How to implement minimally invasive duodenum-preserving total pancreatic head resection for patients with pancreatic head lesions: A retrospective study.

Laparoscopic duodenum-preserving pancreatic head resection (LDPPHR) has been widely reported. However, due to the challenges involved in performing total pancreatic head resection during operation, there are few studies reporting it. Between November 2016 and October 2022, we performed laparoscopic duodenum-preserving total pancreatic head resection (LDPPHRt) on 64 patients in the Department of Hepatobiliary Surgery, the Second Hospital of Hebei Medical University. Perioperative data of the patients such as age, gender, body mass index, operation time, blood loss, and postoperative hospital stay were collected and analyzed. This study included 40 women and 24 men aged 41.4 ±â€…15.7 years. All patients completed the surgery, and none of the patients underwent laparotomy. The average operation time was 275 (255, 310) min. The average postoperative hospital stay was 12 (10, 16) days. The rate of occurrence of pancreatic fistula was 10.9% (7/64), and that of the biliary fistula was 9.4% (6/64). One of the patients underwent cholangiojejunostomy 3 months after the operation due to painless jaundice and bile duct dilatation. By dissecting the space between the pancreatic head and duodenum, the posterior pancreatic duodenal arterial arch and the surface vascular network of the common bile duct (CBD) can be preserved. This ensures the success of LDPPHRt and avoids postoperative complications in the absence of intraoperative image guidance.

Application of a New Approach for Laparoscopic Resection of Bismuth IIIa Hilar Cholangiocarcinoma.

Background: Hilar cholangiocarcinoma (HCCA) has a high degree of malignancy and poor prognosis, and the best long-term prognosis can only be achieved by radical resection. However, the surgical steps are complicated, and the operating space is limited, making it hard to complete laparoscopically. So our team proposes a new surgical approach for laparoscopic left-liver-first anterior radical modular orthotopic right hemihepatectomy (Lap-Larmorh). In this way, we can simplify the operation steps and reduce the difficulty. Materials and Methods: We recorded and analyzed the clinical data of 26 patients with type IIIa HCCA, who underwent laparoscopic radical resection in our department from December 2018 to January 2023. According to the laparoscopic surgical approach, we divided the patients into the new approach (NA) group (n = 14) using the Lap-Lamorh and the traditional approach (TA) group (n = 12) not using the Lap-Lamorh. Results: All surgeries in this study were completed laparoscopically with no conversion to open surgery. The operation time in the NA group and TA group had statistically significant differences, which was 372.5 (332.8, 420.0) minutes versus 423.5 (385.8, 498.8) minutes (P = .019). The two groups showed no significant difference in other characteristics (P > .05). Only 1 patient suffered from transient liver failure due to portal vein thrombosis. Patients with pleural effusion or ascites were cured by catheter drainage and enhanced nutrition. Conclusion: Lap-Larmorh reduces the difficulty of serving the vessels at the second and third hepatic hilum by splitting the right and left livers early intraoperatively. The new approach is more suitable for the narrow space of laparoscopic surgery and reflects the no-touch principle of oncology.

A Novel Polysaccharide Separated from Panax Notoginseng Residue Ameliorates Restraint Stress- and Lipopolysaccharide-induced Enteritis in Mice.

Polysaccharides are rich in Panax notoginseng residue after extraction. This study aims to explore the structural characteristics of PNP-20, which is a homogeneous polysaccharide, separated from P. notoginseng residue by fractional precipitation and evaluate the anti-enteritis effect of PNP-20. The structure of PNP-20 was determined by spectroscopic analyses. A mouse model with enteritis induced by restraint stress (RS) and lipopolysaccharide (LPS) was used to evaluate the pharmacological effect of PNP-20. The results indicated that PNP-20 consisted of glucose (Glc), galactose (Gal), Mannose (Man) and Rhamnose (Rha). PNP-20 was composed of Glcp-(1→, →4)-α-Glcp-(1→, →4)-α-Galp-(1→, →4,6)-α-Glcp-(1→, →4)-Manp-(1→ and →3)-Rhap-(1→, and contained two backbone fragments of →4)-α-Glcp-(1→4)- α-Glcp-(1→ and →4)-α-Galp-(1→4)-α-Glcp-(1→. PNP-20 reduced intestinal injury and inflammatory cell infiltration in RS- and LPS-induced enteritis in mice. PNP-20 decreased the expression of intestinal tumor necrosis factor-α, NOD-like receptor family pyrin domain containing 3, and nuclear factor-κB and increased the expression of intestinal superoxide dismutase 2. In conclusion, PNP-20 may be a promising material basis of P. Notoginseng for the treatment of inflammatory bowel disease.

Genome-wide identification and characterization of tomato 14-3-3 (SlTFT) genes and functional analysis of SlTFT6 under heat stress.

The plant 14-3-3 proteins are essential for many biological processes and responses to abiotic stress. We performed genome-wide identification and analysis of the 14-3-3 family genes in tomato. To explore the properties of the thirteen Sl14-3-3 found in the tomato genome, their chromosomal location, phylogenetic, and syntenic relationships were analyzed. The Sl14-3-3 promoters were found to have a number of growth-, hormone-, and stress-responsive cis-regulatory elements. Moreover, the qRT-PCR assay revealed that Sl14-3-3 genes are responsive to heat and osmotic stress. Subcellular localization experiments evidenced that the SlTFT3/6/10 proteins occur in the nucleus and cytoplasm Additional analysis on Sl14-3-3 putative interactor proteins revealed a number of prospective clients that potentially participate in stress reactions and developmental processes. Furthermore, overexpression of an Sl14-3-3 family gene, SlTFT6, improved tomato plants thermotolerance. Taken together, the study provides basic information on tomato 14-3-3 family genes in plant growth and abiotic stress response (high temperature stress), which can be helpful to further study the underlying molecular mechanisms.

A bHLH transcription factor, SlbHLH96, promotes drought tolerance in tomato.

Drought stress caused by water deficit reduces plant productivity in many regions of the world. In plants, basic helix-loop-helix (bHLH) transcription factors regulate a wide range of cellular activities related to growth, development and stress response; however, the role of tomato SlbHLHs in drought stress responses remains elusive. Here, we used reverse genetics approaches to reveal the function of SlbHLH96, which is induced by drought and abscisic acid (ABA) treatment. We found that SlbHLH96 functions as a positive regulator of drought tolerance in tomato. Overexpression of SlbHLH96 in tomato improves drought tolerance by stimulating the expression of genes encoding antioxidants, ABA signaling molecules and stress-related proteins. In contrast, silencing of SlbHLH96 in tomato reduces drought tolerance. SlbHLH96 physically interacts with an ethylene-responsive factor, SlERF4, and silencing of SlERF4 in tomato also decreases drought tolerance. Furthermore, SlbHLH96 can repress the expression of the ABA catabolic gene, SlCYP707A2, through direct binding to its promoter. Our results uncover a novel mechanism of SlbHLH96-mediated drought tolerance in tomato plants, which can be exploited for breeding drought-resilient crops.

Rapid discovery of potential ADR compounds from injection of total saponins from Panax notoginseng using data-independent acquisition untargeted metabolomics.

Injection of total saponins from Panax notoginseng (ISPN) is a modern preparation derived from traditional Chinese medicine (TCM) and is widely applied in the treatment of cardiovascular, cerebrovascular, ophthalmology, and endocrine system diseases. With the increase in the clinical application of ISPN, its adverse drug reactions (ADRs) and related safety issues have attracted much attention. In the present study, a data-independent acquisition (DIA) strategy was proposed to comprehensively characterize the saponins contained in ISPN based on the ultra-high-performance liquid chromatography/quadrupole-Orbitrap MS (UHPLC/Q-Orbitrap MS) platform. As many as 276 saponins were detected, and 250 compounds were identified or tentatively identified based on the retention times and MS/MS data. Furthermore, a metabolomic strategy was utilized to discover the discriminative saponins between normal and ADR batches. The results showed that six saponins, including ginsenoside Rh4, ginsenoside Rk3, ginsenoside Rg5, ginsenoside Rk1, ginsenoside Rg6, and 20(S)-ginsenoside Rh2, were significantly different between the two groups. According to cytotoxicity analysis and degranulation detection of RBL-2H3 cells, ginsenoside Rg5, ginsenoside Rk1, and 20(S)-ginsenoside Rh2 were considered the potential compounds responsible for clinical ADRs, ultimately. In addition, the quantitative analysis showed that the content of these three compounds in ISPN samples with ADRs was generally higher than that in samples without ADRs. This study demonstrated that it is advisable to screen out potential markers related to ADRs for developing the quality standard of ISPN by the integration of untargeted metabolomic analysis and cell biology study, and thus reduce its ADRs in the clinic.

Cardiotoxicity induced by Cochinchina momordica seed extract in zebrafish.

Momordica cochinchinensis (Lour.) Spreng is an indigenous South Asian edible fruit, and seeds of Momordica cochinchinensis have been used therapeutically in traditional Chinese medicine. Previous studies have shown that M. cochinchinensis seed (Momordicae Semen) has various pharmaceutical properties such as antioxidant and anti-ulcer effects as well as contains secondary metabolites with potential anticancer activities such as triterpenoids and saponins. Recent studies reported that water extract and ethanol extract of M. cochinchinensi seed were tested on mammals using an acute toxic classic method as OECD guidelines 420. No matter injected intravenously or intramuscularly, animals died within several days. In this study, zebrafish embryos were exposed to various doses of Cochinchina momordica seed extract (CMSE) from 2 dpf (days post fertilization, dpf) to 3 dpf. CMSE-induced cardiotoxicity such as pericardial edema, cardiac apoptosis, increased ROS production, cardiac neutrophil infiltration, decreased blood flow velocity, and reduced expression of three marker genes of cardiac functions were found in zebrafish roughly in a dose-dependent manner. These results suggest that CMSE may induce cardiotoxicity through pathways involved in inflammation, oxidative stress, and apoptosis.

Notoginsenoside R1 activates the Ang2/Tie2 pathway to promote angiogenesis.

BACKGROUND: Therapeutic angiogenesis is a novel strategy for the treatment of ischemic diseases that involves promotion of angiogenesis in ischemic tissues via the use of proangiogenic agents. However, effective proangiogenic drugs that activate the Ang2/Tie2 signaling pathway remain scarce. PURPOSE: We aimed to investigate the proangiogenic activity of notoginsenoside R1 (NR1) isolated from total saponins of Panax notoginseng with regard to activation of the Ang2/Tie2 signaling pathway. METHODS: We examined the proangiogenic effects of NR1 by assessing the effects of NR1 on the proliferation, migration, invasion and tube formation of human umbilical vein endothelial cells (HUVECs). The aortic ring assay and vascular endothelial growth factor receptor inhibitor (VRI)-induced vascular regression in the zebrafish model were used to confirm the proangiogenic effects of NR1 ex vivo and in vivo. Furthermore, the molecular mechanism was investigated by Western blot analysis. RESULTS: We found that NR1 promoted the proliferation, mobility and tube formation of HUVECs in vitro. NR1 also increased the number of sprouting vessels in rat aortic rings and rescued VRI-induced vascular regression in zebrafish. NR1-induced angiogenesis was dependent on Tie2 receptor activation mediated by increased autocrine Ang2 in HUVECs, and inhibition of the Ang2/Tie2 pathway abrogated the proangiogenic effects of NR1. CONCLUSIONS: Our results suggest that NR1 promotes angiogenesis by activating the Ang2/Tie2 signaling pathway. Thus, NR1-induced activation of the Ang2/Tie2 pathway is an effective proangiogenic approach. NR1 may be useful agent for the treatment of ischemic diseases.

Aggregation-induced emission compounds based on 9,10-diheteroarylanthracene and their applications in cell imaging.

Four centrosymmetric 9,10-diheteroarylanthracene (DHA) derivatives, including 9,10-dithienylanthracene (DTA), 9,10-difurylanthracene (DFA), 9,10-di-(N-t-butyloxycarboryl-2-pyrryl)anthracene (DBPA), and 9,10-dipyrrylanthracene (DPA) have been synthesized and characterized. All of these DHA derivatives displayed distinct aggregation-induced emission (AIE) behaviors except for DBPA, which showed typical aggregation-caused quenching (ACQ) properties. Their crystal structures exhibited nonplanar conformations on account of the intramolecular torsional effects and intramolecular interactions in rigid molecules. The investigation of the effects of the anthracene core and the side heterocyclic units on the AIE properties demonstrated that the heterocycle moiety is the key factor for the AIE features. These DHA AIEgens exhibited excellent bioimaging performance under physiological conditions.

Bifunctional Cu2+/Fe3+ Probe with Independent Signal Outputs Based on a Photochromic Diarylethene with a Dansylhydrazine Unit.

A novel dual-response fluorescent sensor based on a diarylethene photoswitching unit and a dansylhydrazine functional group has been synthesized. The compound exhibited high selectivity for Fe3+ and Cu2+ with independent fluorescence signal outputs. In the presence of Fe3+, the sensor formed a 1:1 metal complex, resulting in a remarkable "turn-off" fluorescence signal. On the other hand, its fluorescence intensity was notably enhanced (turn-on) and a color change from bright yellow to bright blue was observed when the sensor interacted with Cu2+, which was due to the hydrolysis reaction of the dansyl acid dye, as confirmed by high-resolution mass spectrometry-electrospray ionization and infrared spectrum. The detection limits were 9.73 × 10-8 mol L-1 for Fe3+ and 3.49 × 10-7 mol L-1 for Cu2+, respectively. From the unimolecular platform, two molecular logic circuits were constructed using the fluorescence emission intensity at 557/494 nm (Fe3+/Cu2+) as the outputs and the combined stimuli of Fe3+/ethylenediaminetetraacetic acid, Cu2+, and UV/vis as the inputs. In addition, the sensor was successfully used to determine Fe3+ in water samples from Ganjiang River and soil samples from Nanchang fields.

Effects of heteroaryl ring on the photochromism of asymmetrical diarylethenes containing a naphthalene group.

Photochromic asymmetrical diarylethene derivatives 1o-4o bearing different benzo-five-membered heterocyclic rings were synthesized and characterized with single-crystal X-ray diffraction microscopy. The effects of heterocyclic ring on their properties including the photochromic behaviors in solution, solid state and crystalline phase were systematically investigated. The diarylethenes bearing benzothiophene or indole ring exhibited high cyclization quantum yields in solution, and evidently enhanced the fluorescent modulation efficiency in solid state, while those containing benzofuran or thiophene ring exhibited the opposite behaviors. In addition, indole ring red-shifted the absorption maximum, and notably enhanced the fatigue resistance of the diarylethene. These results indicate that heteroaryl ring played an important role in the photoisomerization of these diarylethenes, causing the heterocyclic effect.

Stress Hormone Cortisol Enhances Bcl2 Like-12 Expression to Inhibit p53 in Hepatocellular Carcinoma Cells.

BACKGROUND AND AIMS: The pathogenesis of hepatocellular carcinoma (HC) is unclear. It is suggested that psychological stress associates with the pathogenesis of liver cancer. Bcl2-like protein 12 (Bcl2L12) suppresses p53 protein. This study tests a hypothesis that the major stress hormone, cortisol, inhibits the expression of p53 in HC cells (HCC) via up regulating the expression of Bcl2L12. METHODS: Peripheral blood samples were collected from patients with HC to be analyzed for the levels of cortisol. HCC were cultured to assess the role of cortisol in the regulation of the expression of Bcl2L12 and p53 in HCC. RESULTS: We observed that the serum cortisol levels were higher in HC patients. Expression of Bcl2L12 in HCC was correlated with serum cortisol. Cortisol enhanced the Bcl2L12 expression in HCC. Bcl2L12 binding to the TP53 promoter was correlated with p53 expression in HCC. Cortisol increased the Bcl2L12 expression in HCC to inhibit p53 expression. CONCLUSIONS: Stress hormone cortisol suppresses p53 in HCC via enhancing Bcl2L12 expression in HCC. The results suggest that cortisol may be a therapeutic target for the treatment of HC.

MiR-7 inhibits progression of hepatocarcinoma by targeting KLF-4 and promises a novel diagnostic biomarker.

BACKGROUND: MicroRNAs are 22-24 nt non-coding RNAs that bind to the 3' UTR of target mRNAs, thereby inducing mRNA degradation or inhibiting mRNA translation. Due to their implication in the regulation of post-transcriptional processes, the role of miRNAs in hepatocellular carcinoma (HCC) has been extensively studied. However, the function of miR-7 in HCC remains to be demonstrated. METHODS: 50 paired HCC tissues and matched peritumor tissues from patients were collected. The mRNA level of miR-7 was detected by qRT-PCR. The protein level of Kruppel-like factor 4 (KLF-4) was determined by western blot. Cell proliferation and invasive ability were measured using MTT and transwell invasion assay, respectively. RESULTS: We demonstrated that miR-7 was downregulated in 50 HCC tissues and the low expression of miR-7 was significantly correlate with tumour size. Moreover, overexpression of miR-7 significantly inhibited the proliferation and invasion of HCC cells. Over 100 target genes of miR-7 were predicted by Targetscan, and KLF-4 was indicated as the most promising candidate. Luciferase report assay showed that KLF-4 could be silenced by miR-7, so as to restore the impairment of cell proliferation and invasion in HCC cells. CONCLUSIONS: In summary, we revealed a role of miR-7-KLF-4 axis in HCC cells, and the combination of both biomarkers might improve HCC diagnosis.

Fine antigenic variation within H5N1 influenza virus hemagglutinin's antigenic sites defined by yeast cell surface display.

Fifteen strains of mAb specific for HA of the A/Hong Kong/482/97 (H5N1) influenza virus were generated. The HA antigenic sites of the human A/Hong Kong/482/97 (H5N1) influenza virus were defined by using yeast cell surface-displaying system and anti-H5 HA mAb. Evolution analysis of H5 HA identified residues that exhibit diversifying selection in the antigenic sites and demonstrated surprising differences between residue variation of H5 HA and H3 HA. A conserved neutralizing epitope in the H5 HA protein recognized by mAb H5M9 was found using viruses isolated from 1997-2006. Seven single amino acid substitutions were introduced into the HA antigenic sites, respectively, and the alteration of antigenicity was assessed. The structure obtained by homology-modeling and molecular dynamic methods showed that a subtle substitution at residue 124 propagates throughout its nearby loop (152-159). We discuss how the structural changes caused by point mutation might explain the altered antigenicity of the HA protein. The results demonstrate the existence of immunodominant positions in the H5 HA protein, alteration of these residues might improve the immunogenicity of vaccine strains.

Evaluation of the safety, immunogenicity and pharmacokinetics of equine anti-SARS-CoV F(ab')(2) in macaque.

To warrant potential clinical testing, the equine anti-SARS-CoV F(ab')(2) requires evaluation in as many animal models as possible and a safety test in a primate model. In this study, we evaluated the pharmacokinetics, tolerance and immunity of this kind of antibody in macaques and rats. Results showed that the F(ab')(2) fragments had a normal metabolism in injected animals. The general physiological indexes did not differ between animals injected with anti-SARS-CoV F(ab')(2) or saline. However, a mild inflammatory response in local injection site and a moderate immune response against this antibody in the successively injected animals were observed, which however recovered 3 weeks after the last injection. The antibody titring from 1:100 to 400 against the equine anti-SARS-CoV F(ab')(2) in the inoculated hosts could be detected at week 2 during the successive injections of the equine F(ab')(2). The considerable safety of this antibody used in primates and the fact that the immune system of the host can be motivated by post-injection of the F(ab')(2) indicate that this type of anti-SARS-CoV antibody can be used for prevention and treatment of SASR, especially at the early stage of this virus infection. In addition, it can also provide the precious time for the combined use of other anti-SARS-CoV agents such as antiviral drug and vaccine.

Protection from infection with severe acute respiratory syndrome coronavirus in a Chinese hamster model by equine neutralizing F(ab')2.

To warrant potential clinical testing, the equine anti-severe acute respiratory syndrome coronavirus (SARS-CoV) F(ab')(2) requires evaluation in as many animal models as possible. In this study, we established a new animal model, the Chinese hamster, susceptible to SARS-CoV infection. SARS-CoV could propagate effectively and sustain high levels for 1 wk in animal lungs. All animals were protected from SARS-CoV infection in preventive settings. Further, when used therapeutically this antibody led to an approximately 4-log(10) decrease in viral burden in infected animal lungs. The pathological changes in lungs correlated closely with the dose of antibody administered. The excellent preventive and therapeutic roles of equine anti-SARS-CoV F(ab')(2) in several animal models, including the novel Chinese hamster model described in this study, have provided exciting data concerning its potential clinical study.

Inhibition of severe acute respiratory syndrome-associated coronavirus infection by equine neutralizing antibody in golden Syrian hamsters.

Equine anti-severe acute respiratory syndrome-associated coronavirus F(ab')(2) has been verified to protect mice from infection with severe acute respiratory syndrome-associated coronavirus (SARS-CoV). However, before potential clinical application, the antibody needs to be tested in as many animal models as possible to ensure its safety and efficiency. In this study, after verification by various methods that the golden Syrian hamster constitutes a model susceptible to SARS-CoV infection, we confirmed that the antibody could protect animals completely from SARS-CoV infection in the preventive setting. More importantly, the antibody could reduce viral titers or copies by approximately 10(3)- to 10(4)-fold in animal lung after virus exposure, compared with negative control. These data provide further evidence to warrant clinical studies of this antibody in the treatment and prevention of SARS.

Inhibition of infection caused by severe acute respiratory syndrome-associated coronavirus by equine neutralizing antibody in aged mice.

The high susceptibility of elderly to severe acute respiratory syndrome-associated coronavirus (SARS-CoV) indicates how crucial it is to protect the elderly by various strategies. Aged BALB/c mice displayed a high susceptibility to SARS-CoV and have been a valuable platform for evaluation of strategies against SARS-CoV infection. In this study, we confirmed the validity of this model using various methods, and verified that equine anti-SARS-CoV F(ab')(2) can prevent aged animals from SARS-CoV infection. In a therapeutic setting, treatment with anti-SARS-CoV F(ab')(2) decreased viral load more than several thousand folds in the lungs. Thus, this antibody should be a potential candidate for treatment of elderly patients suffering from SARS.

TLR2 and TLR4 agonists synergistically up-regulate SR-A in RAW264.7 through p38.

It is known that macrophage scavenger receptor A (SR-A) can protect mice from endotoxemia. In addition, Escherichia coli O111:B4 LPS from Sigma (sLPS), which contains both TLR4 and TLR2 agonists, was previously reported to be able to induce SR-A expression on murine macrophage cell line RAW264.7. However, the relative role of both TLR4 and TLR2 agonists from Sigma (sLPS) in the up-regulation of SR-A on RAW264.7 is still undefined. Here, we found that sLPS could only slightly up-regulate SR-A on RAW264.7 following removing its TLR4 and TLR2 agonists, respectively. In contrast, the combination of TLR4 agonist uLPS (re-extracted sLPS) and TLR2 agonist Pam3CSK4 dramatically induced SR-A expression, and synergistically promoted RAW264.7 to bind and internalize FITC-LPS specifically through SR-A. The combination had no such effect either on TLR2 or TLR4 expression, and incubation with IL-6, IL-10, IL-12 or TNF-alpha alone could not induce SR-A expression on RAW264.7. In addition, treatment with a NF-kappaB inhibitor pyrrolidine dithiocarbamate (PDTC) could only weakly suppress the up-regulation of SR-A by the combination. However, the combination synergistically promoted MAPK p38 phosphorylation, and p38 specific inhibitor SB203580 completely suppressed its inducible effect on SR-A expression. Hence, we demonstrated that up-regulation of SR-A by sLPS was resulted from the cooperation of its TLR4 and TLR2 agonists through p38, and we also presented a novel synergy effect of TLR2 and TLR4 agonists.

Comprehensive antibody epitope mapping of the nucleocapsid protein of severe acute respiratory syndrome (SARS) coronavirus: insight into the humoral immunity of SARS.

BACKGROUND: The epidemic outbreak of severe acute respiratory syndrome (SARS) posed a worldwide threat to public health and economic stability. Although the pandemic has been contained, concerns over its recurrence remain. It is essential to identify specific diagnostic agents and antiviral vaccine candidates to fight this highly contagious disease. METHODS: We generated 14 monoclonal antibodies (mAbs) specific to the SARS coronavirus (SARS-CoV) nucleocapsid (N) protein and used these to thoroughly map the N protein antigenic determinants. We identified the immunodominant antigenic sites responsible for the antibodies in sera from SARS patients and antisera from small animals and differentiated the linear from the conformational antibody-combining sites comprising the natural epitopes by use of yeast surface display. RESULTS: We identified 5 conformational and 3 linear epitopes within the entire N protein; 3 conformational and 3 linear epitopes were immunodominant. The antibody responses to the N protein fragments in mammalian sera revealed that 3 regions of the N protein are strong antigenic domains. We expanded the specificity of the N protein epitope and identified 4 novel conformational epitopes (amino acids 1-69, 68-213, 212-341, and 337-422). CONCLUSION: The antigenic structures identified for the SARS-CoV N protein, the epitope-specific mAbs, and the serum antibody profile in SARS patients have potential use in the clinical diagnosis and understanding of the protective immunity to SARS-CoV.