ABSTRACT
Objective: To examine the impact of varied surgical treatment strategies on the prognosis of patients with initial resectable gastric cancer liver metastases (IR-GCLM). Methods: This is a retrospective cohort study. Employing a retrospective cohort design, the study selected clinicopathological data from the national multi-center retrospective cohort study database, focusing on 282 patients with IR-GCLM who underwent surgical intervention between January 2010 and December 2019. There were 231 males and 51 males, aging (M(IQR)) 61 (14) years (range: 27 to 80 years). These patients were stratified into radical and palliative treatment groups based on treatment decisions. Survival curves were generated using the Kaplan-Meier method and distinctions in survival rates were assessed using the Log-rank test. The Cox risk regression model evaluated HR for various factors, controlling for confounders through multivariate analysis to comprehensively evaluate the influence of surgery on the prognosis of IR-GCLM patients. A restricted cubic spline Cox proportional hazard model assessed and delineated intricate associations between measured variables and prognosis. At the same time, the X-tile served as an auxiliary tool to identify critical thresholds in the survival analysis for IR-GCLM patients. Subgroup analysis was then conducted to identify potential beneficiary populations in different surgical treatments. Results: (1) The radical group comprised 118 patients, all undergoing R0 resection or local physical therapy of primary and metastatic lesions. The palliative group comprised 164 patients, with 52 cases undergoing palliative resections for gastric primary tumors and liver metastases, 56 cases undergoing radical resections for gastric primary tumors only, 45 cases undergoing palliative resections for gastric primary tumors, and 11 cases receiving palliative treatments for liver metastases. A statistically significant distinction was observed between the groups regarding the site and the number of liver metastases (both P<0.05). (2) The median overall survival (OS) of the 282 patients was 22.7 months (95%CI: 17.8 to 27.6 months), with 1-year and 3-year OS rates were 65.4% and 35.6%, respectively. The 1-year OS rates for patients in the radical surgical group and palliative surgical group were 68.3% and 63.1%, while the corresponding 3-year OS rates were 42.2% and 29.9%, respectively. A comparison of OS between the two groups showed no statistically significant difference (P=0.254). Further analysis indicated that patients undergoing palliative gastric cancer resection alone had a significantly worse prognosis compared to other surgical options (HR=1.98, 95%CI: 1.21 to 3.24, P=0.006). (3) The size of the primary gastric tumor significantly influenced the patients' prognosis (HR=2.01, 95%CI: 1.45 to 2.79, P<0.01), with HR showing a progressively increasing trend as tumor size increased. (4) Subgroup analysis indicates that radical treatment may be more effective compared to palliative treatment in the following specific cases: well/moderately differentiated tumors (HR=2.84, 95%CI 1.49 to 5.41, P=0.001), and patients with liver metastases located in the left lobe of the liver (HR=2.06, 95%CI 1.19 to 3.57, P=0.010). Conclusions: In patients with IR-GCLM, radical surgery did not produce a significant improvement in the overall prognosis compared to palliative surgery. However, within specific patient subgroups (well/moderately differentiated tumors, and patients with liver metastases located in the left lobe of the liver), radical treatment can significantly improve prognosis compared to palliative approaches.
Subject(s)
Liver Neoplasms , Stomach Neoplasms , Humans , Male , Stomach Neoplasms/surgery , Stomach Neoplasms/pathology , Female , Retrospective Studies , Middle Aged , Aged , Liver Neoplasms/secondary , Liver Neoplasms/surgery , Adult , Prognosis , Survival Rate , Aged, 80 and over , Proportional Hazards Models , Palliative Care , Kaplan-Meier Estimate , Hepatectomy/methods , Treatment OutcomeABSTRACT
Objective: To investigate the association between the distribution of tumor infiltrating lymphocytes (TIL) in EBV associated lymphoepitheliomatoid carcinoma (LELC) and the pathological subtypes of LELC, as well as the clinical significance of TIL distribution. Methods: The LELC patients with sufficient tumor tissues, complete clinical data and positive EBER, who visited Zhejiang Cancer Hospital, Hangzhou, China from January 2006 to October 2018, were selected. Various immunohistochemical markers (CD20, CD138, CD4, CD8, CD56 and FOXP3) were examined for TIL typing. Two pathologists reviewed the hematoxylin and eosin (HE) staining sections and interpreted the immunohistochemical results. Correlation analysis was used to evaluate the relationship between the distribution of TIL subgroups and LELC's pathological characteristics. Survival analyses were conducted to study the prognostic values of TIL subgrouping. Results: A total of 102 patients with EBV related LELC were included. 46 of them were classic LELC (c-LELC) with rich interstitial TIL, and 56 were non-classic LELC (n-LELC) with relatively fewer interstitial TIL. The results of TIL analysis showed that all subtypes of c-LELC were rich in TIL, with B lymphocytes as the dominant subgroup. The number of TIL in n-LELC was fewer than that in c-LELC, with T lymphocytes as the dominant subgroup. There was no significant difference in the distribution of plasma cells between the two groups. Survival analysis showed that the total number of TIL, and the infiltrations of CD20+B cells, CD4+T cells, and FOXP3+Treg cells were associated with better overall survivals (P=0.004, 0.003, 0.008 and 0.025, respectively) and disease-free survivals (P=0.011, 0.003, 0.038 and 0.041, respectively) in patients with LELC. Conclusions: The morphologic subtypes of EBV-related LELC have different tumor immune characteristics. The total number of TIL in the stroma of c-LELC is significantly higher than that of n-LELC. Interestingly, B lymphocytes are the dominant TIL in c-LELC, while T lymphocytes are the dominant TIL in n-LELC. The infiltration of TIL, CD20+B cells, CD4+T cells and FOXP3+Treg cells in LELC may suggest a better prognosis.
Subject(s)
Carcinoma, Squamous Cell , Lymphocytes, Tumor-Infiltrating , Humans , Herpesvirus 4, Human , Clinical Relevance , Prognosis , Carcinoma, Squamous Cell/pathology , Forkhead Transcription FactorsABSTRACT
Objective: To explore the effect of remote "Internet+" interactive management strategy on blood pressure control in patients with hypertension during normalized epidemic prevention and control of COVID-19. Methods: This is a randomized controlled study. A total of 394 patients with hypertension who were treated in Chinese People's Liberation Army General Hospital from October 2019 to December 2020 were randomly divided into experimental group (197 cases) and control group (197 cases). The experimental group adopted remote "Internet+" interaction mode to carry out remote blood pressure intervention, and the control group received traditional blood pressure control mode, and the intervention time was 6 months. Evaluation indicators included blood pressure level, blood pressure lowering speed, time to target blood pressure, blood pressure measurement times, communication times with doctors, medication compliance, blood pressure measurement compliance and disease awareness after 6 months of intervention. The evaluation indexes of the two groups were compared, and the bivariate Pearson correlation analysis was used to explore the relationship between the speed of blood pressure reduction and the times of blood pressure measurement and doctor communication in all patients. Results: A total of 394 patients with hypertension were included in this study, including 209 males, aged (67.6±2.8) years old. After 6 months of intervention, the systolic and diastolic blood pressure of the two groups were both lower than the baseline blood pressure before intervention (both P<0.05), the systolic blood pressure ((125.7±11.7) mmHg (1 mmHg=0.133 kPa) vs. (132.6±12.9) mmHg, P<0.001) and diastolic blood pressure ((72.4±10.7) mmHg vs. (79.8±11.6) mmHg, P<0.001) in the experimental group were lower than those in the control group. The blood pressure reduction speed of the experimental group was faster than that of the control group ((18.63±1.59) mmHg/d vs. (13.26±2.85) mmHg/d, P<0.001), and the time to reach the target blood pressure in the experimental group was shorter than that in the control group ((23.69±2.93) d vs. (47.12±5.81) d, P<0.001). Compared with the control group, the blood pressure measurement times ((0.98±0.13) times/d vs. (0.20±0.40) times/d, P<0.05) and the number of communications with doctors ((0.97±0.16) times/week vs. (0.12±0.32) times/week, P<0.05) were significantly higher in the experimental group. Correlation analysis showed that the speed of blood pressure reduction was positively correlated with the number of blood pressure measurements (r=0.419, P<0.01) and the number of communications with doctors (r=0.857, P<0.01). The proportion of standardized medication (93.91% (185/197) vs. 51.78% (102/197), P<0.001), timely measurement (97.46% (192/197) vs. 47.21% (93/197), P<0.001) and high-degree disease awareness (94.42% (186/197) vs. 49.24% (97/197), P<0.001) were significantly higher in the experimental group than those in the control group. Conclusions: The remote "Internet+" interactive management strategy can effectively improve patients' blood pressure control. The doctor-patient interaction can improve medication compliance and measurement compliance of patients, and help shorten the time to reach the target blood pressure.
Subject(s)
COVID-19 , Epidemics , Hypertension , Aged , Blood Pressure , Humans , Hypertension/prevention & control , Internet , Male , Middle Aged , SARS-CoV-2ABSTRACT
Objective: To explore the imaging features in age-related cerebral small vessel disease (ArCSVD) with idiopathic normal pressure hydrocephalus (INPH). Methods: Ten cases of age-related cerebral small vessel disease (CSVD) with idiopathic normal pressure hydrocephalus admitted to the Third Affiliated Hospital of Sun Yat-sen University from December 2015 to March 2020 were retrospective analyzed, all patients met the inclusion and exclusion criteria, and completed the head Magnetic resonance angiography plain scan, T2 fluid attenuated inversion recovery and Susceptibility Weighted Imaging sequence. Deep marrow venous signs (DMVs), INPH severity (DESH score), cortical/subcortical and deep microhemorrhages (CMBs) statistics, paraventricular and deep white matter damage (WMH) severity and CSVD imaging burden score were acquired, and correlations of DMVs and DESH scores with CMBs, WMH and Burden scores were evaluated using Spearman correlation analysis. Results: DMVs and DESH scores were significantly and positively correlated (r=0.965 9, P<0.000 1). DMVs and DESH scores were not significantly correlated with cortical/subcortical CMBs and deep CMBs. Likewise, DMVs and DESH scores were not significantly correlated with deep WMH. The WMH score of paraventricular of the 10 cases was 3 points, and the Burden score was 4 points. Conclusion: DMVs may be an indicator of the severity of ArCSVD with INPH, due to the small sample size of the current study, more cases are needed for further verification.
Subject(s)
Cerebral Small Vessel Diseases , Hydrocephalus, Normal Pressure , White Matter , Cerebral Small Vessel Diseases/diagnostic imaging , Humans , Hydrocephalus, Normal Pressure/diagnostic imaging , Magnetic Resonance Imaging , Retrospective StudiesABSTRACT
Objective: To investigate the value of stereotactic biopsy in the accurate diagnosis of lesions in the brain stem and deep brain. Methods: A total of 29 consecutive patients who underwent stereotactic biopsy of brainstem and deep brain lesions between May 2012 and January 2018 were retrospectively reviewed. The Cosman-Roberts-Wells (CRW) stereotactic frame was installed under local anesthesia. Thin-layer CT and MRI scanning were performed. Target coordinates were calculated by inputting CT-MRI data into the radionics surgical planning system. The individualized puncture path was designed according to the location of the lesions and the characteristics of the image. Target distributions were as follows: 12 cases of midbrain or pons, 2 cases of internal capsule, 3 cases of thalamus, 12 cases of basal ganglia. The biopsy samples were used for further pathological and/or genetic diagnosis. Results: Twenty-eight of the 29 cases (96.6%) were diagnosed accurately by histopathology and genomic examination following stereotactic biopsy. Pathological results were as follows: 8 cases of lymphoma, 7 cases of glioma, 4 cases of demyelination, 2 cases of germ cell tumor, 2 cases of metastatic tumor, 1 cases of cerebral sparganosis, 1 case of tuberculous granuloma, 1 case of hereditary prion disease, 1 case of glial hyperplasia, 1 case of leukemia. The accurate diagnosis of one case required a combination of histopathology and genomic examination. Undefined diagnosis was still made in 1 cases (3.45%) after biopsy. After biopsy, there were 2 cases (6.9%) with symptomatic slight hemorrhage, 1 case (3.45%) with symptomatic severe hemorrhage, and 1 cass (3.45%) with permanent neurological dysfunction. No one died because of surgery or surgical complications. Conclusions: Stereotactic biopsy is fast, safe and minimally invasive. It is an ideal strategy for accurate diagnosis of lesions in brain stem and deep brain.
Subject(s)
Brain , Biopsy , Brain Neoplasms , Brain Stem , Humans , Retrospective Studies , Stereotaxic TechniquesABSTRACT
Antibody-secreting plasma cells are nonrecirculatory and lodge in splenic red pulp, lymph node medullary cords, and bone marrow. The factors that regulate plasma cell localization are poorly defined. Here we demonstrate that, compared with their B cell precursors, plasma cells exhibit increased chemotactic sensitivity to the CXCR4 ligand CXCL12. At the same time, they downregulate CXCR5 and CCR7 and have reduced responsiveness to the B and T zone chemokines CXCL13, CCL19, and CCL21. We demonstrate that CXCL12 is expressed within splenic red pulp and lymph node medullary cords as well as in bone marrow. In chimeric mice reconstituted with CXCR4-deficient fetal liver cells, plasma cells are mislocalized in the spleen, found in elevated numbers in blood, and fail to accumulate normally in the bone marrow. Our findings indicate that as B cells differentiate into plasma cells they undergo a coordinated change in chemokine responsiveness that regulates their movements in secondary lymphoid organs and promotes lodgment within the bone marrow.
Subject(s)
Chemokines, CXC/metabolism , Chemokines/metabolism , Plasma/cytology , Plasma/metabolism , Receptors, CXCR4/metabolism , Animals , Bone Marrow/metabolism , Cell Movement , Chemokine CCL19 , Chemokine CCL21 , Chemokine CXCL12 , Chemokine CXCL13 , Chemokines, CC/metabolism , Chemokines, CXC/genetics , Female , Lymph Nodes/physiology , Male , Mice , Mice, Inbred Strains , Mice, Mutant Strains , Receptors, CCR7 , Receptors, CXCR4/genetics , Receptors, CXCR5 , Receptors, Chemokine/metabolism , Receptors, Cytokine/metabolism , Spleen/physiologyABSTRACT
BACKGROUND: Reliable tools for patient selection are critical for clinical drug trials. AIM: To evaluate a consensus-based, standardised magnetic resonance enterography (MRE) protocol for selecting patients for inclusion in Crohn's disease (CD) multicenter clinical trials. METHODS: This study recruited 20 patients [Crohn's Disease Activity Index (CDAI) scores: <150 (n = 8); 150-220 (n = 4); 220-450 (n = 8)], to undergo ileocolonoscopy and two MREs (with and without colonic contrast) within a 14-day period. Procedures were scored centrally using, Magnetic Resonance Index of Activity (MaRIA), and both Crohn's Disease Endoscopic Index of Severity (CDEIS) and Simplified Endoscopic Score (SES-CD). RESULTS: 37 MREs were acquired. Both MREs were evaluable in 16 patients for calculation of test-retest and inter-reader reliability scores. The MaRIA scores for the terminal ileum had excellent test-retest and inter-reader reliability, with correlations >0.9. The proximal ileum showed strong within-reader agreement (0.90-0.96), and fair between-reader agreement (0.59-0.72). MRE procedures were tolerable. MaRIA scores correlated with CDEIS and SES-CD (0.63 and 0.71), but not with CDAI (0.34). MRE identified 3 patients with intra-abdominal complications, who would otherwise have been included in clinical trials. Furthermore, both MRE and ileocolonoscopy identified active bowel wall inflammation in 2 patients with CDAI <150, and none in 1 patient with CDAI > 220. Data quality was good/excellent in 85% of scans, and fair or better in 96%. CONCLUSIONS: Magnetic resonance enterography of high-quality and reproducibility was feasible in a global multi- centre setting, with evidence for improved selectivity over CDAI and ileocolonoscopy in identifying appropriate CD patients for inclusion in therapeutic intervention trials.
Subject(s)
Crohn Disease/pathology , Endoscopy, Gastrointestinal/methods , Magnetic Resonance Spectroscopy/methods , Multicenter Studies as Topic/methods , Patient Selection , Adult , Colon/pathology , Endoscopy, Gastrointestinal/standards , Female , Humans , Ileum/pathology , Inflammation/pathology , Magnetic Resonance Spectroscopy/standards , Male , Middle Aged , Reproducibility of ResultsABSTRACT
OBJECTIVE: To evaluate the patterns, related factors and prognostic value of abnormal magnetic resonance angiography (MRA) in human immunodeficiency virus negative tuberculous meningitis. MATERIALS AND METHODS: We performed a prospective study in patients aged >14 years. Abnormality on MRA was correlated with clinical, laboratory and magnetic resonance imaging findings. Modified Barthel index was used to assess outcome at 6 months after inclusion. RESULTS: Of 101 patients included, MRA was abnormal in 45 (44.6%). The distribution of MRA abnormality was classified as disseminated irregular calibres of intracranial arteries with or without reduction in distant branches (29.7%, pattern 1) and localised stenosis at the base of the brain (26.7%, pattern 2). In logistic regression analysis, pattern 2 was related to stage of the disease (P = 0.002), basal exudates (P = 0.03) and infarction (P = 0.000), while pattern 1 was related to duration of disease (P = 0.050), hydrocephalus (P = 0.032) and age (P = 0.002). Pattern 1 was also correlated with infarction (P = 0.000), particularly infarction in the tubercular zone (P = 0.035) in univariate analysis. MRA abnormality was associated with paradoxical worsening (P = 0.022) and poor prognosis in univariate analysis (P = 0.035). CONCLUSION: MRA abnormality is associated with stroke and poor outcomes. Although it indicates mild vascular injury, pattern 1 MRA abnormality is nevertheless associated with infarction and needs proper intervention.
Subject(s)
Hydrocephalus/diagnosis , Magnetic Resonance Angiography , Stroke/complications , Tuberculosis, Meningeal/complications , Adolescent , Adult , Aged , Aged, 80 and over , Constriction, Pathologic/diagnosis , Female , HIV Seronegativity , Humans , Logistic Models , Male , Middle Aged , Prognosis , Prospective Studies , Young AdultABSTRACT
Lipids (cholesterol and fatty acids) are essential nutriments and have a major impact on gene expression. Hence cholesterol intracellular concentration is precisely controlled by some complex mechanisms involving transcriptional regulations. The excess of cholesterol in cells is converted into oxysterols. These cholesterol metabolites are important signalisation molecules that modulate several transcription factors involved in cholesterol homeostasis. Schematically, regulation of cholesterol homeostasis is achieved by three different but complementary pathways: 1) endogeneous biosynthesis, which corresponds to the de novo synthesis of cholesterol and is controlled by sterol response element binding proteins (SREBPs); 2) the transport, intracellular absorption and esterification of the cholesterol; 3) the metabolic conversion into bile acids and steroid hormones. These three pathways are closely linked, however we will schematically detail the role of the orphan nuclear receptors on the modulation of these three levels of regulation. Phenotype analyses of knock-out or transgenic mice pointed out the respective role of the "enterohepatic" orphan nuclear receptors LXRalpha, LXRB, FXR, LRH-1, the nuclear receptor PPARalpha, and their heterodimeric partner RXR, as well as the peculiar receptor SHP. Complex feed-backs have thus been demonstrated. These transciptional regulations have several targets: the P450 cytochromes involved in the bile acid synthesis Cyp7a1 and Cyp8b1; the intestinal bile acid binding protein IBABP; the cholesteryl ester transfert protein CETP and phospholipid transfert protein PLTP, both involved in the HDL catabolism; the ABC cholesterol transporters ABCG1/ABC8 and ABCAI/ABCI. At last it seems that polyunsaturated fatty acids could activate LXRalpha transcription through its activation by PPARalpha. In the near future, the identification and study of new target genes by transcriptomic or proteomic analyses will allow a better understanding of lipid homeostasis in physiological as well as pathophysiological conditions.
Subject(s)
Homeostasis , Lipid Metabolism , Receptors, Cytoplasmic and Nuclear/physiology , Animals , Bile Acids and Salts/metabolism , Biological Transport , Cholesterol/biosynthesis , Cholesterol/metabolism , Fatty Acids/metabolism , Humans , Mice , Mice, Knockout , Mice, Transgenic , Steroids/metabolismABSTRACT
Platelet-endothelial cell adhesion molecule 1 (PECAM-1, CD31) is a 130-kDa member of the immunoglobulin gene superfamily expressed on endothelial cells, platelets, neutrophils, and monocytes and plays a role during endothelial cell migration. Phosphoamino acid analysis and Western blot analysis with anti-phosphotyrosine antibody show that endothelial PECAM-1 is tyrosine-phosphorylated. Phosphorylation is decreased with endothelial cell migration on fibronectin and collagen and with cell spreading on fibronectin but not on plastic. Cell adhesion on anti-integrin antibodies is also able to specifically induce PECAM-1 dephosphorylation while concurrently inducing pp125 focal adhesion kinase phosphorylation. Inhibition of dephosphorylation with sodium orthovanadate suggests that this effect is at least partially mediated by phosphatase activity. Tyr-663 and Tyr-686 are identified as potential phosphorylation sites and mutated to phenylalanine. When expressed, both mutants show reduced PECAM-1 phosphorylation but Phe-686 mutants also show significant reversal of PECAM-1-mediated inhibition of cell migration and do not localize PECAM-1 to cell borders. Our results suggest that beta 1-integrin engagement can signal to dephosphorylate PECAM-1 and that this signaling pathway may play a role during endothelial cell migration.
Subject(s)
Endothelium, Vascular/physiology , Platelet Endothelial Cell Adhesion Molecule-1/metabolism , 3T3 Cells , Animals , Cell Adhesion , Cell Adhesion Molecules/metabolism , Cell Movement , Cells, Cultured , Endothelium, Vascular/cytology , Fibronectins , Focal Adhesion Kinase 1 , Focal Adhesion Protein-Tyrosine Kinases , Humans , Male , Mice , Mutagenesis, Site-Directed , Phosphorylation , Phosphotyrosine/metabolism , Platelet Endothelial Cell Adhesion Molecule-1/chemistry , Protein Tyrosine Phosphatases/metabolism , Protein-Tyrosine Kinases/metabolism , Rats , Recombinant Proteins/metabolism , Transfection , Tyrosine , Umbilical VeinsABSTRACT
Platelet endothelial cell adhesion molecule-1 (PECAM-1) is 130-kDa member of the immunoglobulin gene superfamily that localizes to cell-cell borders of confluent endothelial cells and has been shown to play a role in the control of endothelial sheet migration and leukocyte transmigration through the endothelium. The cytoplasmic tail plays an important role in the modulation of PECAM-1 function. Mutation of tyrosine 663 or 686 in the cytoplasmic tail reduces phosphorylation and mutation of 686 is associated with a reduction in PECAM-1-mediated inhibition of cell migration (1). We have previously noted that these two tyrosine residues are surrounded by consensus sequences for Src homology 2 (SH2) domain binding (1, 2), and the experiments presented explore the potential for PECAM-1-Src and PECAM-1-SH2 domain interactions. PECAM-1 is more highly phosphorylated in endothelial cells overexpressing c-Src, and in in vitro kinase assays, c-Src can phosphorylate a glutathione S-transferase (GST)-PECAM cytoplasmic tail fusion protein. The phosphorylated fusion protein associates with the bead-bound c-Src. This association appears to be mediated by Src-SH2 domain, because PECAM-1 can be precipitated by a GST-Src-SH2 affinity matrix. The binding to the GST-Src-SH2 affinity matrix correlates directly with the level of PECAM-1 phosphorylation, because more PECAM-1 is precipitated from c-Src overexpressors and from wild-type rather than Tyr663 --> Phe and Tyr686 --> Phe mutant PECAM-1 expressors. Yet unidentified phosphoproteins can also be coimmunoprecipitated with wild-type but not mutant PECAM-1. Finally, we note the similarity of the PECAM-1 cytoplasmic domain sequence to the immunoreceptor tyrosine-based activation motif. Our data begin to delineate how tyrosines 663 and 686 may play a role in mediating PECAM-1 signal transduction.
Subject(s)
Platelet Endothelial Cell Adhesion Molecule-1/chemistry , Receptors, Immunologic/metabolism , src Homology Domains/genetics , Genes, src , Humans , Phosphorylation , Platelet Endothelial Cell Adhesion Molecule-1/genetics , Platelet Endothelial Cell Adhesion Molecule-1/metabolism , Point Mutation , Receptors, Immunologic/genetics , TyrosineABSTRACT
The catabolism of cholesterol into bile acids is regulated by oxysterols and bile acids, which induce or repress transcription of the pathway's rate-limiting enzyme cholesterol 7alpha-hydroxylase (CYP7A1). The nuclear receptor LXRalpha binds oxysterols and mediates feed-forward induction. Here, we show that repression is coordinately regulated by a triumvirate of nuclear receptors, including the bile acid receptor, FXR; the promoter-specific activator, LRH-1; and the promoter-specific repressor, SHP. Feedback repression of CYP7A1 is accomplished by the binding of bile acids to FXR, which leads to transcription of SHP. Elevated SHP protein then inactivates LRH-1 by forming a heterodimeric complex that leads to promoter-specific repression of both CYP7A1 and SHP. These results reveal an elaborate autoregulatory cascade mediated by nuclear receptors for the maintenance of hepatic cholesterol catabolism.