Based on commonly used acupoints in the clinical acupuncture treatment of functional dyspepsia （FD）， this study systematically analyzes the therapeutic differences and synergistic effects between local and distal point selection. It also examines the suitability of primary acupoint selection for different FD subtypes， postprandial distress syndrome （PDS） and epigastric pain syndrome （EPS）. The findings suggest that a combination of local and distal acupoints may be more appropriate as primary points for PDS， whereas local acupoints alone may be more suitable for EPS. Additionally， the study explores the impact of various factors， such as stimulation techniques， needling order， intensity or stimulation parameters， and depth， on the efficacy of acupuncture. It concludes that the intrinsic properties of acupoints are the primary determinants of therapeutic direction. Other factors mainly influence the magnitude rather than the direction of the effect. Future research may further investigate how different acupoint combinations， local versus distal， affect the treatment outcomes of FD subtypes， providing new insights for clinical acupuncture prescriptions.

ObjectiveTo elucidate the correlation between alterations in digestion and absorption functions and hepatic deficiency states in aging rats based on the R-spondin1/Wnt3a signaling pathway， and reveal the intervention mechanism of Bugansan. MethodsForty-eight SPF-grade male SD rats were randomly assigned to six groups： blank control， model， low-， medium-， and high-dose （7.03， 14.06， 28.12 g·kg^-1， respectively） Bugansan， and vitamin E （suspension， 27 mg·kg^-1）， with 8 rats in each group. The rat model of aging was established by intraperitoneal injection of D-galactose （400 mg·kg^-1）， while the blank control group was injected with normal saline. Since the day of modeling， rats in intervention groups received corresponding agents by gavage， and those in blank control and model groups received an equal volume of normal saline （10 mL·kg^-1）. General biological features such as fur color， activity， body mass， water intake， and food intake were observed. Meanwhile， the content of malondialdehyde （MDA） and the activities of superoxide dismutase （SOD） and glutathione peroxidase （GSH-Px） in the serum were measured to assess aging. Grip strength and the content of total bile acids （TBA） and the activity of α-amylase （AMY） in the serum were measured to evaluate hepatic deficiency states. The activity of β-galactosidase （β-gal） in the duodenum was measured to evaluate intestinal senescence. The levels of glucagon-like peptide-1 （GLP-1）， vasoactive intestinal peptide （VIP）， and D-xylose in the serum were determined to assess digestion and absorption functions of the small intestine. Hematoxylin-eosin staining was conducted to observe pathological changes of the duodenum to assess the small intestine damage. Immunohistochemical staining was employed to visualize the expression of B-cell-specific Moloney murine leukemia virus integration site 1 （Bmi1） and leucine-rich repeat-containing G protein-coupled receptor 5 （Lgr5） in the duodenal tissue. Moreover， Real-time quantitative polymerase chain reaction （Real-time PCR） was utilized to quantify the mRNA levels of Ki67， Bmi1， and Lgr5 to assess proliferation and regeneration of the small intestine. Additionally， the mRNA levels of R-spondin1， Wnt3a， β-catenin， and glycogen synthase kinase-3β （GSK-3β） and the protein levels of R-spondin1， Wnt3a， β-catenin， and phosphorylated GSK-3β （p-GSK-3β） in the duodenum were determined by Real-time PCR and Western blot， respectively， to analyze the mechanisms of intestinal digestion and absorption dysfunction in aging rats and the regulatory characteristics of Bugansan. ResultsCompared with blank control group， the model group showed decreases in body mass， water intake， food intake， grip strength， activities of SOD， GSH-Px， and AMY in the serum and content of GLP-1， VIP and D-xylose in the serum （P<0.05）， increases in the content of MDA and TBA in the serum and β-gal activity in the duodenum （P<0.05）， reductions in villus length， villus width， crypt depth， and villi/crypt （V/C） value， down-regulated mRNA and protein levels of Ki67， Lgr5， Bmi1， R-spondin1， Wnt3a， β-catenin， and up-regulated level of GSK-3β， phosphorylation （p）-GSK-3β （P<0.05）. Compared with the model group， Bugansan increased the body mass， water intake， food intake， grip strength， and activities of SOD， GSH-Px， and AMY and levels of GLP-1， VIP and D-xylose in the serum （P<0.05）， while decreasing the content of MDA and TBA in the serum and β-gal activity in the duodenum （P<0.05）. Furthermore， Bugansan increased the villus length， villus width， crypt depth， and V/C value， up-regulated the mRNA and protein levels of Ki67， Lgr5， Bmi1， R-spondin1， Wnt3a， β-catenin， and down-regulated the level of GSK-3β and p-GSK-3β （P<0.05）. ConclusionAging rats exhibit obvious impairments in digestion and absorption functions， accompanied by a state of hepatic deficiency. The traditional Chinese medicine approach of tonifying liver Qi effectively ameliorates aging-related changes by modulating the R-spondin1/Wnt3a signaling pathway to mitigate intestinal senescence and enhance digestion and absorption functions， ultimately contributing to the delay of aging.

ObjectiveTo elucidate the potential mechanism of modified Sinisan （MSNS） in alleviating anxiety-like behaviors induced by chronic restraint stress （CRS） in mice at the metabolic level based on serum untargeted metabolomics and identify key metabolites and metabolic pathways regulated by MSNS. MethodsSeventy-two male C57BL/6 mice were randomly assigned into six groups： control， model， high-dose （2.4 g·kg^-1） MSNS， medium-dose （1.2 g·kg^-1） MSNS， low-dose （0.6 g·kg^-1） MSNS， and positive control （fluoxetine， 2.6 mg·kg^-1）. Except the control group， the other groups were subjected to CRS for the modeling of anxiety. Mice were administrated with corresponding agents by gavage 2 h before daily restraint for 14 days. Anxiety-like behaviors were evaluated by the open field test （OFT）， elevated plus maze （EPM） test， and light/dark box （LDB） test. Serum levels of corticotropin-releasing hormone （CRH）， adrenocorticotrophic hormone （ACTH）， and corticosterone （CORT） were measured via ELISA to assess stress levels. Ultra-performance liquid chromatography-tandem mass spectrometry （UPLC-MS/MS） was employed to detect 9 metabolites in the brain tissue and serum metabolites. Orthogonal partial least squares-discriminant analysis （OPLS-DA） was adopted to identify differential metabolites （VIP>1.0， P<0.05）. MetaboAnalyst 5.0 was used for metabolic pathway enrichment analysis of the differential metabolites. ResultsCompared with the control group， the model group showed reductions in the central activity time and central distance in the OFT （P<0.05）， the proportions of open-arm residence time and open-arm residence times in the EPM test （P<0.01）， and the proportions of open box activity time and open box activity distance in the LDB test （P<0.05）， which were increased in the medium- and high-dose MSNS groups compared with the model group （P<0.05）. Compared with the control group， the model group showed elevated levels of CRH， ACTH， and CORT in the serum （P<0.01）， and the elevations were diminished in the medium- and high-dose MSNS groups （P<0.05）. UPLC-MS results indicated that compared with the control group， the model group presented declined DA， GABA， 5-HIAA， 5-HT， and 5-HT/Trp levels （P<0.05， P<0.01） and raised Glu， NE， Kyn， and Kyn/Trp levels （P<0.05）. Compared with the model group， high-dose MSNS increased the GABA， 5-HIAA， and 5-HT/Trp levels （P<0.05） and lowered the Glu and Kyn/Trp levels （P<0.05）. Untargeted metabolomics identified that 16 CRS-induced metabolic disturbances were reversed by MSNS. KEGG pathway analysis indicated that MSNS primarily modulated eight core pathways including alanine/aspartate/glutamate metabolism， butyrate metabolism， arginine-proline metabolism， TCA cycle， unsaturated fatty acid biosynthesis， and tryptophan metabolism. The mechanisms involved multidimensional biological processes， including neurotransmitter homeostasis regulation， TCA cycle energy metabolism optimization， and inflammatory response suppression. ConclusionMSNS alleviates CRS-induced anxiety-like behaviors in mice by mitigating hypothalamic-pituitary-adrenal axis hyperactivity， improving hippocampal neurotransmitter and tryptophan metabolic pathways， and regulating alanine/aspartate/glutamate metabolism， butyrate metabolism， arginine-proline metabolism， and TCA cycle.

ObjectiveTo elucidate the potential mechanism of modified Sinisan （MSNS） in alleviating anxiety-like behaviors induced by chronic restraint stress （CRS） in mice at the metabolic level based on serum untargeted metabolomics and identify key metabolites and metabolic pathways regulated by MSNS. MethodsSeventy-two male C57BL/6 mice were randomly assigned into six groups： control， model， high-dose （2.4 g·kg^-1） MSNS， medium-dose （1.2 g·kg^-1） MSNS， low-dose （0.6 g·kg^-1） MSNS， and positive control （fluoxetine， 2.6 mg·kg^-1）. Except the control group， the other groups were subjected to CRS for the modeling of anxiety. Mice were administrated with corresponding agents by gavage 2 h before daily restraint for 14 days. Anxiety-like behaviors were evaluated by the open field test （OFT）， elevated plus maze （EPM） test， and light/dark box （LDB） test. Serum levels of corticotropin-releasing hormone （CRH）， adrenocorticotrophic hormone （ACTH）， and corticosterone （CORT） were measured via ELISA to assess stress levels. Ultra-performance liquid chromatography-tandem mass spectrometry （UPLC-MS/MS） was employed to detect 9 metabolites in the brain tissue and serum metabolites. Orthogonal partial least squares-discriminant analysis （OPLS-DA） was adopted to identify differential metabolites （VIP>1.0， P<0.05）. MetaboAnalyst 5.0 was used for metabolic pathway enrichment analysis of the differential metabolites. ResultsCompared with the control group， the model group showed reductions in the central activity time and central distance in the OFT （P<0.05）， the proportions of open-arm residence time and open-arm residence times in the EPM test （P<0.01）， and the proportions of open box activity time and open box activity distance in the LDB test （P<0.05）， which were increased in the medium- and high-dose MSNS groups compared with the model group （P<0.05）. Compared with the control group， the model group showed elevated levels of CRH， ACTH， and CORT in the serum （P<0.01）， and the elevations were diminished in the medium- and high-dose MSNS groups （P<0.05）. UPLC-MS results indicated that compared with the control group， the model group presented declined DA， GABA， 5-HIAA， 5-HT， and 5-HT/Trp levels （P<0.05， P<0.01） and raised Glu， NE， Kyn， and Kyn/Trp levels （P<0.05）. Compared with the model group， high-dose MSNS increased the GABA， 5-HIAA， and 5-HT/Trp levels （P<0.05） and lowered the Glu and Kyn/Trp levels （P<0.05）. Untargeted metabolomics identified that 16 CRS-induced metabolic disturbances were reversed by MSNS. KEGG pathway analysis indicated that MSNS primarily modulated eight core pathways including alanine/aspartate/glutamate metabolism， butyrate metabolism， arginine-proline metabolism， TCA cycle， unsaturated fatty acid biosynthesis， and tryptophan metabolism. The mechanisms involved multidimensional biological processes， including neurotransmitter homeostasis regulation， TCA cycle energy metabolism optimization， and inflammatory response suppression. ConclusionMSNS alleviates CRS-induced anxiety-like behaviors in mice by mitigating hypothalamic-pituitary-adrenal axis hyperactivity， improving hippocampal neurotransmitter and tryptophan metabolic pathways， and regulating alanine/aspartate/glutamate metabolism， butyrate metabolism， arginine-proline metabolism， and TCA cycle.

ObjectiveTo multidimensionally analyze the clinical effects of Qianyang Yuyin granules on elderly hypertensive patients through an "energy-inflammation-aging" network. MethodsRelevant datasets were retrieved from the GEO database. Gene set enrichment analysis （GSEA） was performed on the gene expression profiles of peripheral blood cells from patients with essential hypertension in dataset GSE24752. The GSEA referenced "GO gene sets" and "KEGG gene sets" to identify significantly enriched gene sets. A clinical trial was conducted using a randomized controlled study design. A total of 40 patients meeting the inclusion criteria were enrolled. The control group received standard antihypertensive treatment with angiotensin receptor blockers （ARBs） or combined calcium channel blockers （CCBs）. In contrast，the treatment group received Qianyang Yuyin Granules in addition to the standard treatment for 12 weeks. Blood pressure levels and clinical efficacy were observed，and changes in energy metabolism indicators，DNA damage markers，and senescence-associated secretory phenotype （SASP） in blood were measured using ELISA before and after treatment. ResultsGSEA results indicated significant energy metabolism dysregulation in hypertensive patients. Clinical findings showed that both groups achieved blood pressure control without significant intergroup differences. In terms of clinical efficacy，the treatment group had a significantly higher effective rate compared to the control group （95% vs 65%，P0.05）. After treatment，the treatment group showed a significant increase in NAD⁺ levels （P0.01），with higher levels compared to the control group （P0.05）. The treatment group also exhibited a greater reduction in DNA damage marker 8-OHdG （P0.01） and cell adhesion factors ICAM-1 and VCAM-1 （P0.01） compared to the control group. Pro-inflammatory cytokines IL-1β and IL-6 were significantly reduced in the treatment group （P0.01），with greater reductions compared to the control group （P0.05，P0.01）. Anti-inflammatory cytokines IFN-α，IL-4，and IL-10 were significantly elevated in the treatment group （P0.01），with higher levels compared to the control group （P0.01）. No significant adverse reactions were reported in either group. ConclusionThe "energy- inflammation- aging" network plays an important role in the pathological mechanism of hypertension patients. Qianyang Yuyin granules may delay the aging process by increasing patients' energy metabolism levels，reducing DNA oxidative damage，and maintaining the balance of inflammatory factors.

OBJECTIVE To explore suitable storage and transportation conditions for “internet plus drug delivery” under high- temperature conditions. METHODS A survey on high-temperature conditions in summer in Beijing was conducted； a retrospective analysis was conducted on “internet plus drug delivery” orders in our hospital from July 2021 to June 2022， summarizing the proportion and delivery range of drugs under different storage and transportation conditions. Additionally， simulation and validation experiments were performed to investigate optimal drug storage and transportation devices for “internet plus drug delivery” in Beijing under high-temperature conditions in summer. RESULTS The monthly average temperature in Beijing from June to August consistently exceeded 25.0 ℃ between 1991 and 2022. From July 2021 to June 2022， a total of 104 drugs were required to be stored below 25.0 ℃， accounting for 31.23% of the 333 drugs listed in our hospital’s “internet plus drug delivery” catalog in Beijing. These drugs were delivered 1 058 times， accounting for 19.63% of the total deliveries. Simulation and validation experiments demonstrated that the average maximum temperature during the next-day delivery process of “carton + foam box + composite aluminum film pearl cotton + 500 g ice bag×2 + gas column bag” was 9.6 ℃， the average minimum temperature was 2.7 ℃， and all the temperatures remained below 15.0 ℃， which could effectively ensure the quality of drugs. CONCLUSIONS Under the high-temperature conditions in summer in Beijing， the storage and transportation device of “carton + foam box + composite aluminum film pearl cotton + 500 g ice bag×2 + gas column bag” can meet the temperature requirements specified in the drug storage instructions for Beijing intra-city drug delivery.

ObjectiveTo explore the compliance related factors of repeated screening for colorectal cancer in Jiading District， and to provide a scientific basis for the prevention and control of colorectal cancer. MethodsBased on the natural population cohort in Jiading District， and the screening situation in 2017‒2019 and 2020‒2022， the study subjects were divided into the groups of never participating in screening and participating in screening. Subjects in the participating group were further divided into participating in one round of screening or having repeated screening. SPSS 21.0 software was used to analyze the demographic characteristics of each group. χ² test or Fisher precise probability test were used to conduct univariate analysis of the factors such as gender， age， education level， marital status， retirement status， and type of medical insurance. Factors with the significant difference （P<0.05） were selected for inclusion in multivariate analysis， and factors related to compliance with repeated screening were analyzed by multivariate logistic regression. ResultsA total of 8 179 subjects were included in the study， including 3 323 males （40.6%） and 4 856 females （59.4%）. The average age of the subjects was （61.26±6.06） years old. A total of2 652 （32.4%） had educated in primary school or below， 4 242 （51.9%） in secondary school， and 1 285 （15.7%） in higher secondary school. Mostly， 7 579 （92.7%） were married. Among the participants， 4 062 people had never participated in screening， 4 117 people had participated in screening， and 1 485 of them had repeated screening， with a repeated screening rate of 18.2%. Multivariate logistic regression analysis showed that women had better compliance with repeated screening than men （OR=1.31， 95%CI： 1.14‒1.50）. Compared with the population aged 50 to 54 years， the population aged 55‒59 years （OR=1.57， 95%CI： 1.19‒2.08）， 60-64 years （OR=2.77， 95%CI： 2.13‒3.61）， and 65-69 years （OR=3.31， 95%CI： 2.51‒4.36） had higher compliance with repeated screening. Compared with employees' medical insurance， residents' medical insurance group had worse compliance with repeated screening （OR=0.76， 95%CI： 0.66‒0.87）. People with a history of intestinal polyps were more likely to undergo repeat screening than those without （OR=2.07， 95%CI： 1.50‒2.87）. ConclusionCompliance with repeated screening for colorectal cancer still needs to be improved， and there are differences in compliance with repeated screening for different populations with different characteristics. Identifying groups that are unlikely to adhere to community-based colorectal cancer screening and taking targeted interventions can help improve the continued compliance of residents with colorectal cancer screening.

Objective:To discuss the effect of royal jelly acid(10-HDA)on the proliferation and migration of the human colon cancer SW620 cells based on the network pharmacology,and to clarify its related molecular mechanism.Methods:The active ingredients such as 10-HDA and their corresponding targets were retrieved by using the keyword"royal jelly"from the Traditiomal Chinese Medicine Systems Pharmacology(TMSCP)Database and the Traditiomal Chinese Medicine Integrated Database(TCMID);the small molecule targets were predicted by the Swiss Target Prediction Database.The GeneCards Database and the Online Mendelian Inheritance in Man(OMIM)Database were used to obtain the targets with the keyword"Colon Cancer";the protein-protein interaction(PPI)network was constructed by using the String Database and Cytoscape 3.8.0 Software to screen the core targets;the Gene Ontology(GO)function enrichment analysis and Kyoto Encyclopedia of Genes and Genomes(KEGG)signaling pathway enrichment analysis were analyzed by Metascape Database;the specific ingredient 10-HDA was screened for the in vitro activity experiments.The human colon cancer SW620 cells with good growth status were divided into control group and different doses(1,5,10,15,and 20 mmol·L-1)of 10-HDA groups.The viabilities of the cells in various groups were detected by MTT method and the survival rates of the cells were calculated.The SW620 cells were divided into control group,low dose(5 mmol·L-1)of 10-HDA group,middle dose(10 mmol·L-1)of 10-HDA group,and high dose(15 mmol·L-1)of 10-HDA group;Hoechst33342 staining method was used to observe the morphology of the cells in various groups;cell scratch test was used to detect the scratch healing rates of the cells in various groups;flow cytometry was used to detect the percentages of the cells at different cell cycles in various groups;biochemical method was used to detect the activities of total antioxidant capacity(T-AOC)and superoxide dismutase(SOD)in the cells in various groups;Western blotting method was used to detect the expression levels of B-cell lymphoma 2(Bcl-2),Bcl-2-associated X protein(Bax),cysteine-containing aspartate proteolytic enzyme-3(Caspase-3),cysteine-containing aspartate proteolytic enzyme-9(Caspase-9),glycogen synthase kinase 3β(GSK3β),β-catenin,and cyclin D1 proteins in the cells in various groups.Results:Six active ingredients of royal jelly were screened out by the TCMSP Database,and 28 core targets of 10-HDA in the treatment of colon cancer were obtained.The GO function enrichment analysis mainly included the signaling pathways such as cell proliferation and apoptosis.The KEGG signaling pathway enrichment analysis included the cell cycle,prostate cancer,cell senescence,and p53 signaling pathways;the GSK3β/β-catenin signaling pathway was closely related to the cell cycle.Compared with control group,the viabilities of the cells in 5,10,15,and 20 mmol·L-110-HDA groups were decreased in a dose-dependent manner(P<0.05 or P<0.01),the numbers of apoptotic cells in different doses of 10-HDA groups were significantly increased,and the scratch healing rates of the cells were significantly decreased(P<0.05 or P<0.01);the percentages of the cells at S phase in middle and high doses of 10-HDA groups were significantly increased(P<0.05 or P<0.01),the activities of T-AOC and SOD in the cells in different doses of 10-HDA groups were significantly decreased(P<0.05 or P<0.01).Compared with control group,the expression level of Bcl-2 protein in the cells in low dose of 10-HDA group was significantly decreased(P<0.01),and the expression level of GSK3β protein was significantly increased(P<0.05);compared with control group,the expression levels of Bax,Caspase-3,Caspase-9,and GSK3β proteins in the cells in middle and high doses of 10-HDA groups were significantly increased(P<0.05 or P<0.01),and the expression levels of Bcl-2,β-catenin,and CyclinD1 proteins were significantly decreased(P<0.01).Conclusion:10-HDA can significantly inhibit the proliferation and migration of the colon cancer cells and promote the apoptosis and oxidation levels of the colon cancer cells,and its mechanism may be related to the activation of the GSK3β/β-catenin signaling pathway.

G protein-coupled receptor (GPR) 40, as one of GPRs family, plays a potential role in regulating glucose and lipid metabolism. To study the effect of GPR40 novel agonist SZZ15-11 on hyperglycemia and hyperlipidemia and its potential mechanism, spontaneous type 2 diabetic KKA^y mice, human hepatocellular carcinoma HepG2 cells and murine mature adipocyte 3T3-L1 cells were used. KKA^y mice were divided into four groups, vehicle group, TAK group, SZZ (50 mg·kg^-1) group and SZZ (100 mg·kg^-1) group, with oral gavage of 0.5% sodium carboxymethylcellulose (CMC), 50 mg·kg^-1 TAK875, 50 and 100 mg·kg^-1 SZZ15-11 respectively for 45 days. Fasting blood glucose, blood triglyceride (TG) and total cholesterol (TC), non-fasting blood glucose were tested. Oral glucose tolerance test and insulin tolerance test were executed. Blood insulin and glucagon were measured via enzyme-linked immunosorbent assay (ELISA). After mice′s execution, liver tissue was harvested to test TG and TC content. Then pathological morphology of liver was observed through hematoxylin-eosin (HE) staining, and the lipid metabolism relative signal pathway was analyzed by Western blot and RT-PCR. The experiments were approved by the Institutional Animal Care and Use Committee of the Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College. At the same time, Akt phosphorylation level in HepG2 cells and adiponectin in 3T3-L1 cells treated with TNFα were measured with Western blot. The results show that SZZ15-11 not only decreased blood glucose and lipid, improved insulin sensitivity, but also increased fasting blood glucagon and promoted insulin secretion after glucose loading in KKA^y mice. Additionally, SZZ15-11 alleviated hepatic steatosis and liver dysfunction in KKA^y mice. In liver tissue, SZZ15-11 increased AMPKα phosphorylation level and cholesterol metabolism relative gene Abcg8 transcription. In HepG2 cells, SZZ15-11 increased Akt phosphorylation level. In adipocyte 3T3-L1, SZZ15-11 recovered the decreased adiponectin expression by TNFα. This study proved that GPR40 agonist SZZ15-11 could be a candidate compound for regulating glucolipid metabolic disorder.

Objective:To investigate the expression of Toll-like receptor 4(TLR4)and extracellular signal-regulated protein kinase 1/2(ERK1/2)in decidua tissue of patients with unexplained spontaneous abortion and their correlation.Methods:The expres-sions of TLR4,ERK1/2 and p-ERK1/2 in decidua tissues of 32 patients with unexplained spontaneous abortion(abortion group)and 32 normal pregnancy(control group)were detected by immunohistochemistry and Western blot,respectively.The correlation between TLR4 and p-ERK1/2 in abortion group were analyzed by Pearson hierarchical correlation analysis.Results:In immunohistochemical experiments,the cytoplasm of decidua cells in the two groups is the expression locus of TLR4,ERK1/2 and p-ERK1/2,the expression of the three proteins were different,and the expressions of TLR4 and p-ERK1/2 in abortion group were significantly higher than that in control group(P<0.01).There was no significant difference in ERK1/2 expression between abortion group and control group(P>0.05);In decidua tissue samples of abortion group,the protein level of TLR4 was higher than that of control group(P<0.05);the pro-tein level of p-ERK1/2 was significantly higher than that of control group(P<0.01),and the protein level of ERK1/2 in decidua tissue of abortion group was not statistically different from that of control group(P>0.05).TLR4 was positively correlated with p-ERK1/2 expression in abortion group(r=0.890,P<0.01).Conclusion:Abnormal activation of TLR4/ERK1/2 signaling pathway may be one of the mechanisms of unexplained spontaneous abortion.