Discovery of sesquiterpene lactones with anti-inflammatory effect from Youngia japonica.

The preliminary study revealed that the ethyl acetate eluate of Youngia japonica (YJ-E) could inhibit the expression of key proteins of p-p65, p-IκBα, p-IKKα/ß, and p-AKT in LPS stimulated BV2 cell. Further phytochemical study led to the isolation of eight compounds from YJ-E, including one new sesquiterpene lactone. Their structures were elucidated by several spectroscopic data, and comparing the NMR data of known compound. In addition, all of the isolates were evaluated for the anti-inflammatory effect. As a result, compounds 3 and 4 distinctly attenuated the expressions of p-IκBα, p-p65, and p-AKT in LPS stimulated BV2 cell, respectively.

[Protective effect of salidroside on renal damage in diabetic nephropathy mice by regulating RAGE/JAK1/STAT signaling pathway].

This study aims to investigate the protective effect of salidroside(SAL) on renal damage in diabetic nephropathy(DN) mice based on the receptor for advanced glycation end products/janus activated kinase 1/signal transduction and activator of transcription 3(RAGE/JAK1/STAT3) signaling pathway. The mouse DN model was established by high-fat/high-sucrose diets combined with intraperitoneal injection of streptozocin(STZ). Mice were randomly divided into normal group, model group, low-dose SAL group(20 mg·kg~(-1)), high-dose SAL group(100 mg·kg~(-1)), and metformin group(140 mg·kg~(-1)), with 12 mice in each group. After establishing the DN model, mice were given drugs or solvent intragastrically, once a day for consecutive 10 weeks. Body weight, daily water intake, and fasting blood glucose(FBG) were measured every two weeks. After the last dose, the glucose tolerance test was performed, and the samples of 24-hour urine, serum, and kidney tissue were collected. The levels of 24 hours urinary total protein(24 h-UTP), serum creatinine(Scr), blood urea nitrogen(BUN), triglyceride(TG), total cholesterol(TC), low density lipoprotein cholesterol(LDL-C), and high density lipoprotein cholesterol(HDL-C) were detected by biochemical tests. Periodic acid-schiff(PAS) staining was used to observe the pathological changes in the kidney tissue. The protein expressions of α-smooth muscle actin(α-SMA), vimentin, and advanced glycation end products(AGEs) in kidneys were detected by immunohistochemical staining. The activities of superoxide dismutase(SOD), catalase(CAT), glutathione peroxidase(GSH-PX), and the level of malondialdehyde(MDA) in kidneys were detected by using a corresponding detection kit. Enzyme-linked immunosorbent assay(ELISA) was used to detect the levels of AGEs, carboxymethyllysine(CML), and carboxyethyllysine(CEL) in serum. The protein expressions of RAGE and the phosphorylation level of JAK1 and STAT3 in kidneys were detected by Western blot. Compared with the normal group, the levels of FBG, the area under the curve of glucose(AUCG), water intake, kidney index, 24 h-UTP, tubular injury score, extracellular matrix deposition ratio of the renal glomerulus, the serum levels of Scr, BUN, TG, LDL-C, AGEs, CEL, and CML, the level of MDA, the protein expressions of α-SMA, vimentin, AGEs, and RAGE, and the phosphorylation level of JAK1 and STAT3 in kidney tissue were increased significantly(P<0.01), while the level of HDL-C in serum and the activity of SOD, CAT, and GSH-PX in kidney tissue were decreased significantly(P<0.01). Compared with the model group, the above indexes of the high-dose SAL group were reversed significantly(P<0.05 or P<0.01). In conclusion, this study suggests that SAL can alleviate oxidative stress and renal fibrosis by inhibiting the activation of AGEs-mediated RAGE/JAK1/STAT3 signaling axis, thus playing a potential role in the treatment of DN.

Exercised-enriched blood plasma rescues hippocampal impairments and cognitive deficits in an Alzheimer's disease model.

Alzheimer's disease (AD) is a progressive neurodegenerative disorder, and moderate exercise holds promise in ameliorating the ongoing neurodegeneration and cognitive decline. Here, we investigated whether exercise-enriched blood plasm could yield a beneficial therapeutic effect on AD pathologies and cognitive decline in transgenic AD (P301S) mice. In this investigation, a cohort of 2-month-old C57BL/6 mice were granted continuous access to either a running wheel or a fixed wheel for 6 weeks. After that, their plasmas were extracted and subsequently injected intravenously into 4.5-month-old P301S mice biweekly over a 6-week period. A comprehensive methodology was then employed, integrating behavioral tests, pathology assessments, and biochemical analyses to unveil the potential anti-dementia implications of exercise-enriched blood plasma in P301S mice. Upon systemic administration, the findings revealed a noteworthy attenuation of hippocampus-dependent behavioral impairments in P301S mice. Conversely, blood plasma from sedentary counterparts exhibited no discernible impact. These effects were intricately associated with the mitigation of neuroinflammation, the augmentation of hippocampal adult neurogenesis, and a reduction of synaptic impairments following the administration of exercise-enriched blood plasma. These findings advance the proposition that administering exercise-enriched blood plasma may serve as an effective prophylactic measure against AD, opening avenues for further exploration and potential therapeutic interventions.

Characterization of the complete mitochondrial genome of Ergasilus anchoratus Markevich, 1946 (Ergasilidae) and phylogeny of Copepoda.

The mitochondrial (mt) genome can provide data for phylogenetic analyses and evolutionary biology. Herein, we sequenced and annotated the complete mt genome of Ergasilus anchoratus. This mt genome was 13852 bp long and comprised 13 protein-coding genes (PCGs), 22 tRNAs and 2 rRNAs. All PCGs used the standard ATN start codons and complete TAA/TAG termination codons. A majority of tRNA genes exhibited standard cloverleaf secondary structures, with the exception of one tRNA that lacked the TψC arm (trnC), and three tRNAs that lacked the DHU arm (trnR, trnS1 and trnS2). Phylogenetic analyses conducted using Bayesian inference (BI) and maximum likelihood (ML) methods both supported Ergasilidae as a monophyletic family forming a sister group to Lernaea cyprinacea and Paracyclopina nana. It also supported the monophyly of orders Calanoida, Cyclopoida, and Siphonostomatoida; and the monophyly of families Harpacticidae, Ergasilidae, Diaptomidae, and Calanidae. The gene orders of E. anchoratus and Sinergasilus undulatus were identical, which represents the first instance of two identical gene orders in copepods. More mt genomes are needed to better understand the phylogenetic relationships within Copepoda in the future.

Comprehensive molecular characterisation of the complete mitogenome of Ergasilus tumidus and phylogenetic relationships of Copepoda inferred from mitogenomes.

Although parasitic copepods of the genus Ergasilus von Nordmann, 1832 are globally distributed parasites of fish, their phylogenetic relationships with other Copepoda are not clear, and the characteristics of their mitochondrial genomes (mitogenomes) are not thoroughly understood. The objective of this study was to address these knowledge gaps by sequencing the complete mitogenome of Ergasilus tumidus Markevich, 1940. The complete mitogenome (GenBank Acc. No. OQ596537) was 14,431 bp long and it comprised 13 protein-coding genes (PCGs), 22 tRNAs, two tRNAs, and two control regions (CRs). Phylogenetic analyses, conducted using concatenated nucleotide and amino acid sequences of 13 protein-coding genes, produced two partially incongruent topologies. While the order Calanoida was consistently resolved as the sister lineage to the other three orders, topological instability was observed in the relationships of the orders Cyclopoida, Siphonostomatoida and Harpacticoida. Siphonostomatoida clustered with Cyclopoida in the nucleotide-based phylogeny, but with Harpacticoida in the amino acid-based phylogeny. The latter topology conforms to the widely accepted relationships, but we speculate that the former topology is more likely to be the correct one. Our study provides a complete mitogenome sequence of E. tumidus, which helps us better understand the molecular evolution of the genus Ergasilus. Additionally, we suggest a different perspective on the controversial phylogenetic relationships among Siphonostomatoida, Cyclopoida and Harpacticoida, diverging from previously accepted views.

Discovery of sesquiterpene from Youngia japonica with antitumor effect.

Fourteen sesquiterpenes, including one undescribed sesquiterpene lactone, were isolated from Youngia japonica, and their structures were identified by NMR, HRESIMS, ECD and calculated ECD. Cytotoxic activities of all isolates against A549, HeLa, and 4 T1 cell lines were detected by CCK8 assay. Among them, 2 showed obvious cytotoxic activity against A549 cells. Subsequently, the production of ROS, and apoptosis of A549 cells treated with 2 were evaluated. The result showed that 2 distinctly increased the ROS level, and induced the apoptosis of A549 cells. Further anticancer mechanism studies showed that 2 increased the expression of cleaved caspase 3. Taken together, our results demonstrated that 2 might become potential leading compounds for the treatment of lung cancer.

Four undescribed coumarin derivatives, with ten amides from the roots of Ficus hirta and their cytotoxic activities.

Four undescribed coumarin derivatives, ficusalt A (1) and ficusalt B (2), a pair of racemic coumarins, (±) ficudimer A (3a/3b), along with ten known amides, were isolated from the roots of Ficus hirta. Their structures were elucidated by several spectroscopic data analyses, including HRESIMS, NMR, and X-ray single-crystal diffraction. The cytotoxic activities of all compounds against HeLa, HepG2, MCF-7, and H460 cell lines were detected using the MTT assay. Among these, 5 showed the highest activity against HeLa cells. Subsequently, the apoptotic, anti-invasive, and anti-migration effects of 5 on HeLa cells were determined by flow cytometer, transwell invasion assay, and wound-healing assay, respectively. The result suggested that 5 distinctly induced the apoptosis in HeLa cells and inhibited their invasion and migration. Further studies on anticancer mechanisms were conducted using Western blotting. As a result, 5 increased the cleavage of PARP and the expression of pro-apoptotic protein Bax. Moreover, 5 notably upregulated the phosphorylation of p38 and JNK, whereas inhibited the expression of p-ERK and p-AKT. Our results demonstrated that 5 could be a potential leading compound for further application in the treatment of cervical cancer.

P25/CDK5-mediated Tau Hyperphosphorylation in Both Ipsilateral and Contralateral Cerebra Contributes to Cognitive Deficits in Post-stroke Mice.

OBJECTIVE: Post-stroke cognitive impairment (PSCI) develops in approximately one-third of stroke survivors and is associated with ingravescence. Nonetheless, the biochemical mechanisms underlying PSCI remain unclear. The study aimed to establish an ischemic mouse model by means of transient unilateral middle cerebral artery occlusions (MCAOs) and to explore the biochemical mechanisms of p25/cyclin-dependent kinase 5 (CDK5)-mediated tau hyperphosphorylation on the PSCI behavior. METHODS: Cognitive behavior was investigated, followed by the detection of tau hyperphosphorylation, mobilization, activation of kinases and/or inhibition of phosphatases in the lateral and contralateral cerebrum of mice following ischemia in MACO mice. Finally, we treated HEK293/tau cells with oxygen-glucose deprivation (OGD) and a CDK5 inhibitor (Roscovitine) or a GSK3ß inhibitor (LiCl) to the roles of CDK5 and GSK3ß in mediating ischemia-reperfusion-induced tau phosphorylation. RESULTS: Ischemia induced cognitive impairments within 2 months, as well as causing tau hyperphosphorylation and its localization to neuronal somata in both ipsilateral and contralateral cerebra. Furthermore, p25 that promotes CDK5 hyperactivation had significantly higher expression in the mice with MCAO than in the shamoperation (control) group, while the expression levels of protein phosphatase 2 (PP2A) and the phosphorylation level at Tyr307 were comparable between the two groups. In addition, the CDK5 inhibitor rescued tau from hyperphosphorylation induced by OGD. CONCLUSION: These findings demonstrate that upregulation of CDK5 mediates tau hyperphosphorylation and localization in both ipsilateral and contralateral cerebra, contributing to the pathogenesis of PSCI.

Posttraumatic stress disorder symptoms among Chinese college students following the COVID-19 outbreak.

Objective: This study examined the prevalence of posttraumatic stress disorder (PTSD) symptoms in college students 1 month after the lockdown of Wuhan to identify possible risk factors for PTSD symptoms in a cross-sectional study. Methods: Out of 10,502 who responded, 9,274 students impacted by the COVID-19 pandemic were included in our study. PTSD symptoms was evaluated by the Impact of Event Scale-revised (IES-R). Anxiety/depression symptoms were evaluated by the Kessler Psychological Distress Scale (K10). Personality traits, coping style, and social support were assessed by the Eysenck Personality Questionnaire-Revised Short Scale for Chinese (EPQ-RSC), the Simplified Coping Style Questionnaire (SCSQ), and the Social Support Rating Scale (SSRS). Logistic regression analysis was utilized to further explore risk factors for PTSD symptoms. Results: More than 1 month after the COVID-19 outbreak, 13.1% of college students developed PTSD symptoms, indicating that COVID-19 associated stressful experiences were connected with PTSD symptoms. After the COVID-19 outbreak, subjects with symptomatologic PTSD symptoms were more likely to experience strained relationships with their family, to have close contact with COVID-19 patients and to drop out of college. The logistic regression model demonstrated the association factors of PTSD symptoms. Neuroticism, psychoticism and an avoidant coping style were associated with increased risk for PTSD symptoms, while an active coping style was protective against PTSD symptoms during this pandemic. Conclusion: The results showed that PTSD symptoms was prevalent in Chinese college students 1 month after the COVID-19 outbreak. Effective psychological support work should be carried out accordingly.

Epigallocatechin-3-gallate Alleviates Cognitive Deficits in APP/PS1 Mice.

Alzheimer's disease (AD) shows cognitive impairments in clinic, which is multifactorial with different etiopathogenic mechanisms such as Aß deposition, neuroinflammation and neuronal dystrophy involved. Therefore, multi-targets drugs with neuroprotective, anti-amyloidogenic and anti-inflammatory properties will be effective in AD treatment. Epigallocatechin-3-gallate (EGCG) possesses a broad spectrum of pharmacological activities in the prevention and treatment of multiple neurodegenerative diseases. In the present study, we showed that oral administration of EGCG (50 mg/kg) for 4 months significantly attenuated the cognitive deficits in APP/PS1 transgenic mice, which served as AD model. Moreover, EGCG induced an improvement in dendritic integrity and expression levels of synaptic proteins in the brain of APP/PS1 mice. And EGCG exerted obvious anti-inflammatory effects, which was manifested by alleviating microglia activation, decreasing pro-inflammatory cytokine (IL-1ß) and increasing anti-inflammatory cytokines (IL-10, IL-13). Furthermore, ß-amyloid (Aß) plaques were markedly reduced in the hippocampus of 6-month old APP/PS1 mice after EGCG treatment. In conclusion, these findings indicate that EGCG improves AD-like cognitive impairments through neuroprotective, anti-amyloidogenic and anti-inflammatory effects, thus is a promising therapeutic candidate for AD.

Direct Activation of Protein Phosphatase 2A (PP2A) by Tricyclic Sulfonamides Ameliorates Alzheimer's Disease Pathogenesis in Cell and Animal Models.

Alzheimer's disease (AD) is a multifactorial neurodegenerative disease for which there are limited therapeutic strategies. Protein phosphatase 2A (PP2A) activity is decreased in AD brains, which promotes the hyperphosphorylation of Tau and APP, thus participate in the formation of neurofibrillary tangles (NFTs) and ß-amyloid (Aß) overproduction. In this study, the effect of synthetic tricyclic sulfonamide PP2A activators (aka SMAPs) on reducing AD-like pathogenesis was evaluated in AD cell models and AD-like hyperhomocysteinemia (HHcy) rat models. SMAPs effectively increased PP2A activity, and decreased tau phosphorylation and Aß40/42 levels in AD cell models. In HHcy-AD rat models, cognitive impairments induced by HHcy were rescued by SMAP administration. HHcy-induced tau hyperphosphorylation and Aß overproduction were ameliorated through increasing PP2A activity on compound treatment. Importantly, SMAP therapy also prevented neuronal cell spine loss and neuronal synapse impairment in the hippocampus of HHcy-AD rats. In summary, our data reveal that pharmacological PP2A reactivation may be a novel therapeutic strategy for AD treatment, and that the tricyclic sulfonamides constitute a novel candidate class of AD therapeutic.

SUMOylation at K340 inhibits tau degradation through deregulating its phosphorylation and ubiquitination.

Intracellular accumulation of the abnormally modified tau is hallmark pathology of Alzheimer's disease (AD), but the mechanism leading to tau aggregation is not fully characterized. Here, we studied the effects of tau SUMOylation on its phosphorylation, ubiquitination, and degradation. We show that tau SUMOylation induces tau hyperphosphorylation at multiple AD-associated sites, whereas site-specific mutagenesis of tau at K340R (the SUMOylation site) or simultaneous inhibition of tau SUMOylation by ginkgolic acid abolishes the effect of small ubiquitin-like modifier protein 1 (SUMO-1). Conversely, tau hyperphosphorylation promotes its SUMOylation; the latter in turn inhibits tau degradation with reduction of solubility and ubiquitination of tau proteins. Furthermore, the enhanced SUMO-immunoreactivity, costained with the hyperphosphorylated tau, is detected in cerebral cortex of the AD brains, and ß-amyloid exposure of rat primary hippocampal neurons induces a dose-dependent SUMOylation of the hyperphosphorylated tau. Our findings suggest that tau SUMOylation reciprocally stimulates its phosphorylation and inhibits the ubiquitination-mediated tau degradation, which provides a new insight into the AD-like tau accumulation.

More vulnerability of left than right hippocampal damage in right-handed patients with post-traumatic stress disorder.

Previous studies have shown hippocampal abnormalities in people with post-traumatic stress disorder (PTSD), but findings of diminished volume in shortages in the hippocampus have been inconsistent. In this study, we investigated changes in hippocampal volume and neuronal metabolites in right-handed PTSD patients to determine their possible relationship(s) with PTSD severity. We performed a case-control study of 11 right-handed PTSD patients and 11 healthy controls using magnetic resonance imaging (MRI) and proton magnetic resonance spectroscopy ((1)H MRS). Hippocampal volume and metabolite ratios of N-acetylaspartate (NAA) to creatine (Cr) (NAA/Cr) and choline compounds (Cho) to Cr (Cho/Cr) were calculated. The severity of PTSD was evaluated by the Clinician-Administered PTSD Scale (CAPS). Significantly decreased left and total normalized hippocampal volumes were found in PTSD patients compared with controls (6.6% for the left hippocampus, 5.5% for total hippocampus). Also, the bilateral hippocampal NAA/Cr ratio of PTSD patients was significantly reduced compared with controls. The volume of the left hippocampus was negatively correlated to the CAPS total and CPAS-C scores. The left hippocampal NAA/Cr ratio was negatively correlated to the CAPS-total, CAPS-B, CAPS-C, and CAPS-D scores. The CAPS total and the CAPS-B scores were positively correlated to the Cho/Cr ratio of the right hippocampus. Our results indicate that hippocampal dysfunction is asymmetric in right-handed PTSD patients, with the left side affected more than the right.

Effect of bis(7)-tacrine on cognition in rats with chronic cerebral ischemia.

Bis(7)-tacrine (B7T), a novel dimeric acetyl cholinesterase (AChE) inhibitor, has multiple neuroprotective activities against neuronal damage. However, its therapeutic effects in chronic cerebral ischemia remain unknown. In the present study, adult male Sprague-Dawley rats were subjected with permanent ligation of the bilateral common carotid arteries to investigate the roles of B7T on cognitive function, neuronal apoptosis and neurogenesis in the hippocampus. Results from spatial navigation test showed that chronic cerebral ischemia impaired spatial learning, B7T treatment shorten escape latency of ischemia rats as compared with saline-treated rats. Probe trial test indicated that spatial memory deficit of chronic cerebral ischemic animals was reversed by B7T treatment. Immunohistochemical results showed that B7T reduced neuronal apoptosis in the hippocampal CA1 region as compared with ischemia rats, and B7T treatment increased neurogenesis in the hippocampus. These findings suggest that B7T may exert its neuroprotective effects by inhibiting apoptosis and promoting neurogenesis in 2VO rats.

Tianeptine reverses stress-induced asymmetrical hippocampal volume and N-acetylaspartate loss in rats: an in vivo study.

Stress-induced hippocampal volume loss and decrease in N-acetylaspartate (NAA) level have been reported to be associated with impaired neural plasticity and neuronal damage in adults. Accordingly, reversing structural and metabolite damage in the hippocampus may be a desirable goal for antidepressant therapy. The present study investigated the effects of tianeptine on chronic stress-induced hippocampal volume loss and metabolite alterations in vivo in 24 Sprague-Dawley rats. Rats were subjected to a consecutive 28-day forced swimming test stress. Tianeptine (50mg/kg) or saline was administered intragastrically 4h after swimming each day. Spontaneous behaviors, serum corticosterone concentration, hippocampal volume and NAA level were evaluated after stress. Chronic tianeptine treatment counteracted the chronic stress-induced suppression of spontaneous behaviors, elevated serum corticosterone concentration, reduced hippocampal volume and decreased NAA level. Moreover, we found asymmetrical right-left hippocampal volume loss in stressed rats, with the left hippocampus more sensitive to chronic stress than the right hippocampus. In addition, stressed rats showed a decreased level of hippocampal metabolites, without significant loss of hippocampal volume. These findings provide experimental evidence for impaired structural plasticity of the brain being an important feature of depressive illness and suggest that prophylactic tianeptine treatments could reverse structural changes in brain. The structural and neurochemical alterations in the hippocampus may be valuable indexes for evaluating the prophylactic and curative effect of antidepressant treatments in depressive and stress-related disorders.

Protective effect of granulocyte colony-stimulating factor on intracerebral hemorrhage in rat.

Granulocyte colony-stimulating factor (G-CSF) is a member of the cytokine family of growth factors that can protect the neurons from focal cerebral ischemia-induced injuries. The intracerebral hemorrhage (ICH) has been widely observed in the clinic; however, the protective effect of G-CSF on ICH is still elusive. We found in the present study that the intraperitoneal injection of G-CSF for 5 days could improve the ICH-induced neuronal behavioral impairment measured by limb placement assay. We also observed that injection of G-CSF could increase the number of stem cells in the specific zone of the hemorrhagic areas, demonstrated by the enhanced expression of nestin. Additionally, G-CSF could also promote the mobilization of circulating hemopoietic stem cells (HSCs) to the damaged brain areas and activate the astrocytes. Our results reveal that G-CSF is also protective for the ICH with the mechanisms involving proliferation of neural stem cells, the migration of HSCs and the activation of astrocytes.

[Changes of cyclin D1 expression following human brain contusion].

OBJECTIVE: To study the relationships of Cyclin D1 expression with the posttraumatic intervals (PTI) following the cerebra, brainstem or cerebella contusion in human. METHODS: 88 cases of brain contusions of the closed head injury were investigated with pathological and Cyclin D1 immunohistochemistry methods. The results were analyzed by image analysis technique (IAT). RESULTS: The immunoreactivity of Cyclin D1 was almost disappeared in the core cells of the brain contusion. Cyclin D1-positive cells started to increase in the boundary of the brain contusion in the 1h group. Cyclin D1-positive cells were increased significantly in the 3 h-30 d groups and maintained at a high level in the boundary of the brain contusion of those groups. It is suggested that the Cyclin D1-positive cells were primarily origin from microglia and other glia. A few neurons expressed Cyclin D1. CONCLUSION: Cyclin D1 can express in several kinds of brain cells following the contusion, especially in the glia cells. Cyclin D1-positive cells were increased obviously and rapidly after injury, so it could be used as a reference marker for early stage brain injury.

[Study on relationship between changes of geometry parameters in human spleen nuclei and the postmortem interval].

OBJECTIVE: Using computer image-analyze technique (CIAT) to study changes of geometry parameters in human spleen nuclei and seek a new experimental method to deduce the estimation the postmortem interval (PMI). METHODS: 31 cadavers that known accurate PMI, sampled and smeared respectively every hour within the first 36 hours after death, fixed with cold Carony fixation, stained by Feulgen-van's method, and measured 5 geometry parameters using the image-analyze instrument including Area (A), Mean-Dia (MD), Average Diameter (AD), perimeter (P), Index of density (ID). RESULTS: A, MD, AD and P in the human spleen nuclei have no correlation with the PMI. But ID rose regularly with the prolongation of PMI in 36 hours. There was a definite correlation between ID and the PMI, r=0.983, linear regression equation with PMI (hours) as the dependent variable was calculated for ID. CONCLUSION: Geometry parameter ID was proved to be preferable indexes for estimation of PMI in 36 hours.

[Prognostic significance of lymph node micrometastasis in colorectal cancer].

BACKGROUND & OBJECTIVE: There have been many controversies about the prognostic significance of lymph node micrometastasis. The aim of this study was to characterize the prognostic significance of lymph node micrometastasis of colorectal cancer. METHODS: Specimens of curative resection between 1988 and 2001 were collected from The Affiliated Hospital of Jianghan University Medical and Life Science College. All 80 patients (30 cases of rectal cancer, 50 cases of colon cancer) had complete examination data. A total of 3869 lymph nodes (48.36 per case) were found by clearing fat method. The interrupted serial 4-micron sections, routine hematoxylin and eosin staining and immunohistochemistry methods were used to detect the lymph node metastasis and micrometastasis (small tumor cells cluster diameter