Effects of microbial agent and microbial fertilizer input on soil microbial community structure and diversity in a peanut continuous cropping system.

INTRODUCTION: The soil harbors a diverse array of microorganisms, and these are essential components of terrestrial ecosystems. The presence of microorganisms in the soil, particularly in the rhizosphere, is closely linked to plant growth and soil fertility. OBJECTIVE: The primary objective of this study is to assess the potential advantages of integrating microbial inoculants with compound fertilizer in enhancing peanut yield. METHODS: We utilized Illumina MiSeq high-throughput sequencing technology to conduct our investigation. The experimental design consists of four treatment groups: compound fertilizers (CF), compound fertilizers supplemented with microbial agents (CF + MA), compound fertilizers supplemented with microbial fertilizers (CF + MF), and compound fertilizers supplemented with both microbial agents and microbial fertilizers (CF + MM). RESULTS: The experimental results demonstrated a significant increase in peanut yield upon application of CF + MA, CF + MF, and CF + MM treatments. During the blossom stage and pod-setting stage, the soil's catalase, urease, and acid phosphatase activities were significantly increased in the CF + MA, and CF + MM treatments compared to the CF treatment. The application of CF + MA resulted in an increase in bacterial richness in the rhizosphere soil of peanuts, as indicated by the sequencing results. The application of CF + MA, CF + MF, and CF + MM resulted in a reduction of fungal diversity. Proteobacteria, Actinobacteria, and Acidobacteria were the dominant bacterial phyla, while Ascomycota and Basidiomycota were the dominant phyla in the fungal component of the rhizosphere soil microbiome across all experimental treatments. CONCLUSION: Microbial agents and fertilizers modify the peanut rhizosphere soil's microbial community structure, as per our findings. The abundance of potentially beneficial bacteria (Bradyrhizobium, Rhizobium, and Burkholderia) and fungi (Trichoderma and Cladophialophora) could increase, while pathogenic fungi (Penicillium and Fusarium) decreased, thereby significantly promoting plant growth and yield of peanut.

Motion Decoupling Network for Intra-Operative Motion Estimation Under Occlusion.

In recent intelligent-robot-assisted surgery studies, an urgent issue is how to detect the motion of instruments and soft tissue accurately from intra-operative images. Although optical flow technology from computer vision is a powerful solution to the motion-tracking problem, it has difficulty obtaining the pixel-wise optical flow ground truth of real surgery videos for supervised learning. Thus, unsupervised learning methods are critical. However, current unsupervised methods face the challenge of heavy occlusion in the surgical scene. This paper proposes a novel unsupervised learning framework to estimate the motion from surgical images under occlusion. The framework consists of a Motion Decoupling Network to estimate the tissue and the instrument motion with different constraints. Notably, the network integrates a segmentation subnet that estimates the segmentation map of instruments in an unsupervised manner to obtain the occlusion region and improve the dual motion estimation. Additionally, a hybrid self-supervised strategy with occlusion completion is introduced to recover realistic vision clues. Extensive experiments on two surgical datasets show that the proposed method achieves accurate motion estimation for intra-operative scenes and outperforms other unsupervised methods, with a margin of 15% in accuracy. The average estimation error for tissue is less than 2.2 pixels on average for both surgical datasets.

Partly recovery and compensation in anterior cingulate cortex after SSRI treatment-evidence from multi-voxel pattern analysis over resting state fMRI in depression.

BACKGROUND: Anterior cingulate cortex (ACC) plays an essential role in the pathophysiology of major depressive disorder (MDD) and its treatment. However, it's still unclear whether the effects of disease and antidepressant treatment on ACC perform diversely in neural mechanisms. METHODS: Fifty-nine MDD patients completed resting-state fMRI scanning twice at baseline and after 12-week selective serotonin reuptake inhibitor (SSRI) treatment, respectively in acute state and remission state. Fifty-nine demographically matched healthy controls were enrolled. Using fractional amplitude of low-frequency fluctuation (fALFF) in ACC as features, we performed multi-voxel pattern analysis over pretreatment MDD patients vs health control (HC), and over pretreatment MDD patients vs posttreatment MDD patients. RESULTS: Discriminative regions in ACC for MDD impairment and changes after antidepressants were obtained. The intersection set and difference set were calculated to form ACC subregions of recovered, unrecovered and compensative, respectively. The recovered ACC subregion mainly distributed in rostral ACC (80 %) and the other two subregions had nearly equal distribution over dorsal ACC and rostral ACC. Furthermore, only the compensative subregion had significant changed functional connectivity with cingulo-opercular control network (CON) after antidepressant treatment. LIMITATIONS: The number of subjects was relatively small. The results need to be validated with larger sample sizes and multisite data. CONCLUSIONS: This finding suggested that the local function of ACC was partly recovered on regulating emotion after antidepressant by detecting the common subregional targets of depression impairment and antidepressive effect. Besides, changed fALFF in the compensative ACC subregion and its connectivity with CON may partly compensate for the cognition deficits.

Attenuated alpha-gamma coupling in emotional dual pathways with right-Amygdala predicting ineffective antidepressant response.

AIMS: The diversity of treatment outcomes for major depressive disorder (MDD) remains uncertain in neuropathology. The current study aimed at exploring electrophysiological biomarkers associated with treatment response. METHODS: The present study recruited 130 subjects including 100 MDD patients and 30 healthy controls. All subjects participated in a sad expression recognition task while their magnetoencephalography data were recorded. Patients who had a reduction of at least 50% in disorder severity at endpoint (>2 weeks) were considered as responders. Within-frequency power and phase-amplitude coupling were measured for the brain regions involved in the emotional visual information processing pathways. RESULTS: The significant alpha-gamma decoupling from the right thalamus to the right amygdala in unconscious processing and from right orbital frontal cortices to the right amygdala in conscious processing was found in non-responders relative to responders and healthy controls. These kinds of dysregulation could also predict the potential treatment response. CONCLUSION: The attenuated alpha-gamma coupling in dual pathways indicated increased sensitivity to the negative emotional information and reduced moderated effect of the amygdala, which might cause insensitivity to antidepressant treatment and could be regarded as potential neural mechanisms for treatment response prediction.

Functional impairment-based segmentation of anterior cingulate cortex in depression and its relationship with treatment effects.

In major depressive disorder (MDD), the anterior cingulate cortex (ACC) is widely related to depression impairment and antidepressant treatment response. The multiplicity of ACC subdivisions calls for a fine-grained investigation of their functional impairment and recovery profiles. We recorded resting state fMRI signals from 59 MDD patients twice before and after 12-week antidepressant treatment, as well as 59 healthy controls (HCs). With functional connectivity (FC) between each ACC voxel and four regions of interests (bilateral dorsolateral prefrontal cortex [DLPFC] and amygdalae), subdivisions with variable impairment were identified based on groups' dissimilarity values between MDD patients before treatment and HC. The ACC was subdivided into three impairment subdivisions named as MedialACC, DistalACC, and LateralACC according to their dominant locations. Furthermore, the impairment pattern and the recovery pattern were measured based on group statistical analyses. DistalACC impaired more on its FC with left DLPFC, whereas LateralACC showed more serious impairment on its FC with bilateral amygdalae. After treatment, FCs between DistalACC and left DLPFC, and between LateralACC and right amygdala were normalized while impaired FC between LateralACC and left amygdala kept dysfunctional. Subsequently, FC between DistalACC and left DLPFC might contribute to clinical outcome prediction. Our approach could provide an insight into how the ACC was impaired in depression and partly restored after antidepressant treatment, from the perspective of the interaction between ACC subregions and critical frontal and subcortical regions.

LMNB2 promotes the progression of colorectal cancer by silencing p21 expression.

Colorectal cancer is the second common cause of death worldwide. Lamin B2 (LMNB2) is involved in chromatin remodeling and the rupture and reorganization of nuclear membrane during mitosis, which is necessary for eukaryotic cell proliferation. However, the role of LMNB2 in colorectal cancer (CRC) is poorly understood. This study explored the biological functions of LMNB2 in the progression of colorectal cancer and explored the possible molecular mechanisms. We found that LMNB2 was significantly upregulated in primary colorectal cancer tissues and cell lines, compared with paired non-cancerous tissues and normal colorectal epithelium. The high expression of LMNB2 in colorectal cancer tissues is significantly related to the clinicopathological characteristics of the patients and the shorter overall and disease-free cumulative survival. Functional analysis, including CCK8 cell proliferation test, EdU proliferation test, colony formation analysis, nude mouse xenograft, cell cycle, and apoptosis analysis showed that LMNB2 significantly promotes cell proliferation by promoting cell cycle progression in vivo and in vitro. In addition, gene set enrichment analysis, luciferase report analysis, and CHIP analysis showed that LMNB2 promotes cell proliferation by regulating the p21 promoter, whereas LMNB2 has no effect on cell apoptosis. In summary, these findings not only indicate that LMNB2 promotes the proliferation of colorectal cancer by regulating p21-mediated cell cycle progression, but also suggest the potential value of LMNB2 as a clinical prognostic marker and molecular therapy target.

Predicting Neuroimaging Biomarkers for Antidepressant Selection in Early Treatment of Depression.

BACKGROUND: Due to the biological heterogeneity, 60%-70% of patients with major depressive disorder (MDD) do not respond to or achieve remission from first-line antidepressants. Predicting neuroimaging biomarkers for early antidepressant treatment could guide initial antidepressant therapy. PURPOSE: To assess for neuroimaging biomarkers for antidepressant selection in early antidepressant treatment. STUDY TYPE: Prospective. SUBJECTS: A total of 85 MDD patients from the major site and 33 MDD patients from an out-of-sample test site. FIELD STRENGTH/SEQUENCE: A 3.0 T, T1-weighted imaging using a magnetization-prepared rapid acquisition gradient-echo sequence and diffusion tensor imaging (DTI) using an echo-planar sequence. ASSESSMENT: Baseline DTI data of patients who achieved early improvement after 2-weeks of antidepressant treatment (selective serotonin reuptake inhibitors [SSRI] or serotonin-norepinephrine reuptake inhibitors [SNRI]) were analyzed. An ensemble model was constructed using data from the major site and then applied to assess the early response of patients at the out-of-sample test site. STATISTICAL TESTS: Support vector machine combined with leave-one-out cross-validation were applied to construct the whole model from individual base models from different brain regions. Discriminative biomarkers were evaluated by calculating the changes in sensitivity and specificity obtained when removing a single base model from the whole model, the base model being removed changing in each run. RESULTS: Training performance over MDD patients at the major site achieved 75% accuracy while performance with accuracy of 70% was achieved in the out-of-sample test site. Assessing sensitivity and specificity changes following the removal of single base models from the prominent model highlighted the functions of two neural circuitries: SSRI-related emotion regulation circuitry, centered on the hippocampus (sensitivity changes: 10%) and amygdala (sensitivity changes: 11%); and SNRI-related emotion and reward circuitry, centered on the putamen (specificity changes: 8%) and orbital part of superior frontal gyrus (specificity changes: 12%). DATA CONCLUSION: These findings support future research on clinical antidepressant selection for MDD. EVIDENCE LEVEL: 1 TECHNICAL EFFICACY: Stage 2.

[Analysis on Polymorphism of Platelet Antigen Gene in Shandong Han Population].

OBJECTIVE: To study the Polymorphism of the human platelet antigen(HPA) gene 1-17 and human leukocyte antigen(HLA) gene-A and B locus in Shandong Han population. METHODS: A total of 962 samples from routine voluntary platelet donors were genotyped for HPA1-17 system and HLA-A site, B by PCR-SSP and PCR-SSOP respectively．Gene frequencies were calculated by counting. HPA1-17 and HLA genotype combinations were analyzed by Arelequin 3.5. RESULTS: The gene frequencies of HPA-la, -1b, HPA-2a, -2b, HPA-3a, -3b, HPA-4a, -4b, HPA-5a, -5b, HPA-6a, -6b, HPA-15a, -15b were 0.9918, 0.0082, 0.9419, 0.0592, 0.5841, 0.4174, 0.9969, 0.0031, 0.9892, 0.0108, 0.9835, 0.0175,0.5488 and 0.4512, respectively． The most common HPA genotype combination was HPA-(1, 2, 4, 5, 6, 7-14, 16, 17) aa-3ab-15ab (0.2048). Moreover, HLA-A*2(0.3094) and HLA-B*13(0.1513) showed the highest frequency in their respective locus. The most common HLA genotype combination was HLA-A*2-B*13(0.1397) . CONCLUSION: Distributions of HPA and HLA show high polymorphism in Shandong Han population. The ethnic and territorial difference of HPA distribution is also confirmed. It is imperative to establish local genetic database of volunteer platelet donors.

Long noncoding RNA MAPKAPK5-AS1 promotes colorectal cancer progression by cis-regulating the nearby gene MK5 and acting as a let-7f-1-3p sponge.

BACKGROUND: Long noncoding RNAs (lncRNAs) are considered critical regulators in cancers; however, the clinical significance and mechanisms of MAPKAPK5-AS1 (hereinafter referred to as MK5-AS1) in colorectal cancer (CRC) remain mostly unknown. METHODS: In this study, quantitative real-time PCR (qPCR) and western blotting were utilized to detect the levels of MK5-AS1, let-7f-1-3p and MK5 (MAPK activated protein kinase 5) in CRC tissues and cell lines. The biological functions of MK5-AS1, let-7f-1-3p and MK5 in CRC cells were explored using Cell Counting Kit-8 (CCK8), colony formation and transwell assays. The potential mechanisms of MK5-AS1 were evaluated by RNA pull-down, RNA immunoprecipitation (RIP), dual luciferase reporter assay, chromatin immunoprecipitation (ChIP) and bioinformatics analysis. The effects of MK5-AS1 and MK5 on CRC were investigated by a xenotransplantation model. RESULTS: We confirmed that MK5-AS1 was significantly increased in CRC tissues. Knockdown of MK5-AS1 suppressed cell migration and invasion in vitro and inhibited lung metastasis in mice. Mechanistically, MK5-AS1 regulated SNAI1 expression by sponging let-7f-1-3p and cis-regulated the adjacent gene MK5. Moreover, MK5-AS1 recruited RBM4 and eIF4A1 to promote the translation of MK5. Our study verified that MK5 promoted the phosphorylation of c-Jun, which activated the transcription of SNAI1 by directly binding to its promoter. CONCLUSIONS: MK5-AS1 cis-regulated the nearby gene MK5 and acted as a let-7f-1-3p sponge, playing a vital role in CRC tumorigenesis. This study could provide novel insights into molecular therapeutic targets of CRC.

Ensemble Learning for Early-Response Prediction of Antidepressant Treatment in Major Depressive Disorder.

BACKGROUND: In order to reduce unsuccessful treatment trials for depression, neuroimaging and genetic information can be considered as biomarkers. Together with machine-learning methods, prediction models have proved to be valuable for baseline prediction. PURPOSE: To propose an ensemble learning modeling framework that integrates imaging and genetic information for individualized baseline prediction of early-stage treatment response of antidepressants in major depressive disorder (MDD). STUDY TYPE: Prospective. SUBJECTS: In all, 98 inpatients with MDD. FIELD STRENGTH/SEQUENCE: 3.0T MRI and gradient-echo echo-planar imaging sequence. ASSESSMENT: Participants were divided into responders and nonresponders based on reducing rates of HDRS-6 after early-stage treatment of 2 weeks. Fourteen brain regions of interest were selected according to previous studies. An ensemble learning modeling framework was used to integrate imaging data and genetic data. STATISTICAL TESTS: Support vector machine (SVM) with linear kernel was utilized to integrate multimode information and then to construct the prediction model. Leave-one-out cross-validation (LOOCV) was used to evaluate the performance. The position characteristics obtained through SVM-RFE (recursive feature elimination) algorithm and LOOCV was considered to compare each feature's relative importance for the prediction model. RESULTS: Compared with the single-level prediction model, the ensemble learning prediction model showed improvement in prediction performance (accuracy from 0.61 to 0.86 with imaging data and genetic data). Integrated with 14 priori brain regions, the region of interest (ROI) map ensemble learning prediction model can achieve a performance that is analogous with the model with information from whole-brain regions (both with accuracy of 0.81). The integration of genetic features further improved the sensitivity of prediction (sensitivity from 0.78 to 0.87 under the ensemble learning framework). DATA CONCLUSION: Our ensemble learning prediction model demonstrated significant advantages in interpretability and information integration. The findings may provide more assistance for clinical treatment selection in MDD at the individual level. LEVEL OF EVIDENCE: 1 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2020;52:161-171.

Increased DKC1 expression in glioma and its significance in tumor cell proliferation, migration and invasion.

The dyskeratosis congenita 1 (DKC1) gene is located on the X chromosome at Xq28. Dyskerin encoded by the DKC1 gene is associated with the formation of certain small RNAs and the telomerase activity. Inherited mutations in DKC1 inactivate the dyskerin and causes dyskeratosis congenital, which is characterized by skin defects, hematopoiesis failure, and increased susceptibility to cancer. DKC1 reportedly up-regulates in several human cancers, including renal cell carcinoma and prostate cancer. Dyskerin is deregulated in B-chronic lymphocytic leukemia and breast carcinomas, but its expression and function in glioma have hardly been investigated. Hence, we were prompted to collect tissue samples and implement cell experiments. Our study reveals that DKC1 expression is significantly increased in the pathological tissues of glioma compared with that in normal tissues. The increased staining of DKC1 is related to the World Health Organization stages of tumors. DKC1 knockdown also significantly inhibits glioma cell growth by altering the expression of cell cycle-relative molecules to arrest at the G1 phase. In the transwell chamber, DKC1 knockdown glioma cells exhibit low motility. Consistent with classic oncogenic pathways, N-cadherin, HIF-1α, and MMP2 expression levels are lower compared with those of the control group. Therefore, DKC1 up-regulation in gliomas is common and necessary for extensive tumor growth. The phenotype of glioma cell lines after DKC1 down-regulation suggests its use as a valuable clinical treatment strategy.

KIF4A facilitates cell proliferation via induction of p21-mediated cell cycle progression and promotes metastasis in colorectal cancer.

Kinesin family member 4A (KIF4A) was found to be implicated in the regulation of chromosome condensation and segregation during mitotic cell division, which is essential for eukaryotic cell proliferation. However, little is known about the role of KIF4A in colorectal carcinoma (CRC). This study explored the biological function of KIF4A in CRC progression and investigated the potential molecular mechanisms involved. Here, we found that KIF4A was remarkably upregulated in primary CRC tissues and cell lines compared with paired non-cancerous tissues and normal colorectal epithelium. Elevated expression of KIF4A in CRC tissues was significantly correlated with clinicopathological characteristics in patients as well as with shorter overall and disease-free cumulative survival. Multivariate Cox regression analysis revealed that KIF4A was an independent prognostic factor for poor survival in human CRC patients. Functional assays, including a CCK-8 cell proliferation assay, colony formation analysis, cancer xenografts in nude mice, cell cycle and apoptosis analysis, indicated that KIF4A obviously enhanced cell proliferation by promoting cell cycle progression in vitro and in vivo. Furthermore, gene set enrichment analysis, Luciferase reporter assays, and ChIP assays revealed that KIF4A facilitates cell proliferation via regulating the p21 promoter, whereas KIF4A had no effect on cell apoptosis. In addition, Transwell analysis indicated that KIF4A promotes migration and invasion in CRC. Taken together, these findings not only demonstrate that KIF4A contributes to CRC proliferation via modulation of p21-mediated cell cycle progression but also suggest the potential value of KIF4A as a clinical prognostic marker and target for molecular treatments.

Interlocked Photo-degradable Macrocycles Allow One-Off Photo-triggerable Gelation of Organo- and Hydrogelators.

[2]Rotaxanes displaying one-off photo-triggerable gelation properties have been synthesized through the "clipping" of photo-degradable macrocycles around the amide or urea functionalities of organo- and hydrogelators. Irradiation with UV-light cleaved the photo-labile macrocyclic components from the [2]rotaxanes, resulting in the free gelators being released into solution and, thereafter, forming gels. When the rate of gelation was sufficiently rapid, selective gelation of specific regions of the solution-and, indeed, photo-patterning of the solution-was possible.

A randomized, controlled multicentric study of inhaled budesonide and intravenous methylprednisolone in the treatment on acute exacerbation of chronic obstructive pulmonary disease.

BACKGROUND: Almost all international guidelines recommend corticosteroids for management of exacerbations of chronic obstructive pulmonary disease (COPD), because it leads to improved outcomes of acute exacerbations of chronic obstructive pulmonary disease (AECOPD). Nevertheless, due to its side effects, there are still concerns regarding the use of systemic corticosteroid (SC). Inhaled corticosteroids (IC) can be used as an alternative to SC, while reducing the risk of occurrence of side effects. PURPOSE: To measure the clinical efficacy and side effects of nebulized budesonide and systemic methylprednisolone in AECOPD. METHODS: Valid data from 410 AECOPD patients in 10 hospitals was collected. Patients were randomly divided into 2 groups; budesonide group, treated with nebulized budesonide (2 mg 3 times/day); and methylprednisolone group, treated with intravenously injected methylprednisolone (40 mg/day). COPD assessment test (CAT), arterial blood gas analysis, hospitalization days, adverse effects, fasting blood glucose, serum creatinine, alanine aminotransferase levels, and blood drug were measured and analyzed in both groups. RESULTS: Symptoms, pulmonary function and arterial blood gas analysis were significantly improved after treatment in both groups (P < 0.05), with no significant differences between them (P > 0.05), while incidence of adverse events in the budesonide group was lower (P < 0.05). No significant differences in CAT score, days of admission, blood gas analysis results and physiological and biochemical indexes were found between the two groups. Patients treated with methylprednisolone showed a higher degree of PaO2 level improvement. CONCLUSION: Results show that inhalation of budesonide (2 mg 3 times/day) and systemic methylprednisolone (40 mg/day) had similar clinical outcome in AECOPD. In conclusion, inhaled budesonide is an alternative to systemic corticosteroids in AECOPD treatment.

[Role of acute kidney injury staging by KDIGO criteria in choosing the opportune time of continuous blood purification].

OBJECTIVE: To investigate the role of acute kidney injury staging in multiple organ dysfunction syndrome (MODS) patients with acute kidney injury (AKI) for deciding the opportune time of continuous blood purification (CBP). METHODS: A retrospective study was conducted. One hundred and twenty-six MODS patients with AKI in general intensive care unit (ICU) and emergency intensive care unit (EICU) requiring continuous venous-venous hemofiltration treatment were enrolled. According to the criteria of "Kidney Disease: Improving Global Outcomes Organization (KDIGO standard)" and acute physiology and chronic health evaluation II (APACHEII) score, the patients were stratified into KDIGO 1, 2, 3 groups and APACHEII score of <15, 15-25, >25 groups. ICU survival rate and renal function outcome, CBP treatment total ultrafiltration, average ICU day and the average medical costs of survivals were compared among groups. RESULTS: Compared with APACHEII ≤ 25, KDIGO 1, 2 hospitalized patients had significantly higher survival rate [94.1% (32/34) vs. 76.8% (43/56), P<0.05]. Renal function improvement rate in survivors of KDIGO 1, 2 patients was significantly higher than that in APACHEII ≤ 25 [90.6% (29/32) vs. 62.8 (27/43), P<0.01], and number of patients requiring CBP treatment, mean ICU day, and medical expenses were significantly reduced (CBP treatment of total ultrafiltration: 199.0±44.7 L vs. 239.0 ± 73.3 L, the mean length of stay in ICU: 12.9±3.4 days vs. 15.1±4.8 days, medical expenses: 2.6±0.4 million vs. 3.0±1.0 million, all P<0.05). There was no significant difference in above indexes between survivors in KDIGO 3 and APACHEII>25, and the indexes in KDIGO 3 and APACHEII >25 were worse than those in KDIGD 1, 2 and APACHEII>25. CONCLUSIONS: In patients of MODS accompanied by AKI, compared using as APACHEIIscore≤25 as opportune time to start CBP, to commence the treatment in the period of KDIGO standard 1, 2 cannot only improve patient survival with recovery of renal function, but also can reduce the ICU stay and medical expenses.

[Identification of a novel HLA allele, HLA-B*35:03:07, by sequencing-based typing].

This study was purposed to analyze and identify a novel HLA allele in Chinese population. A new HLA-B allele which is closely related to HLA-B*35:03:01 was initially detected by PCR-SSOP, then DNA sequencing was performed to identify the difference between the novel allele and HLA-B*35:03:01 allele. The result showed that the sequence of the new allele was different from all other known sequence. It differs from the closest matching HLA-B*35:03:01 by a single substitution at position 387 C→G in exon 3, no resulting in amino acid change. It is concluded that this allele is a novel one and has been officially named B*35:03:07 by the WHO Nomenclature Committee.

[Survey on the foci of Paragonimus in Youxi, Yongtai and Pinghe Counties of Fujian Province].

OBJECTIVE: To investigate the natural foci of paragonimiasis in Youxi, Yongtai and Pinghe Counties of Fujian Province. METHODS: One village each from the three counties was selected according to reported paragonimiasis cases. Freshwater snails collected from fields were examined for cercariae. Freshwater crabs obtained in the fields were examined for metacercariae by washing filtration method or direct compression method. Feces of cats and dogs were collected for the detection of eggs by water precipitation. In order to identify the species of Paragonimus, 4 cats were orally fed with metacercariae. At the same time, the habitat of three survey sites was observed. RESULTS: Three fluke species, namely, P. skrjabini, P. westermani and P. cenocopiosus(Syn. Euparagonimus cenocopiosus) were found. In Banlin Village of Youxi County and Chishui Village of Yongtai County, the seropositive rate by IgG ELISA were 6.8% (21/309) and 6.8% (9/133), respectively. Four species of freshwater snails were found, two species of Tricula and one species of Pseudobythinella were newly identified first intermediate hosts of Paragonimus. Four species of freshwater carbs were found, one species of Nanhaipotamon served as a new second intermediate host of Paragonimus. In Youxi, the infection rate of P. skrjabini cercariae in snails and metacercariae in crabs was 2.1% (27/1 344) and 92.1% (58/63), respectively; the index of crab infection and the positive ratio of Paragonimus eggs in cat feces was 171.91 and 1/7, respectively. In Yongtai, the cercariae infection rate in Pseudobythinella and Tricula snails infected with P. skrjabini was 0.6% (4/690) and 0.1% (2/ 2330), respectively; the infection rate of P. skrjabini metacercariae in crabs was 18.2% (18/99); the index of crab infection was 9.12. In Pinghe, the infection rate of cercariae in Semisulcospira libertina and metacercariae in crabs was 03% (3/1092) and 44.9% (35/78), respectively; the index of crab infection was 616. CONCLUSION: Paragonimus skrjabini P. westermani and P. cenocopiosus have been found from the three counties of Fujian Province with different infection level in snails and crabs.