densities whereas dense material was seen only rarely at sites of extrasynaptic NMDA receptors in the adult hippocampus in vivo. This difference probably indicates that many sites of extrasynaptic NMDA receptors in early postnatal ages represent synapse formation or possibly sites for synapse elimination. At all ages, as suggested in both in vivo and in vitro studies, extrasynaptic NMDA receptors on dendrites or the sides of spines may form complexes with other proteins, in many cases, at stable associations with adjacent cell processes. These associations may facilitate unique functions for extrasynaptic NMDA receptors.

Fabrication of transparent capacitive structure by self-assembled thin films

An approach to fabricating transparent electronic devices by using nanomaterial and nanofabrication is presented in this paper. A see-through capacitor is constructed from self-assembled silica nanoparticle layers that are stacked on the transparent substrate. The electrodes are made of indium tin oxide. Unlike the traditional processes used to fabricate such devices, the self-assembly approach enables one to synthesize the thin film layers at lower temperature and cost, and with a broader availability of nanomaterials. The vertical dimension of the self-assembled thin films can be precisely controlled, as well as the molecular order in the thin film layers. The shape of the capacitor is generated by planar micropatterning. The monitoring by quartz crystal demonstrates the steady growth of the silica nanoparticle multilayer. In addition, because the material synthesis and the device fabrication steps are separate, the fabrication is not affected by the harsh conditions required for the material synthesis. As a result, a clear pattern is allowed over a large area on the substrate. The prepared capacitive structure has an optical transparency higher than 92% over the visible spectrum. The capacitive impedance is measured at different frequencies and fit the theoretical results. As one of the fundamental components, this type of capacitive structure can serve in the transparent circuits, interactive media and sensors, as well as being applicable to other transparent devices.

Upregulation of non-mutated H-ras and its upstream and downstream signaling proteins in colorectal cancer

We analyzed H-ras protein expression in 38 human colon cancers and the paired normal tissues. H-ras levels were significantly higher in the malignant tumor (average 0.19+/-0.27) than in its normal adjacent tissues (average 0.06+/-0.15) (p<0.05). The H-ras protein expressed in colon carcinomas contained activated form of H-ras without mutation, based on the findings obtained by RBD-binding (ras binding domain of Raf protein) assay and PCR-SSCP analysis. In addition, we found that H-ras expression was higher in female patients than male, and in cancers with distant metastasis compared to those with non-distant metastasis. Good correlation between H-ras expression levels and those of the upstream and downstream signaling proteins of EGFR, MEK and ERK was found, suggesting that H-ras may play a significant role in carcinogenesis of colorectal cancer.

Thermoreversible gelation of biodegradable poly(epsilon-caprolactone) and poly(ethylene glycol) multiblock copolymers in aqueous solutions

The multiblock copolymers composed of poly(ethylene glycol)s (PEGs) and biodegradable poly(epsilon-caprolactone)s (PCLs) were synthesized through one-step condensation copolymerization with hexamethylene diisocyanate (HDI) as a coupling agent. The typical phase diagram of these multiblock copolymers in aqueous solution displayed a critical gel concentration (CGC) and an upper phase-transition temperature, which were mainly determined by the PEG/PCL block ratio, the PEG or PCL block lengths and the molecular weight. With decreasing PEG/PCL block ratio, the CGC decreased with an elevated sol-gel transition temperature on account of the enhanced hydrophobicity. The HDI/Diols ratio was used to control the molecular weight. At high molecular weights, the CGC decreased, related to the enhanced aggregation of PCL blocks and physical crosslinkage between PCL block domains due to the increased number of PCL blocks in each molecule. For the sample containing the long PCL(2000) block (M(n), 2000), the CGC dropped dramatically due to the high hydrophobicity and the poor compatibility between PCL and PEG. The dynamic phase transition process was observed by combining optical microscopy (OM) and differential scanning calorimetry (DSC) in a certain heating/cooling rate. Finally, a possible phase separation-induced gelation mechanism is suggested.

[Study of "living" radical polymerization by FTIR in situ]

Three types of living radical polymerization processes were monitored by means of FTIR spectrometer with handful diamond detector called as Dicomp in situ. It was found that both styrene and styrene/hydroxylpropyl methyacrylate (HPMA) could polymerize according to stable free radical polymerization (SFRP) mechanism in presence of 4-hydroxyl tetramethypiperidiyl-1-oxy(HTEMPO). For styrene/HPMA system, the styrene and HPMA conversion monitored by FTIR were linear with increase of molecular weight, but it gave longer induction period compared with that for St bulk polymerization. It was related to the hydrogen-transfer reaction between the propagating radicals with the end HPMA unit and HTEMPO. Furthermore, This following method in situ could be introduced into monitoring heterogeneous polymerization of styrene during atom transfer radical polymerization (ATRP). The apparent kinetics was found to be about zero order and not 1.0 order, due to propagating on the complex including radicals, CuX and bpy in heterogeneous interface. The polymerization rate will be not related to the St in bulk St phase.

The p185(neu)-containing glycoprotein complex of a microfilament-associated signal transduction particle. Purification, reconstitution, and molecular associations with p58(gag) and actin

Microfilaments associate with the microvillar membrane of 13762 ascites mammary adenocarcinoma cells via a large transmembrane complex (TMC) comprising the major glycoproteins TMC-gp120, -110, -80, -65, and -55, the receptor kinase p185(neu), and the cytoplasmic proteins actin and p58(gag), linking the receptor with microfilaments in a signal transduction particle. Immunoblot screening with polyclonal antisera to TMC glycoproteins showed selective epithelial expression in normal rat tissues and epithelially derived tumor cells. The TMC glycoproteins were isolated by solubilization of microfilament core preparations in SDS, dilution, and separation on a concanavalin A-agarose affinity column. The large p185(neu)-containing complex was reconstituted from the column eluate after displacement of SDS with nonionic detergent, demonstrated by gel filtration and co-immunoprecipitation of the glycoproteins with anti-gp55 or anti-p185(neu). Exhaustive biotinylation of the glycoproteins gave a stoichiometry of gp120:gp110:gp80:gp65:gp55 of approximately 1:1:1:0.5:1. Overlay blots with biotinylated actin and in vitro translated, [(35)S]methionine-labeled p58(gag), respectively, showed specific interactions of actin with gp55 and gp120 and of p58(gag) with gp65 and gp55. These results provide evidence for a specific complex of microfilament-associated glycoproteins containing p185(neu) and p58(gag) and suggest a role for the complex in signal transduction scaffolding.

Mortality of Italian lead smelter workers

OBJECTIVES

The purpose of this study was to evaluate the health consequences of employment in the lead-smelting industry.

METHODS

A mortality study of 1388 workers and laborers in production and maintenance departments was conducted in an Italian lead-smelting plant. The vital status of cohort members was determined from 1950 to 1992. Standardized mortality ratios were calculated for specific causes of death on the basis of national and regional reference rates. The relative risk for selected causes of death was also modeled as a function of age, calendar period, latency, and duration of employment with Poisson regression analysis.

RESULTS

A significant 4.5-fold excess mortality from pneumoconiosis and other diseases of the respiratory system was observed, but the risk of pneumoconiosis did not show a significant trend by duration of employment. Mortality from all cancers, stomach cancer, and lung cancer was lower than expected. The standardized mortality ratios for genitourinary diseases and kidney cancer were not significantly elevated, but the Poisson regression analysis showed that both risks increased significantly by duration of employment.

CONCLUSIONS

These findings provide limited evidence that long-term employment in lead-smelting plants increases the risk of genitourinary diseases and kidney cancer. The observed increase in mortality from pneumoconiosis and other diseases of the respiratory system was more likely related to silica exposure in other workplaces.

[Subfractionation of serum high density lipoproteins and its clinical significance]

Serum concentrations of HDL subfractions, LpAI and LpAI:AII, were simultaneously determined simply, specifically and rapidly by use of rocket immunoelectrophoresis with the home-made gel plates. The method was reproducible, and the results correlated well with those obtained with Sebia's kits. The normal levels of LpAI were 57 +/- 13 mg/dl in males and 59 +/- 15 mg/dl in females. LpAI levels were significantly lower in patients with renal failure and atherosclerosis, and tended to decrease in hepatic diseases than those in normal subjects. The levels of LpAI:AII were also decreased in these three diseased groups. Decreases in LpAI levels were more slightly in patients with hepatic or renal diseases than those in LpAI:AII levels. On the contrary, decrease in LpAI level was more markedly in patients with atherosclerosis than that in the other subfraction. The results in the present study suggest that the determination of HDL subfractions will be useful for diagnosis of various diseases.

Comparison of rac- and meso-2,3-dimercaptosuccinic acids for chelation of mercury and cadmium using chemical speciation models

The formation constants of various mercury and cadmium chelates of the stereoisomers of 2,3-dimercaptosuccinic acid (DMSA) have been determined from potentiometric titrations in the presence of the competing ligand EDTA. The mercury chelates formed at pH 7.4 are the monomeric HgL of the DMSA diastereoisomers and HHgL2 of rac-DMSA. Mercury is completely complexes at pH greater than 3.0 in solutions containing more than 1 equiv of either rac- or meso-DMSA. At high concentrations (10 microM and above) mercury tends to bind to a greater extent to rac- than to meso-DMSA. At pH 7.4, the predominant cadmium meso-DMSA chelate species in solution is CdL, and HCdL is present at a much smaller concentration. With rac-DMSA, however, the predominant cadmium chelate species is HCdL at a low concentration of the ligand, and at a high concentration of the ligand the species CdL2 predominates. Cadmium is completely chelated at pH 7.4 in solutions containing more than 1 equiv of either rac- or meso-DMSA. At pH around 5.5, which corresponds to the pH of the kidney, however, a significant amount of free cadmium is present in solutions containing 1 equiv or less of either DMSA stereoisomer. From the results of an analysis of speciation models, probable kidney damage, that may result from free cadmium ion release in the kidney during chelation therapy, is inferred when meso-DMSA is used for mobilizing cadmium. In contrast, the release of free cadmium ion is negligible in the pH range in the kidney when rac-DMSA is used. On the basis of the speciation models, rac-DMSA is found to be far superior to meso-DMSA in the treatment of acute cadmium poisoning.

Are antibodies reactive with chondrocyte proteins enriched in synovial fluids of patients with rheumatoid arthritis?

In this study we examined the reactivity of synovial fluid (SF) antibodies (Abs) from patients with rheumatoid arthritis (RA) against chondrocyte proteins. The levels of IgG, IgM and IgA in the synovial fluids varied from patient to patient, but were similar to the levels found in each individual's serum. Although the Abs in SF and serum of RA patients reacted with several molecular weight classes of chondrocyte proteins, this reactivity was very low. Synovial fluid and serum Abs from the same patients reacted with similar chondrocyte proteins and to a similar extent, suggesting that the level of Abs reactive with chondrocyte proteins is not enriched in the SF. These data demonstrate that SF from RA patients contain high levels of Abs, however, there is very little reactivity with chondrocyte proteins beyond that observed in serum of normal and RA patients.