Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 13 de 13
Filtrar
Mais filtros










Intervalo de ano de publicação
1.
World J Gastroenterol ; 28(20): 2163-2175, 2022 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-35721885

RESUMO

Pancreatic neuroendocrine neoplasms (PanNENs) are rare neoplasms with strong heterogeneity that have experienced an increasing incidence rate in recent years. For patients with locally advanced or distant metastatic PanNENs, systemic treatment options vary due to the different differentiations, grades and stages. The available options for systemic therapy include somatostatin analogs, mole-cularly targeted agents, cytotoxic chemotherapeutic agents, immune checkpoint inhibitors, and peptide receptor radionuclide therapy. In addition, the development of novel molecularly targeted agents is currently in progress. The sequence of selection between different chemotherapy regimens has been of great interest, and resistance to chemotherapeutic agents is the major limitation in their clinical application. Novel agents and high-level clinical evidence continue to emerge in the field of antiangiogenic agents. Peptide receptor radionuclide therapy is increasingly employed for the treatment of advanced neuroendocrine tumors, and greater therapeutic efficacy may be achieved by emerging radio-labeled peptides. Since immune checkpoint inhibitor monotherapies for PanNENs appear to have limited antitumor activity, dual immune checkpoint inhibitor therapies or combinations of antiangiogenic therapies and immune checkpoint inhibitors have been applied in the clinic to improve clinical efficacy. Combining the use of a variety of agents with different mechanisms of action provides new possibilities for clinical treatments. In the future, the study of systemic therapies will continue to focus on the screening of the optimal benefit population and the selection of the best treatment sequence strategy with the aim of truly achieving individualized precise treatment of PanNENs.


Assuntos
Antineoplásicos , Tumores Neuroendócrinos , Neoplasias Pancreáticas , Inibidores da Angiogênese/uso terapêutico , Antineoplásicos/uso terapêutico , Humanos , Inibidores de Checkpoint Imunológico , Tumores Neuroendócrinos/tratamento farmacológico , Tumores Neuroendócrinos/patologia , Neoplasias Pancreáticas/tratamento farmacológico , Neoplasias Pancreáticas/patologia , Radioisótopos/uso terapêutico , Receptores de Peptídeos , Somatostatina
2.
World J Gastroenterol ; 27(21): 2895-2909, 2021 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-34135560

RESUMO

BACKGROUND: Poorly differentiated gastric neuroendocrine neoplasms (PDGNENs) include gastric neuroendocrine carcinoma (NEC) and mixed adenoneuroendocrine carcinoma, which are highly malignant and rare tumors, and their incidence has increased over the past few decades. However, the clinicopathological features and outcomes of patients with PDGNENs have not been completely elucidated. AIM: To investigate the clinicopathological characteristics and prognostic factors of patients with PDGNENs. METHODS: The data from seven centers in China from March 2007 to November 2019 were analyzed retrospectively. RESULTS: Among the 232 patients with PDGNENs, 191 (82.3%) were male, with an average age of 62.83 ± 9.11 years. One hundred and thirteen (49.34%) of 229 patients had a stage III disease and 86 (37.55%) had stage IV disease. Three (1.58%) of 190 patients had no clinical symptoms, while 187 (98.42%) patients presented clinical symptoms. The tumors were mainly (89.17%) solitary and located in the upper third of the stomach (cardia and fundus of stomach: 115/215, 53.49%). Most lesions were ulcers (157/232, 67.67%), with an average diameter of 4.66 ± 2.77 cm. In terms of tumor invasion, the majority of tumors invaded the serosa (116/198, 58.58%). The median survival time of the 232 patients was 13.50 mo (7, 31 mo), and the overall 1-year, 3-year, and 5-year survival rates were 49%, 19%, and 5%, respectively. According to univariate analysis, tumor number, tumor diameter, gastric invasion status, American Joint Committee on Cancer (AJCC) stage, and distant metastasis status were prognostic factors for patients with PDGNENs. Multivariate analysis showed that tumor number, tumor diameter, AJCC stage, and distant metastasis status were independent prognostic factors for patients with PDGNENs. CONCLUSION: The overall prognosis of patients with PDGNENs is poor. The outcomes of patients with a tumor diameter > 5 cm, multiple tumors, and stage IV tumors are worse than those of other patients.


Assuntos
Tumores Neuroendócrinos , Neoplasias Gástricas , Idoso , China/epidemiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Tumores Neuroendócrinos/patologia , Prognóstico , Estudos Retrospectivos , Neoplasias Gástricas/epidemiologia , Neoplasias Gástricas/patologia
3.
BMC Gastroenterol ; 21(1): 188, 2021 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-33892648

RESUMO

BACKGROUND: Currently, there are no circulating diagnostic biomarkers for gastric neuroendocrine neoplasms (g-NENs). In previous studies, we found that miRNA-202-3p is overexpressed in the tumour tissue of type 1 g-NEN. We speculated that miRNA-202-3p is also likely to be highly expressed in circulating blood. METHODS: A total of 27 patients with type 1 g-NEN and 27 age- and sex-matched control participants were enrolled in this study. The miRNA-202-3p levels in serum obtained from the participants were measured by qRT-PCR. The expression level of miRNA-202-3p in the samples was calculated by comparison with a standard curve. RESULTS: The clinical characteristics of the patients were similar to those of the patient samples in previous reports. Expression of miRNA-202-3p was significantly higher in the patient group (3.84 × 107 copies/nl) than in the control group (0.635 × 107 copies/nl). The area under the ROC curve (AUC) was 0.878 (95% CI: 0.788-0.968), and the optimal cut-off point was approximately 1.12 × 107 copies/nl. The sensitivity and specificity were 88.9% and 77.8%, respectively. CONCLUSION: This study suggests that miRNA-202-3p is potentially useful as a biomarker of type 1 g-NEN; further investigation and verification should be performed in future research.


Assuntos
MicroRNAs/sangue , Tumores Neuroendócrinos , Neoplasias Gástricas , Biomarcadores , Biomarcadores Tumorais/genética , Perfilação da Expressão Gênica , Humanos , Tumores Neuroendócrinos/diagnóstico , Tumores Neuroendócrinos/genética , Curva ROC , Neoplasias Gástricas/diagnóstico , Neoplasias Gástricas/genética
4.
Neuroendocrinology ; 111(8): 752-763, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-32668427

RESUMO

OBJECTIVE: The efficacy of the capecitabine/temozolomide (CAPTEM) regimen has been demonstrated in metastatic neuroendocrine neoplasms (NENs), but because of varying response rates among the patients, biomarkers to predict its response are greatly needed. Here, we investigated the clinical utility of a Ki-67 index to predict the CAPTEM regimen objective responses and select patients who could benefit from this regimen. METHODS: Metastatic NENs patients treated with the CAPTEM regimen from 4 high-volume medical centers were selected and grouped in a training and validation cohort. The classification and regression tree (CART) was generated to identify the optimal threshold of Ki-67 for stratifying the patients into different Ki-67 range groups based on their response to the CAPTEM regimen. RESULTS AND CONCLUSIONS: The overall response rate (ORR) and disease control rate of the entire cohort (N = 151) were 26.5 and 76.2%, respectively, with a median progression-free survival (PFS) of 12.0 months. CART analysis showed that patients in the Ki-67 range group 10-40% demonstrated a significantly higher ORR than those in Ki-67 >40 and <10% groups (p < 0.001 in the training cohort and p = 0.036 in the validation cohort). Response to the CAPTEM regimen was not influenced by the expression of O6-methylguanine-DNA methyltransferase or primary tumor location. Multivariate analysis identified the Ki-67 index as the only independent prognostic factor for overall survival (p = 0.031) and PFS (p = 0.006). The proposed Ki-67 index was externally validated and could be used to clinically identify suitable metastatic NENs patients who could achieve an optimal cytoreduction using the CAPTEM regimen.


Assuntos
Antineoplásicos/farmacologia , Capecitabina/farmacologia , Antígeno Ki-67/sangue , Tumores Neuroendócrinos/tratamento farmacológico , Avaliação de Resultados em Cuidados de Saúde , Temozolomida/farmacologia , Adolescente , Adulto , Idoso , Quimioterapia Combinada , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Tumores Neuroendócrinos/sangue , Prognóstico , Estudos Retrospectivos , Adulto Jovem
5.
World J Gastrointest Oncol ; 12(12): 1416-1427, 2020 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-33362912

RESUMO

BACKGROUND: For the rarity of type 3 gastric neuroendocrine tumours (g-NETs), their clinicopathological characteristics and prognosis are not well illustrated. AIM: To describe the clinicopathological features and outcome of type 3 g-NETs in the Chinese population. METHODS: Based on the 2019 WHO pathological classification, the clinicopathological characteristics and prognosis of patients with type 3 g-NETs in China were retrospectively analysed. RESULTS: A total of 77 patients (55.8% of females) with type 3 g-NETs were analysed, with a median age of 48 years (range: 28-79 years). The tumours were mainly located in the gastric fundus/body (83.1%) and were mostly solitary (83.1%), with a median size of 1.5 cm (0.8-3.5 cm). Of these, there were 37 G1 tumours (48.1%), 31 G2 (40.3%), and 9 G3 (11.7%). Ten (13.0%) and 24 (31.2%) patients had lymph node and distant metastasis, respectively. In addition, type 3 g-NETs were heterogeneous. Compared with G1 NETs, G2 NETs had a higher lymph node metastasis rate, and G3 NETs had a higher distant metastasis rate. G1 and G2 NETs with stage I/II disease (33/68) received endoscopic treatment, and no tumour recurrence or tumour-related death was observed within a median follow-up time of 36 mo. Grade and distant metastasis were identified to be independent risk factors for prognosis in multivariable analysis. CONCLUSION: Type 3 g-NETs are obviously heterogeneous, and the updated WHO 2019 pathological classification may be used to effectively evaluate their biological behaviors and prognosis. Also, endoscopic treatment should be considered for small (< 2 cm), low grade, superficial tumours.

6.
World J Surg Oncol ; 17(1): 66, 2019 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-30975157

RESUMO

BACKGROUND: Well-differentiated pancreatic neuroendocrine tumors (PanNETs) usually have a good prognosis; however, there are patients that experience recurrence after curative resection. AIM: To explore recurrence-related risk factors by analyzing clinicopathological data of PanNETs after radical surgery. METHODS: Clinical and pathological data from 47 patients with well-differentiated PanNETs at China-Japan Friendship Hospital from January 2012 to March 2016 were analyzed retrospectively. Univariate and multivariate analyses of the risk factors of PanNETs for postoperative recurrence were conducted. RESULTS: Among the 47 patients with well-differentiated PanNETs, there were 38 cases with non-functioning tumors, 9 cases with functional tumors (6 insulinomas, 1 gastrinoma, 1 glucagonoma, and 1 VIPomas). There are 17 cases (36.2%) in the pancreatic head, 17 (36.2%) in the body and tail, 9 (19.1%) in the tail, and 4 (8.5%) in the body. The median tumor size was 3.65 (IQR 2-5.5) cm. Fourteen cases (29.8%) were NET G1, and 33 cases (70.2%) were NET G2. In regard to the clinical stage, 9 (19.1%) cases were IA, 14 (29.8%) cases were IB, 7 (14.9%) cases were IIA, 14 (29.8%) cases were IIB, and 3 cases unknown. There were 17 patients who presented with postoperative recurrence. Univariate analysis showed that AJCC TNM staging, Ki67 index, vascular invasion, margin status, and the regional stage of the tumors are related to the recurrence of patients with PanNETs (p < 0.05). The results of multivariate analysis showed that Ki67 index ≥ 10% is an independent risk factor for the postoperative recurrence of PanNETs (p < 0.05). CONCLUSION: The Ki67 index ≥ 10% is an independent risk factor for recurrence in well-differentiated PanNETs after radical surgery, and close surveillance for these patients may be needed.


Assuntos
Recidiva Local de Neoplasia/patologia , Tumores Neuroendócrinos/patologia , Neoplasias Pancreáticas/patologia , Adulto , Estudos de Casos e Controles , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/cirurgia , Tumores Neuroendócrinos/cirurgia , Neoplasias Pancreáticas/cirurgia , Prognóstico , Estudos Retrospectivos , Fatores de Risco , Taxa de Sobrevida
7.
World J Gastroenterol ; 24(5): 573-582, 2018 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-29434446

RESUMO

AIM: To detect abnormal microRNA (miRNA) expression in type 1 gastric neuroendocrine neoplasms (g-NENs) and find potential target genes. METHODS: Tumour tissues from patients with type 1 g-NENs were used as experimental samples, and gastric mucosal tissues from the same patients obtained during gastroscopy review after several months were used as control samples. miRNA expression was examined with Agilent human miRNA chips and validated via RT-PCR. Three types of target gene prediction software (TargetScan, PITA, and microRNAorg) were used to predict potential target genes of the differentially expressed miRNAs, and a dual-luciferase reporter assay system was used for verification. RESULTS: Six miRNAs were significantly upregulated or downregulated in the tumours compared to the control samples. Among them, miR-202-3p was extraordinarily upregulated. RT-PCR of seven sample sets confirmed that miR-202-3p was upregulated in tumour tissues. In total, 215 target genes were predicted to be associated with miR-202-3p. Among them, dual-specificity phosphatase 1 (DUSP1) was reported to be closely related to tumour occurrence and development. The dual-luciferase reporter assay showed that miR-202-3p directly regulated DUSP1 in 293T cells. CONCLUSION: miR-202-3p is upregulated in type 1 g-NEN lesions and might play important roles in the pathogenesis of type 1 g-NENs by targeting DUSP1.


Assuntos
Fosfatase 1 de Especificidade Dupla/genética , Regulação Neoplásica da Expressão Gênica , MicroRNAs/metabolismo , Tumores Neuroendócrinos/genética , Neoplasias Gástricas/genética , Biópsia , Regulação para Baixo , Fosfatase 1 de Especificidade Dupla/metabolismo , Mucosa Gástrica/patologia , Perfilação da Expressão Gênica , Células HEK293 , Humanos , MicroRNAs/genética , Tumores Neuroendócrinos/patologia , Neoplasias Gástricas/patologia , Regulação para Cima
8.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-312326

RESUMO

<p><b>OBJECTIVE</b>To investigate the expression of connective tissue growth factor (CTGF) in colorectal cancer(CRC) and its association with clinicopathologic parameters and overall survival rate.</p><p><b>METHODS</b>Fresh tumor tissues and matched distal normal colon tissues were collected from 92 patients diagnosed as CRC by surgical operation. The expression level of CTGF mRNA was quantified by quantitative reverse transcription PCR. Thirty out of 92 pairs of tissue specimens were selected randomly to detect CTGF protein by immunohistochemistry. All the cases were followed up to identify prognostic factors for survival.</p><p><b>RESULTS</b>CTGF mRNA expression was up-regulated in CRC. The positive rate of CTGF protein expression tissues (73.3%) was significantly higher than that in the corresponding normal tissues (23.3%, P<0.01). CTGF expression was lower in patients with lymphatic metastasis or stage III/IIII disease (all P<0.05). A negative association was also observed between the CTGF protein positive rate and tumor infiltration depth (P<0.05). The relative expression of CTGF mRNA in tumor tissues was classified into high and low expression groups. The 5-year cumulative survival rate was lower in patients with low CTGF expression (29.3%) as compared to those with high CTGF expressions (68.3%) (P<0.01). Cox regression analysis revealed that the relative expression level of CTGF was independent factor of overall survival (RR=2.960, 95%CI:1.491-1.587, P<0.01). ROC curve analysis showed that sensitivity and specificity of CTGF mRNA expression for prediction of 5-year survival were 64.9% and 74.5%, respectively.</p><p><b>CONCLUSIONS</b>The aberrant expression of CTGF is associated with the malignant biological behaviors of CRC. Low expression of CTGF is associated with worse prognosis of CRC.</p>


Assuntos
Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias Colorretais , Diagnóstico , Metabolismo , Patologia , Fator de Crescimento do Tecido Conjuntivo , Genética , Metabolismo , Prognóstico , RNA Mensageiro , Genética
9.
Ying Yong Sheng Tai Xue Bao ; 22(4): 1067-74, 2011 Apr.
Artigo em Chinês | MEDLINE | ID: mdl-21774334

RESUMO

This paper presented a new and simple assessment method for the quality of ecological monitoring data. This method theorized the associations between the data reliability as an ordinal variable with different number of classes and the data sources such as natural main ecological processes, secondary ecological processes, and extraneous and exotic processes, and offered a new data quality index to estimate the quality of the whole dataset by using the reasonableness ratio of observations. The assessment results provided the reliability class of each dataset, good explanations for outlier (or error data) flagging decisions, and quality value of the whole dataset. The method was applied to assess two tree growth datasets from Chinese Ecosystem Research Network (CERN), and the results demonstrated that the new data quality index could quantitatively evaluate the quality of the tree growth datasets. The new method would facilitate the development of corresponding software.


Assuntos
Ecossistema , Monitoramento Ambiental/métodos , Medição de Risco/métodos , Árvores/crescimento & desenvolvimento , Coleta de Dados , Tomada de Decisões , Ecologia/métodos , Controle de Qualidade
10.
Ying Yong Sheng Tai Xue Bao ; 22(2): 280-6, 2011 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-21608237

RESUMO

By using indicator species analysis (ISA) method, this paper studied the feasibility of using indicator species to reflect the responses of species diversity and community composition of subtropical forests in Huitong of China to forest management. Ninety-four significant indicator species from 357 understory species were identified, and a new indicator species dataset (community level) was constructed to examine the association between indicator species dataset and original community dataset, and to evaluate the predictive potential of indicator species in reflecting forest management effect. There existed a strong association between the two datasets (Mantel r = 0.898). The indicator species dataset could well predict the management effect on species diversity (regression analysis, R2 > 0.74) and community composition (ANOVA, F >16.79). When the two datasets were applied to Nonmetric Multi-Dimensional Scaling (NMDS) ordination and K-mean cluster analysis, the indicator species dataset could well identify the forest types with different management treatments, as the original community dataset did. Also, the indicator species dataset nearly played the same role as the original community dataset in identifying the species diversity, community composition, and forest type. It was suggested that for saving costs in overall investigation of forest ecosystem, indicator species could be used as a surrogate of full community to predict forest management effect.


Assuntos
Biodiversidade , Conservação dos Recursos Naturais , Ecossistema , Agricultura Florestal/métodos , Árvores/classificação , China , Previsões , Dinâmica Populacional , Especificidade da Espécie , Árvores/crescimento & desenvolvimento
11.
Ying Yong Sheng Tai Xue Bao ; 22(10): 2560-6, 2011 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-22263458

RESUMO

A short-term understory vegetation removal experiment was conducted at three experimental sites of Chinese fir (Cunninghamia lanceolata) plantation in Huitong of Hunan Province, South-central China to examine the short-term effects of the absence of understory vegetation on litter decomposition. In the plantation, the standing stock of the litter in L layer (un-decomposed litter), F layer (semi-decomposed litter), and H layer (decomposed litter) under understory intact condition was (123.7 +/- 46.3) g m(-2), (204.2 +/- 79.1) g m(-2), and (187.1 +/- 94.8) g m(-2), and the corresponding nutrient storage was (447.51 +/- 16.75) g kg(-1), (418.89 +/- 35.75) g kg(-1), and (376.11 +/- 47.33) g kg(-1) for carbon, (4.87 +/- 1.24) g kg(-1), (6.4 +/- 2.38) g kg(-1), and (4.66 +/- 2.64) g kg(-1) for nitrogen, and (0.14 +/- 0.01) g kg(-1), (0.16 +/- 0.03) g kg(-1), and (0.16 +/- 0.02) g kg(-1) for phosphorus, respectively. At sites DL87 and MS90, understory vegetation removal had significant effects on the standing stock of litter and the corresponding storage of carbon, nitrogen, and phosphorus in F layer, though the effects varied with sites (e. g., the storage of litter carbon, nitrogen, and phosphorus decreased by more than 55% at DL87 while increased by about 1 time at MS90). Across the three sites, understory vegetation removal had little effects on the standing stock and nutrient storage of the litter in L layer and H layer. In addition, the removal had little effects on the litter decomposition at its early stage, but showed significant inhibitory effects after 150 days elapsed, with the decomposition rate decreased by 20.8%. These results suggested that the short-term effects of understory vegetation removal on the litter nutrient cycling could be depended on the forest site condition and the duration after the understory vegetation removal.


Assuntos
Abies/crescimento & desenvolvimento , Ecossistema , Agricultura Florestal/métodos , Folhas de Planta/metabolismo , Abies/metabolismo , Carbono/metabolismo , China , Nitrogênio/metabolismo , Fósforo/metabolismo
12.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-266286

RESUMO

<p><b>OBJECTIVE</b>To investigate the effect of fragile histidine triad (FHIT) gene transfection on human colorectal cancer cell line SW480 through up-regulation of caspase-8 expression.</p><p><b>METHODS</b>The eukaryotic expression plasmid containing FHIT, pRc/CMV2-FHIT was prepared and purified, and then identified by restrictive enzyme digestion. pRc/CMV2-FHIT was transfected into SW480 cells, and positive cell clones (SW480-FHIT, study group) were selected and amplified. Empty plasmid-transfected SW480 cells(SW480-pRc/CMV2, negative control) and normal SW480 cells (bland control) were used as control. Methyl thiazolyl tetrazolium (MTT) assay was used to test the changes in the proliferation of SW480 cells. Cell-cycle kinetics and apoptosis were analyzed by flow cytometry (FCM). The changes of pro-caspase-8, caspase-8 mRNA and caspase-8 relative activity were analyzed by Western blot, semi-quantitative RT-PCR and colorimetric assay with pan labeled substrate, respectively.</p><p><b>RESULTS</b>At 96 hours after transfection, cell inhibition rates of the study group and the negative control group were 71.7% and 16.9%. G0/G1 ratio was (63.2±3.5)% and (50.6±2.1)%, optical density of caspase-8 mRNA band 107 and 41, and relative activity of caspase-8 0.43 and 0.25, respectively. All the differences above were statistically significant (P<0.05). When FHIT inhibitor was added, the relative activity of caspase-8 decreased to 0.22, comparable to that in the control group.</p><p><b>CONCLUSIONS</b>FHIT gene transfection can significantly inhibit the proliferation and induce G0/G1 arrest in human colon cancer cell line SW480. The mechanism is related to the up-regulation of caspase-8 expression.</p>


Assuntos
Humanos , Hidrolases Anidrido Ácido , Genética , Apoptose , Caspase 8 , Metabolismo , Linhagem Celular Tumoral , Proliferação de Células , Neoplasias do Colo , Genética , Patologia , Proteínas de Neoplasias , Genética , RNA Mensageiro , Genética , Transfecção
13.
Ying Yong Sheng Tai Xue Bao ; 20(1): 65-70, 2009 Jan.
Artigo em Chinês | MEDLINE | ID: mdl-19449567

RESUMO

In January 2008, southern China suffered an unusual heavy snowstorm and freezing rain over a large area for almost a month long. This catastrophic event was the worst one in past 50 years, which brought the area a serious impact on the infrastructure, ecology, and environment. To understand the long-term impact of this catastrophic event on the forest ecosystems in this area, a field investigation was conducted on the soil fauna in a pure Chinese fir plantation and a mixed Chinese fir plantation-alder plantation in Huitong County of Hunan Province on March 23, 2008, the date 40 days after the heavy snowstorm and freezing rain. With the abundance and community composition as the main parameters and the monitoring data from the two plantations on March 23, 2007 as the reference, the flexibility and resistance of soil fauna to the disturbances of the catastrophic event was preliminarily evaluated. The results showed that there was a significant deviation of soil fauna communities in the two plantations from the reference. An outbreak increase in microfauna nematode abundance was found from 12216.9 ind x m(-2) to 118343.9 ind x m(-2) in pure Chinese fir plantation and from 25435.9 ind x m(-2) to 84573.0 ind x m(-2) in mixed Chinese fir plantation-alder plantation, while a 27.0% and 85.6% decrease of macrofauna abundance was found in the two plantations, respectively, compared with the reference. Mesofauna abundance also had a significant decrease in litter layer but not in soil. The abundance recovery displayed a trend from quick rate for microfauna to slow rate for macrofauna, which indicated that the soil fauna functional groups, in terms of body size, could be used as a vulnerable indicator in evaluating disturbance event and post-disturbance recovery. By using community ordinations, no shift in soil fauna community composition was detected 40 days after the catastrophic event, suggesting that the community composition of soil invertebrate had a high resistance to catastrophic snowstorm and freezing rain disturbances.


Assuntos
Cunninghamia/crescimento & desenvolvimento , Desastres , Monitoramento Ambiental/métodos , Nematoides/crescimento & desenvolvimento , Solo/parasitologia , Animais , Biodiversidade , Invertebrados/crescimento & desenvolvimento , Dinâmica Populacional , Chuva , Neve
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...