Association of serum concentrations of remnant cholesterol with incident cardiovascular disease in patients with rheumatoid arthritis: A real-world data from 2001 to 2022

BACKGROUND

Remnant cholesterol (RC) promotes cardiovascular disease (CVD) in the general population, but its role among rheumatoid arthritis (RA) patients remains unknown. We aimed to investigate circulating RC levels associated with incident CVD among Chinese patients with RA.

METHODS

A total of 1018 RA patients free of baseline CVD were included and followed up in a prospective RA CVD cohort from 2001 to 2022. Fasting serum levels of triglycerides, total cholesterol (TC), low-density (LDL-C), and high-density lipoprotein cholesterol (HDL-C) were measured, while RC and Non-HDL-C levels were calculated. The primary exposure was RC levels. A LASSO Cox model was used to select covariates. The Fine-Gray competing risk model was used to estimate hazard ratios (HRs).

RESULTS

RA patients had a mean age of 53.9 years, and 802 (78.8%) were females. After a median follow-up of 5.54 years, 131 patients developed CVD with an incidence rate of 21.6 per 1000 person-years. Continuous and quartile-categorized RC levels were associated with incident CVD before and after multivariate adjustment and Bonferroni correction (all P < 0.001). There were no robust associations of other lipids with incident CVD. The fully adjusted HRs for RC were 2.30 (95% CI 1.58-3.35) per 1 mmol/L increase, and 2.40 (1.36-4.25) and 2.81 (1.60-4.94) for patients in the 3rd and 4th versus the 1st quartile, respectively.

CONCLUSIONS

Circulating RC levels are positively associated with incident CVD among Chinese RA patients independent of known risk factors, implying its clinically preferable use for improving the stratification of CVD risk in RA patients.

AHA Life's Essential 8 and new-onset CKD: a prospective cohort study from the UK Biobank

BACKGROUND

The AHA has recently introduced a novel metric, Life's Essential 8, to assess cardiovascular health (CVH). Nevertheless, the association between varying levels of LE8 and the propensity for CKD is still unclear from a large prospective cohort. Our objective is to meticulously examine the relationship between LE8 and its associated susceptibilities to CKD.

METHODS

A total of 251,825 participants free of CKD from the UK Biobank were included. Cardiovascular health was scored using LE8 and categorized as low, moderate, and high. Cox proportional hazard models were employed to evaluate the associations of LE8 scores with new-onset CKD. The genetic risk score for CKD was calculated by a weighted method.

RESULTS

Over a median follow-up of 12.8 years, we meticulously documented 10,124 incident cases of CKD. Remarkably, an increased LE8 score correlated with a significant reduction of risk in new-onset CKD (high LE8 score vs. low LE8 score: HR = 0.300, 95% CI 0.270-0.330, p < 0.001; median LE8 score vs. low LE8 score: HR = 0.531, 95% CI 0.487-0.580, p < 0.001). This strong LE8-CKD association remained robust in extensive subgroup assessments and sensitivity analysis. Additionally, these noteworthy associations between LE8 scores and CKD remained unaffected by genetic predispositions to CKD.

CONCLUSIONS

An elevated degree of CVH, as delineated by the discerning metric LE8, exhibited a pronounced and statistically significant correlation with a marked reduction in the likelihood of CKD occurrence.

Cardiovascular health metrics defined by Life's Essential 8 scores and subsequent macrovascular and microvascular complications in individuals with type 2 diabetes: A prospective cohort study

AIM

To investigate the association between cardiovascular health metrics defined by Life's Essential 8 (LE8) scores and vascular complications among individuals with type 2 diabetes (T2D).

MATERIALS AND METHODS

This prospective study included 11 033 participants with T2D, all devoid of macrovascular diseases (including cardiovascular and peripheral artery disease) and microvascular complications (e.g. diabetic retinopathy, neuropathy and nephropathy) at baseline from the UK Biobank. The LE8 score comprised eight metrics: smoking, body mass index, physical activity, non-high-density lipoprotein cholesterol, blood pressure, glycated haemoglobin, diet and sleep duration. Cox proportional hazards models were established to assess the associations of LE8 scores with incident macrovascular and microvascular complications.

RESULTS

During a median follow-up of 12.1 years, we identified 1975 cases of incident macrovascular diseases and 1797 cases of incident microvascular complications. After adjusting for potential confounders, each 10-point increase in the LE8 score was associated with an 18% lower risk of macrovascular diseases and a 15% lower risk of microvascular complications. Comparing individuals in the highest and lowest quartiles of LE8 scores revealed hazard ratios of 0.55 (95% confidence interval 0.47-0.62) for incident macrovascular diseases, and 0.61 (95% confidence interval 0.53-0.70) for incident microvascular complications. This association remained robust across a series of sensitivity analyses and nearly all subgroups.

CONCLUSION

Higher LE8 scores were associated with a lower risk of incident macrovascular and microvascular complications among individuals with T2D. These findings underscore the significance of adopting fundamental strategies to maintain optimal cardiovascular health and curtail the risk of developing diabetic vascular complications.

The association between tinnitus and risk of cardiovascular events and all-cause mortality: insight from the UK Biobank

BACKGROUND

The potential influence of tinnitus on cardiovascular disease (CVD) and all-cause mortality has yet to be explored. We aim to examine the correlations between tinnitus and the risk of cardiovascular events and all-cause mortality.

METHODS

We conducted a prospective cohort study utilising data from the UK Biobank. The presence of tinnitus was evaluated through a questionnaire. The primary outcome was defined as a composition of cardiovascular events, including myocardial infarction (MI), stroke, and mortality from CVD, as well as all-cause mortality. Cox proportional hazard models were employed to examine the associations between tinnitus and both the primary outcome and its individual components. Sensitivity analyses were conducted to evaluate the robustness of the primary analysis.

RESULTS

A total of 140,146 participants were included in the study. The presence of tinnitus was found to be associated with a higher incident rate of the primary outcome (HR = 1.057, 95%CI: 1.017-1.099, p = 0.005), MI (HR = 1.139, 95%CI: 1.061-1.222, p < 0.001) and all-cause mortality (HR = 1.053, 95%CI: 1.003-1.105, p = 0.038) after adjusting for confounders. However, there was no significant association between tinnitus and stroke or mortality from CVD. Subgroup analysis revealed that the association between tinnitus and the primary outcome was significant in females, participants with abnormal BMI, and those without hearing difficulty, depression or anxiety. Sensitivity analyses yielded consistent results.

CONCLUSION

The findings from this study contribute to the existing body of evidence suggesting an association between tinnitus and an increased risk of cardiovascular events and all-cause mortality.

Association between daytime napping and incident arrhythmias: A prospective cohort study and mendelian randomization analysis

BACKGROUND

Emerging evidence has linked daytime napping with the risk of cardiovascular events. Cardiac arrhythmias are considered an early clinical stage for cardiovascular diseases. However, whether napping frequency is associated with incident arrhythmias remains unknown.

OBJECTIVE

This study aimed to prospectively investigate the association between napping frequency and cardiac arrhythmias.

METHODS

Daytime napping frequency was self-reported in response to touchscreen questionnaires. The primary outcomes were incident arrhythmias including atrial fibrillation/flutter (AF/Af), ventricular arrhythmia, and bradyarrhythmia. Cox regression analysis was conducted on the basis of 491,117 participants free of cardiac arrhythmias from the UK Biobank. The 2-sample mendelian randomization (MR) and 1-sample MR were used to ensure a causal effect of genetically predicted daytime napping on the risk of arrhythmias.

RESULTS

During a median follow-up of 11.91 years, 28,801 incident AF/Af cases, 4132 incident ventricular arrhythmias, and 11,616 incident bradyarrhythmias were documented. Compared with never/rarely napping, usually napping was significantly associated with higher risks of AF/Af (hazard ratio, 1.141; 95% CI, 1.083-1.203) and bradyarrhythmia (hazard ratio, 1.138; 95% CI, 1.049-1.235) but not ventricular arrhythmia after adjustment for various covariates. The 2-sample MR and 1-sample MR analysis showed that increased daytime napping frequency was likely to be a potential causal risk factor for AF/Af in FinnGen (odds ratio, 1.626; 95% CI, 1.061-2.943) and bradyarrhythmia in the UK Biobank (odds ratio, 1.005; 95% CI, 1.002-1.008).

CONCLUSION

The results of this study add to the burgeoning evidence of an association between daytime napping frequency and an increased risk of cardiac arrhythmias including AF/Af, ventricular arrhythmia, and bradyarrhythmia.

Remnant cholesterol and risk of incident hypertension: a population-based prospective cohort study

Remnant cholesterol (RC) has been associated with atherosclerotic cardiovascular disease, but its relationship with hypertension remains unclear. This prospective cohort study aimed to investigate the association between RC and subsequent hypertension risk. Data from the UK Biobank, comprising 295,062 participants initially free of hypertension, were analyzed. Cox proportional hazards regression assessed the association between RC quartiles and hypertension risk. Discordance analysis evaluated the risk of hypertension in discordant/concordant groups of RC and low-density lipoprotein cholesterol (LDL-C) using the difference in percentile units (>10 units). Restricted cubic spline curves were used to model the relationship between RC and hypertension risk. The mean ± SD age of participants was 55.1 ± 8.1 years, with 40.6% being men and 94.7% White. During a median follow-up of 12.8 years, 39,038 participants developed hypertension. Comparing extreme quartiles of RC, the hazard ratio (HR) for incident hypertension was 1.20 (95% CI: 1.17-1.24). After adjusting for traditional risk factors, each 1 mmol/L increase in RC levels was associated with a 27% higher risk of incident hypertension (HR: 1.27; 95% CI: 1.23-1.31). The discordant group with high RC/low LDL-C exhibited a higher risk of incident hypertension compared to the concordant group (HR: 1.06; 95% CI: 1.03-1.09). Spline curves further demonstrated a positive association between RC and the risk of incident hypertension. We concluded that elevated RC emerged as an independent risk factor of incident hypertension, extending beyond traditional risk factors. Monitoring RC levels and implementing interventions to lower RC may have potential benefits in preventing hypertension.

Remnant cholesterol and the risk of aortic valve calcium progression: insights from the MESA study

BACKGROUND

Remnant cholesterol (RC) is implicated in the risk of cardiovascular disease. However, comprehensive population-based studies elucidating its association with aortic valve calcium (AVC) progression are limited, rendering its precise role in AVC ambiguous.

METHODS

From the Multi-Ethnic Study of Atherosclerosis database, we included 5597 individuals (61.8 ± 10.1 years and 47.5% men) without atherosclerotic cardiovascular disease at baseline for analysis. RC was calculated as total cholesterol minus high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C), as estimated by the Martin/Hopkins equation. Using the adjusted Cox regression analyses, we examined the relationships between RC levels and AVC progression. Furthermore, we conducted discordance analyses to evaluate the relative AVC risk in RC versus LDL-C discordant/concordant groups.

RESULTS

During a median follow-up of 2.4 ± 0.9 years, 568 (10.1%) participants exhibited AVC progression. After adjusting for traditional cardiovascular risk factors, the HRs (95% CIs) for AVC progression comparing the second, third, and fourth quartiles of RC levels with the first quartile were 1.195 (0.925-1.545), 1.322 (1.028-1.701) and 1.546 (1.188-2.012), respectively. Notably, the discordant high RC/low LDL-C group demonstrated a significantly elevated risk of AVC progression compared to the concordant low RC/LDL-C group based on their medians (HR, 1.528 [95% CI 1.201-1.943]). This pattern persisted when clinical LDL-C threshold was set at 100 and 130 mg/dL. The association was consistently observed across various sensitivity analyses.

CONCLUSIONS

In atherosclerotic cardiovascular disease-free individuals, elevated RC is identified as a residual risk for AVC progression, independent of traditional cardiovascular risk factors. The causal relationship of RC to AVC and the potential for targeted RC reduction in primary prevention require deeper exploration.

Predictors of long-term absence of coronary artery calcium in individuals with high blood pressure: results from the MESA study

BACKGROUND & AIMS

Individuals with high blood pressure (BP) have varying risks of cardiovascular events due to other coexisting factors. We aimed to identify the predictors of long-term absence of coronary artery calcium (CAC) in individuals with high BP, which is an indicator of healthy arterial aging and can guide preventive strategies.

METHODS

We analyzed data from participants with high BP (≥120/80 mm Hg) in the Multi-Ethnic Study of Atherosclerosis who had baseline CAC = 0 and underwent a second CAC scanning after 10 years. We used multivariable logistic regression to evaluate the association between various risk factors for atherosclerotic cardiovascular disease (ASCVD) and long-term CAC = 0. We also calculated the area under the receiver operating characteristic curve (AUC) to predict the phenotype of healthy arterial aging in this population.

RESULTS

We included 830 participants (37.6% male, mean ± SD age of 59.4 ± 8.7 years). During follow-up, 46.5% of participants (n = 386) had CAC = 0, and they were younger and had fewer metabolic syndrome components. Adding ASCVD risk factors to the demographic model (age, sex, and ethnicity) moderately increased the predictive value for long-term CAC = 0 (AUC: demographic model + ASCVD risk factors vs. demographic model alone, 0.653 vs. 0.597, p < .001; category net reclassification improvement = 0.104, p = .044; integrated discrimination improvement = 0.040, p < .001).

CONCLUSION

In individuals with high BP and initial CAC = 0, over 40% maintained CAC = 0 during a 10-year follow-up, which was associated with fewer ASCVD risk factors. These findings may have implications for preventive strategies in individuals with high BP.Clinical Trial registration number: The MESA was registered at clinical trials. gov as NCT00005487.KEY MESSAGESNearly half (46.5%) of individuals with high blood pressure (BP) maintained a long-term absence of coronary artery calcium (CAC) during a 10-year follow-up, and this was associated with a 66.6% lower risk of atherosclerotic cardiovascular disease (ASCVD) events compared to those who developed incident CAC.Individuals with high BP, who are usually assumed to have an increased risk of ASCVD, exhibit significant heterogeneity in their ASCVD risk; those who maintain CAC = 0 have a lower ASCVD risk.Adding overall ASCVD risk factors to demographic information resulted in a moderate improvement in predicting long-term CAC = 0.

Upregulated LncRNA H19 Sponges MiR-106a-5p and Contributes to Aldosterone-Induced Vascular Calcification via Activating the Runx2-Dependent Pathway

BACKGROUND

Excess aldosterone is implicated in vascular calcification (VC), but the mechanism by which aldosterone-MR (mineralocorticoid receptor) complex promotes VC is unclear. Emerging evidence indicates that long-noncoding RNA H19 (H19) plays a critical role in VC. We examined whether aldosterone-induced osteogenic differentiation of vascular smooth muscle cells (VSMCs) through H19 epigenetic modification of Runx2 (runt-related transcription factor-2) in a MR-dependent manner.

METHODS

We induced in vivo rat model of chronic kidney disease using a high adenine and phosphate diet to explore the relationship among aldosterone, MR, H19, and VC. We also cultured human aortic VSMCs to explore the roles of H19 in aldosterone-MR complex-induced osteogenic differentiation and calcification of VSMCs.

RESULTS

H19 and Runx2 were significantly increased in aldosterone-induced VSMC osteogenic differentiation and VC, both in vitro and in vivo, which were significantly blocked by the MR antagonist spironolactone. Mechanistically, our findings reveal that the aldosterone-activated MR bound to H19 promoter and increased its transcriptional activity, as determined by chromatin immunoprecipitation, electrophoretic mobility shift assay, and luciferase reporter assay. Silencing H19 increased microRNA-106a-5p (miR-106a-5p) expression, which subsequently inhibited aldosterone-induced Runx2 expression at the posttranscriptional level. Importantly, we observed a direct interaction between H19 and miR-106a-5p, and downregulation of miR-106a-5p efficiently reversed the suppression of Runx2 induced by H19 silencing.

CONCLUSIONS

Our study clarifies a novel mechanism by which upregulation of H19 contributes to aldosterone-MR complex-promoted Runx2-dependent VSMC osteogenic differentiation and VC through sponging miR-106a-5p. These findings highlight a potential therapeutic target for aldosterone-induced VC.

Lung Function Decline in Young Adulthood and Coronary Artery Calcium Progression in Midlife

BACKGROUND

Reduced lung function has been linked to cardiovascular disease, but population-based evidence on the relationship between lung function decline and coronary artery calcium (CAC) progression is rare.

METHODS

A total of 2694 participants (44.7% men) with a mean ± standard deviation age of 40.4 ± 3.6 years from the Coronary Artery Risk Development in Young Adults (CARDIA) were included. The rates of decline in forced vital capacity (FVC) and forced expiratory volume in 1 second (FEV1) over a 20-year period were calculated for each participant and categorized into quartiles. The primary outcome was CAC progression.

RESULTS

During a mean follow-up of 8.9 years, 455 (16.9%) participants had CAC progression. After adjusting for traditional cardiovascular risk factors, the hazard ratios (95% confidence intervals [CIs]) for CAC progression were higher for participants in the 2nd (Q2), 3rd (Q3), and highest quartiles (Q4) of FVC decline compared with those in the lowest quartile (Q1): 1.366 (1.003-1.861), 1.412 (1.035-1.927), and 1.789 (1.318-2.428), respectively. Similar trends were observed for the association between FEV1 and CAC progression. The association remained robust across a series of sensitivity analyses and all subgroups.

CONCLUSIONS

A faster decline in FVC or FEV1 during young adulthood is independently associated with an increased risk of CAC progression in midlife. Maintaining optimal lung function during young adulthood may improve future cardiovascular health.

Serum albumin and risk of incident diabetes and diabetic microvascular complications in the UK Biobank cohort

AIM

To examine the associations between serum albumin and the incidences of diabetes and diabetic microvascular complications in participants of the UK Biobank cohort.

METHODS

There were 398,146 participants without diabetes and 30,952 patients with diabetes from the UK Biobank cohort included in this study. Multivariate-adjusted Cox proportional hazard models were used to analyze the association of albumin with the incidences of diabetes and diabetic microvascular complications. Mendelian randomization (MR) analysis was used to determine the genetic relationships between serum albumin and diabetes.

RESULTS

After a median 12.90 years follow-up, 14,710 participants developed incident diabetes (58.83 ± 7.52 years, 56.10% male). After multivariate adjustment, serum albumin was inversely associated with incident diabetes: hazard ratio (HR) [95% confidence interval] per 10 g/l increase 0.88 [0.82;0.94]. MR analyses suggested a potential genetic influence of serum albumin on diabetes in both the UK Biobank and the FinnGen consortium: odds ratios (ORs) [95% confidence interval per 1 g/l increase 0.99 [0.98;1.00] and 0.78 [0.67;0.92], respectively. In patients with diabetes, higher serum albumin levels were significantly associated with lower risk for diabetic microvascular complications. Specifically, per 10 g/l increase in serum albumin, the HRs for diabetic nephropathy, ophthalmopathy, and neuropathy were 0.42 [0.30;0.58], 0.61 [0.52;0.72], and 0.67 [0.51;0.88], respectively.

CONCLUSION

In this large prospective study, serum levels of albumin were inversely associated with the incidences of diabetes and diabetic microvascular complications. These findings underscore the importance of maintaining optimal nutrient status in reducing the risk of diabetes and its complications.

Prevalence and influence of hypouricemia on cardiovascular diseases in patients with rheumatoid arthritis

BACKGROUND

Serum uric acid (SUA) acts as an antioxidant and abnormally low SUA may raise the risk of developing atherosclerotic disorders. There is a U-shaped association between SUA with cardiovascular diseases (CVDs) in general population. However, the prevalence of hypouricemia and its influence on CVDs in rheumatoid arthritis (RA) remains unclear.

METHODS

This cross-sectional study collected clinical data from a Chinese RA cohort. Hypouricemia was defined as SUA ≤ 3.0 mg/dL, and hyperuricemia was defined as SUA ≥ 7.0 mg/dL. CVDs were defined as a history of angina pectoris, myocardial infarction, heart failure, stroke and peripheral arterial disease. Restricted cubic spline regression and logistic regression analysis were conducted to evaluate the associations between SUA levels and CVDs.

RESULTS

Among 1130 RA patients recruited, the mean age was 53.2 years and 79.0% were female. The prevalence of hypouricemia and hyperuricemia were 10.6% and 12.0%, respectively. RA patients with hyperuricemia had a higher rate of CVDs than normouricemic patients (27.9% vs. 7.1%, P < 0.05). Surprisingly, RA patients with hypouricemia also had a higher rate of CVDs (20.7% vs. 7.1%, P < 0.05) even without higher traditional cardiovascular risk factors. A U-shaped association between SUA levels and total CVDs was found (P_non-linear < 0.001). Multivariate logistic regression analysis revealed that compared with normouricemia, both hypouricemia [adjusted OR (AOR) = 4.707, 95% CI 2.570-8.620] and hyperuricemia (AOR = 3.707, 95% CI 2.174-6.321) were associated with higher risk of CVDs.

CONCLUSIONS

Hypouricemia may be a potential risk factor of CVDs in RA patients.

Potential ferroptosis key genes in calcific aortic valve disease

Calcific aortic valve disease (CAVD) is a highly prevalent condition that comprises a disease continuum, ranging from microscopic changes to profound fibro-calcific leaflet remodeling, culminating in aortic stenosis, heart failure, and ultimately premature death. Ferroptosis has been hypothesized to contribute to the pathogenesis of CAVD. We aimed to study the association between ferroptosis genes and CAVD and reveal the potential roles of ferroptosis in CAVD. CAVD-related differentially expressed genes (DEGs) were identified via bioinformatic analysis of Datasets GSE51472 and GSE12644 obtained from Gene Expression Omnibus. A ferroptosis dataset containing 259 genes was obtained from the Ferroptosis Database. We then intersected with CAVD-related DEGs to identify the ferroptosis DEGs. Subsequently, protein–protein interaction networks and functional enrichment analyses were performed for ferroptosis DEGs. Then, we used miRWalk3.0 to predict the target pivotal microRNAs. An in vitro model of CAVD was constructed using human aortic valve interstitial cells. The qRT-PCR and western blotting methods were used to validate the ferroptosis DEGs identified by the microarray data. A total of 21 ferroptosis DEGs in CAVD containing 12 upregulated and nine downregulated genes were identified. The results of the Gene Set Enrichment Analysis (GSEA) and analysis of the KEGG pathway by WebGestalt indicated that the ferroptosis DEGs were enriched in six signaling pathways among which NAFLD (including IL-6, BID, and PRKAA2 genes) and HIF-1 (including IL-6, HIF-1, and HMOX1 genes) signaling pathways were also verified by DAVID and/or Metascape. Finally, the in vitro results showed that the mRNA and protein expression levels of IL-6, HIF-1α, HMOX1, and BID were higher, while the levels of PRKAA2 were lower in the Pi-treated group than those in the control group. However, the addition of ferrostatin-1 (a selective ferroptosis inhibitor) significantly reversed the above changes. Therefore, IL-6, HIF-1α, HMOX1, BID, and PRKAA2 are potential key genes closely associated with ferroptosis in CAVD. Further work is required to explore the underlying ferroptosis-related molecular mechanisms and provide possible therapeutic targets for CAVD.

Clinical application of parathyroid autotransplantation in endoscopic radical resection of thyroid carcinoma

Purpose

This study aimed to examine the effect of selective inferior parathyroid gland autotransplantation on central lymph node dissection(CLND) and incidence of postoperative hypoparathyroidism in patients undergoing endoscopic radical resection of thyroid carcinoma.

Methods

The data of 310 patients undergoing endoscopic radical resection of thyroid carcinoma will be retrospectively analyzed. The patients will be divided into the experimental group and the control group according to whether they combined with parathyroid autotransplantation. Statistics of the incidence rate of postoperative hypoparathyroidism, the concentration of PTH and Calcium in the systemic circulation at different time points in the two groups, the concentration of PTH in the cubital fossa vein in the transplantation region in the experimental group, and the number of central lymph nodes and positive lymph nodes dissection will be carried out.

Results

The incidence rate of temporary and permanent hypoparathyroidism in the experimental group was 33.75% and 0.625%, respectively, and in the control group was 22% and 5%, respectively; its difference was statistically significant (X^{2 =} 10.255, P=0.006). Parathyroid autotransplantation increased incidence of transient hypoparathyroidism (OR, 1.806; Cl, 1.088-2.998; P=0.022), and lower incidence of permanent hypoparathyroidism (OR, 0.112; Cl, 0.014-0.904; P=0.040). The diameters of thyroid cancer nodules was not associated with the occurrence of transient hypoparathyroidism (OR, 0.769; Cl, 0.467-1.265; P=0.301) or permanent hypoparathyroidism (OR, 1.434; Cl, 0.316-6.515; P=0.641). Comparison of systemic circulation PTH, between the two groups showed that the PTH of patients in the experimental group was higher than that in the control group from 1 week to 12 months after the operation, and the difference was statistically significant (P<0.05). In the experimental group, from 1 week to 12 months after surgery, PTH concentrations was significantly higher in the cubital fossa of the transplantation side than in the contralateral side, and the differences were statistically significant (P<0.05). The mean number of central lymph node dissected per patient was significantly higher in the experimental group (7.94 ± 3.03 vs. 6.99 ± 2.86; P <0.05); The mean number of positive nodes per patient was significantly higher in the experimental group (3.16 ± 1.86 vs. 2.53 ± 1.59; P <0.05).

Conclusions

In endoscopic radical resection of thyroid carcinoma, parathyroid autotransplantation is more beneficial to postoperative parathyroid glands function recovery, effectively preventing postoperative permanent hypoparathyroidism and realizing more thorough CLND.

Remnant Cholesterol and the Risk of Coronary Artery Calcium Progression: Insights From the CARDIA and MESA Study

BACKGROUND:

Remnant cholesterol (RC) contributes to residual risk of atherosclerotic cardiovascular disease, but population-based evidence on the prospective relationship between RC and coronary artery calcium (CAC) progression is rare.

METHODS:

We pooled data obtained from 6544 atherosclerotic cardiovascular disease–free individuals from the CARDIA study (Coronary Artery Risk Development in Young Adults; n=2635) and MESA (Multi-Ethnic Study of Atherosclerosis; n=3909), with a mean±SD age of 47.2±19.8 years; 3019 (46.1%) were men who completed computed tomography of CAC at baseline. RC was measured as total cholesterol minus HDL (high-density lipoprotein) cholesterol minus calculated LDL (low-density lipoprotein) cholesterol (LDL-C) estimated by using the Martin/Hopkins equation. Adjusted Cox models were used to assess the relationships between RC levels and CAC progression. We also performed discordance analyses examining the risk of CAC progression in RC versus LDL-C discordant/concordant groups using median cut points and clinically relevant LDL-C targets.

RESULTS:

During a median follow-up of 8.6 years, 2778 (42.5%) participants had CAC progression. After multivariable adjustment for demographics and cardiovascular risk factors, a 1-mg/dL increase in RC levels was associated with a 1.3% higher risk of CAC progression (hazard ratio, 1.013 [95% CI, 1.008–1.017]). Results were similar when we categorized individuals by RC quartiles. Furthermore, the discordant high RC/low LDL-C group had a significantly higher risk of CAC progression than the concordant low RC/LDL-C group regarding their medians (hazard ratio, 1.195 [95% CI, 1.063–1.343]) or when setting the clinical LDL-C cut points at 100 and 130 but not 70 mg/dL. The association remained robust across a series of sensitivity analyses.

CONCLUSIONS:

Elevated RC levels were associated with an increased risk of CAC progression independent of traditional cardiovascular risk factors, even in individuals with optimal LDL-C levels.

REGISTRATION:

URL: https://www.clinicaltrials.gov ; Unique identifier: NCT00005130 (CARDIA) and NCT00005487 (MESA).

Association Between Metabolic Dysfunction-Associated Fatty Liver Disease and Cardiovascular Risk in Patients With Rheumatoid Arthritis: A Cross-Sectional Study of Chinese Cohort

Background

The nomenclature from non-alcoholic fatty liver disease (NAFLD) to metabolic dysfunction-associated fatty liver disease (MAFLD) is considered to identify more cardiovascular disease (CVD) risks in the general population. Patients with rheumatoid arthritis (RA) carry an excess risk for CVD. However, the prevalence of MAFLD and its relationship with CVD risks in RA have not been reported.

Methods

This cross-sectional study retrospectively analyzed clinical data from a Chinese RA cohort. MAFLD was diagnosed according to the criteria proposed by an international expert panel from 22 countries in 2020. CVD risk in patients with RA was estimated by the Prediction for Atherosclerotic Cardiovascular Disease Risk in China with a 1.5 multiplication factor.

Results

Among 513 included patients with RA, 78.4% were women and the mean ± SD age was 51.8 ± 12.6 years. The prevalence of MAFLD was 21.4%. There were 10.9% patients with RA concomitated with CVD events and 32.4% with a high-estimated 10-year CVD risk. Besides a higher liver fibrosis score and a higher ratio of advanced fibrosis, RA patients with MAFLD had a higher rate of CVD events (17.3 vs. 9.2%) and a higher proportion of high estimated 10-year CVD risk (55.5 vs. 26.1%) than those without. Multivariate logistic regression analysis showed that MAFLD was associated with an increase in CVD events [adjusted odds ratio (AOR) = 2.190, 95% CI 1.135–4.227] and high estimated 10-year CVD risk (AOR = 2.483, 95% CI 1.412–4.365, all p < 0.05).

Conclusion

Metabolic dysfunction-associated fatty liver disease was associated with increased CVD risk in patients with RA, which implies the importance of early detection and management of MAFLD in patients with RA.

Different Metabolic Phenotypes of Obesity and Risk of Coronary Artery Calcium Progression and Incident Cardiovascular Disease Events: The CARDIA Study

BACKGROUND

To investigate whether obesity with or without metabolic syndrome is prospectively associated with coronary artery calcium (CAC) progression and incident cardiovascular disease events.

METHODS

A total of 1730 participants from the CARDIA study (Coronary Artery Risk Development in Young Adults) were included (age, 40.1±3.6 years; 38.3% men), who completed computed tomography of CAC at baseline (year 15: 2000-2001) and follow-up (year 20 or 25). Metabolically healthy obesity (MHO) was defined as body mass index≥30 kg/m² without any metabolic syndrome components in our main analysis. Sensitivity analyses were conducted for several conditions characterizing 4 metabolic phenotypes.

RESULTS

During a mean follow-up of 9.1 years, 439 participants had CAC progression. MHO subjects had a significantly higher risk of CAC progression than their metabolically healthy normal weight counterparts (adjusted hazard ratios [95% CIs] from 1.761 [1.369-2.264] to 2.047 [1.380-3.036]) depending on the definition of MHO adopted. Obesity with unhealthy metabolic profile remained the highest significant risk of CAC progression and cardiovascular disease events whatever the definitions adopted for metabolically unhealthy status. Up to 60% of participants with MHO converted to metabolically unhealthy obesity from year 15 to year 20 or year 25. Further sensitivity analysis showed that MHO throughout carried a similar risk of incident cardiovascular disease events compared with metabolically healthy normal weight throughout.

CONCLUSIONS

Different metabolic phenotypes of obesity beginning at a young age exhibit distinct risks of CAC progression and subsequent cardiovascular disease events in later midlife. MHO represents an intermediate phenotype between metabolically low- to high-risk obese individuals.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT00005130.

Associations of long-term physical activity trajectories with coronary artery calcium progression and cardiovascular disease events: results from the CARDIA study

OBJECTIVE

The study aimed to assess the associations of physical activity (PA) trajectories across a 25-year span with coronary artery calcium (CAC) progression, and subsequent risk of cardiovascular disease (CVD) events.

METHODS

We included 2497 participants from the Coronary Artery Disease Risk Development in Young Adults study who had computed tomography-assessment of CAC at baseline (year 15: 2000-2001) and follow-up (year 20 or 25) and at least three measures of PA from year 0 to year 25. Long-term PA trajectories were determined by latent class modelling using a validated questionnaire.

RESULTS

Among the included participants, 1120 (44.9%) were men, 1418 (56.8%) were white, and the mean (SD) age was 40.4 (3.6) years. We identified three distinct PA trajectories based on PA average levels and change patterns: low (below PA guidelines, n=1332; 53.3%); moderate (meeting and slightly over PA guidelines, n=919; 36.8%) and high (about three times PA guidelines or more, n=246; 9.9%). During a mean (SD) follow-up of 8.9 (2.1) years, 640 (25.6%) participants had CAC progression. Participants in the high PA trajectory group had a higher risk of CAC progression than those in the low PA trajectory group after adjustment for traditional cardiovascular risk factors (HR 1.51; 95% CI 1.18 to 1.94). However, high PA trajectory was not associated with an increased risk of incident CVD events (HR 1.01; 95% CI 0.44 to 2.31) and the incidence of CVD events in participants with CAC progression was similar across all three PA trajectory groups (p=0.736).

CONCLUSION

Long-term PA about three times the guidelines or more is independently associated with CAC progression; however, no additional risk of incident CVD events could be detected.

Triglyceride-glucose index in the development of peripheral artery disease: findings from the Atherosclerosis Risk in Communities (ARIC) Study

Background

It remains unclear whether triglyceride-glucose (TyG) index, a surrogate marker of insulin resistance, is prospectively associated with incident peripheral arterial disease (PAD).

Methods

We included 12,320 Atherosclerosis Risk in Communities Study participants (aged 54.3 ± 5.7 years) free of a history of PAD at baseline (visit 1: 1987–1989). The TyG index was determined using ln (fasting triglycerides [mg/dL] × fasting glucose [mg/dL]/2), and measured at 5 visits between 1987 and 2013. Incident PAD was defined as the first hospitalization with PAD diagnosis or a new onset of measured ABI < 0.90 during follow-up visits. We quantified the association of both baseline and trajectories of TyG index with incident PAD using Cox regression and logistic regression analysis, respectively.

Results

Over a median follow-up of 23 years, 1300 participants developed PAD. After adjustment for traditional PAD risk factors, each 1-SD (0.58) increase in TyG index was associated with an 11.9% higher risk of incident PAD [hazard ratio, 1.119 (95% CI, 1.049–1.195)]. Results were similar when individuals were categorized by TyG index quartiles [hazard ratio, 1.239 (95% CI, 1.028–1.492); comparing extreme quartiles]. Four distinct trajectories of stable TyG indexes at various levels along the follow-up duration were identified [low (22.2%), moderate (43.2%), high (27.5%), and very high (7.1%) trajectory groups]. Compared with those with a TyG index trajectory at a low level, those participants with TyG index trajectories at high and very high levels had an even greater risk of future incident PAD [odds ratio (95%CI): 1.404 (1.132–1.740) and 1.742 (1.294–2.344), respectively] after multivariate adjustments for traditional PAD risk factors.

Conclusions

Higher TyG index is independently associated with an increased risk of incident PAD. Long-term trajectories of TyG index help identify individuals at a higher risk of PAD who deserve specific preventive and therapeutic approaches.

Trial registration: Clinical trial registration number: The ARIC trial was registered at clinicaltrials.gov as NCT00005131.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12933-021-01319-1.

Aldosterone enhances high phosphate-induced vascular calcification through inhibition of AMPK-mediated autophagy

It remains unclear whether the necessity of calcified mellitus induced by high inorganic phosphate (Pi) is required and the roles of autophagy plays in aldosterone (Aldo)‐enhanced vascular calcification (VC) and vascular smooth muscle cell (VSMC) osteogenic differentiation. In the present study, we found that Aldo enhanced VC both in vivo and in vitro only in the presence of high Pi, alongside with increased expression of VSMC osteogenic proteins (BMP2, Runx2 and OCN) and decreased expression of VSMC contractile proteins (α‐SMA, SM22α and smoothelin). However, these effects were blocked by mineralocorticoid receptor inhibitor, spironolactone. In addition, the stimulatory effects of Aldo on VSMC calcification were further accelerated by the autophagy inhibitor, 3‐MA, and were counteracted by the autophagy inducer, rapamycin. Moreover, inhibiting adenosine monophosphate‐activated protein kinase (AMPK) by Compound C attenuated Aldo/MR‐enhanced VC. These results suggested that Aldo facilitates high Pi‐induced VSMC osteogenic phenotypic switch and calcification through MR‐mediated signalling pathways that involve AMPK‐dependent autophagy, which provided new insights into Aldo excess‐associated VC in various settings.

Pauli Shielding and Breakdown of Spin Statistics in Multielectron Multi-Open-Shell Dynamical Atomic Systems

We report on C^{3+}(1s2ℓ2ℓ^{'} ^{2S+1}L)-resolved cross sections of electron capture in collisions of swift C^{4+}(1s2s ^{3}S) ions with helium and hydrogen. The study focuses on the formation of doubly excited triply open-shell C^{3+}(1s2s2p) ^{4}P and ^{2}P_{±} states with emphasis on the ratio R of their cross sections as a measure of spin statistics. Using zero-degree Auger projectile spectroscopy and a three-electron close-coupling semiclassical approach, we resolve a long-standing puzzle and controversy on the value of R and on the effect of cascades, to clarify the underlying physics. The present results invalidate the frozen core approximation generally used in the past when considering electron capture in multielectron multi-open-shell quantum systems. A distinctive screening effect due to the Pauli exclusion principle (Pauli shielding) is proposed to account for the value of R, consistent with our findings.

Associations Between Metabolic Profiles and Target-Organ Damage in Chinese Individuals With Primary Aldosteronism

Purpose: Patients with primary aldosteronism (PA) have an increased risk of target-organ damage (TOD), but whether metabolic syndrome (MetS) is more prevalent and contributes to TOD in PA patients remains unresolved. We aimed to evaluate the associations between MetS profiles and TOD in Chinese PA individuals. Methods: Metabolic parameters and pre-clinical TOD including left ventricular hypertrophy, estimated glomerular filtration, and microalbuminuria; insulin sensitivity or resistance; and islet β-cell function were assessed by the homeostasis models (HOMA-IR, HOMA-β) and the other surrogate indexes [composite insulin sensitivity index (ISI), modified β-cell function index (MBCI)] determined from the oral glucose tolerance test were compared in PA vs. matched essential hypertension (EH) patients. Results: A total of 109 PA patients and 109 essential hypertension (EH) controls individually matched for sex, age, and office systolic blood pressure and duration of hypertension were studied. The prevalence of MetS and its individual components in PA was significantly lower than in EH [MetS: 28 (25.6%) vs. 54 (49.5%), P < 0.001]. PA patients had a higher composite ISI but a lower HOMA-IR, HOMA-β, and MBCI than EH controls (all P < 0.05). Concerning TOD, PA patients had significantly higher prevalence of microalbuminuria and left ventricular hypertrophy (LVH), and lower levels of estimated glomerular filtration (eGFR) than EH controls (all P < 0.05). On multivariate logistic regression analysis, female gender and elevated plasma aldosterone levels were significantly associated with TOD in PA. However, there were no significant associations between MetS and its individual components and TOD in PA patients. Conclusions: PA patients had a lower MetS prevalence but exhibited more severe TOD than matched EH controls. The study highlights the deleterious effects of aldosterone excess on the development of TOD, whereas MetS or its individual components might be less influential in PA.

Evaluation and Countermeasures of the Implementation of Forensic Clinical Identification Standards Based on the Perspective of Accreditation

Abstract

The new Standardization Law, implemented in 2018, has added a standard post-implementation evaluation system, aiming to continuously improve the quality of standards through post-implementation evaluation. Standards in the forensic science field are closely related to accreditation activities. Forensic science standards are not only the criteria on which accreditation activities are carried out, but also one of the key contents of the inspection of forensic science institutions in accreditation activities. Since 2018, the certification and accreditation policies in the forensic science field have also been changed, which has brought impacts on the construction of a standard system based on accreditation.This paper analyzes the standard data from China National Accreditation Center from Conformity Assessment on forensic clinical identification accreditation assessment. It points out that the current coverage of laboratory accreditation activities is limited, the development in different provinces is unbalanced, and there is overlap and crossover in the standards in use. It is emphasized that the construction of the national forensic science standardization technical committee, the improvement of the forensic science standard system, the establishment of the standard implementation evaluation index system, and promotion of the coordination of standards, and the certifications and accreditations should be accelerated, in order to continue to promote the standardization and accreditation activities in the field of forensic science.

Double Electron Capture in H^{+}+H^{-} Collisions

We have investigated the double electron capture process in the H^{+}+H^{-} collision system for energies from 60 eV to 20 keV. Despite the apparent simplicity of this highly correlated system, all previous calculations fail to reproduce the experimental total cross sections. Moreover, the latter exhibit oscillations that have been previously attributed to quantum interferences between the gerade and ungerade ionic states of the transient molecule formed during the collision. For this process, we present the absolute cross sections obtained from a fully correlated two-active-electron semiclassical atomic-orbital close-coupling approach. Our results reproduce well the experimental data in both magnitude and shape. Furthermore, we demonstrate that the oscillations stem from coherence effects between double electron capture and other two-electron inelastic channels, namely the transfer-excitation processes. This alternative interpretation is supported by a Rosenthal-like model based on a molecular treatment of the collision. Our results shed new light on this old but challenging problem.

Differentiation of human umbilical cord Wharton's jelly-derived mesenchymal stem cells into endometrial cells

BACKGROUND

Wharton's jelly-derived mesenchymal stem cells (WJ-MSCs) are a novel and promising strategy for tissue engineering because of their ability to differentiate into many cell types. We characterized the differentiation of WJ-MSCs into endometrial epithelial cell (EEC)-like and endometrial stromal cell (ESC)-like cells and assessed the effect of 17β-estradiol and 8-Br-cAMP on the differentiation system.

METHODS

WJ-MSCs were treated in two ways to differentiate into EEC-like and ESC-like cells respectively: cocultured with ESCs in control/differentiation medium (17β-estradiol, growth factors); and cultured in control/differentiation medium (8-Br-cAMP alone or 8-Br-cAMP plus 17β-estrogen and growth factors). Three signaling pathway inhibitors (SB203580, PD98059, H89) were used to investigate the mechanism of WJ-MSC differentiation into ESC-like cells. Immunofluorescence, western blot and flow cytometry analyses were used to analyze expression of epithelial markers and stromal cell markers. Enzyme-linked immunosorbent assays were used to test the production of secretory proteins associated with the differentiation of ESC-like cells.

RESULTS

17β-estradiol at 1 μM downregulated vimentin and CD13 and upregulated cytokeratin and CD9 proteins, promoting the differentiation of WJ-MSCs into EEC-like cells in the coculture system. 8-Br-cAMP at 0.5 mM upregulated vimentin and CD13 and downregulated CK and CD9, promoting the differentiation of WJ-MSCs into ESC-like cells. Prolactin (PRL) and insulin-like growth factor-binding protein 1 (IGFBP1) were upregulated and the protein kinase A (PKA) signaling pathway was activated, whereas extracellular signal-regulated (ERK)1/2 and p38 mitogen-activated protein kinase (MAPK) were not affected.

CONCLUSIONS

17β-estradiol at 1 μM is a good inducer for facilitating the differentiation of WJ-MSCs into EEC-like cells. 8-Br-cAMP plus estrogen and growth factors can induce the differentiation of WJ-MSCs into ESC-like cells. During the differentiation of WJ-MSCs into ESC-like cells, PRL and IGFBP1 were upregulated by the treatment and the PKA signaling pathway was activated, whereas ERK1/2 and p38 MAPK were not affected. These findings suggest a promising approach to the treatment of endometrial damage and other endometrial diseases and suggest new applications for WJ-MSCs in clinical practice.

Serum matrix metalloproteinases-3 levels in patients with ankylosing spondylitis

Cumulated evidence indicates that matrix metalloproteinase-3 (MMP-3) is significantly involved in cancer progression. Recent studies yielded conflicting results regarding the association between serum MMP-3 and ankylosing spondylitis (AS). To clarify this correlation, we performed a meta-analysis. Potential relevant studies were identified by searching the following databases: PubMed, Embase, CINAHL, Science Citation Index database, the Cochrane Library, Current Contents Index, Chinese Biomedical, the Chinese Journal Full-Text, and the Weipu Journal. Data from eligible studies were extracted and included into the meta-analysis using a random-effect model. Standardized mean differences (SMDs) and 95% confidence intervals (CIs) were used to assess the association between serum MMP-3 levels and AS. Thirteen case-control studies, including 707 AS cases and 442 healthy controls, were selected for the meta-analysis. The results indicate a significantly higher serum MMP-3 level in patients with AS than that in the controls (cases vs controls: SMD = 1.31, 95%CI = 0.84-1.78, P < 0.001). Ethnicity-subgroup analysis indicated a higher MMP-3 level in Asian and Caucasian patients with AS (all P < 0.05). This meta-analysis indicates that increased serum MMP-3 level correlates with the development of AS, suggesting that MMP-3 may present a clinical value in reflecting the progression of AS. Further larger sample size studies are warranted.

[Effect of hypobaric hypoxia exposure on memory and tau phosphorylation in brain of mice]

OBJECTIVE

To investigate the effect of hypobaric hypoxia (HH)on the cognitive function of mice and the phosphorylation of tau protein in mice brain.

METHODS

Forty male mice were randomly divided into 4 groups (n = 10): static control (control) group, 8 hours (8 h) group, 7 days(7 d) group and 28 days(28 d) group, which were exposed to simulated HH equivalent to 5 500 m in an animal decompression chamber for 0 hour, 8 hours, 7 days and 28 days, respectively. Cognitive performances were examined by open field and passive avoidance test, tan phosphorylation was assayed by Western blot.

RESULTS

In open field test,the group exposed in hypobaric hypoxia for 28 d showed lower mean velocity (P < 0.05), time in central zone (P < 0.05) was longer than control group. In passive avoidance test 28 d group presented worse performance in both latency time and number of mistakes (P < 0.05) compared with control group. Western blot showed that phosphorylated tau was increased significantly following exposure to HH for 7 d in cortex and 28 d in hippocampus (P < 0.05).

CONCLUSION

Tau hyperphosphorylation in brain of mice may play a role in chronic HH-induced cognitive function impairment.

Room temperature electrical and thermal switching CNT/hexadecane composites

A large contrast in the electrical and thermal conductivities via a first order phase transition in surface-functionalized carbon nanotube(CNT)/hexadecane composites is reported. Surface modification of the CNTs improves the electrical conductivity contrast and the stability of the composites. We demonstrate that, with these composites, the electrical conductivity changes above 10(5) times and the thermal conductivity varies up to 3 times at 18 °C.

Experimental investigation of heat conduction mechanisms in nanofluids. Clue on clustering

Heat conduction mechanisms in nanofluids, fluids seeded with nanoparticles, have been extensively scrutinized in the past decades to explain some experimental observations of their enhanced thermal conductivity beyond the effective medium theory. Although many mechanisms such as Brownian motion, clustering, ballistic transport, and internanoparticle potential are speculated, experimental proof of any of the mechanisms has been difficult. Here, we investigate the mechanisms experimentally by thermal conductivity measurements and structural analysis for the same materials in both liquid and solid states. These studies strongly suggest that clustering holds the key to the thermal conductivity enhancement of nanofluids.

[Impacts of the hydraulic characteristics of pilot clearwell on chlorine disinfection efficiency]

A pilot clearwell was used to simulate the chlorine disinfection process with the Bacillus subtilis spores as the target microbe. The effluent of the activated carbon filter tank was radiated by low pressure UV lamp and then used as the influent the pilot clearwell. The impacts of hydraulic characteristics of pilot clearwell on disinfection efficiency of Bacillus subtilis spores was studied under different hydraulic characteristics which was changed by the number of the baffles. Under the conditions of this experiment, the inactivation coefficients of Bacillus subtilis spores with NaC10 as disinfectant which were calculated by Ct10 value were almost same under different hydraulic characteristics, but the inactivation coefficients which were calculated by CT value were very different under different hydraulic characteristics. This verified that it was more reasonable to evaluate the disinfection efficiency by Ct10 value than CT value. When Ct10 value was in the range of 100 - 300 mg x min/L, the inactivation coefficient of Bacillus subtilis spores with NaClO as disinfectant was 0.001 6 L(mg x min), which highly coincided with others' results. When CT value was in the range of 100 - 700 mg x min/L, under the same CT value, the disinfection efficiency of target microbe would be notably enhanced by increasing the number of baffles which would improve the hydraulic characteristics. So the results verified that the disinfection efficiency could be enhanced by improving the hydraulic characteristics of the clearwell.

Enhanced recovery of a secreted mammalian protein from suspension culture of genetically modified tobacco cells

Increasing the level of recovery of mammalian proteins secreted by a genetically modified Nicotiana tabacum was explored in suspension culture. As a model protein system, a mouse monoclonal antibody heavy chain gamma (MAb HC) with an antigen specificity for p-azophenylarsonate was used. Consistent with findings for other plant cell suspension culture systems expressing proteins with mammalian leader sequences, the synthesized mouse MAb HC was secreted through the plasma membrane. In addition, the majority of the MAb HC was also secreted through the cell wall into the growth medium. However, efficient recovery of the protein was only possible when the protein stabilizing agent, polyvinylpyrrolidone (PVP) was present in the plant cell growth medium. The presence of PVP increased the recovered concentration of secreted protein 35-fold from 0.010 to 0.36 micrograms protein/ml culture medium. Biological activity of the approximately 50-kDa MAb HC polypeptide was demonstrated by arsonate affinity matrix binding as determined by Western blot analysis. In addition to antigen binding activity, the secreted protein also exhibited reactivity to protein G, a protein which specifically binds mouse IgG. These findings are important because they demonstrate that culture conditions can significantly influence the concentration of a biologically active foreign protein secreted from plant cells into the media of suspension cultures. The ability to increase the efficiency of mammalian protein production in plant suspension culture systems should provide significant advantage over protein production in intact transgenic plants which require cultivation, harvesting, and expensive extraction procedures to obtain nonsecreted foreign proteins.