Combined multiplex panel test results are a poor estimate of disease prevalence without adjustment for test error

Multiplex panel tests identify many individual pathogens at once, using a set of component tests. In some panels the number of components can be large. If the panel is detecting causative pathogens for a single syndrome or disease then we might estimate the burden of that disease by combining the results of the panel, for example determining the prevalence of pneumococcal pneumonia as caused by many individual pneumococcal serotypes. When we are dealing with multiplex test panels with many components, test error in the individual components of a panel, even when present at very low levels, can cause significant overall error. Uncertainty in the sensitivity and specificity of the individual tests, and statistical fluctuations in the numbers of false positives and false negatives, will cause large uncertainty in the combined estimates of disease prevalence. In many cases this can be a source of significant bias. In this paper we develop a mathematical framework to characterise this issue, we determine expressions for the sensitivity and specificity of panel tests. In this we identify a counter-intuitive relationship between panel test sensitivity and disease prevalence that means panel tests become more sensitive as prevalence increases. We present novel statistical methods that adjust for bias and quantify uncertainty in prevalence estimates from panel tests, and use simulations to test these methods. As multiplex testing becomes more commonly used for screening in routine clinical practice, accumulation of test error due to the combination of large numbers of test results needs to be identified and corrected for.

Methods for the estimation of direct and indirect vaccination effects by combining data from individual- and cluster-randomized trials

Both individually and cluster randomized study designs have been used for vaccine trials to assess the effects of vaccine on reducing the risk of disease or infection. The choice between individually and cluster randomized designs is often driven by the target estimand of interest (eg, direct versus total), statistical power, and, importantly, logistic feasibility. To combat emerging infectious disease threats, especially when the number of events from one single trial may not be adequate to obtain vaccine effect estimates with a desired level of precision, it may be necessary to combine information across multiple trials. In this article, we propose a model formulation to estimate the direct, indirect, total, and overall vaccine effects combining data from trials with two types of study designs: individual-randomization and cluster-randomization, based on a Cox proportional hazards model, where the hazard of infection depends on both vaccine status of the individual as well as the vaccine status of the other individuals in the same cluster. We illustrate the use of the proposed model and assess the potential efficiency gain from combining data from multiple trials, compared to using data from each individual trial alone, through two simulation studies, one of which is designed based on a cholera vaccine trial previously carried out in Matlab, Bangladesh.

Association of ABO and Rhesus blood groups with severe outcomes from non-SARS-CoV-2 respiratory infection: A prospective observational cohort study in Bristol, UK 2020-2022

Despite significant global morbidity associated with respiratory infection, there is a paucity of data examining the association between severity of non-SARS-CoV-2 respiratory infection and blood group. We analysed a prospective cohort of adults hospitalised in Bristol, UK, from 1 August 2020 to 31 July 2022, including patients with acute respiratory infection (pneumonia [n = 1934] and non-pneumonic lower respiratory tract infection [NP-LRTI] [n = 1184]), a negative SARS-CoV-2 test and known blood group status. The likelihood of cardiovascular complication, survival and hospital admission length was assessed using regression models with group O and RhD-negative status as reference groups. Group A and RhD-positive were over-represented in both pneumonia and NP-LRTI compared to a first-time donor population (p < 0.05 in all); contrastingly, group O was under-represented. ABO group did not influence cardiovascular complication risk; however, RhD-positive patients with pneumonia had a reduced odds ratio (OR) for cardiovascular complications (OR = 0.77 [95% CI = 0.59-0.98]). Compared to group O, group A individuals with NP-LRTI were more likely to be discharged within 60 days (hazard ratio [HR] = 1.17 [95% CI = 1.03-1.33]), while group B with pneumonia was less likely (HR = 0.8 [95% CI = 0.66-0.96]). This analysis provides some evidence that blood group status may influence clinical outcome following respiratory infection, with group A having increased risk of hospitalisation and RhD-positive patients having reduced cardiovascular complications.

[The predictive value of microvascular obstruction for adverse left ventricular remodeling after primary percutaneous coronary intervention in patients with acute ST-elevation myocardial infarction: a prospective study]

Objectives: Microvascular obstruction (MVO) is a specific cardiac magnetic resonance (CMR) imaging feature in patients with acute myocardial infarction. The purpose of this study was to elucidate the predictive value of MVO in left ventricular adverse remodeling after primary percutaneous coronary intervention (PCI) in patients with acute ST-elevation myocardial infarction (STEMI). Methods: A total of 167 patients with STEMI undergoing primary PCI in the Chinese PLA General Hospital from 2016 to 2020 were enrolled in this prospective cohort study, the average age of study patients was 57±10 years old, with 151 males (90.4%) and 16 females (9.6%). The patients were divided into the MVO group (n=81) and non-MVO group (n=86) according to the presence or absence of MVO on CMR imaging, respectively. The primary endpoint of the study was the occurrence of left ventricular adverse remodeling, which was defined as an increase in left ventricular end diastolic volume (LVEDV) by >20% at 6 months after primary PCI compared with the baseline. Patients who completed follow-up were diagnosed as left ventricular adverse remodeling or no left ventricular adverse remodeling according to CMR. The baseline data, perioperative data, and related data of end points were compared between the MVO group and non-MVO group. Finally, the predictive value of MVO in left ventricular adverse remodeling was calculated by receiver operating characteristic curve analysis. Results: In the baseline data, preoperative thrombolysis in myocardial infarction (TIMI) flow (χ2=13.74, P=0.003) and postoperative TIMI flow (χ2=14.87, P=0.001) were both obviously decreased in the MVO group. After 6 months of follow-up, the incidence of left ventricular adverse remodeling in the MVO group was significantly higher than that in the non-MVO group [37.0%(27/73) vs. 18.9%(14/74), χ2=5.96, P=0.015]. The left ventricular end systolic volume at 6 months post infarction in the MVO group was significantly larger than that in the non-MVO group [(94±32) vs. (68±20) ml, t=-5.98, P<0.001], as well as the LVEDV [(169±38) vs. (143±29) ml, t=-4.74, P<0.001]. Receiver operating characteristic curve showed that the area under the curve of MVO size for predicting left ventricular adverse remodeling was 0.637. Conclusion: The risk of left ventricular adverse remodeling is significantly increased in patients with MVO after primary PCI for acute STEMI.

Impact of SARS-CoV-2 infective exacerbation of chronic obstructive pulmonary disease on clinical outcomes in a prospective cohort study of hospitalised adults

OBJECTIVES

To determine whether acute exacerbations of chronic obstructive pulmonary disease (AECOPD) triggered by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), have worse outcomes than AECOPD caused by other infectious agents or non-infective AECOPD (NI-COPD).

DESIGN

A two-hospital prospective cohort study of adults hospitalised with acute respiratory disease. We compared outcomes with AECOPD and a positive test for SARS-CoV-2 (n = 816), AECOPD triggered by other infections (n = 3038) and NI-COPD (n = 994). We used multivariable modelling to adjust for potential confounders and assessed variation by seasons associated with different SARS-CoV-2 variants.

SETTING

Bristol UK, August 2020-May 2022.

PARTICIPANTS

Adults (≥18 y) hospitalised with AECOPD.

MAIN OUTCOME MEASURES

We determined the risk of positive pressure support, longer hospital admission and mortality following hospitalisation with AECOPD due to non-SARS-CoV-2 infection compared with SARS-CoV-2 AECOPD and NI-COPD.

RESULTS

Patients with SARS-CoV-2 AECOPD, in comparison to non-SARS-CoV-2 infective AECOPD or NI-COPD, more frequently required positive pressure support (18.5% and 7.5% vs. 11.7%, respectively), longer hospital stays (median [interquartile range, IQR]: 7 [3-15] and 5 [2-10] vs. 4 [2-9] days, respectively) and had higher 30-day mortality (16.9% and 11.1% vs. 5.9%, respectively) (all p < 0.001). In adjusted analyses, SARS-CoV-2 AECOPD was associated with a 55% (95% confidence interval [95% CI]: 24-93), 26% (95% CI: 15-37) and 35% (95% CI: 10-65) increase in the risk of positive pressure support, hospitalisation length and 30-day mortality, respectively, relative to non-SARS-CoV-2 infective AECOPD. The difference in risk remained similar during periods of wild-type, Alpha and Delta SARS-CoV-2 strain dominance, but diminished during Omicron dominance.

CONCLUSIONS

SARS-CoV-2-related AECOPD had worse patient outcomes compared with non-SARS-CoV-2 AECOPD or NI-AECOPD, although the difference in risks was less pronounced during Omicron dominance.

Molecular Features and Stages of Pulmonary Fibrosis Driven by Type 2 Inflammation

Systemic sclerosis (SSc) is a progressive, multiorgan disease with limited treatment options. Although a recent proof-of-concept study using romilkimab or SAR156597, a bispecific IL-4/IL-13 antibody, suggests a direct role of these cytokines in the pathophysiology of SSc, their contributions to the balance between inflammation and fibrosis are unclear. Here, we determine the roles of type 2 inflammation in fibrogenesis using FRA2-Tg (Fos-related antigen 2-overexpressing transgenic) mice, which develop spontaneous, age-dependent progressive lung fibrosis. We defined the molecular signatures of inflammation and fibrosis at three key stages in disease progression, corresponding to preonset, inflammatory dominant, and fibrosis dominant biology, and revealed an early increase in cytokine-cytokine receptor interactions and antigen-processing and presentation pathways followed by enhanced Th2- and M2 macrophage-driven type 2 responses. This type 2 inflammation progressed to extensive fibrotic pathology by 14-18 weeks of age, with these gene signatures overlapping significantly with those seen in the lungs of patients with SSc with interstitial lung disease (ILD). These changes were also evident in the histopathology, which showed perivascular and peribronchiolar inflammation with prominent eosinophilia and accumulation of profibrotic M2-like macrophages followed by rapid progression to fibrosis with thickened alveolar walls with multifocal fibrotic bands and signs of interstitial pneumonia. Critically, treatment with a bispecific antibody targeting IL-4 and IL-13 during the inflammatory phase abrogated the Th2 and M2 responses and led to near-complete abrogation of lung fibrosis. These data recapitulate important features of fibrotic progression in the lungs of patients with SSc-ILD and enhance our understanding of the progressive pathobiology of SSc. This study also further establishes FRA2-Tg mice as a valuable tool for testing future therapeutic agents in SSc-ILD.

[Protection of side-branch ostium by the jailed balloon technique validated by three-dimensional optical coherence tomography]

Objective: To evaluate the protective effect of jailed balloon technique on side branch (SB) ostium using three-dimensional optical coherence tomography(OCT). Methods: This is a retrospective study. Consecutive coronary disease patients with coronary artery bifurcation lesions who underwent percutaneous coronary intervention (PCI) and completed pre-and post-procedural OCT examinations at the Chinese People's Liberation Army General Hospital from September 2019 to March 2022 were enrolled. Patients were divided into the jailed balloon technique group and the unprotected group according to the options applied for the SB. The SB ostium area difference was calculated from OCT images (SB ostium area difference=post-PCI SB ostium area-pre-PCI SB ostium area). The SB ostium area differences were compared between the two groups and compared further in the subgroup of true bifurcation lesions and non-true bifurcation lesions. In the jailed balloon group, the SB ostium area difference was compared between the active jailed balloon technique and the conventional jailed balloon technique, between the jailed balloon>2.0 mm diameter and the jailed balloon≤2.0 mm diameter, and between the higher balloon pressure (>4 atm, 1 atm=101.325 kPa) and the lower balloon pressure (≤4 atm). Multivariate linear regression analysis was used to explore the correlation between the technical parameters of the jailed balloon technique and the SB protection effect. Results: A total of 176 patients with 236 bifurcation lesions were enrolled, aged (60.7±9.3) years, and there were 128 male patients (72.7%). There were 67 patients in the jailed balloon technique group with 71 bifurcation lesions and 123 patients in the unprotected group with 165 bifurcation lesions. Fourteen patients had 2 to 3 lesions, which were treated in different ways, so they appeared in the unprotected group and the jailed balloon technique group at the same time. The area difference in SB ostium was greater in the jailed balloon group than in the unprotected group (0.07 (-0.43, 1.05)mm² vs.-0.33 (-0.83, 0.26)mm², P<0.001), and the results were consistent in the true bifurcation lesion subgroup (0.29 (-0.35, 0.96)mm² vs.-0.26 (-0.64, 0.29)mm², P=0.004), while the difference between the two groups in the non-true bifurcation lesion subgroup was not statistically significant (P=0.136). In the jailed balloon technique group, the SB ostium area difference was greater in patients treated with the active jailed balloon technique than in those treated with the conventional jailed balloon technique ((0.43±1.36)mm² vs. (-0.22±0.52)mm², P=0.013). The difference in SB ostium area was greater in those using>2.0 mm diameter jailed balloons than in those using≤2.0 mm diameter jailed balloons (0.25 (-0.51, 1.31) mm² vs.-0.01 (-0.45, 0.63) mm², P=0.020), while SB ostium area difference was similar between those endowed with higher balloon pressure (>4 atm) compared to those with lower balloon pressure (≤4 atm) (P=0.731). Multivariate linear regression analysis showed that there was a positive correlation between jailed balloon diameter and SB ostium area difference (r=0.344, P=0.019). Conclusions: The jailed balloon technique significantly protects SB ostium, especially in patients with true bifurcation lesions. The active jailed balloon technique and larger diameter balloons may provide more protection to the SB.

Cellular mechanisms and effects of IL-4 receptor blockade in experimental conjunctivitis evoked by skin inflammation

Ocular surface diseases, including conjunctivitis, are recognized as common comorbidities in atopic dermatitis (AD) and occur at an increased frequency in patients with AD treated with biologics targeting IL-4 receptor α (IL-4Rα) or IL-13. However, the inflammatory mechanisms underlying this pathology are unknown. Here, we developed a potentially novel mouse model of skin inflammation-evoked conjunctivitis and showed that it is dependent on CD4+ T cells and basophils. Blockade of IL-4Rα partially attenuated conjunctivitis development, downregulated basophil activation, and led to a reduction in expression of genes related to type 2 cytokine responses. Together, these data suggest that an IL-4Rα/basophil axis plays a role in the development of murine allergic conjunctivitis. Interestingly, we found a significant augmentation of a number of genes that encode tear proteins and enzymes in anti-IL-4Rα-treated mice, and it may underlie the partial efficacy in this model and may represent candidate mediators of the increased frequency of conjunctivitis following dupilumab in patients with AD.

A platform trial design for preventive vaccines against Marburg virus and other emerging infectious disease threats

BACKGROUND

The threat of a possible Marburg virus disease outbreak in Central and Western Africa is growing. While no Marburg virus vaccines are currently available for use, several candidates are in the pipeline. Building on knowledge and experiences in the designs of vaccine efficacy trials against other pathogens, including SARS-CoV-2, we develop designs of randomized Phase 3 vaccine efficacy trials for Marburg virus vaccines.

METHODS

A core protocol approach will be used, allowing multiple vaccine candidates to be tested against controls. The primary objective of the trial will be to evaluate the effect of each vaccine on the rate of virologically confirmed Marburg virus disease, although Marburg infection assessed via seroconversion could be the primary objective in some cases. The overall trial design will be a mixture of individually and cluster-randomized designs, with individual randomization done whenever possible. Clusters will consist of either contacts and contacts of contacts of index cases, that is, ring vaccination, or other transmission units.

RESULTS

The primary efficacy endpoint will be analysed as a time-to-event outcome. A vaccine will be considered successful if its estimated efficacy is greater than 50% and has sufficient precision to rule out that true efficacy is less than 30%. This will require approximately 150 total endpoints, that is, cases of confirmed Marburg virus disease, per vaccine/comparator combination. Interim analyses will be conducted after 50 and after 100 events. Statistical analysis of the trial will be blended across the different types of designs. Under the assumption of a 6-month attack rate of 1% of the participants in the placebo arm for both the individually and cluster-randomized populations, the most likely sample size is about 20,000 participants per arm.

CONCLUSION

This event-driven design takes into the account the potentially sporadic spread of Marburg virus. The proposed trial design may be applicable for other pathogens against which effective vaccines are not yet available.

POS1234 DMARD DISRUPTION, INCREASED DISEASE ACTIVITY, AND PROLONGED SYMPTOM DURATION AFTER ACUTE COVID-19 AMONG PATIENTS WITH RHEUMATIC DISEASE: A PROSPECTIVE STUDY

Background

Systemic autoimmune rheumatic disease (SARD) patients may be at risk for disease flare and prolonged symptom duration after COVID-19, perhaps related to DMARD disruption and immune activation.

Objectives

To describe DMARD disruption and identify differences in SARD activity among patients with and without prolonged COVID-19 symptom duration.

Methods

We identified all SARD patients with confirmed COVID-19 at the Mass General Brigham healthcare system in Boston, USA; prospective recruitment is ongoing. Surveys were used to collect demographics, clinical characteristics, DMARD disruption, COVID-19 course, and SARD disease activity before and after COVID-19. The survey included validated instruments measuring disease activity, pain, fatigue, functional status, and respiratory quality of life. Prolonged symptom duration was defined as COVID-19 symptoms lasting ≥28 days. We compared differences in patient-reported measures between those with and without prolonged symptoms.

Results

We analyzed survey responses from 174 COVID-19 survivors with SARDs (mean age 52±16 years, 81% female, 80% White). The most common SARDs were RA (40%) and SLE (14%). Fifty-one percent of the 127 respondents on any DMARD reported a disruption to their regimen at COVID-19 onset (Figure 1). Among individual DMARDs, 56-77% were reported to have any change, except for hydroxychloroquine (23%) and rituximab (46%). SARD flare after COVID-19 was reported by 41% of respondents (Table 1). Patient global assessment of SARD activity was worse after COVID-19 (mean 7.6±2.3 before vs. 6.6±2.9 after COVID-19, p<0.001). Prolonged symptom duration was reported by 45% of participants. Those with prolonged symptoms had a higher initial COVID-19 symptom count (median 7 vs. 4, p<0.001) and were more likely to be hospitalized for COVID-19 (28% vs. 17%, p=0.001). Respondents experiencing prolonged symptom duration had higher disease activity on RAPID3 (p=0.007) as well as more pain (p<0.001) and fatigue (p=0.03) compared to those without prolonged symptoms.

Table 1.

Acute COVID-19 course, SARD flare/activity, and patient-reported outcomes among COVID-19 survivors with SARDs.

All COVID-19 survivors with SARDs (n=174)Prolonged symptom duration ≥28 days (n=78)No prolonged symptom duration/(n=96)p-value (prolonged vs. not)Acute COVID-19 courseCOVID-19 symptom duration, days, median [IQR]14 [9, 29]46 [30, 65]11 [7, 14]<0.0001Initial symptom count, median [IQR]6 [3, 8]7 [6, 9]4 [2, 7]<0.001Hospitalized, n (%)38 (22)22 (28)16 (17)0.001SARD flare/activitySelf-reported SARD flare after COVID-19, n (%)71 (41)38 (49)33 (34)0.15Disease activity by RAPID3, median [IQR]9 [4, 14]11.2 [6, 16]7 [3, 13]0.0067RAPID3 categorical score, n (%)0.13Remission (0)11 (7)4 (5)7 (7)Near remission (0.3-1.0)23 (14)5 (7)18 (19)Low severity (1.3-2.0)26 (15)10 (14)16 (17)Moderate severity (2.3-4.0)55 (33)27 (36)28 (29)High severity (4.3-10.0)54 (32)28 (38)26 (27)Patient-reported outcomesPain by SF-MPQ, median [IQR]2 [1, 2]2 [1, 2]1 [0, 2]0.0008Fatigue by FSI, median [IQR]53 [27, 84]66 [31, 91.5]43 [26, 76]0.031mHAQ, median [IQR]0.125 [0, 0.38]0.25 [0, 0.75]0.125 [0, 0.38]0.11Respiratory quality of life by SGRQ, global [IQR]15 [4, 29]16 [4, 36]10 [4, 26]0.49

RAPID3, Routine Assessment of Patient Index Data 3; SF-MPQ, Short-form McGill Pain Questionnaire; FSI, Fatigue Symptom Inventory; mHAQ, modified Health Assessment Questionnaire; SGRQ, Saint George’s Respiratory Questionnaire.

Figure 1.

Frequency of baseline DMARD use and proportion with any disruption at COVID-19 onset.

Conclusion

DMARD disruption, SARD flare, and prolonged symptoms were common in this prospective study of COVID-19 survivors with SARDs. Those with prolonged COVID-19 symptom duration, defined as ≥28 days, had higher SARD activity, more pain, and more fatigue compared to those without prolonged symptoms. These findings suggest that post-acute sequelae of COVID-19 may have a large impact on underlying SARD activity and quality of life.

Disclosure of Interests

Michael Di Iorio: None declared, Claire Cook: None declared, Kathleen Vanni: None declared, Naomi Patel Consultant of: Receives consulting fees from FVC Health unrelated to this work., Kristin D’Silva: None declared, Xiaoqing Fu: None declared, Jiaqi Wang: None declared, Lauren Prisco: None declared, Emily Kowalski: None declared, Alessandra Zaccardelli: None declared, Lily Martin: None declared, Grace Qian: None declared, Tiffany Hsu: None declared, Zachary Wallace Consultant of: Receives consulting fees from Viela Bio, Zenas BioPharma, and MedPace unrelated to this work., Grant/research support from: Receives research support from Bristol-Myers Squibb and Principia/Sanofi., Jeffrey Sparks Consultant of: Receives consultant fees from AbbVie, Amgen, Boehringer Ingelheim, Bristol Myers Squibb, Gilead, Inova Diagnostics, Janssen, Optum, and Pfizer unrelated to this work., Grant/research support from: Receives research support from Bristol Myers Squibb.

OP0251 IMPACT OF INTERSTITIAL LUNG DISEASE ON SEVERE COVID-19 OUTCOMES FOR PATIENTS WITH RHEUMATOID ARTHRITIS: A MULTICENTER STUDY

Background

RA has been associated with poor COVID-19 outcomes, but few studies have investigated outcomes in RA features such as interstitial lung disease.

Objectives

To assess COVID-19 outcomes in patients with RA overall, and those with and without ILD, compared to general population comparators.

Methods

A multicenter, retrospective cohort study was conducted at Mayo Clinic (19 hospitals and affiliated outpatient centers in 4 states) and Mass General Brigham (14 hospitals and affiliated outpatient centers in New England). Consecutive patients with RA meeting ACR/EULAR criteria and a positive COVID-19 test from March 1, 2020 through June 6, 2021 were matched 1:5 on age, sex, race, and COVID-19 test date with general population comparators without RA. RA features assessed included: RA-ILD per Bongartz criteria [1], duration, rheumatoid factor (RF), cyclic citrullinated peptide antibody (CCP), bone erosions, and treatments. The primary outcome was a composite of hospitalization or death following COVID-19 diagnosis. We used multivariable Cox regression to investigate the association of RA, and features such as ILD, with COVID-19 outcomes compared to matched comparators.

Results

We analyzed 582 patients with RA and 2892 comparators without RA, all with COVID-19. Mean age was 62 years, 51% were female, and 79% were White. Mean RA duration was 11 years, 67% were seropositive (52% RF+ and 54% CCP+), 27% had bone erosions, 28% were on steroids, and 79% were on DMARDs. 50/582 (9%) patients with RA had ILD.

The COVID-19 hospitalization or death rate for RA patients was higher than comparators (3.0 per 1,000 days [95% CI 2.5-3.6] vs. 1.9 per 1,000 days [95% CI 1.7-2.1], respectively). Overall, RA patients had a 53% higher risk of hospitalization or death than comparators after adjustment (95% CI 1.20-1.94).

Among those with RA-ILD, the hospitalization or death rate was significantly higher than comparators (10.9 [95% CI 6.7-15.2] vs. 2.5 per 1,000 days [1.8-3.2], respectively). RA-ILD was associated with nearly 3-fold higher risk for hospitalization or death than comparators (multivariable HR 2.84 [95% CI 1.64-4.91], Table 1). There was a significant interaction between RA/comparator status and presence/absence of ILD for risk of severe COVID-19 (p<0.001, Figure 1). The elevated risk for severe COVID-19 was similar for RA subgroups defined by serostatus or bone erosions.

Table 1.

Frequencies, proportions, and hazard ratios for COVID-19 outcomes, comparing all RA patients, and subgroups with or without RA-ILD, to matched comparators.

COVID-19 OutcomesAll RA Patients (n=582)RA-ILD (n=50)RA Patients without ILD (n=532)Comparators (n=2,892)Hospitalization, n (%)121 (21)24 (48)97 (18)402 (14)Unadjusted HR (95% CI)1.58 (1.27, 1.96)2.65 (1.71, 4.09)1.43 (1.12, 1.82)Ref.Adjusted* HR (95% CI)1.45 (1.14, 1.83)2.35 (1.38, 4.00)1.31 (1.00, 1.70)Ref.Death, n (%)26 (4)9 (18)17 (3)63 (2)Unadjusted HR (95% CI)1.72 (0.98, 3.01)5.88 (2.07, 16.71)1.13 (0.56, 2.29)Ref.Adjusted* HR (95% CI)1.24 (0.66, 2.32)13.94 (4.30, 45.18)0.75 (0.35, 1.63)Ref.Hospitalization or death, n (%)126 (22)25 (50)101 (19)419 (14)Unadjusted HR (95% CI)1.66 (1.33, 2.07)3.01 (1.93, 4.70)1.47 (1.14, 1.89)Ref.Adjusted* HR (95% CI)1.53 (1.20, 1.94)2.84 (1.64, 4.91)1.34 (1.02, 1.77)Ref.

*Adjusted for age, sex, race, and smoking

Figure 1.

Multivariable hazard ratios for the composite outcome of hospitalization or death from COVID-19, comparing all RA and subgroups by serostatus, bone erosions, and ILD to matched comparators without RA.

Conclusion

We confirmed that RA was associated with severe COVID-19 outcomes compared to the general population. We found evidence that ILD may be an effect modifier for the relationship between RA and severe COVID-19 outcomes, but RA subgroups defined by serostatus and bone erosions had similarly elevated risk. These findings suggest that ILD or its treatment may be a major contributor to severe COVID-19 outcomes in RA.

References

[1]Bongartz, T, et al, Arthritis Rheum. 2010 Jun;62(6):1583-91.

Disclosure of Interests

None declared

Association of pneumococcal carriage in infants with the risk of carriage among their contacts in Nha Trang, Vietnam: A nested cross-sectional survey

BACKGROUND

Infants are at highest risk of pneumococcal disease. Their added protection through herd effects is a key part in the considerations on optimal pneumococcal vaccination strategies. Yet, little is currently known about the main transmission pathways to this vulnerable age group. Hence, this study investigates pneumococcal transmission routes to infants in the coastal city of Nha Trang, Vietnam.

METHODS AND FINDINGS

In October 2018, we conducted a nested cross-sectional contact and pneumococcal carriage survey in randomly selected 4- to 11-month-old infants across all 27 communes of Nha Trang. Bayesian logistic regression models were used to estimate age specific carriage prevalence in the population, a proxy for the probability that a contact of a given age could lead to pneumococcal exposure for the infant. We used another Bayesian logistic regression model to estimate the correlation between infant carriage and the probability that at least one of their reported contacts carried pneumococci, controlling for age and locality. In total, 1,583 infants between 4 and 13 months old participated, with 7,428 contacts reported. Few infants (5%, or 86 infants) attended day care, and carriage prevalence was 22% (353 infants). Most infants (61%, or 966 infants) had less than a 25% probability to have had close contact with a pneumococcal carrier on the surveyed day. Pneumococcal infection risk and contact behaviour were highly correlated: If adjusted for age and locality, the odds of an infant's carriage increased by 22% (95% confidence interval (CI): 15 to 29) per 10 percentage points increase in the probability to have had close contact with at least 1 pneumococcal carrier. Moreover, 2- to 6-year-old children contributed 51% (95% CI: 39 to 63) to the total direct pneumococcal exposure risks to infants in this setting. The main limitation of this study is that exposure risk was assessed indirectly by the age-dependent propensity for carriage of a contact and not by assessing carriage of such contacts directly.

CONCLUSIONS

In this study, we observed that cross-sectional contact and infection studies could help identify pneumococcal transmission routes and that preschool-age children may be the largest reservoir for pneumococcal transmission to infants in Nha Trang, Vietnam.

[Bax inhibitor-1 inhibits calcification of vascular smooth muscle cells in vitro]

OBJECTIVE

To investigate the effect of Bax inhibitor-1(BI-1)on calcification of vascular smooth muscle cells(VSMCs).

METHODS

VSMCs were isolated from the thoracic aorta of SD rats.VSMCs or BI-1-overexpressing VSMCs(transfected with a BI-1-overexpressing plasmid) were cultured in normal medium or calcified medium containing β-glycerophosphate and calcium chloride, and the cell calcification was examined with Alizarin red staining.Enzyme-linked immunosorbent assay was used to determine the intracellular calcium content and alkaline phosphatase activity.The expression levels of Runt-related transcription factor 2 (RUNX2), bone morphogenetic protein 2 (BMP-2) and caspase-3 were detected with Western blotting.

RESULTS

After 14 days of culture in the calcified medium, the VSMCs showed significantly reduced expression of BI-1 protein(P=0.001).BI-1 overexpression in the VSMCs caused a significant reduction of calcium level and alkaline phosphatase activities(P=0.0006) and lowered the expression levels of RUNX2 and BMP-2 (P=0.0001) in the cells.The VSMCs with induced calcification exhibited a significantly increased apoptosis rate, but BI-1 overexpression obviously inhibited VSMC apoptosis in the calcified medium (P=0.0003).

CONCLUSION

BI-1 may attenuate vascular calcification by inhibiting calcium deposition, osteogenic differentiation and apoptosis.

The effect of maternal low flow oxygen administration during the second stage of labour on umbilical cord artery pH: a randomised controlled trial

OBJECTIVE

To assess the effect of maternal low flow oxygen administration during the second stage of labour on umbilical cord artery pH.

DESIGN

A randomised controlled trial.

SETTING

A tertiary teaching hospital in China.

POPULATION

Women in the second stage of labour with no complications.

METHODS

About 443 women were randomly allocated to receive either supplemental oxygen at a flow rate of 2 l/min or a sham supplementation by nasal cannula. Healthcare providers, women and outcome assessors were blinded to allocation.

MAIN OUTCOME MEASURES

Umbilical cord artery pH and fetal heart rate (FHR) pattern.

RESULTS

Baseline characteristics were similar between the two groups. There were no significant differences between the two groups in the umbilical cord artery pH [median 7.261, interquartile range (IQR) 7.228-7.295 versus 7.266 (IQR 7.232-7.297), P = 0.64], the proportion with pH less than 7.2 [30/219 versus 34/224, P = 0.66, RR (relative risk) 0.9, 95% CI 0.57-1.42], and the proportion with normal FHR pattern (147/219 versus 153/224, P = 0.79, RR 0.98, 95% CI 0.86-1.12). Maternal partial pressure of dissolved oxygen was significantly higher in the oxygen group than in the sham group [median 150.0 mmHg (IQR 142.6-156.7) versus 112.0 (IQR 104.8-118.3), P < 0.001], whereas carbon dioxide was significantly lower in the oxygen group than in the sham group (mean difference -1.1, 95% CI -2.1 to -0.1, P = 0.03).

CONCLUSION

The use of 2 l/min maternal oxygen during the second stage of labour did not adversely affect either the umbilical artery pH or the FHR pattern distribution.

TWEETABLE ABSTRACT

No difference in abnormal fetal acid base or normal heart rate if maternal O₂ given, randomised trial finds.

Variants in mitochondrial tRNA gene may not be associated with thyroid carcinoma

Thyroid cancer is a very common form of endocrine system malignancy. To date, the molecular mechanism underlying thyroid cancer remains poorly understood. Studies of oncocytic tumors have led to a hypothesis which proposes that defects in oxidative phosphorylation (OX- PHOS) may result in a compensatory increase in mitochondrial replication and gene expression. As a result, mitochondrial DNA (mtDNA) mutation analysis has become a useful tool to explore the molecular basis of this disease. Among these mutations, mitochondrial transfer RNAs (mttRNAs) are the hot spots for pathogenic mutations associated with thyroid cancer. However, due to its high mutation rate, the role of mt-tRNA variants in thyroid cancer is still controversial. To address this problem, in this study, we reassessed seven reported mt-tRNA variants: tRNA^Asp G7521A, tRNA^Arg T10411C and T10463C, tRNA^Leu(CUN) A12308G, tRNA^Ile G4292C and C4312T, and tRNA^Ala T5655C, in clinical manifestations of thyroid cancer. We first performed the phylogenetic conservation analysis for these variants; moreover, we used a bioinformatic tool to compare the minimum free energy (G) of mt-tRNA with and without mutations. Most strikingly, none of these variants caused the significant change of the G between the wild-type and the mutant form, suggesting that they may not play an important roles in thyroid cancer. In addition, we screened the frequency of the “pathogenic” A12308G alternation in 300 patients with thyroid cancer and 200 healthy controls. We found that there were five patients and three control subjects carrying this variant. It seemed that the A12308G variant may be a common polymorphism in the human population. Taken together, our study indicated that variants in mt-tRNA genes may not play active roles in patients with thyroid cancer.

Mitochondrial ND3 G10398A mutation: a biomarker for breast cancer

Mitochondrial DNA mutations have been found to play important roles in carcinogenesis. The most common G10398A mutation, a non-conservative amino acid substitution from Thr to Ala, seems to be involved in the tumorigenesis of breast cancer. Results from studies concerning this mutation remain inconclusive. In the current study, we first took clinical and molecular datasets from case-control studies to determine the association between the G10398A mutation and breast cancer. We further used the Phylotree to determine the haplogroups of this mutation. The frequencies of this mutation in 500 unrelated healthy controls were also screened. We found that this mutation is very common in the human population, and may be a polymorph.

Systemic lupus erythematosus patients in the low-latitude plateau of China: altitudinal influences

The current study was to investigate the features of hospitalized patients with systemic lupus erythematosus (SLE) at different altitudes. The correlation between SLE activity and altitudinal variations was also explored. Medical records of 1029 patients were retrospectively reviewed. Activity of SLE in each organ system was recorded using the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI). There was no significant correlation between SLE activity and altitudes (r = 0.003, p = 0.159). Age at onset for SLE patients at high altitudes was significantly younger than that at low and moderate altitudes (p = 0.022 and p = 0.004, respectively). Age at SLE admission at low altitudes was significant older than those at moderate and high altitudes (p = 0.011 and p < 0.001, respectively). Patients at high altitudes had shorter duration from disease onset to admission than those at moderate altitudes (p = 0.009). Incidence of Sm antibodies-positive for resident patients at high altitudes was 36.4%, which were higher than that at moderate altitudes (p = 0.003). We found increasing trends of CNS activity in active patients; immunological and renal activities in inactive patients were correlated with elevated altitudes (p = 0.024, p = 0.004, p = 0.005), while arthritis scores in active patients showed the tendency of decreasing with the rise of elevation (p = 0.002). Hemoglobin level, red blood cell and platelet counts at high altitudes were significantly lower than those at low altitudes (p < 0.05, respectively). There was no significant difference in hemoglobin level between moderate- and low-altitude groups (p > 0.05). No significant difference in platelet counts between moderate- and high-altitude groups was observed (p > 0.05). Our findings suggest that some clinical features, laboratory tests and activity of main organs in SLE are influenced by altitudes. Furthermore, organ activities of active and inactive SLE patients have different patterns of altitudinal variations. These distinctive variations likely reveal that peculiar environmental factors at high altitudes can affect the development of SLE.

Teriflunomide attenuates immunopathological changes in the dark agouti rat model of experimental autoimmune encephalomyelitis

Teriflunomide is an oral disease-modifying therapy recently approved in several locations for relapsing-remitting multiple sclerosis. To gain insight into the effects of teriflunomide, immunocyte population changes were measured during progression of experimental autoimmune encephalomyelitis in Dark Agouti rats. Treatment with teriflunomide attenuated levels of spinal cord-infiltrating T cells, natural killer cells, macrophages, and neutrophils. Teriflunomide also mitigated the disease-induced changes in immune cell populations in the blood and spleen suggesting an inhibitory effect on pathogenic immune responses.

Socio-demographic determinants of aflatoxin B1-lysine adduct levels among pregnant women in Kumasi, Ghana

OBJECTIVES

Aflatoxins are fungal metabolites that contaminate staple food crops in many developing countries. Although studies have linked these toxins to adverse birth outcomes and poor infant development, no study has investigated the socio-demographic and economic determinants of aflatoxin levels among pregnant women living in sub-Saharan Africa.

DESIGN

A cross-sectional study was conducted among 785 pregnant women in Kumasi. Aflatoxin B1 lysine adduct levels (AF-ALB) were determined by High Performance Liquid Chromatography. Analysis of variance was used to determine mean log AF-ALB levels and significance of differences in these levels according to socio-demographic variables. Logistic regression was used to identify independent associations of socio-demographics with having AF-ALB levels (≥ 11.34 pg/mg; upper quartile).

RESULTS

AF-ALB levels ranged from 0.44 pg/mg to 268.73 pg/mg albumin with a median level of 5.0 pg/mg. Bivariate analyses indicates that mean ln AF-ALB as well as the percent of women having high AF-ALB levels (≥ 11.34 pg/mg; upper quartile) were inversely associated with indices of higher socioeconomic status: higher education and income, being employed and having a flush toilet. Higher income, being employed, having one child (verses no children) and having a flush toilet (verses no toilet facilities) were each independently associated with a 30-40% reduced odds of high AF-ALB levels.

CONCLUSIONS

Additional research is needed to investigate how socio-demographic and economic factors interact to influence aflatoxin ingestion by individuals in regions with high aflatoxin crop contamination. This knowledge can be used to formulate and implement policies that will reduce exposure of women and their unborn children to these toxins.

Cannabinoid 1 receptors modulate intestinal sensory and motor function in rat

BACKGROUND

Cannabinoid receptors are involved in visceral pain perception and control of intestinal motility in vivo. The underlying mechanisms are not well characterized. We aimed to determine whether the cannabinoid-1 (CB(1)) receptor modulates intestinal afferent nerve discharge and the peristaltic reflex.

METHODS

Rats were anesthetized and intestinal segments were removed. Afferent nerve discharge from a mesenteric nerve was investigated in vitro in the presence of the CB(1) antagonist SR 141716A or the CB(1) agonist WIN 55212-2. The myenteric peristaltic reflex was induced by electrical field stimulation and influence of SR 141716A or WIN 55212-2 was recorded.

KEY RESULTS

Afferent nerve discharge to the algesic mediator bradykinin was reduced to 11 +/- 5.1 imp s(-1) following pretreatment with SR 141716A and unchanged after WIN 55212-2 compared to 63 +/- 15.4 imp s(-1) in controls. At maximum distension pressure (80 cmH(2)O) during ramp distension, 92 +/- 12.4 imp s(-1) were reached following SR 141716A compared to 260 +/- 13.2 in vehicle controls and 227 +/- 15.4 in WIN 55212-2 pretreated animals. In contrast, afferent discharge to 5-HT (500 micromol L(-1)) was increased to 75 +/- 24.6 imp s(-1) following WIN 55212-2 compared to 18 +/- 5.9 imp s(-1) in controls, whereas SR 141716A had no effect. Ascending neuronal contractions were dose-dependently attenuated in the presence of SR 141716A and latency of these contractions was reduced. WIN 55212-2 had opposite effects that were abolished by SR 141716A.

CONCLUSIONS & INFERENCES

Activation of the CB(1) receptor differentially alters afferent intestinal nerve sensitivity to bradykinin, 5-HT, and noxious mechanical distension, while it strengthens ascending neuronal contractions. Further studies are needed to determine the physiological relevance of these observations.

Potential therapy of Fc-antigen combination-encoding DNA vaccination in mouse allergic airway inflammation

Vaccination with allergen-encoding DNA has been proposed as having potential for allergen-specific immunotherapy. In this study, we examine the therapeutic effect of allergen-encoding DNA vaccination directly to dendritic cells (DCs) on allergen-induced allergic airway inflammation in a mouse model and explore potential mechanism. Ovalbumin (OVA)-sensitized and challenged mice were immunized with DNA vaccine and received bronchoalveolar lavage (BAL) 1 day after the last challenge, to measure BAL levels of interleukin (IL)-4, IL-5, interferon (IFN)-gamma and differential cell count. Pulmonary DCs and Spleen DCs were purified and sorted according to the expression of CD(11c) (+)CD(80) (+) and CD(11c) (+)CD(86) (+) co-stimulatory molecules. Our data demonstrated that DNA vaccine therapy with OVA-Fc-pcDNA(3.1) significantly prevented OVA-increased levels of IL-4, IL-5 and the percentage of eosinophils and OVA-decreased level of IFN-gamma. OVA-Fc-pcDNA(3.1)-treated mice had less severity of airway inflammation, and lower expression of CD(11c) (+)CD(80) (+) and CD(11c) (+)CD(86) (+) on pulmonary DCs, as compared with animals with OVA-pcDNA(3.1,) pcDNA(3.1) and OVA respectively. DNA vaccine encoding both Fc and OVA was shown to be more effective than DNA vaccine encoding OVA alone. Our data indicate that Fc-antigen combination-encoding DNA vaccination has better preventive effects on antigen-induced airway inflammation by regulating DCs, and may be a new alternative therapy for asthma.

[Sequences variation and classification of B-hordein genes in hull-less barley from Qinghai-Tibet Plateau]

The goal of this study is to understand the evolution relationship of the members of B-hordein gene family in hull-less barley by analysis of their structure and to explore their utility in grain quality improvement. Six copies of B-hordein gene (Hn1-Hn3, Hn7-Hn9) were cloned from six hull-less barley cultivars collected from Qinghai-Tibet Plateau and molecularly characterized. Comparison of their predicted polypeptide sequences with the published suggested that they all share the same basic protein structures. In addition, we found that the C-terminal end sequences of all B-hordeins shared a similar feature. In the six clones and the other three published (Hn4, Hn5 and Hn6) from hull-less barley, Hn2 and Hn7 contained identical C-terminal end sequence DIMPVDFWH, Hn3, Hn4, Hn5, Hn8 and Hn9 also shared the common sequence DIMPPDFWH, which was similar to that of a B-hordein reported previously. Both Hnl and Hn6 exhibited differences in their C-terminal end sequences, and they clustered into different subgroups. The B-hordeins with identical C-terminal end sequences were clustered into a same subgroup, so we believe that B-hordein gene subfamilies possibly can be classified on the basis of the conserved C-terminal end sequences of predicted polypeptide. Phylogenetic analysis also indicated that there is a relatively weak identity between our predicted B-hordeins and those reported from H. chilense and H. brevisubulatum. All of our nine predicted B-hordeins were clustered together and other B-hordeins formed another cluster. The possible use of these genes in relation to the barley quality is discussed.

Blocking Notch1 signaling by RNA interference can induce growth inhibition in HeLa cells

The Notch proteins constitute a family of transmembrane receptors that play a pivotal role in cellular differentiation, proliferation, and apoptosis. RNA interference of Presenilin1 (PS1) and Notch1 was carried out in this research to determine whether it could block Notch signaling and induce growth inhibition in HeLa cells. We transfected synthesized target small interfering RNA (siRNA) into HeLa cells, and blocking of Notch signaling was detected by C-promoter binding factor-1 (CBF1) reporter. We then conducted cell proliferation assay. Cells transfected with PS1 and Notch1 siRNA showed great inhibition in proliferation compared to the controls in vitro and in vivo. We conclude that RNA interference of PS1 or Notch1 can block Notch signaling and consequently induce growth inhibition of HeLa cells.

LBP inhibitory peptide reduces endotoxin-induced macrophage activation and mortality

OBJECTIVE AND DESIGN

The aim of this study was to investigate whether P12, a lipopolysaccharide (LPS)-binding protein (LBP) inhibitory peptide could reduce LPS induced inflammation in vitro and in vivo.

MATERIAL AND METHODS

Human monocyte-like cell line (U937 cells) was grown in RPMI 1640 and stimulated with PMA in order to induce differentiation to the macrophage stage. A total of 70 Kunming mice (8-12 wk old) were used in our experiments. The effects of P12 on the binding of LPS to U937 cells and alveolar macrophages (AMs) were determined by flow cytometric analysis. Nuclear factor kappa B (NF-kappa B) translocation was evaluated with subunit P65 by Western blotting. The production of tumor necrosis factor-alpha (TNF-alpha), alanine transaminase (ALT), and nitric oxide (NO) as measured by ELISA, enzymatic activity assay, and enzymatic assay with nitrate reductase. Differences among groups were determined using one-way ANOVA test and Fisher exact test.

TREATMENT

U937 cells were treated with LPS, LBP, and indicated concentrations of P12. Mice were administered LPS intraperitoneally and P12 via the tail vein.

RESULTS

P12 inhibited the binding of FITC-conjugated LPS (FITC-LPS) to U937 cells and AMs. NF-kappa B translocation and the production of TNF-alpha, ALT, and NO induced by LPS was also significantly suppressed by P12. Furthermore P12 protected mice from LPS-induced death.

CONCLUSIONS

The results suggest that blockade of LBP at inflammation sites might attenuate LPS-induced circulatory shock. This results in a beneficial effect in a mouse model of endotoxemia.

Robust structure from motion estimation using inertial data

The utility of using inertial data for the structure-from-motion (SfM) problem is addressed. We show how inertial data can be used for improved noise resistance, reduction of inherent ambiguities, and handling of mixed-domain sequences. We also show that the number of feature points needed for accurate and robust SfM estimation can be significantly reduced when inertial data are employed. Cramér-Rao lower bounds are computed to quantify the improvements in estimating motion parameters. A robust extended-Kalman-filter-based SfM algorithm using inertial data is then developed to fully exploit the inertial information. This algorithm has been tested by using synthetic and real image sequences, and the results show the efficacy of using inertial data for the SfM problem.

[Construction of a subtracted cDNA library of differentially expressed genes in human normal liver tissue and primary hepatocellular carcinoma tissue]

OBJECTIVE

To construct a subtracted cDNA library of differentially expressed genes in human normal liver tissue and primary hepatocellular carcinoma (HCC) tissue.

METHODS

Using the suppression subtractive hybridization (SSH), a novel technique has been described recently. cDNA fragments of missing or low expressing tumor suppressor genes in HCC tissue were isolated using paracancerous normal liver tissue and HCC tissue as targets. Then these cDNA fragments were directly inserted into T/A cloning vector to set up the subtractive library. Amplification of the library was carried out with transformation of E.coli by high voltage electroperforation. One hundred positive bacteria clones were randomly picked and identified using enzyme restriction method.

RESULTS

The amplified library contained more than 4,000 positive bacteria clones. Random analysis of 100 clones with enzyme restriction method showed that all clones contained 200-600 bp inserts.

CONCLUSIONS

A subtracted cDNA library of differentially expressed genes in human normal liver tissue and HCC tissue is constructed successfully with SSH and T/A cloning techniques. The library is efficient and lays solid foundation for screening and cloning new and specific missing or low expressing tumor suppressor genes of HCC.

[Changes of L-selectin expression on polymorphonuclear leukocytes and its role during polymorphonuclear leukocytes sequestration in lungs of rats with acute lung injury]

OBJECTIVE

To explore the changes of L-selectin protein expression on peripheral blood polymorphonuclear leukocytes (PMN) and their role during PMN sequestration in the lungs of rats with acute lung injury (ALI).

METHODS

The model of ALI in rat was established by intravenous injection of E. Coli endotoxin (ET). The protein expression of L-selectin on peripheral blood PMNs was measured by immunofluorescence and flow cytometry. Myeloperoxidase (MPO) enzyme analysis and histology were employed to estimate the quantity of PMN sequestration in lungs of rats during ALI.

RESULTS

(1) The protein expression of L-selectin on PMN after injection of ET (7.8 +/- 1.6) was all significantly lower than that in control group (10.5 +/- 2.1, P < 0.05). (2) MPO activity increased significantly after injection of ET in comparison with the control group [0.069 +/- 0.011) U/mg lung tissue, P < 0.01]. The difference was not significant between the fucodin treated 5 min group [(0.391 +/- 0.071) U/mg lung tissue] and ET-treated 5 min group [(0.359 +/- 0.074) U/mg lung tissue]. But MPO activity was significantly lower in fucodin-treated 15 min group [(0.396 +/- 0.061) U/mg lung tissue] than that in ET-treated group at same time point [(0.490 +/- 0.069) U/mg lung tissue, P < 0.05].

CONCLUSIONS

(1) In physiological state, L-selectin are consistently expressed on the surface of PMN membrane. The protein expression of L-selectin on PMNs reduces rapidly after injection of ET and is the lowest at 15 min, then gradually increases. (2) The early stage of PMN sequestration in lungs is not dependent on L-selectin, but L-selectin is still important for maintaining a continual PMN sequestration in lungs of rats with ALI.

[The effect of monocarboxylate transporter gene on the regulation of pHi and growth character in cancer cells]

OBJECTIVE

To study the influence of the first subtype of monocarboxylate transporter (MCT1) gene on pHi regulation, lactate transport and cell growth in tumor cells.

METHODS

(1) With RT-PCR technique, MCT1 cDNA fragment was cloned from human lung cancer cells A549, and the cloned fragment MCT1 was reversely inserted into the vector pLXSN to acquire antisense expression recombinant vector pLXSN-MCT1. (2) pLXSN, pLXSN-MCT1 were respectively introduced into the A549 cells by electroporation. The transfected A549 cell resistant to G418 drug was selected as positive clones and proved by PCR. The changes of intracellular pH and lactate in the transfected A549 cells were detected by spectrophotometric method. Cell growth was studied by cell growth curve.

RESULTS

(1) The cloned fragment was in the length of 640 bp and successfully bound to pLXSN. It was also proved to be the objective one by DNA sequencing. (2) Intracellular pH and lactate were remarkably decreased in the cells transfected pLXSN-MCT1, comparing to A549 cells without transfection (P < 0.001). The growth of A549 cells transfected pLXSN-MCT1 was also inhibited remarkably.

CONCLUSION

MCT1 gene could play an important role in pHi regulation, lactate transport and cell growth in tumor cells.

Recovery of heavy metals and stabilization of spent hydrotreating catalyst using a glass-ceramic matrix

Chemical analysis of spent Co/Mo/gamma Al(2)O(3) catalyst revealed the presence of carbon, molybdenum, sulfur, vanadium and cobalt at levels of 16.0, 10.9, 7.3, 4.6 and 4.0 wt.%, respectively. It was found that calcination at 500 degrees C provides an effective solution for the removal of carbon and sulfur and this generates the oxide form of the heavy metals. The removal of these heavy metals can be achieved through a two-stage leaching process. During the first stage, in which concentrated ammonia is used and it has been found that this process can be successful in removing as much as 83% (w/v) Mo. In a second stage, it was found that using 10% (v/v) of sulfuric acid, it was possible to account for up to 77% (w/v) Co and 4% (w/v) Mo removal. Leaching test results indicated that the vanadium present in the heated spent catalyst was almost stabilized but the molybdenum and cobalt were not. The combination of two solid wastes, ladle furnace slag (LFS) and treated residue of spent catalyst, could be used for making a high value-added anorthite glass-ceramic materials. Further leaching tests showed that ceramic glass materials provided a very effective method of Co, Mo and V heavy metals stabilization resulting in a product with a possible commercial value.

Adolescent smoking in Wuhan, China: baseline data from the Wuhan Smoking Prevention Trial

BACKGROUND

This study reports the prevalence of adolescent smoking in the urban and rural areas of Wuhan, China, the capital of Hubei Province, on the Yangtze River in central China.

METHODS

Smoking behavior was examined by age, gender, and urbanicity as part of the Wuhan Smoking Prevention Trial. Subjects included 6994 seventh- to ninth-grade students attending 22 randomly selected schools in urban and rural districts. Outcome measures included lifetime smoking, past-30-day smoking, established smoking (>100 cigarettes in lifetime), and susceptibility to smoking (absence of a firm commitment not to smoke).

RESULTS

Lifetime smoking prevalence was 47% among boys and 18% among girls. Past-30-day smoking prevalence was 16% among boys and 4% among girls. Established smoking prevalence was 2% among boys and 0% among girls. The prevalence of susceptibility to smoking was 31% among boys and 10% among girls. Smoking increased significantly with age (p<.0005). Susceptibility was more prevalent in rural areas than in urban areas (p<.05), but there were no urban-rural differences in lifetime, past 30-day smoking, or established smoking. Trend analyses revealed that smoking increased with age more rapidly among boys than among girls (p<.05). Smoking was more prevalent among rural boys than among urban boys, but it was more prevalent among urban girls than among rural girls (p<.05).

CONCLUSIONS

Adolescent smoking is a significant public health problem in China. Boys are at particularly high risk, as are girls living in urban areas. Effective smoking prevention programs for adolescents, as well as restrictions on tobacco industry marketing and youth access to tobacco, are needed to prevent tobacco-related morbidity and mortality in China.

[The influence of dexamethasone on mRNA expression of interleukin-5, interleukin-3 and granulocyte-macrophage colony-stimulating factor receptors in eosinophils of guinea pig asthma model]

OBJECTIVE

To investigate the iufluence of dexamethasone (DM) on expression of interleukin-5 receptor alpha(IL-5R alpha), interleukin-3 receptor alpha (IL-3R alpha), granulocyte-macrophage-colony-stimulating factor receptor alpha(GM-CSFR alpha) and common beta receptor (beta cR) in bronchalveolar lavage fluid (BALF) eosinophils in guinea pig asthma model, and to study the mechanism of promotion effect of steroid on eosinophil apoptosis.

METHODS

18 guinea pigs were divided into three groups randomly, normal control group, asthma group and DM-treated group. Asthma models of guinea pig were sensitized by ovalbumin(OVA). Hypodense EOS (HEOS) and normodense EOS (NEOS) were purified from BALF by gradients of percoll. Apoptosis was detected by method of TdT-mediated dUTP nick end labeling. The mRNA expression of IL-5R alpha, IL-3R alpha, GM-CSFR alpha and common beta receptor (beta cR) in eosinophils were measured by RT-PCR and in situ hybridization.

RESULTS

Apoptosis of HEOS and NEOS in asthma group(4.0 +/- 2.0 and 3.0 +/- 2.0, respectively) were significanteylower than normal group(8.0 +/- 2.0 and, 7.0 +/- 2.0 respectively, P < 0.01), while the numbers of EOS cells (75.2 +/- 12.6 and 50.7 +/- 11.2, respectively) were significantly higher than normal group (4.8 +/- 1.5 and 9.5 +/- 2.6, respectively, P < 0.01). The BALF HEOS and NEOS of asthma group were remarkably reduced after DM treatment (14.8 +/- 8.0 and 20.0 +/- 7.0, respectively, P < 0.01), Eosinophils apoptosis in DM-treated group (24.0 +/- 5.0 and 22.0 +/- 4.0, respectively) was remarkably higher than those in asthma group (P < 0.01); The expressions of IL-5R alpha, IL-3R alpha, GM-CSFR alpha mRNA of BALF EOS of asthma group were significantly lower, but the expression of beta cR mRNA was significantly higher than those of normal group(P < 0.01, 0.05). The expressions of IL-5R alpha, IL-3R alpha, GM-CSFR alpha mRNA in EOS of DM-treated group were significantly higher, while the expression of beta cR mRNA were significantly lower than those of asthma group (P < 0.01, 0.05).

CONCLUSIONS

DM promote the apoptosis of BALF EOS of guinea pigs asthma models. and reduce EOS infiltration in lung of guinea pigs asthma models. It also decreased the effect of IL-5, IL-3 and GM-CSF and promoted the apoptosis of lung EOS through inducing the mRNA expression of their specific alpha chain and reducing the mRNA expression of the common beta chain.

[Impact of quantitative and qualitative pathogen culture on the outcome of ventilator-associated pneumonia]

OBJECTIVE

To evaluate the impact diagnostic methods with either quantitative culture (QC) or qualitative routine culture (RC) on the outcome of VAP.

METHODS

A prospective, controlled clinical trial in 93 consecutive VAP episodes of 31 patients receiving mechanical ventilation was conducted. VAP episodes were randomly and crossly divided into QC (43 episodes, underwent FOB-PSB-QC) and RC group (50 episodes, underwent ETA-RC). Empirical antibiotic treatment was given according to the attending physician and modified according to the results of culture and sensitivity. The outcomes of VAP were assessed.

RESULTS

There were no differences with regard to mortality, super-infection rate, antibiotic resistance rate and cost of antibiotics when comparing QC versus RC diagnostic methods and management based on two diagnostic strategies. Inappropriate initial empirical antibiotic treatment led to a higher mortality (17.7%) when compared with those with appropriate treatment.

CONCLUSION

The present study demonstrates that the outcome of VAP is probably more dependent on the adequacy of the initial antibiotic treatment than on the use of either diagnostic sampling.

[Correlation of endotracheal tube biofilm and recurrent ventilator-associated pneumonia with Pseudomonas aeruginosa]

OBJECTIVE

To determine the correlation of endotracheal tube biofilm (ETT-BF) and recurrent ventilator-associated pneumonia with Pseudomonas aeruginosa (PA-VAP) in long-term ventilation patients.

METHODS

Pulsed-field gel electrophoresis (PFGE) of Spe I enzyme-restricted chromosomal DNA was performed to identify the DNA patterns of Pseudomonas aeruginosa from ETT-BF, pharynx and lower respiratory tract secretion in 15 VAP patients. The chromosomal DNA fingerprint profile of each strain was compared with those from all other strains to calculate the similarity by using the correlation coefficient. The strains were then grouped and groups were depicted as a dendrite using the average clustering algorithm.

RESULTS

When bacteria has been isolated from ETT-BF, the same DNA pattern species are isolated from the lower respiratory tract secretion in 7 of 15 patients. Recurrent PA-VAP is caused by closely related and indistinguishable isolates in 6 of 15 patients. All PEGE patterns from 9 patients are different from one another (correlation coefficient < 31.2%).

CONCLUSIONS

The close pathogenic relationship between ETT-BF and lower airway secretion suggests that adhesive colonization of ETTs may be an important factor in the pathogenesis of VAP.

Ultrasonographic texture analysis of parenchymatous organs by the four-neighborhood-pixels algorithm: clinical experiment

OBJECTIVE

The parenchyma of organs such as liver, thyroid, and mammary gland during climacterium have common ultrasonographic textural features, which together form what we call small-dot-structure texture. To study this texture we designed the 4-neighborhood-pixels algorithm, an ultrasonographic texture analysis algorithm. The objective of this study was to confirm whether the 4-neighborhood-pixels algorithm can reflect the features of small-dot-structure texture.

METHODS

A changed small-dot-structure texture and 3 other textures were compared with the normal small-dot-structure texture in 4 groups, and a histogram algorithm was used for contrast with the 4-neighborhood-pixels algorithm.

RESULTS

The 4-neighborhood-pixels algorithm could reflect all the textural differences, but the histogram algorithm could reflect only some of them.

CONCLUSIONS

The 4-neighborhood-pixels algorithm is a good algorithm for analyzing ultrasonographic small-dot-structure texture. Not only can it reflect changes in the small-dot-structure texture, but it can also differentiate between small-dot-structure and non-small-dot-structure textures.

[Detection of aflatoxin-albumin adducts in human serum and its application]

Exposure to aflatoxin B1 (AFB1) is one of the major risk factors in the etiology of human hepatocellular carcinoma (HCC). The development of highly sensitive and specific methods for detecting AFB1 and its macromolecular biomarkers are critical for identifying individuals at risk for hepatocellular carcinoma. The detection of aflatoxin-albumin adducts (AFB-ALB) in serum has been used to investigate the relationship between aflatoxin exposure and HCC. A more sensitive and reliable method to detect AFB-ALB in serum was modified by separating serum albumin with Microcon-50 microconcentrators in stead of using precipitation. The method could separate serum albumin quickly and make protein digested in the same container. Thus, the step for transferring samples was reduced and recovery rate was improved. The AFB-ALB adducts were then determined by radioimmunoassay. The AFB-ALB adducts of human serum samples from Qidong, Jiangsu Province, and Fusui, Guangxi Zhuang Autonomous Region of the People's Republic of China were detected. The results indicated that the exposure of AFB1 is common and the positive rate for AFB-ALB adducts in serum of these populations is high.

[Experimental study on human pulmonary adenocarcinoma cell A549 transfected with HSV₁-TK gene in vitro and in vivo]

BACKGROUND

To observe killing effect of HSV₁-TK/GCV system on human pulmonary adenocarcinoma cell A549 in vitro and in vivo.

METHODS

A retroviral vector containing TK gene was constructed and transduced into pulmonary adenocarcinoma cell A549 by electroporation. The sensitivity of transfected cell to GCV in vitro and bystander effect and cellular apoptosis were observed. The recombination and expression of TK gene were examined by DNA PCR and in situ hybridization individually. In addition, the therapeutic effect of GCV on subcutaneous tumors inoculated with transfected and parental cells respectively was observed.

RESULTS

The transfected cells were irregular in shape, polyangular and easy of vacuolization. The double time of A549,A549-PLXSN and A549-TK was 36.15±3.27,40.82±3.75 and 42.06±4.12 hours respectively (P>0.05). The sensitivity of transfected cells to GCV was 46 times higher than that of parental cells and bystander effect was more apparent in high density inoculation cells than in low density. Apoptotic bodies and semimoon feature in nuclear were observed in transfected cells, but not in parental cell. Apoptotic cells were found significantly more in transfected cells than in parental cells by FCM and TUNEL (P<0.001). The recombination and expression of TK gene were positive in the transfected cells. In vivo, growth of tumors which formed by transfected cells was significantly inhibited by GCV, however, there was no similar inhibitive effect found in control group.

CONCLUSIONS

The transfected cells have obtained sensitivity to GCV. The killing effect of TK/GCV system on tumor cells is probably related to apoptosis. GCV could inhibit growth of tumors inoculated by transfected cells.

Changes and significance of circulating hepatocellular carcinoma cells in recurrent hepatocellular carcinoma patients after combined treatment

OBJECTIVE

To study the changes and significance of circulating hepatocellular carcinoma cells in recurrent hepatocellular carcinoma (HCC) patients after combined treatment of transarterial chemo-embolization(TACE) and percutaneous ethanol injection(PEI).

METHODS

We detected 19 blood samples from the recurrent HCC patients by nested RT-PCR to find out AFP mRNA before and after the treatment.

RESULTS

There were 7 patients with AFP mRNA positive before treatment (36.8%), and none of patients with AFP mRNA positive after treatment.

CONCLUSIONS

Combined treatment of TACE and PEI can effectively eliminate circulating hepatocellular carcinoma cells and thereby prevent metastasis and recurrence of HCC.