Is musculoskeletal pain related to locomotive syndrome even in young and middle-aged adults?

OBJECTIVES: Locomotive syndrome (LS) is the leading cause of persons needing long-term care in old age and is characterized by locomotive organ impairment including musculoskeletal pain. The aim was to examine the association between musculoskeletal pain and LS in young and middle-aged persons. METHODS: A total of 836 participants (male 667, female 169; mean age 44.4 years) were examined in this cross-sectional study. The LS was evaluated by three screening tools: the two-step test, the stand-up test, and the 25-question Geriatric Locomotive Function Scale. Musculoskeletal pain, exercise habits, physical function (walkability and muscle strength), and physical activity were also assessed. RESULTS: The LS was found in 22.8% of participants. The number with musculoskeletal pain was significantly higher in those with the LS. A significant correlation was found between the degree of musculoskeletal pain and exercise habits. Less regular exercise was significantly associated with higher LS prevalence. Physical activity and function were greater in participants with more regular exercise. CONCLUSION: Musculoskeletal pain was significantly related to LS even in young and middle-aged persons. The present results suggest that control of musculoskeletal pain and improvement of exercise habits in young and middle-aged persons might help prevent the LS.

Feature selection for RNA cleavage efficiency at specific sites using the LASSO regression model in Arabidopsis thaliana.

BACKGROUND: RNA degradation is important for the regulation of gene expression. Despite the identification of proteins and sequences related to deadenylation-dependent RNA degradation in plants, endonucleolytic cleavage-dependent RNA degradation has not been studied in detail. Here, we developed truncated RNA end sequencing in Arabidopsis thaliana to identify cleavage sites and evaluate the efficiency of cleavage at each site. Although several features are related to RNA cleavage efficiency, the effect of each feature on cleavage efficiency has not been evaluated by considering multiple putative determinants in A. thaliana. RESULTS: Cleavage site information was acquired from a previous study, and cleavage efficiency at the site level (CSsite value), which indicates the number of reads at each cleavage site normalized to RNA abundance, was calculated. To identify features related to cleavage efficiency at the site level, multiple putative determinants (features) were used to perform feature selection using the Least Absolute Shrinkage and Selection Operator (LASSO) regression model. The results indicated that whole RNA features were important for the CSsite value, in addition to features around cleavage sites. Whole RNA features related to the translation process and nucleotide frequency around cleavage sites were major determinants of cleavage efficiency. The results were verified in a model constructed using only sequence features, which showed that the prediction accuracy was similar to that determined using all features including the translation process, suggesting that cleavage efficiency can be predicted using only sequence information. The LASSO regression model was validated in exogenous genes, which showed that the model constructed using only sequence information can predict cleavage efficiency in both endogenous and exogenous genes. CONCLUSIONS: Feature selection using the LASSO regression model in A. thaliana identified 155 features. Correlation coefficients revealed that whole RNA features are important for determining cleavage efficiency in addition to features around the cleavage sites. The LASSO regression model can predict cleavage efficiency in endogenous and exogenous genes using only sequence information. The model revealed the significance of the effect of multiple determinants on cleavage efficiency, suggesting that sequence features are important for RNA degradation mechanisms in A. thaliana.

Changes in mRNA Degradation Efficiencies under Varying Conditions Are Regulated by Multiple Determinants in Arabidopsis thaliana.

Multiple mechanisms are involved in gene expression, with mRNA degradation being critical for the control of mRNA accumulation. In plants, although some trans-acting factors and motif sequences have been identified in deadenylation-dependent mRNA degradation, endonucleolytic cleavage-dependent mRNA degradation has not been studied in detail. Previously, we developed truncated RNA-end sequencing (TREseq) in Arabidopsis thaliana and detected G-rich sequence motifs around 5' degradation intermediates. However, it remained to be elucidated whether degradation efficiencies of 5' degradation intermediates in A. thaliana vary among growth conditions and developmental stages. To address this issue, we conducted TREseq of cultured cells under heat stress and at three developmental stages (seedlings, expanding leaves and expanded leaves) and compared 5' degradation intermediates data among the samples. Although some 5' degradation intermediates had almost identical degradation efficiencies, others differed among conditions. We focused on the genes and sites whose degradation efficiencies differed. Changes in degradation efficiencies at the gene and site levels revealed an effect on mRNA accumulation in all comparisons. These changes in degradation efficiencies involved multiple determinants, including mRNA length and translation efficiency. These results suggest that several determinants govern the efficiency of mRNA degradation in plants, helping the organism to adapt to varying conditions by controlling mRNA accumulation.

Affinity-based high-resolution analysis of DNA binding by VASCULAR-RELATED NAC-DOMAIN7 via fluorescence correlation spectroscopy.

VASCULAR-RELATED NAC-DOMAIN7 (VND7) is the master transcription factor for vessel element differentiation in Arabidopsis thaliana. To identify the cis-acting sequence(s) bound by VND7, we employed fluorescence correlation spectroscopy (FCS) to find VND7-DNA interactions quantitatively. This identified an 18-bp sequence from the promoter of XYLEM CYSTEINE PEPTIDASE1 (XCP1), a direct target of VND7. A quantitative assay for binding affinity between VND7 and the 18-bp sequence revealed the core nucleotides contributing to specific binding between VND7 and the 18-bp sequence. Moreover, by combining the systematic evolution of ligands by exponential enrichment (SELEX) technique with known consensus sequences, we defined a motif termed the Ideal Core Structure for binding by VND7 (ICSV). We also used FCS to search for VND7 binding sequences in the promoter regions of other direct targets. Taking these data together, we proposed that VND7 preferentially binds to the ICSV sequence. Additionally, we found that substitutions among the core nucleotides affected transcriptional regulation by VND7 in vivo, indicating that the core nucleotides contribute to vessel-element-specific gene expression. Furthermore, our results demonstrate that FCS is a powerful tool for unveiling the DNA-binding properties of transcription factors.

Different Plant Species Have Common Sequence Features Related to mRNA Degradation Intermediates.

mRNA degradation is an important cellular mechanism involved in the control of gene expression. Several genome-wide profiling methods have been developed for detecting mRNA degradation in plants and animals. However, because many of these techniques use poly (A) mRNA for library preparation, degradation intermediates are often only detected near the 3'-ends of transcripts. Previously, we developed the Truncated RNA End Sequencing (TREseq) method using Arabidopsis thaliana, and demonstrated that this method ameliorates 3'-end bias. In analyses using TREseq, we observed G-rich sequences near the 5'-ends of degradation intermediates. However, this finding remained to be confirmed in other plant species. Hence, in this study, we conducted TREseq analyses in Lactuca sativa (lettuce), Oryza sativa (rice) and Rosa hybrida (rose). These species including A. thaliana were selected to encompass a diverse range in the angiosperm phylogeny. The results revealed similar sequence features near the 5'-ends of degradation intermediates, and involvement of translation process in all four species. In addition, homologous genes have similar efficiencies of mRNA degradation in different plants, suggesting that similar mechanisms of mRNA degradation are conserved across plant species. These strong sequence features were not observed in previous degradome analyses among different species in plants.

Tendoscopic peroneal retinaculum repair for recurrent peroneal tendon dislocation enables earlier return to sports than the open procedure.

PURPOSE: The purpose of this study was to evaluate whether tendoscopic peroneal retinaculum repair for patients with recurrent peroneal tendon dislocation (RPTD) is more useful than an open procedure. METHODS: Twenty-five patients with RPTD were retrospectively reviewed. Twelve patients (13 ankles) with RPTD underwent the open procedure (Group A) between 2008 and 2014, and 13 patients (14 ankles) underwent the tendoscopic procedure (Group B) between 2014 and 2017. Evaluation parameters included clinical results [the Japanese Society for Surgery of the Foot (JSSF) ankle-hind foot scale], operation time, complications, return to sports, and recurrence. RESULTS: Postoperative JSSF ankle/hindfoot scale scores were significantly better than the pre-surgical scores in both groups. The mean operation time was significantly longer in Group B than in Group A (75.7 ± 20.5 vs 38.4 ± 10.5 min). There was one recurrence in Group A, but none in Group B. Group A had no complications, and Group B had one wound infection. Group B, excluding the case of infection, could return to sports earlier than Group A, excluding the recurrent case (13.4 ± 1.5 vs 12.2 ± 0.6 weeks). CONCLUSIONS: This tendoscopic procedure needs longer operation time and is more technically demanding, but it is a useful procedure, because it is less invasive and can accelerate return to sports. LEVEL OF EVIDENCE: III.

Locomotive syndrome testing in young and middle adulthood.

Background: Previous epidemiological studies on locomotive syndrome (LS) have been mainly conducted in retired elderly people. However, from the view point of its prevention, it is important to assess currently working younger people. The purpose of this study was to examine the status of the level of LS in young and middle-aged adult workers.Methods: This cross-sectional study was performed at four companies. We used the two-step test, stand-up test, and 25-question Geriatric Locomotive Function Scale (GLFS-25) as screening tools of LS. We also questioned the subjects for knee pain and low back pain.Results: A total of 715 workers participated in this study. The percentage of females with LS increased with age. However, the percentage of males with LS was approximately 20% in each age category. Two-step and stand-up test scores worsened in an age-dependent manner, although GLFS-25 scores varied independently of age. Knee pain, low back pain and physical activity were significantly related to LS-level.Conclusion: Our results suggest that there is some degree of LS even in young and middle-aged adults. Knee pain, low back pain and physical activity levels are key factors related to LS even in young and middle-aged adults.

Does hallux valgus impair physical function?

BACKGROUND: The relationships between radiographic hallux valgus (HV) and various physical functions independent of knee osteoarthritis (KOA) were examined among residents of a mountain village in Japan. METHODS: Study participants were recruited from mountain village residents aged ≥50 years. Participants' height, weight, and body mass index (BMI) were measured, and baseline data, including age, sex, and foot pain, were obtained using interviews and questionnaires. Radiography of the feet and knees was performed to assess the presence of HV (HV angle ≥20°) and KOA (Kellgren-Lawrence grade ≥ II). Grip strength, 6-m walk at usual and maximum speeds, single-leg stance time, and stand up from a chair time were evaluated as physical function performance tests. Plantar pressure patterns were also examined. RESULTS: Moderate-severe HV (HV angle ≥30 degrees), impaired grip strength and maximum walking speed, and painful HV reduced usual and maximum walking speeds independent of KOA. Hallux plantar pressure decreased according to the HV angle. Hallux plantar pressure was significantly lower in painful HV than in the no HV feet or painless HV. CONCLUSIONS: Moderate-severe HV deformity and HV-related pain impaired physical function independent of KOA. By controlling the pain and severe deformity of HV by treatments such as surgery, the physical function of HV patients might be improved.

Shoulder and elbow pain in elementary school baseball players: The results from a nation-wide survey in Japan.

BACKGROUND: Despite recommendations on how to prevent baseball injuries in youths by the Japanese Society of Clinical Sports Medicine, shoulder and elbow pain still frequently occurs in young baseball players. We conducted a questionnaire survey among baseball players at elementary schools across the country to understand the practice conditions of players, examining the risk factors of shoulder and elbow pain in baseball players. METHODS: The questionnaire survey was conducted among elementary school baseball players as members of the Baseball Federation of Japan in September 2015. RESULTS: A total of 8354 players belonging to 412 teams (average age: 8.9) responded to the survey. Among 7894 players who did not have any shoulder and/or elbow pain in September 2014, elbow pain was experienced in 12.3% of them, shoulder pain in 8.0% and shoulder and/or elbow pain in 17.4% during the previous one year. A total of 2835 (39.9% of the total) practiced four days or more per week and 97.6% practiced 3 h or more per day on Saturdays and Sundays. The risk factors associated shoulder and elbow pain included a male sex, older age, pitchers and catchers, and players throwing more than 50 balls per day. CONCLUSIONS: It has been revealed that Japanese elementary school baseball players train too much. Coaches should pay attention to older players, male players, pitchers and catchers in order to prevent shoulder and elbow pain. Furthermore, elementary school baseball players should not be allowed to throw more than 50 balls per day. STUDY DESIGN: Retrospective cohort study.

Endoscopic Versus Open Surgery for Calcaneal Bone Cysts: A Preliminary Report.

The purpose of the present study was to evaluate the advantages and disadvantages of an endoscopic procedure for patients with symptomatic calcaneal bone cyst compared with an open procedure. The cases of 16 consecutive patients with a calcaneal bone cyst were reviewed. Of the 16 patients, 8 had undergone the open procedure (O group) from October 2003 to August 2011, and 8 had undergone the endoscopic procedure (E group) from September 2011 to April 2013. The endoscopic procedure used a 2-portal technique in which skin incisions were made to avoid the peroneal tendon according to the preoperative ultrasonography. All surgeries (open or endoscopic) consisted of curettage of the inner wall of the bone cyst, followed by injection of calcium phosphate cement. The following factors were evaluated: radiographic assessment, operative time, postoperative adverse effects, and interval to the return to sports. No significant difference between the 2 groups was observed in the operative time (53.5 ± 6.5 minutes in the O group and 56.1 ± 13.8 minutes in the E group). The E group experienced no adverse effects; however, the O group had 1 temporary irritation in the sural nerve area and 1 calcium phosphate cement leakage along the peroneal tendon sheath. The interval to a return to sports was significantly shorter in the E group (14.5 ± 0.9 weeks in the O group and 6.5 ± 1.1 weeks in the E group; p < .01). In conclusion, endoscopic surgery is a useful approach for the treatment of calcaneal bone cysts, allowing early rehabilitation and an early return to sports without any adverse effects.

Changes in Polysome Association of mRNA Throughout Growth and Development in Arabidopsis thaliana.

Translational control is a key regulatory step in the expression of genes as proteins. In plant cells, the translational efficiency of mRNAs differs for different mRNA species, and the efficiency dynamically changes in various conditions. To gain a global view of translational control throughout growth and development, we performed genome-wide analysis of polysome association of mRNA during growth and leaf development in Arabidopsis thaliana by subjecting the mRNAs in polysomes to DNA microarray. This analysis revealed that the degree of polysome association of mRNA was different depending on the mRNA species, and the polysome association changed greatly throughout growth and development for each. In the growth stage, transcripts showed varying changes in polysome association from strongly depressed to unchanged, with the majority of transcripts showing dissociation from ribosomes. On the other hand, during leaf development, the polysome association of transcripts showed a normal distribution from repressed to activated mRNAs when comparing expanding and expanded leaves. In addition, functional category analysis of the microarray data suggested that translational control has a physiological significance in the plant growth and development process, especially in the categories of signaling and protein synthesis. In addition to this, we compared changes in polysome association of mRNAs between various conditions and characterized translational controls in each. This result suggested that mRNA translation might be controlled by complicated mechanisms for response to each condition. Our results highlight the importance of dynamic changes in mRNA translation in plant development and growth.

Multiple classes of transcription factors regulate the expression of VASCULAR-RELATED NAC-DOMAIN7, a master switch of xylem vessel differentiation.

The secondary cell walls of xylem cells, including vessel elements, provide mechanical strength and contribute to the conduction of water and minerals. VASCULAR-RELATED NAC-DOMAIN7 (VND7) is a NAC-domain transcription factor that regulates the expression of genes required for xylem vessel element formation. Transient expression assays using 68 transcription factors that are expressed during xylem vessel differentiation showed that 14 transcription factors, including VND1-VND7, are putative positive regulators of VND7 expression. Electrophoretic mobility shift assays revealed that all seven VND proteins bound to the VND7 promoter region at its SMBE/TERE motif, indicating that VND7 is a direct target of all of the VND transcription factors. Overexpression of VND1-VND5, GATA12 and ANAC075, newly identified transcription factors that function upstream of VND7, resulted in ectopic xylem vessel element formation. These data suggest that VND7 transcription is a regulatory target of multiple classes of transcription factors.

Vascular safety during arthroscopic all-inside meniscus suture.

PURPOSE: The purpose of the study is to assess the orientation and distance of the popliteal artery (PA) from both the anteromedial and anterolateral portals. METHODS: The records of 97 patients (100 knees) who underwent knee arthroscopy were reviewed. The shortest distance from the posterior tibial cortex to the PA on the lines from both the medial and lateral borders of the patellar tendon to the PA was evaluated by magnetic resonance imaging at full knee extension. The figure-of-four position was compared between patients with intact and deficient anterior cruciate ligaments (ACLs). The shortest distances from the posterior cruciate ligament (PCL) to the lines running from the medial and lateral borders of the patellar tendon to the PA were also measured. RESULTS: The shortest distances from the posterior tibial cortex to the PA were significantly longer in the figure-of-four position than at full knee extension and during extension in the ACL-deficient than intact group. Distances did not significantly differ in the figure-of-four position. The PA was hidden from the anteromedial portal by the PCL, but remained vulnerable from the anterolateral portal. CONCLUSIONS: All-inside meniscus suturing of the posterior horn of the lateral meniscus inserted through the anteromedial portal is safer when the knee is in the figure-of-four position than fully extended. Meniscus repairs should be completed before ACL reconstruction due to vascular positions and the ease of approach. LEVEL OF EVIDENCE: Prospective correlation study, Level IV.

Prevalence of hallux valgus and risk factors among Japanese community dwellers.

BACKGROUND: To investigate the prevalence and severity of radiographically detected hallux valgus (HV) as well as associated risk factors among Japanese residents of Miyagawa, a mountain village located in the center of Mie Prefecture. METHODS: The height, weight and body mass index (BMI) of 403 participants (male n = 135, female n = 268) recruited from among the residents of Miyagawa Village, Japan aged ≥65 years were measured, and baseline data, including age, sex and medical history were obtained from interviews and questionnaires. Knee osteoarthritis (KOA) was determined from radiographs of the feet and knees, and osteoporosis was determined by measuring bone mineral density. Hallux valgus, defined as angulation of the big toe at the first metatarsophalangeal joint of >20°, was classified as: mild (20°-30°), moderate (30°-40°) or severe (>40°). Risk factors for HV were calculated using multivariate logistic regression analysis that included age, sex, obesity (BMI ≥25), KOA, osteoporosis, Heberden's nodes and low back pain as variables. RESULTS: The overall prevalence of definite radiographic HV was 22.8 % (184/806), and mild, moderate and severe HV was found in 66.3, 27.2 and 6.5 % of the participants, respectively. Hallux valgus was found in at least one foot in 120 (29.8 %) of the participants and the prevalence significantly differed between females with and without HV and KOA (odds ratios: 2.54 and 1.71, respectively). CONCLUSIONS: The prevalence of definite radiographic HV was 29.8 %. Female sex and KOA were significantly associated with increased risk for radiographic HV.

Osteoporosis, vertebral fractures and mortality in a Japanese rural community.

OBJECTIVES: The present study aims to determine the relationship between osteoporosis (OP), vertebral fracture (VF) and mortality. METHODS: We followed up 1024 residents of Miyagawa village every 2 years for a mean of 8.4 years between 1997 and 2009. The residents were assessed every 2 years. We defined OP as T scores for bone mineral density that were < 2.5 standard deviations below peak bone mass. VF was assessed by lateral radiography of the thoracic and lumbar spine. The participants were allocated as follows depending on the presence or absence of OP and VF: with OP and without VF (OP group), with VF and without OP (VF group), with OP and VF (OP + VF group) and without OP and VF (Control group). We determined survival/mortality rates until 2011 by reviewing medical histories and death certificates. RESULTS: By 2011, 304 participants had died. The respective 5-year survival rates for the OP + VF, OP, VF and Control groups were 80.6%, 93.7%, 87.8% and 94.2%. Mortality rates were significantly worse for the OP + VF group than the Control group (OP + VF Hazard Ratio: 1.89; 95% CI, 1.27-2.77). CONCLUSION: Prevention of osteoporotic VF in elderly persons is very important from the viewpoint of increasing life expectancy.

A computational and experimental approach reveals that the 5'-proximal region of the 5'-UTR has a Cis-regulatory signature responsible for heat stress-regulated mRNA translation in Arabidopsis.

Translation of specific plant mRNAs is differentially regulated under certain abiotic stress conditions such as heat, oxygen deprivation and dehydration. The majority of transcripts exhibit varying degrees of translational repression, whereas a subset of transcripts escape such repression and remain actively translated. The underlying mechanisms that mediate this control, and in particular the identities of the regulatory RNA elements involved, remain poorly understood. Using a combined computational and experimental approach, we identified a novel cis-regulatory element in the 5'-untranslated region (5'-UTR) that affects differential translation in response to heat stress (HS) in Arabidopsis thaliana. First, we selected a set of genes with distinct translational responses to HS, based on our previously reported genome-wide data regarding changes in polysome loading induced by HS in A. thaliana cultured cells. We evaluated the 5'-UTRs of these messages for their ability to mediate expression, when fused to reporter mRNAs, in protoplasts under HS. The data from the reporter assay and the nucleotide sequences of the 5'-UTRs tested were used to define regulatory elements in the 5'-UTRs, with the help of a partial least square (PLS) regression model. The computational analysis using PLS and subsequent experimental characterization of a series of 5'-UTR mutants provided evidence that the 5'-proximal sequence of the 5'-UTR is a primary and position-dependent determinant of 5'-UTR-mediated differential translation in response to HS. Finally, we discuss the possible mechanism underlying HS regulation of differential mRNA translation.

NAC domain transcription factors VNI2 and ATAF2 form protein complexes and regulate leaf senescence.

The NAM, ATAF1/2, and CUC2 (NAC) domain transcription factor VND-INTERACTING2 (VNI2) negatively regulates xylem vessel formation by interacting with another NAC domain transcription factor, VASCULAR-RELATED NAC-DOMAIN7 (VND7), a master regulator of xylem vessel formation. Here, we screened interacting proteins with VNI2 using yeast two-hybrid assay and isolated two NAC domain transcription factors, Arabidopsis thaliana ACTIVATION FACTOR 2 (ATAF2) and NAC DOMAIN CONTAINING PROTEIN 102 (ANAC102). A transient gene expression assay showed that ATAF2 upregulates the expression of genes involved in leaf senescence, and VNI2 effectively inhibits the transcriptional activation activity of ATAF2. vni2 mutants accelerate leaf senescence, whereas ataf2 mutants delay leaf senescence. In addition, the accelerated leaf senescence phenotype of the vni2 mutant is recovered by simultaneous mutation of ATAF2. Our findings strongly suggest that VNI2 interacts with and inhibits ATAF2, resulting in negatively regulating leaf senescence.

VASCULAR-RELATED NAC-DOMAIN7 directly regulates the expression of a broad range of genes for xylem vessel formation.

The Arabidopsis thaliana NAC domain transcription factor, VASCULAR-RELATED NAC-DOMAIN7 (VND7), acts as a key regulator of xylem vessel differentiation. In order to identify direct target genes of VND7, we performed global transcriptome analysis using Arabidopsis transgenic lines in which VND7 activity could be induced post-translationally. This analysis identified 63 putative direct target genes of VND7, which encode a broad range of proteins, such as transcription factors, IRREGULAR XYLEM proteins and proteolytic enzymes, known to be closely associated with xylem vessel formation. Recombinant VND7 protein binds to several promoter sequences present in candidate direct target genes: specifically, in the promoter of XYLEM CYSTEINE PEPTIDASE1, two distinct regions were demonstrated to be responsible for VND7 binding. We also found that expression of VND7 restores secondary cell wall formation in the fiber cells of inflorescence stems of nst1 nst3 double mutants, as well as expression of NAC SECONDARY WALL THICKENING PROMOTING FACTOR3 (NST3, however, the vessel-type secondary wall deposition was observed only as a result of VND7 expression. These findings indicated that VND7 upregulates, directly and/or indirectly, many genes involved in a wide range of processes in xylem vessel differentiation, and that its target genes are partially different from those of NSTs.

Genome-wide analyses of changes in translation state caused by elevated temperature in Oryza sativa.

It has been reported that the translational status of mRNAs responds dramatically to abiotic stresses. While many useful results have demonstrated translational control in dicotyledonous model plants, little is known about changes in the translation state in response to abiotic stresses in monocotyledonous plants. To understand global changes in translation of mRNAs, we performed genome-wide analyses using Oryza sativa treated with heat stress (HS). These analyses showed that most mRNAs were translationally repressed, while the translation of some mRNAs was maintained. In addition to other regulatory steps in gene expression, including transcription and processing, it is thought that translational regulation is a critical step in adaptation to new conditions because of the functional tendencies of proteins that are either translationally maintained or highly repressed upon HS. When we compared the functional tendencies of translationally regulated proteins in rice with those in Arabidopsis thaliana cells exposed to HS, some showed similar regulation, arguing for both common and different features of translational regulation in the two plants.

Characterization of bisphenol A metabolites produced by Portulaca oleracea cv. by liquid chromatography coupled with tandem mass spectrometry.

The garden plant portulaca (Portulaca oleracea cv.) efficiently removes bisphenol A (BPA), an endocrine-disrupting chemical, from a hydroponic solution, but the molecular mechanisms underlying BPA metabolism by portulaca remain unclear. In this study, BPA metabolites converted by portulaca were analyzed by liquid chromatography coupled with tandem mass spectrometry. We observed the hydroxylation of BPA and the oxidization of it to quinone. Polyphenol oxidases are likely to contribute to BPA degradation by portulaca.