[Diagnostic value of high frequency oscillation in localization of type Ⅱ focal cortical dysplasia epilepsy]

Retrospective analysis was conducted on 9 patients with type Ⅱ focal cortical dysplasia (FCD) who underwent stereo-electroencephalography (SEEG) implantation in the Department of Neurosurgery of the First Affiliated Hospital of Fujian Medical University from November 2020 to February 2023. The onset area, onset time, and frequency of high-frequency oscillations (HFO) were analyzed and the correlation of HFOs with interictal, preictal, and ictal periods. SEEG recordings of 80-500 Hz HFOs were observed in both interictal and ictal periods in 9 patients, with 6 patients exhibiting fast ripples (FR) in the range of 250-500 Hz. Surgical resection of the seizure onset area and FR-generating electrodes was performed, and postoperative follow-up for over 2 years indicated Engel I in 5 cases. 6 patients showed continuous discharge during the preictal period, and the distribution index of continuous discharge was positively correlated with seizure frequency. HFOs in the range of 80-500 Hz were present in all four seizure onset patterns during the ictal period. The onset area and FR-emitting electrode were surgically removed in 6 patients with continuous discharge and overlapping HFOs during the preictal period, with 5 cases of Engel I. Type Ⅱ FCD discharges exhibited complexity, high discharge indices, and a close association with HFOs. Compared with the spike wave, the electrode range of HF is more limited, and the incidence of HF before attack is significantly increased, which is closely correlated with the onset area. The simultaneous occurrence of HFO and the spike waves has higher diagnostic value than the individual occurrence, effectively enhancing surgical efficacy.

Association between serum urea concentrations and the risk of colorectal cancer, particularly in individuals with type 2 diabetes: A cohort study

Dysregulation of the urea cycle (UC) has been detected in colorectal cancer (CRC). However, the impact of the UC's end product, urea, on CRC development remains unclear. We investigated the association between serum urea and CRC risk based on the data of 348 872 participants cancer-free at recruitment from the UK Biobank. Multivariable Cox proportional hazards models were fitted to conduct risk estimates. Stratification analyses based on sex, diet pattern, metabolic factors (including body mass index [BMI], the estimated glomerular filtration rate [eGFR] and type 2 diabetes [T2D]) and genetic profiles (the polygenic risk score [PRS] of CRC) were conducted to find potential modifiers. During an average of 9.0 years of follow-up, we identified 3408 (1.0%) CRC incident cases. Serum urea showed a nonlinear relationship with CRC risk (P-nonlinear: .035). Lower serum urea levels were associated with a higher CRC risk, with a fully-adjusted hazard ratio (HR) of 1.26 (95% confidence interval [CI]: 1.13-1.41) in the first quartile (Q1) of urea, compared to the Q4. This association was largely consistent across subgroups of sex, protein diet, BMI, eGFR and CRC-PRSs (P-interaction >.05); however, it was stronger in the T2D, with an interaction between urea and T2D on both additive (synergy index: 3.32, [95% CI: 1.24-8.88]) and multiplicative scales (P-interaction: .019). Lower serum urea concentrations were associated with an increased risk of CRC, with a more pronounced effect observed in individuals with T2D. Maintaining stable levels of serum urea has important implications for CRC prevention, particularly in individuals with T2D.

Efficacy and safety of bicyclol for treating patients with antituberculosis drug-induced liver injury

BACKGROUND: Bicyclol was used for treating idiosyncratic acute drug-induced liver injury (DILI) in a phase II trial. This study was aimed at evaluating the efficacy and safety of bicyclol 25 and 50 mg thrice a day (TID) for treating acute DILI caused by anti-TB drugs in the light of the trial results.METHODS: We analysed clinical data of patients with TB drug-induced DILI in the trial database. The primary endpoint was reduction in serum alanine aminotransferase (ALT) levels after 4 weeks of treatment compared to baseline.RESULTS: Overall, 148 patients were included, with respectively 48, 52 and 48 patients included in the control (456 mg polyene phosphatidylcholine TID), high-dose (50 mg bicyclol TID) and low-dose (25 mg bicyclol TID) groups. ALT levels decreased by respectively â-"149.0 (IQR â-"299.3 to â-"98.3 (), â-"225.5 (IQR â-"309.3 to â-"181.8 ) and â-"242.5 (IQR â-"364.8 to â-"153.8) U/L in the control, high-dose and low-dose groups (P < 0.001). The ALT normalisation rates at weeks 1, 2, 4, 6 and 8 were higher in the high- and low-dose groups, while adverse events and serious adverse events were similar across groups.CONCLUSIONS: Bicyclol (25 and 50 mg TID) is effective and safe in treating anti-TB DILI, and bicyclol 50 mg TID showed higher efficacy.

Association Between Bowel Movement Pattern and Cognitive Function: Prospective Cohort Study and a Metagenomic Analysis of the Gut Microbiome

BACKGROUND AND OBJECTIVES

Little is known regarding the association between intestinal motility patterns and cognitive function in individuals who are baseline cognitively healthy. The gut microbiome may contribute to the association. We examined the association between bowel movement (BM) pattern and cognitive function and explored the role of the gut microbiome in explaining this association.

METHODS

In this prospective study, we leveraged 3 cohort studies, Nurses' Health Study (NHS), NHSII, and Health Professionals Follow-Up Study (HPFS). Participants reported BM frequency and subjective cognitive function. In a subset of NHSII participants, we assessed cognitive function using an objective neuropsychological battery. We profiled the gut microbiome in a subset of participants using whole-genome shotgun metagenomics. General linear models, Poisson regression, and logistic regression were used to quantify the association of BM frequency with different cognitive measurements.

RESULTS

We followed 112,753 men and women (women: 87.6%) with a mean age of 67.2 years at baseline (NHS: 76 years, NHSII: 59 years, HPFS: 75 years) for a median follow-up of 4 years (NHSII and HPFS: 4 years, NHS: 2 years). Compared with those with BM once daily, participants with BM frequency every 3+ days had significantly worse objective cognitive function, equivalent to 3.0 (95% confidence interval [CI],1.2-4.7) years of chronological cognitive aging. We observed similar J-shape dose-response relationships of BM frequency with the odds of subjective cognitive decline and the likelihood of having more subsequent subjective cognitive complaints (both p nonlinearity < 0.001). BM frequencies of every 3+ days and ≥twice/day, compared with once daily, were associated with the odds ratios of subjective cognitive decline of 1.73 (95% CI 1.60-1.86) and 1.37 (95% CI 1.33-1.44), respectively. BM frequency and subjective cognitive decline were significantly associated with the overall gut microbiome configuration (both p < 0.005) and specific microbial species in the 515 participants with microbiome data. Butyrate-producing microbial species were depleted in those with less frequent BM and worse cognition, whereas a higher abundance of proinflammatory species was associated with BM frequency of ≥twice/day and worse cognition.

DISCUSSION

Lower BM frequency was associated with worse cognitive function. The gut microbial dysbiosis may be a mechanistic link underlying the association.

Exposure to Multiple Air Pollutants and the Risk of Fractures: A Large Prospective Population-Based Study

Atmospheric chemistry studies suggest air pollution impedes ultraviolet B photons and thus reduces cutaneous vitamin D3 synthesis. Biological evidence shows that inhaled pollutants disrupt circulating 25-hydroxyvitamin D (25[OH]D) metabolism and ultimately impact bone health. The hypothesis is that higher air pollution concentrations are associated with a higher risk of fractures, mediated by lower circulating 25(OH)D. The study included participants of the UK Biobank who were free of fracture history at enrollment (2006 to 2010) and analyzed their environmental exposure data (2007 to 2010). Air pollution measurements included the annual averages of air particulate matter (PM2.5 , PM2.5-10 , and PM10 ), nitrogen oxides (NO2 and NOx ), and a composite air pollution score. Multivariable Cox proportional hazard models were used to assess the associations of the individual pollutants and the score with fracture risks. Mediation analyses were conducted to assess the underlying role of serum 25(OH)D in such associations. Among 446,395 participants with a median of 8-year follow-up, 12,288 incident fractures were documented. Participants living in places with the highest quintile of air pollution score had a 15.3% increased risk of fractures (hazard ratio [95%CI]: 1.15[1.09,1.22]) compared to those in the lowest, and 5.49% of this association was mediated through serum 25(OH)D (pmediation  < 0.05). Pollutant-specific hazard of top-to-bottom quintiles was 16% for PM2.5 , 4% for PM2.5-10 , 5% for PM10 , 20% for NO2 , and 17% for NOx , with a 4% to 6% mediation effect of serum 25(OH)D concentrations. The associations of the air pollution score with fracture risks were weaker among female participants, those who drank less alcohol, and consumed more fresh fruit than their counterparts (pinteraction  < 0.05). © 2023 American Society for Bone and Mineral Research (ASBMR).

Gut Microbiome Alterations in Pulmonary Hypertension in Highlanders and Lowlanders

Background

Alterations in the gut microbiota have been observed in patients with pulmonary hypertension (PH), though whether the roles of the gut microbiota in PH at different altitudes are the same is unknown. This study aims to evaluate the associations of the gut microbiome with PH in the highlanders and lowlanders.

Methods

PH patients and controls were recruited from those who permanently live on the Tibetan plateau (highlanders) or the plains (lowlanders), and underwent transthoracic echocardiography close to their altitude of residence (at 5070 m for highlandersversus6 m for lowlanders). The gut microbiome was profiled using metagenomic shotgun sequencing.

Results

In total, 13 PH patients (46% highlanders) and 88 controls (70% highlanders) were included. The overall microbial composition was different in PH patients compared to controls (p=0.003). Notably, among lowlanders, a composite microbial score of pro-atherosclerotic trimethylamine-producing species was increased in PH patients compared with that in controls (p=0.028), while among highlanders no such difference was observed (p=0.087). Another composite gut microbial score including eight species ofLactobacillus, which has shown beneficial effects on cardiovascular functions, was higher in highlanders than lowlanders (p<0.01). Furthermore, this score tended to be lower in PH patients than controls among highlanders (p=0.056) but not among lowlanders (p=0.840). In addition, the gut microbiome showed a good performance in distinguishing PH patients from controls in both lowlanders and highlanders.

Conclusions

Our study reported differently altered gut microbiome profiles between highland and lowland PH patients, highlighting the distinct microbial mechanism in PH between highlanders and lowlanders.

Gut microbiota and plasma metabolites associated with bone mineral density in women with or at risk of HIV infection

OBJECTIVE

To evaluate gut microbiota (GMB) alterations and metabolite profile perturbations associated with bone mineral density (BMD) in the context of HIV infection.

DESIGN

Cross-sectional studies of 58 women with chronic HIV infection receiving antiretroviral therapy and 33 women without HIV infection.

METHODS

We examined associations of GMB and metabolites with BMD among 91 women. BMD was measured by dual-energy X-ray absorptiometry (DXA), and T -scores of lumbar spine or total hip less than -1 defined low BMD. GMB was measured by 16S rRNA V4 region sequencing on fecal samples, and plasma metabolites were measured by liquid chromatography-tandem mass spectrometry. Associations of GMB with plasma metabolites were assessed in a larger sample (418 women; 280 HIV+ and 138 HIV-).

RESULTS

Relative abundances of five predominant bacterial genera ( Dorea , Megasphaera , unclassified Lachnospiraceae, Ruminococcus , and Mitsuokella ) were higher in women with low BMD compared with those with normal BMD (all linear discriminant analysis (LDA) scores >2.0). A distinct plasma metabolite profile was identified in women with low BMD, featuring lower levels of several metabolites belonging to amino acids, carnitines, caffeine, fatty acids, pyridines, and retinoids, compared with those with normal BMD. BMD-associated bacterial genera, especially Megasphaera , were inversely associated with several BMD-related metabolites (e.g. 4-pyridoxic acid, C4 carnitine, creatinine, and dimethylglycine). The inverse association of Megasphaera with dimethylglycine was more pronounced in women with HIV infection compared with those without HIV infection ( P for interaction = 0.016).

CONCLUSION

Among women with and at risk of HIV infection, we identified altered GMB and plasma metabolite profiles associated with low BMD.

The causal associations of circulating amino acids with blood pressure: a Mendelian randomization study

BACKGROUND

Circulating levels of amino acids were associated with blood pressure (BP) in observational studies. However, the causation of such associations has been hypothesized but is difficult to prove in human studies. Here, we aimed to use two-sample Mendelian randomization analyses to evaluate the potential causal associations of circulating levels of amino acids with BP and risk of hypertension.

METHODS

We generated genetic instruments for circulating levels of nine amino acids by conducting meta-analyses of genome-wide association study (GWAS) in UK Biobank participants with metabolomic data (n = 98,317) and another published metabolomics GWAS (n = 24,925). Data on the associations of the genetic variants with BP and hypertension were obtained in the UK Biobank participants without metabolomic data (n = 286,390). The causal effects were estimated using inverse-variance weighted method.

RESULTS

Significant evidence consistently supported the causal effects of increased branched-chain amino acids (BCAAs, i.e., leucine, isoleucine, and valine) levels on higher BP and risk of hypertension (all P < 0.006 after Bonferroni correction except for P_{leucine-on-diastolicBP} = 0.008). For example, per standard deviation higher of genetically predicted isoleucine levels were associated with 2.71 ± 0.78 mmHg higher systolic BP and 1.24 ± 0.34 mmHg higher diastolic BP, as well as with 7% higher risk of hypertension (odds ratio: 1.07, [95% CI: 1.04-1.10]). In addition, per standard deviation higher of genetically predicted glycine level was associated with lower systolic BP (- 0.70 ± 0.17 mmHg, P = 4.04 × 10^-5) and a lower risk of hypertension (0.99 [0.98-0.99], P = 6.46 × 10^-5). In the reverse direction, genetically predicted higher systolic BP was associated with lower circulating levels of glycine (- 0.025±0.008, P = 0.001).

CONCLUSIONS

This study provides evidence for causal impacts of genetically predicted circulating BCAAs and glycine levels on BP. Meanwhile, genetically predicted higher BP was associated with lower glycine levels. Further investigations are warranted to clarify the underlying mechanisms.

Associations of visceral adipose tissue with bone mineral density and fracture: observational and Mendelian randomization studies

BACKGROUND

The associations between visceral adipose tissue (VAT) and bone mineral density (BMD) or fracture have been controversial and the causality of the associations remains to be assessed. This study aimed to explore the associations of VAT^ (predicted value of VAT mass) with BMD and fracture risk in men and women, and to examine their potential causation by two-sample Mendelian randomization (MR) analyses.

METHODS

UK Biobank is a large, population-based prospective cohort study that recruited more than 500,000 participants aged 40-69 in the United Kingdom from 2006 to 2010. In this study, we used a validated and reliable prediction model to estimate the VAT amount of the participants. On this basis, linear and nonlinear multivariable statistical models were used to explore the association of VAT^ with BMD and fracture risk in different groups of sex and BMI. In observational analyses, the multivariable linear regression model and Cox proportional-hazards model were used to assess VAT^ association with BMD and fracture risk, respectively. Inverse variance weighting was used as the main result of MR analysis.

RESULTS

In 190,836 men, an inverted U-shaped association was observed between VAT^ and heel BMD (P for nonlinearity < 0.001), with a turning point of VAT^ = 1.25 kg. Per kg increase in VAT^ was associated with a 0.13 standard deviation (SD) increase in heel BMD (P = 1.5 × 10^-16) among men with lower amounts of VAT^, and associated with a 0.05 SD decrease in heel BMD (P = 1.3 × 10^-15) among men with higher amounts of VAT^. In 193,592 women, per kg increase in VAT^ was monotonically associated with a 0.16 SD increase in heel BMD (P = 1.2 × 10^-136, P for VAT^-sex interaction = 8.4 × 10^-51). During a median follow-up of 8.2 years, VAT^ was associated with lower risks of hip fractures in the overall men and women (P for VAT^-sex interaction = 1.9 × 10^-4 for total fractures; 1.5 × 10^-4 for other fractures). There were significant interactions of VAT^ and BMI on heel BMD and fracture risks in men only (P for VAT^-BMI interaction = 5.9 × 10^-31 for heel BMD; 2.7 × 10^-4 for total fractures; 5.7 × 10^-3 for hip fractures; 6.8 × 10^-3 for other fractures). In two-sample MR analyses, evidence of causality was not observed between VAT^ and DXA-derived BMD or fractures.

CONCLUSIONS

These novel findings demonstrated gender-dependent associations of VAT^ with BMD and fracture risk, with the association in men being modified by adiposity. Evidence of causality was not observed, suggesting that the observational association of VAT^ with BMD and fracture risk could be the result of confounding.

Identification of SCAR markers for genetic authentication of Dendrobium nobile Lindl

Dendrobium nobile Lindl. is an orcid plant with important medicinal values. This is a colourful houseplant, and also a popular herb in traditional Chinese medicine (TCM). The variants of this plant from different geographic regions might be high, and in this study, we aimed to develop specific sequence characterized amplified region (SCAR) markers for the identification of specific variant of this plant. Different cultivars of D. nobile were collected from nine different places of China, and one cultivar from Myanmar. DNA materials were extracted from the plant samples, random amplified polymorphic DNA (RAPD) were developed, cloned and sequenced for the development of SCAR markers. We have developed four SCAR markers, which are specific to the cultivar from Luzhou China, and clearly distinguishable (genetically) from other cultivars. These SCAR markers are deposited in GenBank (accession number MZ417502, MZ484089, MZ417504 and MZ417505). Four SCAR markers for D. nobile are effective molecular technique to genetically identify the different cultivars or species, and this method is applicable for genetic characterization and identification of other plant species too.

Gut microbiome alterations and gut barrier dysfunction are associated with host immune homeostasis in COVID-19 patients

BACKGROUND

COVID-19 is an infectious disease characterized by multiple respiratory and extrapulmonary manifestations, including gastrointestinal symptoms. Although recent studies have linked gut microbiota to infectious diseases such as influenza, little is known about the role of the gut microbiota in COVID-19 pathophysiology.

METHODS

To better understand the host-gut microbiota interactions in COVID-19, we characterized the gut microbial community and gut barrier function using metagenomic and metaproteomic approaches in 63 COVID-19 patients and 8 non-infected controls. Both immunohematological parameters and transcriptional profiles were measured to reflect the immune response in COVID-19 patients.

RESULTS

Altered gut microbial composition was observed in COVID-19 patients, which was characterized by decreased commensal species and increased opportunistic pathogenic species. Severe illness was associated with higher abundance of four microbial species (i.e., Burkholderia contaminans, Bacteroides nordii, Bifidobacterium longum, and Blautia sp. CAG 257), six microbial pathways (e.g., glycolysis and fermentation), and 10 virulence genes. These severity-related microbial features were further associated with host immune response. For example, the abundance of Bu. contaminans was associated with higher levels of inflammation biomarkers and lower levels of immune cells. Furthermore, human-origin proteins identified from both blood and fecal samples suggested gut barrier dysfunction in COVID-19 patients. The circulating levels of lipopolysaccharide-binding protein increased in patients with severe illness and were associated with circulating inflammation biomarkers and immune cells. Besides, proteins of disease-related bacteria (e.g., B. longum) were detectable in blood samples from patients.

CONCLUSIONS

Our results suggest that the dysbiosis of the gut microbiome and the dysfunction of the gut barrier might play a role in the pathophysiology of COVID-19 by affecting host immune homeostasis.

The gut microbiome and microbial metabolites in acute myocardial infarction

Emerging evidence has highlighted the role of the gut microbiome in human health. However, the integrative role of the gut microbiome and microbial metabolites in acute myocardial infarction (AMI) remains unclear. The current study profiled the microbial community through 16S rRNA gene sequencing and shotgun metagenomic sequencing, and measured fecal short-chain fatty acids and circulating choline pathway metabolites among 117 new-onset AMI cases and 78 controls. Significant microbial alternations were observed in AMI patients compared with controls (P = 0.001). The abundances of nine species (e.g., Streptococcus salivarius, Klebsiella pneumoniae) were positively associated, and one species (Roseburia hominis) was inversely associated with AMI status and severity. A gut microbial score at disease onset was associated with the risk of major adverse cardiovascular events in 3.2 years (hazard ratio [95% CI]: 2.01 [1.04-4.24]) in AMI patients. The molar proportions of fecal acetate and butyrate were higher, and the circulating levels of choline and carnitine were lower in AMI patients than in controls. In addition, disease classifiers showed that AMI cases and controls had a more distinct pattern in taxonomical composition than in pathways or metabolites. Our findings suggested that microbial composition and functional potentials were associated with AMI status and severity.

A Predictive Model Based on a New CI-AKI Definition to Predict Contrast Induced Nephropathy in Patients With Coronary Artery Disease With Relatively Normal Renal Function

Background: Contrast induced nephropathy (CIN) is a common complication in patients receiving intravascular contrast media. In 2020, the American College of Radiology and the National Kidney Foundation issued a new contrast induced acute kidney injury (CI-AKI) criteria. Therefore, we aimed to explore the potential risk factors for CIN under the new criteria, and develop a predictive model for patients with coronary artery disease (CAD) with relatively normal renal function (NRF).

Methods: Patients undergoing coronary angiography or percutaneous coronary intervention at Zhongshan Hospital, Fudan University between May 2019 and April 2020 were consecutively enrolled. Eligible candidates were selected for statistical analysis. Univariate and multivariate logistic regression analyses were used to identify the predictive factors. A stepwise method and a machine learning (ML) method were used to construct a model based on the Akaike information criterion. The performance of our model was evaluated using the area under the receiver operating characteristic curves (AUC) and calibration curves. The model was further simplified into a risk score.

Results: A total of 2,009 patients with complete information were included in the final statistical analysis. The results showed that the incidence of CIN was 3.2 and 1.2% under the old and new criteria, respectively. Three independent predictors were identified: baseline uric acid level, creatine kinase-MB level, and log (N-terminal pro-brain natriuretic peptide) level. Our stepwise model had an AUC of 0.816, which was higher than that of the ML model (AUC = 0.668, P = 0.09). The model also achieved accurate predictions regarding calibration. A risk score was then developed, and patients were divided into two risk groups: low risk (total score < 10) and high risk (total score ≥ 10).

Conclusions: In this study, we first identified important predictors of CIN in patients with CAD with NRF. We then developed the first CI-AKI model on the basis of the new criteria, which exhibited accurate predictive performance. The simplified risk score may be useful in clinical practice to identify high-risk patients.

Habitual use of fish oil supplements, genetic predisposition, and risk of fractures: a large population-based study

BACKGROUND

Epidemiologic studies have suggested an inverse association between circulating concentrations of long-chain ω-3 PUFAs and fracture risk. However, whether supplementation of long-chain ω-3 PUFA (i.e. fish oil) is associated with fracture risk, and whether the association is modified by genetic predisposition to fracture risk remain unclear.

OBJECTIVES

To evaluate the associations of habitual fish oil supplement use with fracture risk, and to explore the potential effect modification by genetic predisposition.

METHODS

This study included 492,713 participants from the UK Biobank who completed a questionnaire on habitual fish oil supplement use between 2006 and 2010. HRs and 95% CIs for fractures were estimated from multivariable Cox proportional hazards models. A weighted fracture-genetic risk score (GRS) was derived from 14 validated single nucleotide polymorphisms.

RESULTS

During a median follow-up of 8.1 y, 12,070 incident fractures occurred among participants free of fracture at baseline (n = 441,756). Compared with nonuse, habitual use of fish oil supplements was associated with a lower risk of total fractures (HR = 0.93; 95% CI: 0.89, 0.97), hip fractures (HR = 0.83; 95% CI: 0.75, 0.92), and vertebrae fractures (HR = 0.85; 95% CI: 0.72, 0.99). The inverse association for total fractures was more pronounced among participants having a higher fracture-GRS than among those with a lower fracture-GRS (P-interaction <0.001). Among participants with a history of fracture at baseline (n = 50,957), fish oil use was associated with a lower risk of total recurrent fractures (HR = 0.88; 95% CI: 0.82, 0.96) and vertebrae recurrent fractures (HR = 0.64; 95% CI: 0.46, 0.88) but not with hip fracture recurrence.

CONCLUSIONS

Our findings suggest that habitual fish oil supplement use is associated with lower risks of both incident and recurrent fractures. The inverse associations of fish oil use with total fractures appeared to be more pronounced among individuals at higher genetic risk of fractures than those with lower genetic risk.

Increased risk of diabetes in cancer survivors: a pooled analysis of 13 population-based cohort studies

BACKGROUND

Diabetes is considered as an established risk factor for cancer development. However, the link between diabetes among cancer survivors remains inconclusive. The hypothesis of this study was to assess the hazard ratio (HR) of incidence of diabetes in cancer survivors compared with the HR in the general population.

PATIENTS AND METHODS

A comprehensive literature search was performed in PubMed, Embase, and the Cochrane Library from database inception to 15 December 2020 for population-based cohort studies. Summary effect estimates were combined using random-effects models. We also performed subgroup analyses to test sources of heterogeneity and the stability of the results stratified by various study and participant characteristics.

RESULTS

Thirteen population-based cohort studies involving 1 686 595 participants were analyzed. The HR for the development of diabetes in cancer survivors was 1.39 [95% confidence interval (CI) 1.29-1.50; I2 = 82.3%; P < 0.001] compared with that in noncancer controls, among which survivors of hematological, gynecologic, breast, colorectal and urinary tract cancer (all P < 0.05) showed consistent significant results, whereas no significant increased risk was observed for other cancer types. The effects were more prominent in populations of shorter cancer survival duration (<1 year) (HR 2.09, 95% CI 1.32-3.32; P = 0.009). Moreover, cancer survivors with a longer follow-up period (>10 years) had a relatively higher risk of diabetes (HR 1.54, 95% CI 1.34-1.77) than those with a shorter follow-up period.

CONCLUSIONS

In this large pooled analysis of population-based cohorts, evidence supports the hypothesis that the risk of developing diabetes is increased in cancer survivors compared with the general population. We should interpret the results with caution for considerable interstudy heterogeneity. However, health policy makers should take this as a challenge for the early prevention and effective intervention of diabetes.

Sexual Dysfunction and the Impact of Beta-Blockers in Young Males With Coronary Artery Disease

Objective: We aimed to assess the association of erectile dysfunction (ED) with the extent of coronary atherosclerosis, and to examine whether revascularization and medication use have an impact on ED status in patients with early onset of coronary artery disease (EOCAD).

Methods: International Index of Erectile Function (IIEF-5) was used to evaluate sexual function in 296 male patients with EOCAD (age, 39.9 ± 4.8 years), and 354 male controls (age, 40.6 ± 4.4 years). The extent of coronary atherosclerosis was measured by Gensini score. Endothelial function was evaluated by two vasomotor indexes including endothelin-1 (ET-1) and nitric oxide (NO) by ELISA.

Results: ED was more frequent (57.8 vs. 31.1%, P < 0.001) and serious (IIEF-5 score:17.7 ± 6.0 vs. 21.6 ± 5.0, P < 0.001) among EOCAD patients than that among controls. IIEF-5 score was negatively correlated with Gensini score (r = −0.383, P < 0.001). The adjusted odds ratio (OR) for the presence of ED (EOCAD vs. controls) was 1.88 [95% confidential interval (CI), 1.12-3.18]. However, ET-1 and NO attenuated the association between ED and EOCAD (adjusted OR: 1.54, 95% CI: 0.84-2.80). IIEF-5 score increased after coronary revascularization in patients not on beta-blockers (18.71 ± 4.84 vs. 17.59 ± 6.05, P < 0.001) as compared with baseline, while stayed unchanged in the subgroup using beta-blockers (17.82 ± 5.12 vs. 17.70 ± 5.98, P = 0.09).

Conclusions: ED was common in patients with EOCAD, and associated with the severity of coronary atherosclerosis. Endothelial dysfunction may be a pathophysiologic mechanism underlying both ED and EOCAD. Coronary revascularization confers a benefit in ED amelioration, while this effect did not appear in patients using beta-blocker.

Dietary factors, gut microbiota, and serum trimethylamine-N-oxide associated with cardiovascular disease in the Hispanic Community Health Study/Study of Latinos

BACKGROUND

Trimethylamine-N-oxide (TMAO), a diet-derived and gut microbiota-related metabolite, is associated with cardiovascular disease (CVD). However, major dietary determinants and specific gut bacterial taxa related to TMAO remain to be identified in humans.

OBJECTIVES

We aimed to identify dietary and gut microbial factors associated with circulating TMAO.

METHODS

This cross-sectional study included 3972 participants (57.3% women) aged 18-74 y from the Hispanic Community Health Study/Study of Latinos in the United States. Dietary information was collected by 24-h dietary recalls at baseline interview (2008-2011), and baseline serum TMAO and its precursors were measured by an untargeted approach. Gut microbiome was profiled by shotgun metagenomic sequencing in a subset of participants (n = 626) during a follow-up visit (2016-2018). Logistic and linear regression were used to examine associations of inverse-normalized metabolites with prevalent CVD, dietary intake, and bacterial species, respectively, after adjustment for sociodemographic, behavioral, and clinical factors.

RESULTS

TMAO was positively associated with prevalent CVD (case number = 279; OR = 1.34; 95% CI: 1.17, 1.54, per 1-SD). Fish (P = 1.26 × 10-17), red meat (P = 3.33 × 10-16), and egg (P = 3.89 × 10-5) intakes were top dietary factors positively associated with TMAO. We identified 9 gut bacterial species significantly associated with TMAO (false discovery rate <0.05). All 4 species positively associated with TMAO belong to the order Clostridiales, of which 3 might have homologous genes encoding carnitine monooxygenase, an enzyme converting carnitine to trimethylamine (TMA). The red meat-TMAO association was more pronounced in participants with higher abundances of these 4 species compared with those with lower abundance (Pinteraction = 0.013), but such microbial modification was not observed for fish-TMAO or egg-TMAO associations.

CONCLUSION

In US Hispanics/Latinos, fish, red meat, and egg intakes are major dietary factors associated with serum TMAO. The identified potential TMA-producing gut microbiota and microbial modification on the red meat-TMAO association support microbial TMA production from dietary carnitine, whereas the fish-TMAO association is independent of gut microbiota.

Association of Oily and Nonoily Fish Consumption and Fish Oil Supplements With Incident Type 2 Diabetes: A Large Population-Based Prospective Study

OBJECTIVE

To evaluate associations of oily and nonoily fish consumption and fish oil supplements with incident type 2 diabetes (T2D).

RESEARCH DESIGN AND METHODS

We included 392,287 middle-aged and older participants (55.0% women) in the UK Biobank who were free of diabetes, major cardiovascular disease, and cancer and had information on habitual intake of major food groups and use of fish oil supplements at baseline (2006-2010). Of these, 163,706 participated in one to five rounds of 24-h dietary recalls during 2009-2012.

RESULTS

During a median 10.1 years of follow-up, 7,262 incident cases of T2D were identified. Compared with participants who reported never consumption of oily fish, the multivariable-adjusted hazard ratios of T2D were 0.84 (95% CI 0.78-0.91), 0.78 (0.72-0.85), and 0.78 (0.71-0.86) for those who reported <1 serving/week, weekly, and ≥2 servings/week of oily fish consumption, respectively (P-trend < 0.001). Consumption of nonoily fish was not associated with risk of T2D (P-trend = 0.45). Participants who reported regular fish oil use at baseline had a 9% (95% CI 4-14%) lower risk of T2D compared with nonusers. Baseline regular users of fish oil who also reported fish oil use during at least one of the 24-h dietary recalls had an 18% (8-27%) lower risk of T2D compared with constant nonusers.

CONCLUSIONS

Our findings suggest that consumption of oily fish but not nonoily fish was associated with a lower risk of T2D. Use of fish oil supplements, especially constant use over time, was also associated with a lower risk of T2D.

Association between the metabolome and bone mineral density in a Chinese population

BACKGROUND

Osteoporosis is a common metabolic bone disease, which always leads to osteoporotic fractures. Biomarkers of bone mineral density (BMD) are helpful for prevention and early diagnosis of osteoporosis. This study aims to identify metabolomic biomarkers of low BMD.

METHODS

We included 701 participants who had BMD measures by dual-energy X-ray absorptiometry scans and donated fasting plasma samples from three clinical centres as a discovery set and another 278 participants from the fourth centre as an independent replication set. We used a liquid chromatography-mass spectrometry-based metabolomics approach to profile the global metabolites of fasting plasma.

FINDINGS

Among the 265 named metabolites identified in our study, six were associated with low BMD (FDR-adjusted P<0.05) in the discovery set and were successfully validated in the independent replication set. The circulating levels of five metabolites, i.e., inosine, hypoxanthine, PC (O-18:0/22:6), SM (d18:1/21:0) and isoleucyl-proline were associated with decreased odds of low BMD, and PC (16:0/18:3) level was associated with increased odds of low BMD. Per 1-SD increase in a composite metabolite score of these six metabolites was associated with about half decreased odds of low BMD (odds ratio 0.59, 95% confidence interval: 0.52-0.68). Furthermore, introduction of a panel of metabolites selected by elastic net regression to a prediction model of classical risk factors and plasma biomarker of bone resorption substantially improved the prediction performance for low BMD (AUCs: 0.782 vs. 0.698, P=0.002).

INTERPRETATION

Metabolomics profiling may help identify novel biomarkers of low BMD and be helpful for early diagnosis of osteoporosis beyond the current clinical index.

FUNDING

This study was supported by the National Key R&D Program of China [2018YFC2001500 to J.S.], Shanghai Municipal Science and Technology Major Project [2017SHZDZX01], the National Natural Science Foundation of China [Key Program, 91749204 to J.S.], the National Natural Science Foundation of China [General Program, 81771491 to J.S.], the Project of Shanghai Subject Chief Scientist [2017BR011 to J.S.], Grants from the TCM Supported Project [18431902300 to J.S.] from the Science and Technology Commission of Shanghai Municipality, and the National Natural Science Foundation of China [General Program, 81972089 to Z.X.]. Y.Z. was supported by the Program for Professor of Special Appointment (Eastern Scholar) at Shanghai Institutions of Higher Learning, and the National Natural Science Foundation of China [81973032].

Myocardial injury and COVID-19: Serum hs-cTnI level in risk stratification and the prediction of 30-day fatality in COVID-19 patients with no prior cardiovascular disease

Introduction: To explore the involvement of the cardiovascular system in coronavirus disease 2019 (COVID-19), we investigated whether myocardial injury occurred in COVID-19 patients and assessed the performance of serum high-sensitivity cardiac Troponin I (hs-cTnI) levels in predicting disease severity and 30-day in-hospital fatality.

Methods: We included 244 COVID-19 patients, who were admitted to Renmin Hospital of Wuhan University with no preexisting cardiovascular disease or renal dysfunction. We analyzed the data including patients' clinical characteristics, cardiac biomarkers, severity of medical conditions, and 30-day in-hospital fatality. We performed multivariable Cox regressions and the receiver operating characteristic analysis to assess the association of cardiac biomarkers on admission with disease severity and prognosis.

Results: In this retrospective observational study, 11% of COVID-19 patients had increased hs-cTnI levels (>40 ng/L) on admission. Of note, serum hs-cTnI levels were positively associated with the severity of medical conditions (median [interquartile range (IQR)]: 6.00 [6.00-6.00] ng/L in 91 patients with moderate conditions, 6.00 [6.00-18.00] ng/L in 107 patients with severe conditions, and 11.00 [6.00-56.75] ng/L in 46 patients with critical conditions, P for trend=0.001). Moreover, compared with those with normal cTnI levels, patients with increased hs-cTnI levels had higher in-hospital fatality (adjusted hazard ratio [95% CI]: 4.79 [1.46-15.69]). The receiver-operating characteristic curve analysis suggested that the inclusion of hs-cTnI levels into a panel of empirical prognostic factors substantially improved the prediction performance for severe or critical conditions (area under the curve (AUC): 0.71 (95% CI: 0.65-0.78) vs. 0.65 (0.58-0.72), P=0.01), as well as for 30-day fatality (AUC: 0.91 (0.85-0.96) vs. 0.77 (0.62-0.91), P=0.04). A cutoff value of 20 ng/L of hs-cTnI level led to the best prediction to 30-day fatality.

Conclusions: In COVID-19 patients with no preexisting cardiovascular disease, 11% had increased hs-cTnI levels. Besides empirical prognostic factors, serum hs-cTnI levels upon admission provided independent prediction to both the severity of the medical condition and 30-day in-hospital fatality. These findings may shed important light on the clinical management of COVID-19.

Circulating metabolites from the choline pathway and acute coronary syndromes in a Chinese case-control study

Background

Accumulating evidence shows that circulating levels of trimethylamine N-oxide, which is generated from the metabolism of dietary choline, may predict cardiovascular disease among Caucasians. Acute coronary syndrome (ACS), one common presentation of cardiovascular disease, is a spectrum of signs and symptoms due to acute decreased blood flow in the coronary arteries. The relationship between the metabolites from choline pathway and ACS remains unclear. We aimed to assess the associations of circulating metabolites from the choline pathway with ACS among a Chinese population, who consume a different dietary pattern than their Western counterparts.

Methods

We recruited 501 participants who were admitted to the Department of Cardiology, Zhongshan Hospital,Shanghai China between March 2017 and June 2018, including 254 ACS cases and 247 controls. Liquid chromatography-tandem mass spectrometry was used to measure circulating concentrations of metabolites in the choline pathway, including betaine, choline, trimethylamine, and trimethylamine N-oxide. A composite metabolite score using a weighted sum of these four metabolites, and the betaine/choline ratio were calculated. Multivariable logistic regressions were applied to estimate the association of metabolites with ACS, with adjustment of age, sex, body mass index, smoking index, history of diseases, and kidney function.

Results

After adjusting for traditional risk factors, per 1-standard deviation (SD) increment in choline was positively associated with the odds of ACS [odds ratio (OR), 95% confidence interval (CI), 1.77(1.44-2.18)], and the other metabolites were not associated with ACS at a statistical significance level. Compared with participants in the lowest quartile of the metabolite score, those in the highest quartile had higher odds of ACS [OR (95% CI), 3.18(1.85-5.54), p < 0.001 for trend]. Per 1-SD increment in metabolite score was positively associated with higher odds of ACS [OR (95% CI), 1.80 (1.37-2.40)], and per 1-SD increment in the betaine/choline ratio was inversely associated with the odds of ACS [OR (95% CI), 0.49 (0.39-0.60)].

Conclusions

Among our Chinese participants, trimethylamine N-oxide was not associated with ACS, while a composite metabolite score of metabolites from the choline pathway was associated with increased odds of ACS. The choline pathway metabolites may be related to the pathophysiology of ACS among Chinese.

Mendelian randomization analysis does not support causal associations of birth weight with hypertension risk and blood pressure in adulthood

Epidemiology studies suggested that low birthweight was associated with a higher risk of hypertension in later life. However, little is known about the causality of such associations. In our study, we evaluated the causal association of low birthweight with adulthood hypertension following a standard analytic protocol using the study-level data of 183,433 participants from 60 studies (CHARGE-BIG consortium), as well as that with blood pressure using publicly available summary-level genome-wide association data from EGG consortium of 153,781 participants, ICBP consortium and UK Biobank cohort together of 757,601 participants. We used seven SNPs as the instrumental variable in the study-level analysis and 47 SNPs in the summary-level analysis. In the study-level analyses, decreased birthweight was associated with a higher risk of hypertension in adults (the odds ratio per 1 standard deviation (SD) lower birthweight, 1.22; 95% CI 1.16 to 1.28), while no association was found between genetically instrumented birthweight and hypertension risk (instrumental odds ratio for causal effect per 1 SD lower birthweight, 0.97; 95% CI 0.68 to 1.41). Such results were consistent with that from the summary-level analyses, where the genetically determined low birthweight was not associated with blood pressure measurements either. One SD lower genetically determined birthweight was not associated with systolic blood pressure (β = - 0.76, 95% CI - 2.45 to 1.08 mmHg), 0.06 mmHg lower diastolic blood pressure (β = - 0.06, 95% CI - 0.93 to 0.87 mmHg), or pulse pressure (β = - 0.65, 95% CI - 1.38 to 0.69 mmHg, all p > 0.05). Our findings suggest that the inverse association of birthweight with hypertension risk from observational studies was not supported by large Mendelian randomization analyses.

Elevated serum urate is a potential factor in reduction of total bilirubin: a Mendelian randomization study

Aim

A Mendelian randomization study (MRS) can be linked to a "natural" randomized controlled trial in order to avoid potential bias of observational epidemiology. We aimed to study the possible association between serum urate (SU) and total bilirubin (TBIL) using MRS.

Materials and Methods

An observational epidemiological study using ordinary least squares (OLS) regression and MRS using two-stage least square (TLS) regression was conducted to assess the effect of SU on TBIL. The comparison between the OLS regression and the TLS regression was analyzed by the Durbin-Hausman test. If the p value is significant, it suggests that the OLS regression cannot evaluate the relationship between exposure and outcome, and the TLS regression is precise; while if the p value is not significant, there would be no significant difference between the two regressions.

Results

A total of 3,753 subjects were analyzed. In OLS regression, there was no significant association between SU and TBIL in all subjects and subgroup analysis (all p > 0.05). However, MRS revealed a negative correlation between SU and TBIL after adjustment for confounders (beta = -0.021, p = 0.010). Further analysis was conducted in different SU subgroups, and results show that elevated SU was associated with a significant reduction in TBIL after adjustment for hyperuricemic subjects (beta = -0.053, p = 0.027). In addition, the results using the Durbin-Hausman test further confirmed a negative effect of SU on TBIL (p = 0.002 and 0.010, respectively).

Conclusions

This research shows for the first time that elevated SU was a potential causal factor in the reduction of TBIL and it provides strong evidence to resolve the controversial association between SU and TBIL.

Increased TEAD4 expression and nuclear localization in colorectal cancer promote epithelial-mesenchymal transition and metastasis in a YAP-independent manner

Dysregulation of the Hippo pathway occurs in a variety of cancers and often correlates with a poor prognosis. To further explore the potential role of Hippo pathway dysregulation in tumor development and progression, we investigated its downstream transcription factor TEAD4 in colorectal cancer (CRC). Increased expression and nuclear localization of TEAD4 were found in a significant portion of CRC tissues, in association with metastasis and a poor prognosis. In CRC cells, TEAD4 knockdown induced the mesenchymal-epithelial transition and decreased cell mobility in vitro and metastasis in vivo. Microarray analysis revealed that TEAD4 promoted cell adhesion and upregulated the epithelial-mesenchymal transition-related transcriptome in CRC cells. Vimentin was identified as a new direct target gene mediating TEAD4 function in CRC cells, whereby forced vimentin expression markedly reversed TEAD4-knockdown-induced cell morphological changes and decreased mobility. Interestingly, rescued expression of both WT TEAD4 and a Y429H mutant can reverse the mesenchymal-epithelial transition and increase vimentin expression, cell mobility and metastatic potential in TEAD4-knockdown CRC cells. The discrepant expression of YAP and TEAD4 in CRC tissues, the rescue ability of TEAD4 mutant defect in YAP binding and no effect on vimentin expression by YAP knockdown in CRC cells, all implicated a YAP-independent manner of TEAD4 function in CRC. Furthermore, vimentin positively correlated and CDH1 reversely correlated with the level of TEAD4 in CRC tissues and xenograft tumors. Our results suggest that TEAD4 nuclear expression can serve as a biomarker for CRC progression and poor prognosis. The transcription factor TEAD4 regulates a pro-metastasis transcription program in a YAP-independent manner in CRC, thus providing a novel mechanism of TEAD4 transcriptional regulation and its oncogenic role in CRC, independently of the Hippo pathway.

High-intensity focused ultrasound ablation: an effective and safe treatment for secondary hypersplenism

OBJECTIVE

Hypersplenism is a common disease. The conventional treatment is splenectomy and partial splenic embolization; however, both of them have high complication rates and technical defects. Therefore, safer and more effective techniques should be considered for the treatment of hypersplenism. High-intensity focused ultrasound (HIFU) may provide an effective and safe way for treatment of hypersplenism. Therefore, we conducted this study to assess the safety and efficacy of HIFU in treatment of secondary hypersplenism.

METHODS

A total of 28 patients who suffered from secondary hypersplenism were treated with HIFU ablation. All patients who underwent HIFU were closely followed-up over a year. MRI scan was performed, and the spleens were observed. Blood counts and liver function tests were also carried out.

RESULTS

In the follow-up process, the levels of white blood cells and platelets in the blood after HIFU were significantly higher than those before HIFU, liver function also improved after HIFU treatment. In addition, the symptoms were ameliorated significantly or even disappeared. The MRI showed that the ablation area had turned into a non-perfused volume, and after 12 months of HIFU ablation, the ablated area shrank evidently; the sunken spleen formed a lobulated shape and the splenic volume decreased.

CONCLUSION

HIFU ablation is a safe, effective and non-invasive approach for secondary hypersplenism.

ADVANCES IN KNOWLEDGE

For the first time we used HIFU ablation to treat secondary hypersplenism. It not only expands indications of HIFU but also provides better choice for the treatment of secondary hypersplenism.

Tumour-infiltrating inflammation and prognosis in colorectal cancer: systematic review and meta-analysis

Background:

The role of tumour-infiltrating inflammation in the prognosis of patients with colorectal cancer (CRC) has not been fully evaluated. The primary objective of our meta-analysis was to determine the impact of tumour-infiltrating inflammation on survival outcomes.

Methods:

Ovid MEDLINE and EMBASE were searched to identify studies reporting the prognostic significance of tumour-infiltrating inflammation for patients with CRC. The primary outcome measures were overall survival (OS), cancer-specific survival (CS) and disease-free survival (DFS).

Results:

A total of 30 studies involving 2988 patients were identified. Studies were subdivided into those considering the associations between CRC survival and generalised tumour inflammatory infiltrate (n=12) and T lymphocyte subsets (n=18). Pooled analyses revealed that high generalised tumour inflammatory infiltrate was associated with good OS (HR, 0.59; 95% CI, 0.48–0.72), CS (HR, 0.40; 95% CI, 0.27–0.61) and DFS (HR, 0.72; 95% CI, 0.57–0.91). Stratification by location and T lymphocyte subset indicated that in the tumour centre, CD3⁺, CD8⁺ and FoxP3⁺ infiltrates were not statistically significant prognostic markers for OS or CS. In the tumour stroma, high CD8⁺, but not CD3⁺ or FoxP3⁺ cell infiltrates indicated increased OS. Furthermore, high CD3⁺ cell infiltrate was detected at the invasive tumour margin in patients with good OS and DFS; and high CCR7⁺ infiltrate was also indicated increased OS.

Conclusion:

Overall, high generalised tumour inflammatory infiltrate could be a good prognostic marker for CRC. However, significant heterogeneity and an insufficient number of studies underscore the need for further prospective studies on subsets of T lymphocytes to increase the robustness of the analyses.

Change of cholinergic transmission and memory deficiency induced by injection of beta-amyloid protein into NBM of rats

The change of cholinergic transmission of beta-amyloid protein (beta-AP) treated rats was studied by intracerebral microdialysis sampling combined with HPLC analysis. beta-AP(1-40) was injected into nucleus basalis magnocellularis (NBM). Passive avoidance response test (step-down test) and delayed alternation task were used for memory testing. The impairment of memory after injection of beta-AP(1-40) into NBM exhibited mainly the deficiency of short-term working memory. One week after injection of beta-AP(1-40) the release of acetylcholine (ACh) from frontal cortex of freely-moving rats decreased significantly, and the response of cholinergic nerve ending to the action of high [K(+)] solution was rather weak. In control animals the percentage of increase of ACh-release during behavioral performance was 57%, while in beta-AP(1-40)-treated rats it was 34%. The temporary increase of the ACh-release of the rat put into a new place was also significantly diminished in beta-AP(1-40) -treated rats. The results show that the injection of beta-AP(1-40) into NBM impairs the cholinergic transmission in frontal cortex, and the impairment of cholinergic transmission may be the main cause of the deficit of working memory.

Relation of BMI to fat and fat-free mass among children and adolescents

OBJECTIVE

Although the body mass index (BMI, kg/m2) is widely used as a surrogate measure of adiposity, it is a measure of excess weight, rather than excess body fat, relative to height. We examined the relation of BMI to levels of fat mass and fat-free mass among healthy 5- to 18-y-olds.

METHODS AND PROCEDURES

Dual-energy X-ray absorptiometry was used to measure fat and fat-free mass among 1196 subjects. These measures were standardized for height by calculating the fat mass index (FMI, fat mass/ht2) and the fat-free mass index (FFMI, fat-free mass/ht2).

RESULTS

The variability in FFMI was about 50% of that in FMI, and the accuracy of BMI as a measure of adiposity varied greatly according to the degree of fatness. Among children with a BMI-for-age > or =85th P, BMI levels were strongly associated with FMI (r=0.85-0.96 across sex-age categories). In contrast, among children with a BMI-for-age <50th P, levels of BMI were more strongly associated with FFMI (r=0.56-0.83) than with FMI (r=0.22-0.65). The relation of BMI to fat mass was markedly nonlinear, and substantial differences in fat mass were seen only at BMI levels > or =85th P.

DISCUSSION

BMI levels among children should be interpreted with caution. Although a high BMI-for-age is a good indicator of excess fat mass, BMI differences among thinner children can be largely due to fat-free mass.

Peptide derived from insulin with regulatory activity of dopamine transporter

A nonapeptide derived from the C terminus of the insulin B chain, H(2)N-Arg-Gly-Phe-Phe-Tyr-Thr-Pro-Lys-Ala-COOH, was found to strongly inhibit dopamine (DA) uptake by rat dopamine transporter (DAT) stably expressed in CHO cells (designated D8 cells). The kinetic experiments on D8 cells gave a curve typical of competitive inhibition with an IC(50)=6.9 microM. This inhibitory effect was also confirmed by experiments on striatal synaptosomes. The rat administered with the nonapeptide unilaterally into substantia nigra showed dose-dependent velocity and duration of the round movement contralateral to the nonapeptide-injected side. In addition, the nonapeptide dose-dependently reduced the binding of the tritium-labeled cocaine analog (-)-2 beta-carbomethoxy-3 beta-(4-fluorophenyl)tropane (WIN35,428) to DAT of D8 cells, which suggests that the nonapeptide may inhibit the transport activity of DAT in the way as cocaine does. Meanwhile, the peptide DOI (insulin with 8 amino acid residues deleted at the C terminus of the B chain) shows a significantly stimulating effect on DAT uptake activity in D8 cells. So insulin is proposed as a kind of neuropeptide precursor in the brain and insulin-derived peptides may be involved in the process of regulating the DA system, and these peptides may be developed into new medicines for disorders concerning the DA system such as Parkinson's disease and cocaine addiction.