The lethal K18-hACE2 knock-in mouse model mimicking the severe pneumonia of COVID-19 is practicable for antiviral development.

Animal models of COVID-19 facilitate the development of vaccines and antivirals against SARS-CoV-2. The efficacy of antivirals or vaccines may differ in different animal models with varied degrees of disease. Here, we introduce a mouse model expressing human angiotensin-converting enzyme 2 (ACE2). In this model, ACE2 with the human cytokeratin 18 promoter was knocked into the Hipp11 locus of C57BL/6J mouse by CRISPR - Cas9 (K18-hACE2 KI). Upon intranasal inoculation with high (3 × 105 PFU) or low (2.5 × 102 PFU) dose of SARS-CoV-2 wildtype (WT), Delta, Omicron BA.1, or Omicron BA.2 variants, all mice showed obvious infection symptoms, including weight loss, high viral loads in the lung, and interstitial pneumonia. 100% lethality was observed in K18-hACE2 KI mice infected by variants with a delay of endpoint for Delta and BA.1, and a significantly attenuated pathogenicity was observed for BA.2. The pneumonia of infected mice was accompanied by the infiltration of neutrophils and pulmonary fibrosis in the lung. Compared with K18-hACE2 Tg mice and HFH4-hACE2 Tg mice, K18-hACE2 KI mice are more susceptible to SARS-CoV-2. In the antivirals test, REGN10933 and Remdesivir had limited antiviral efficacies in K18-hACE2 KI mice upon the challenge of SARS-CoV-2 infections, while Nirmatrelvir, monoclonal antibody 4G4, and mRNA vaccines potently protected the mice from death. Our results suggest that the K18-hACE2 KI mouse model is lethal and stable for SARS-CoV-2 infection, and is practicable and stringent to antiviral development.

G-protein-coupled estrogen receptor 1 promotes peritoneal metastasis of gastric cancer through nicotinamide adenine dinucleotide kinase 1-mediated redox modulation.

Adipose tissue is the second most important site of estrogen production, where androgens are converted into estrogen by aromatase. While gastric cancer patients often develop adipocyte-rich peritoneal metastasis, the underlying mechanism remains unclear. In this study, we identified the G-protein-coupled estrogen receptor (GPER1) as a promoter of gastric cancer peritoneal metastasis. Functional in vitro studies revealed that ß-Estradiol (E2) or the GPER1 agonist G1 inhibited anoikis in gastric cancer cells. Additionally, genetic overexpression or knockout of GPER1 significantly inhibited or enhanced gastric cancer cell anoikis in vitro and peritoneal metastasis in vivo, respectively. Mechanically, GPER1 knockout disrupted the NADPH pool and increased reactive oxygen species (ROS) generation. Conversely, overexpression of GPER1 had the opposite effects. GPER1 suppressed nicotinamide adenine dinucleotide kinase 1(NADK1) ubiquitination and promoted its phosphorylation, which were responsible for the elevated expression of NADK1 at protein levels and activity, respectively. Moreover, genetic inhibition of NADK1 disrupted NADPH and redox homeostasis, leading to high levels of ROS and significant anoikis, which inhibited lung and peritoneal metastasis in cell-based xenograft models. In summary, our study suggests that inhibiting GPER1-mediated NADK1 activity and its ubiquitination may be a promising therapeutic strategy for peritoneal metastasis of gastric cancer.

NSUN2-mediated m5C modification of HBV RNA positively regulates HBV replication.

Chronic hepatitis B virus (HBV) infection is a major cause of liver cirrhosis and liver cancer, despite strong prevention and treatment efforts. The study of the epigenetic modification of HBV has become a research hotspot, including the N6-methyladenosine (m6A) modification of HBV RNA, which plays complex roles in the HBV life cycle. In addition to m6A modification, 5-methylcytosine (m5C) is another major modification of eukaryotic mRNA. In this study, we explored the roles of m5C methyltransferase and demethyltransferase in the HBV life cycle. The results showed that m5C methyltransferase NSUN2 deficiency could negatively regulate the expression of HBV while m5C demethyltransferase TET2 deficiency positively regulates the expression of HBV. Subsequently, we combined both in vitro bisulfite sequencing and high-throughput bisulfite sequencing methods to determine the distribution and stoichiometry of m5C modification in HBV RNA. Two sites: C2017 and C131 with the highest-ranking methylation rates were identified, and mutations at these two sites could lead to the decreased expression and replication of HBV, while the mutation of the "fake" m5C site had no effect. Mechanistically, NSUN2-mediated m5C modification promotes the stability of HBV RNA. In addition, compared with wild-type HepG2-NTCP cells and primary human hepatocytes, the replication level of HBV after NSUN2 knockdown decreased, and the ability of the mutant virus to infect and replicate in wild-type HepG2-NTCP cells and PHHs was substantially impaired. Similar results were found in the experiments using C57BL/6JGpt-Nsun2+/- mice. Interestingly, we also found that HBV expression and core protein promoted the endogenous expression of NSUN2, which implied a positive feedback loop. In summary, our study provides an accurate and high-resolution m5C profile of HBV RNA and reveals that NSUN2-mediated m5C modification of HBV RNA positively regulates HBV replication by maintaining RNA stability.

Broadly neutralizing antibodies derived from the earliest COVID-19 convalescents protect mice from SARS-CoV-2 variants challenge.

Coronavirus disease 2019 (COVID-19) was first reported three years ago, when a group of individuals were infected with the original SARS-CoV-2 strain, based on which vaccines were developed. Here, we develop six human monoclonal antibodies (mAbs) from two elite convalescents in Wuhan and show that these mAbs recognize diverse epitopes on the receptor binding domain (RBD) and can inhibit the infection of SARS-CoV-2 original strain and variants of concern (VOCs) to varying degrees, including Omicron strains XBB and XBB.1.5. Of these mAbs, the two most broadly and potently neutralizing mAbs (7B3 and 14B1) exhibit prophylactic activity against SARS-CoV-2 WT infection and therapeutic effects against SARS-CoV-2 Delta variant challenge in K18-hACE2 KI mice. Furthermore, post-exposure treatment with 7B3 protects mice from lethal Omicron variants infection. Cryo-EM analysis of the spike trimer complexed with 14B1 or 7B3 reveals that these two mAbs bind partially overlapped epitopes onto the RBD of the spike, and sterically disrupt the binding of human angiotensin-converting enzyme 2 (hACE2) to RBD. Our results suggest that mAbs with broadly neutralizing activity against different SARS-CoV-2 variants are present in COVID-19 convalescents infected by the ancestral SARS-CoV-2 strain, indicating that people can benefit from former infections or vaccines despite the extensive immune escape of SARS-CoV-2.

Shared IGHV1-69-encoded neutralizing antibodies contribute to the emergence of L452R substitution in SARS-CoV-2 variants.

SARS-CoV-2 variants continue to emerge facing established herd immunity. L452R, previously featured in the Delta variant, quickly emerged in Omicron subvariants, including BA.4/BA.5, implying a continued selection pressure on this residue. The underlying links between spike mutations and their selective pressures remain incompletely understood. Here, by analyzing 221 structurally characterized antibodies, we found that IGHV1-69-encoded antibodies preferentially contact L452 using germline-encoded hydrophobic residues at the tip of HCDR2 loop. Whereas somatic hypermutations or VDJ rearrangements are required to acquire L452-contacting hydrophobic residues for non-IGHV1-69 encoded antibodies. Antibody repertoire analysis revealed that IGHV1-69 L452-contacting antibody lineages are commonly induced among COVID-19 convalescents but non-IGHV1-69 encoded antibodies exhibit limited prevalence. In addition, we experimentally demonstrated that L452R renders most published IGHV1-69 antibodies ineffective. Furthermore, we found that IGHV1-69 L452-contacting antibodies are enriched in convalescents experienced Omicron BA.1 (without L452R) breakthrough infections but rarely found in Delta (with L452R) breakthrough infections. Taken together, these findings support that IGHV1-69 population antibodies contribute to selection pressure for L452 substitution. This study thus provides a better understanding of SARS-CoV-2 variant genesis and immune evasion.

Drastic decline in sera neutralization against SARS-CoV-2 Omicron variant in Wuhan COVID-19 convalescents.

Global concern has been raised by the emergence and rapid transmission of the heavily mutated SARS-CoV-2 Omicron variant (B.1.1.529). So far, the infection features and immune escape ability of the Omicron variant have not been extensively studied. Here, we produced the Omicron pseudovirus and compared its entry, membrane fusion, and immune escape efficiency with the original strain and the dominating Delta variant. We found the Omicron variant showed slightly higher infectivity than the Delta variant and a similar ability to compete with the Delta variant in using Angiotensin-converting enzyme 2 (ACE2) in a BHK21-ACE2 cell line. However, the Omicron showed a significantly reduced fusogenicity than the original strain and the Delta variant in both BHK21-ACE2 and Vero-E6 cells. The neutralization assay testing the Wuhan convalescents' sera one-year post-infection showed a more dramatic reduction (10.15 fold) of neutralization against the Omicron variant than the Delta variant (1.79 fold) compared with the original strain with D614G. Notably, immune-boosting through three vaccine shots significantly improved the convalescents' immunity against the Omicron variants. Our results reveal a reduced fusogenicity and a striking immune escape ability of the Omicron variant, highlighting the importance of booster shots against the challenge of the SARS-CoV-2 antigenic drift.

Antibody neutralization to SARS-CoV-2 and variants after 1 year in Wuhan, China.

Most COVID-19 convalescents can build effective anti-SARS-CoV-2 humoral immunity, but it remains unclear how long it can maintain and how efficiently it can prevent the reinfection of the emerging SARS-CoV-2 variants. Here, we tested the sera from 248 COVID-19 convalescents around 1 year post-infection in Wuhan, the earliest known epicenter. SARS-CoV-2 immunoglobulin G (IgG) was well maintained in most patients and potently neutralizes the infection of the original strain and the B.1.1.7 variant. However, varying degrees of immune escape was observed on the other tested variants in a patient-specific manner, with individuals showing remarkably broad neutralization potency. The immune escape can be largely attributed to several critical spike mutations. These results suggest that SARS-CoV-2 can elicit long-lasting immunity but this is escaped by the emerging variants.

Live attenuated coronavirus vaccines deficient in N7-Methyltransferase activity induce both humoral and cellular immune responses in mice.

Coronaviruses (CoVs) can infect a variety of hosts, including humans, livestock and companion animals, and pose a serious threat to human health and the economy. The current COVID-19 pandemic, which is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has killed millions of people. Unfortunately, effective treatments for CoVs infection are still lacking, suggesting the importance of coronavirus vaccines. Our previous work showed that CoV nonstuctural protein 14 (nsp14) functions as (guanine-N7)-methyltransferase (N7-MTase), which is involved in RNA cap formation. Moreover, we found that N7-MTase is well conserved among different CoVs and is a universal target for developing antivirals against CoVs. Here, we show that N7-MTase of CoVs can be an ideal target for designing live attenuated vaccines. Using murine hepatitis virus strain A59 (MHV-A59), a representative and well-studied model of coronaviruses, we constructed N7-MTase-deficient recombinant MHV D330A and Y414A. These two mutants are highly attenuated in mice and exhibit similar replication efficiency to the wild-type (WT) virus in the cell culture. Furthermore, a single dose immunization of D330A or Y414A can induce long-term humoral immune responses and robust CD4+ and CD8+ T cell responses, which can provide full protection against the challenge of a lethal-dose of MHV-A59. Collectively, this study provides an ideal strategy to design live attenuated vaccines for coronavirus by abolishing viral RNA N7-MTase activity. This approach may apply to other RNA viruses that encode their own conservative viral N7-methyltransferase.

A retrospective cohort study of preoperative lipid indices and their impact on new-onset diabetes after liver transplantation.

BACKGROUND: The correlation between preoperative lipid profiles and new-onset diabetes after transplantation (NODAT) remains relatively unexplored in liver transplant recipients (LTRs). Thus, we aimed to investigate the preoperative lipid profiles in Chinese LTRs and evaluate the different influences of preoperative total cholesterol, total triglycerides (TG), high-density lipoprotein cholesterol, and low-density lipoprotein cholesterol on the development of NODAT in both sexes. METHODS: A total of 767 Chinese LTRs from Zhongshan Hospital were retrospectively evaluated. NODAT was defined according to the American Diabetes Association guidelines; the relationship between each preoperative lipid index and NODAT development was analyzed separately in men and women. RESULTS: Pretransplant hypotriglyceridemia was observed in 35.72% of the total LTRs. In men, only the preoperative TG level was significantly associated with incident NODAT after adjusting for potential confounders (hazard ratio 1.37, 95% confidence interval 1.13-1.66, P = .001). There was a nonlinear relationship between the preoperative TG level and NODAT risk. The risk of NODAT significantly increased with preoperative a TG level above 0.54 mmol/L (log-likelihood ratio test, P = .043). In women, no significant association was observed. CONCLUSION: Among male LTRs, a higher preoperative TG level, even at a low level within the normal range, was significantly and nonlinearly associated with an increased risk of NODAT.

Circulating osteocalcin: A potential predictor of ketosis in type 2 diabetes.

AIMS: Osteocalcin contributes to the regulation of endocrine system. However, the association between osteocalcin and ketosis has not been evaluated. We thus aimed to explore the relationship between total osteocalcin and risk of ketosis in type 2 diabetes (T2DM). MATERIALS AND METHODS: We identified 6157 diabetes patients from Shanghai Tenth People's Hospital between 1 January 2011 and 1 March 2017. Six hundred eight subjects were enrolled in the retrospective cross-sectional study: 304 T2DM patients with ketosis whose age, gender, and body mass index were matched with 304 T2DM patients without ketosis. A further retrospective nested case-control study was conducted in 252 T2DM patients without ketosis for a mean duration of 21.58 ± 12.43 months to investigate the occurrence of ketosis. RESULTS: Osteocalcin levels were negatively correlated with blood ketones (adjusted r = -0.263) and urine ketones (adjusted r = -0.183). The inverse dose-dependent relationship of osteocalcin and risk of ketosis was present across osteocalcin level quintiles (top quintile as the reference, adjusted odds ratio [95% CI] = 2.56 [0.80-8.17], 3.71 [0.90-15.29], 10.77 [2.63-44.15], 23.81 [4.32-131.17] per osteocalcin quintile, respectively). Ketosis occurred in 17 of the 252 T2DM patients during follow-up. The Cox regression analysis indicated that osteocalcin was an independent protective factor against development of ketosis (adjusted hazard ratio [95% CI]: 0.668 [0.460-0.971]). CONCLUSIONS: Total osteocalcin can be used as a predictor of ketosis in T2DM.

Pretransplant C-reactive protein as a prognostic marker in allogeneic stem cell transplantation: A PRISMA-compliant meta-analysis.

BACKGROUND: Numerous reports have explored the prognostic value of pretransplant serum C-reactive protein (CRP) in patients receiving allogeneic stem cell transplant (ASCT), but the results remain conflicting. Therefore, we performed a meta-analysis to comprehensively assess the prognostic value of pretransplant serum CRP in patients receiving ASCT. METHODS: We systematically searched eligible studies in PubMed, Embase, and Web of Science from 1999 to September 2018. The pooled hazard ratios (HRs) and their corresponding 95% CIs were used to synthetically assess the prognostic value of pre-ASCT CRP in terms of overall survival (OS), non-relapse mortality (NRM), and acute graft versus host disease (aGVHD). RESULTS: A total of 14 articles with 15 studies containing 3458 patients were included in this meta-analysis. The pooled results showed that high pre-ASCT CRP level was significantly related to worse OS (HR = 1.63; 95% CI: 1.34-1.98; P < .05), to an increased risk of NRM (HR = 2.06; 95% CI: 1.62-2.62; P < .05), and aGVHD (HR = 1.35; 95% CI: 1.07-1.71; P < .05). Additionally, sensitivity and subgroup analyses demonstrated that our pooled results were stable and reliable. CONCLUSIONS: High pre-ASCT serum CRP was significantly associated with worse OS, as well as higher risk of NRM and aGVHD. CRP may be a candidate factor of updating the existing risk scoring systems or establishing a novel risk scoring systems, which has the potential of guiding patient selection for ASCT and proceeding with risk-adapted therapeutic strategies. However, more high-quality clinical studies and basic research are required to further validate our findings in view of several limitations in our meta-analysis.

Effect of pre-transplantation serum ferritin on outcomes in patients undergoing allogeneic hematopoietic stem cell transplantation: A meta-analysis.

BACKGROUND: Pre-transplantation serum ferritin (SF) has been considered to be a potential prognostic biomarker in patients undergoing allogeneic hematopoietic stem cell transplantation (allogeneic HSCT), but this conclusion remains controversial. Thus, we performed a meta-analysis to investigate the prognostic significance of pre-transplantation SF in patients undergoing allogeneic HSCT. METHODS: We systematically searched PubMed, Embase, and Web of Science up to September 2017, and finally identified a total of 25 eligible studies with 4545 patients. RESULTS: The pooled results of our meta-analysis showed that high pre-transplantation SF was markedly related to worse overall survival (OS) [hazard ratio (HR) = 1.82; 95% confidence interval (95% CI): 1.47-2.26; P < .001], nonrelapse mortality (NRM) (HR = 2.28; 95% CI: 1.79-2.89; P < .001), and progression-free survival (PFS) (HR = 1.72; 95% CI: 1.27-2.33; P < .001). In addition, high pre-transplantation SF was closely associated with a lower incidence of chronic graft versus host disease (cGVHD) (OR = 0.74, 95% CI: 0.58-0.96; P < .05), and a higher incidence of blood stream infections (BSIs) (OR = 1.67, 95% CI: 0.93-3.01; P = .09). However, no significance relationship was found between elevated pre-transplantation SF and acute graft versus host disease (aGVHD) (OR = 1.08, 95% CI:.72-1.62; P = .70). CONCLUSION: In patients undergoing allogeneic HSCT for hematological malignancies, elevated pre-transplantation SF was significantly associated with worse OS and PFS, higher incidence of NRM and BSI, and lower incidence of cGVHD, but it had no effect on aGVHD. Considering the limitations in our meta-analysis, more prospective and homogeneous clinical studies are needed to further confirm our findings.

Donor liver steatosis: A risk factor for early new-onset diabetes after liver transplantation.

AIMS/INTRODUCTION: To investigate whether donor liver steatosis increases the incidence of new-onset diabetes after transplantation (NODAT) in liver transplant recipients. MATERIALS AND METHODS: We retrospectively analyzed liver transplant recipients at Zhongshan Hospital, Shanghai, China, from April 2001 to December 2014. The final analysis involved 763 patients. The cumulative incidence of NODAT at 1, 3, 5 and 10 years after liver transplantation was investigated. Furthermore, according to the findings of donor liver biopsy before transplantation, patients were divided into steatotic and non-steatotic donor liver groups, and NODAT incidence was compared between these groups. Multivariate Cox regression was used to explore the risk factors for NODAT in the patients. RESULTS: Of the 763 donors, 309 (40.5%) had liver steatosis. At the end of follow up, 130 (42.1%) patients in the steatotic donor liver group developed NODAT, an incidence that exceeded that in the non-steatotic donor liver group (P = 0.001). The cumulative incidence of NODAT among all patients at 1, 3, 5, and 10 years after transplantation was 33, 43, 50 and 56%, respectively. The cumulative incidences of NODAT at 1, 3, 5 and 10 years in the steatotic donor liver group were significantly higher than those in the non-steatotic donor liver group (P = 0.003). Multivariate Cox regression analyses showed that donor liver steatosis was an independent risk factor for NODAT among liver transplant recipients, after other potential risk factors were adjusted for (hazard ratio 1.774, 95% confidence interval: 1.025-3.073; P = 0.041). CONCLUSIONS: Donor liver steatosis increases NODAT incidence among liver transplant recipients.

Effect of interleukin-2 receptor antagonists on new-onset diabetes after liver transplantation: A retrospective cohort study.

BACKGROUND: The aim of the present retrospective observational study was to examine the effect of interleukin-2 receptor antagonists (IL-2Ra) on new-onset diabetes after transplantation (NODAT) in liver transplant recipients. METHODS: Pre- and postoperative clinical data of 781 patients undergoing liver transplantation between April 2001 and December 2014 at Zhongshan Hospital, Fudan University, were analyzed. Patients were divided into two groups depending on the use of IL-2Ra (IL-2Ra and non-IL-2Ra). The cumulative incidence of NODAT was compared between the IL-2Ra and non-IL-2Ra groups and the effect of IL-2Ra on the incidence of NODAT in liver transplant recipients was evaluated. RESULTS: Of the 781 patients in the study, 451 received IL-2Ra. During follow-up, 138 (41.8%) and 137 (30.4%) patients in the non-IL-2Ra and IL-2Ra groups, respectively, developed NODAT (P = 0.001). The cumulative incidence of NODAT at 1, 3, 5, and 8 years after transplantation in the IL-2Ra group was 30%, 38%, 45%, and 54%, respectively; these values were substantially lower than corresponding values for the non-IL-2Ra group (P < 0.05). Cox regression analyses showed that IL-2Ra was a protective factor against NODAT development (odds ratio 0.685; 95% confidence interval 0.473-0.991; P = 0.044). This was independent of age, sex, donor type, hepatitis virus infection, body mass index, history of hypertension, preoperative liver function, preoperative fasting plasma glucose, total cholesterol, and total triglyceride levels, severity of liver cirrhosis, acute rejection, initial immunosuppressant regimen type, and postoperative immunosuppressant levels. CONCLUSION: In conclusion, IL-2Ra reduces the risk of NODAT in liver transplant recipients.

New-onset diabetes after liver transplantation and its impact on complications and patient survival.

BACKGROUND: The aim of the present study was to investigate the incidence and risk factors of new-onset diabetes after transplantation (NODAT) in liver transplant recipients and the influence of NODAT on complications and long-term patient survival. METHODS: We examined 438 patients who underwent liver transplantation between April 2001 and December 2008 and were not diabetic before transplantation. RESULTS: The mean (± SD) follow-up duration was 2.46 ± 1.62 years. The incidence of NODAT 3, 6, 9, 12, 36, and 60 months after transplantation was 44.24%, 25.59%, 23.08%, 25.17%, 17.86%, and 18.18%, respectively. Multifactor analysis indicated that preoperative fasting plasma glucose (FPG) levels and donor liver steatosis were independent risk factors for NODAT, whereas administration of an interleukin-2 receptor (IL-2R) antagonist reduced the risk of NODAT. Compared with the no NODAT group (N-NODAT), the NODAT group had a higher rate of sepsis and chronic renal insufficiency. Mean survival was significantly longer in the N-NODAT than NODAT group. Cox regression analysis showed that pre- and/or postoperative FPG levels, tumor recurrence or metastasis, and renal insufficiency after liver transplantation were independent risk factors of mortality. Pulmonary infection or multisystem failure were specific causes of death in the NODAT group, whereas patients in both groups died primarily from tumor relapse or metastasis. CONCLUSIONS: Preoperative FPG levels and donor liver steatosis were independent risk factors for NODAT, whereas administration of an IL-2R antagonist reduced the risk of NODAT. Patients with NODAT had reduced survival and an increased incidence of sepsis and chronic renal insufficiency. Significant causes of death in the NODAT group were pulmonary infection and multisystem failure.

Curcumol suppresses RANKL-induced osteoclast formation by attenuating the JNK signaling pathway.

Osteoclasts, derived from hemopoietic progenitors of the monocyte/macrophage lineage, have a unique role in bone resorption, and are considered a potential therapeutic target in the treatment of such pathologic bone diseases as osteoporosis, rheumatoid arthritis, and periodontitis. In the present study, we demonstrate that curcumol, one of the major components of the essential oil of Rhizoma Curcumae, exhibits an inhibitory effect on receptor activator of nuclear factor kappaB ligand (RANKL)-induced osteoclast differentiation with both bone marrow-derived macrophages and RAW264.7 cells in a dose-dependent manner. In addition, RANKL-induced mRNA expression of osteoclast-specific genes, such as tartrate-resistant acid phosphatase, calcitonin receptor, and cathepsin K, is prominently reduced in the presence of curcumol. Furthermore, the molecular mechanism of action was investigated, and curcumol inhibited osteoclastogenesis by specifically impairing RANKL-induced c-Jun N-terminal kinase (JNK)/activator protein-1 (AP-1) signaling, which was further identified in rescue studies by means of anisomycin, a JNK signaling-specific activator. Taken together, these findings suggest that curcumol suppresses RANKL-induced osteoclast differentiation through the JNK/AP-1 signaling pathway, and may be useful as a therapeutic treatment for bone resorption-associated diseases.

Gallbladder motility in patients with hepatic cirrhosis before and after portal azygous disconnection.

AIM: To determine and compare the effect of vagus nerve on gallbladder motility in patients with hepatic cirrhosis before and after portal azygous disconnection (PAD). METHODS: PAD operation (or Hassab's operation) was performed on 18 patients with portal hypertension, and anterior and posterior vagal trunks were cut. On d 3 before operation and d 10 after operation, (99m)Tc-EHIDA 185 MBq was administered intravenously to the patients, and scintigraphy was performed at 0.25 min/frame. A standard fat meal was administered 30 min after scintigraphy, and dynamic imaging was performed 60 min after the fat meal. Following appearance of the region of interest (ROI) in gallbladder, the time-activity curve of ROI was established. The following seven parameters were used: radioactivity at 30 min after injection of (99m)Tc-EHIDA (RC 30 min), bile emptying fraction (EF), bile emptying period (EP), emptying rate (ER), latent period (LP), latent period radiocounting increment (LI), and latent period radiocounting increment rate (LR). RESULTS: The RC 30 min decreased significantly after operation, compared with that before operation (2 693.6+/- 2 406.9 vs 5 606.8+/-2 625.4, P<0.05). The radiocounting of gallbladder increased gradually during LP. LP after operation was significantly longer than that before operation (13.36+/-5.92 vs 2.24+/-1.48, P<0.01). LI and LR after operation were significantly higher than those before operation (2 861.62+/-028.3 vs 331.21+/-421.02, and 113.42+/-49.52 vs 7.57+/-10.75, respectively, both P<0.01). EP after operation was significantly shorter than that before operation (18.5+/-6.3 vs 24.1+/-6.4, P<0.05). EF and ER after operation were significantly lower than those before operation (13.1+/-5.4 vs 32.3+/-16.3, and 0.7+/-0.3 vs 1.4+/-0.8, respectively, both P<0.01). CONCLUSION: PAD operation is a good clinical model in studying the effect of vagus on gallbladder motility. The gallbladder tension after PAD operation decreases significantly during the interdigestive phase. The latent period of gallbladder contraction prolongs and the motility weakens apparently after a standard fat meal. Human vagus influences the gallbladder motility, and cutting of the nerve inhibits the gallbladder motility.