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Nurse logs are common in modern forests from boreal to temperate and tropical ecosystems. However, the evolution of the nurse-log strategy remains elusive because of their rare occurrence in the fossil record. We report seven coniferous nurse logs from lowermost to uppermost Permian strata of northern China that have been colonized by conifer and sphenophyllalean roots. These roots are associated with two types of arthropod coprolites and fungal remains. Our study provides the first glimpse into plant-plant facilitative relationships between late Paleozoic gymnosperms and sphenopsids. Detritivorous arthropods and fungi appear to have been crucial for the utilization of nurse logs in Permian forests. The phylogenetically distant roots demonstrate that nurse-log interaction was a sophisticated seedling strategy in late Paleozoic humid tropical forests, and this approach may have been adopted and developed by a succession of plant groups leading to its wide representation in modern forest ecosystems.
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OBJECTIVE: To study the effect of Bifidobacterium on the expression of ß-defensin-2 (BD-2) in intestinal tissue of neonatal rats with necrotizing enterocolitis (NEC). METHODS: A total of 40 rats were randomly divided into four groups: normal control, Bifidobacterium control, NEC model, and Bifidobacterium treatment, with 10 rats in each group. A rat model of NEC was induced by hypoxia, cold stimulation, and artificial feeding. The rats in the Bifidobacterium control and Bifidobacterium treatment groups were given Bifidobacterium via the gastric tube after cold stimulation once a day for three consecutive days. The morphological changes of the terminal ileum were observed under a light microscope and the intestinal injury score was determined. Immunohistochemistry and qRT-PCR were used to measure the protein and mRNA expression of BD-2 in the ileal mucosal tissue. RESULTS: The NEC model group had a significantly higher intestinal injury score than the normal control, Bifidobacterium control, and Bifidobacterium treatment groups (P<0.05). The Bifidobacterium treatment group had a significantly higher intestinal injury score than the normal control and Bifidobacterium control groups (P<0.05). The mRNA and protein expression of BD-2 in the normal control group was significantly lower than in the Bifidobacterium control, NEC model, and Bifidobacterium treatment groups (P<0.05). The Bifidobacterium control group had significantly higher mRNA and protein expression of BD-2 than the NEC model and Bifidobacterium treatment groups (P<0.05). The Bifidobacterium treatment group had significantly higher mRNA and protein expression of BD-2 than the NEC model group (P<0.05). CONCLUSIONS: Bifidobacterium can induce the expression of BD-2 in intestinal tissue of rats and reduce inflammatory response by increasing the expression of BD-2. This provides a protective effect on neonatal rats with NEC.
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Bifidobacterium , Enterocolite Necrosante/terapia , Mucosa Intestinal/metabolismo , beta-Defensinas/fisiologia , Animais , Modelos Animais de Doenças , Humanos , Recém-Nascido , NF-kappa B/fisiologia , Ratos , Ratos Sprague-Dawley , Transdução de Sinais/fisiologia , beta-Defensinas/análise , beta-Defensinas/genéticaRESUMO
Today, cycads are a small group of gymnospermous plants with a limited distribution in the (sub)tropics, but they were major constituents of Mesozoic floras. Fossil leaves sporadically found in latest Carboniferous and Permian floras have putatively been ascribed to cycads. However, their true affinity remains unclear due to the lack of anatomical evidence. Virtually all modern cycads have pinnate leaves, but this type of leaf morphology is by no means unique for cycads. Pinnate leaves of Plagiozamites oblongifolius Halle 1927 with well-preserved cuticles showing the epidermal anatomy are here described from the upper Permian Xuanwei Formation of Yunnan Province, Southwest China. The cuticles show a clear differentiation into costal and intercostal zones; stomata are confined to the intercostal zones on both the upper and lower leaf surfaces. The external morphology and the epidermal anatomy of these fossil leaves are closely comparable with those of extant cycads, particularly members of the family Zamiaceae.
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Cycadopsida/anatomia & histologia , Fósseis , Folhas de Planta/anatomia & histologia , ChinaRESUMO
Leaf traces are important structures in higher plants that connect leaves and the stem vascular system. The anatomy and emission pattern of leaf traces are well studied in extant vascular plants, but remain poorly understood in fossil lineages. We quantitatively analysed the leaf traces in the late Permian conifer Ningxiaites specialis from Northwest China based on serial sections through pith, primary and secondary xylems. A complete leaf traces emission pattern of a conifer is presented for the first time from the late Palaeozoic. Three to five monarch leaf traces are grouped in clusters, arranged in a helical phyllotaxis. The leaf traces in each cluster can be divided into upper, middle and lower portions, and initiate at the pith periphery and cross the wood horizontally. The upper leaf trace increases its diameter during the first growth increment and then diminishes completely, which indicates leaf abscission at the end of the first year. The middle trace immediately bifurcates once or twice to form two or three vascular bundles. The lower trace persists as a single bundle during its entire length. The intricate leaf trace dynamics indicates this fossil plant had a novel evolutionary habit by promoting photosynthetic capability for the matured plant.
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BACKGROUND AND AIMS: Our knowledge of tylosis formation is mainly based on observations of extant plants; however, its developmental and functional significance are less well understood in fossil plants. This study, for the first time, describes a complete tylosis formation in a fossil woody conifer and discusses its ecophysiological implications. METHODS: The permineralized stem of Shenoxylon mirabile was collected from the upper Permian (Changhsingian) Sunjiagou Formation of Shitanjing coalfield, northern China. Samples from different portions of the stem were prepared by using the standard thin-sectioning technique and studied in transmitted light. KEY RESULTS: The outgrowth of ray parenchyma cells protruded into adjacent tracheids through pits initially forming small pyriform or balloon-shaped structures, which became globular or slightly elongated when they reached their maximum size. The tracheid luminae were gradually occluded by densely spaced tyloses. The host tracheids are arranged in distinct concentric zones representing different growth phases of tylosis formation within a single growth ring. CONCLUSIONS: The extensive development of tyloses from the innermost heartwood (metaxylem) tracheids to the outermost sapwood tracheids suggests that the plant was highly vulnerable and reacted strongly to environmental stress. Based on the evidence available, the tyloses were probably not produced in response to wound reaction or pathogenic infection, since evidence of wood traumatic events or fungal invasion are not recognizable. Rather, they may represent an ecophysiological response to the constant environmental stimuli.
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Fósseis , Traqueófitas/crescimento & desenvolvimento , Madeira/crescimento & desenvolvimento , ChinaRESUMO
BACKGROUND: Platinum-based regimens are used as standard first-line chemotherapy in non-small cell lung cancer (NSCLC) patients. To study if pharmacogenetic approach may allow a tailored selection of platinum chemotherapy for advanced NSCLC, we performed a meta-analysis to compare chemosensitivity to platinum with different ERCC1 C118T/ MDR1 C3435T single-nucleotide polymorphism (SNP). METHODS: Relevant studies were identified by searching the PubMed, Embase, Cochrane, OVID, Springer, EBSCO and CNKI databases. Inclusion criteria were patients with advanced NSCLC who received platinum-based chemotherapy, an evaluated polymorphism of ERCC/MDR1 and overall response rate. We excluded duplicate publications, letters and review articles. The RevMan 4.2 and STATA 11 package were used to do comprehensive quantitative assessment. RESULTS: A total of 11 studies were included in this meta-analysis. For studies evaluating ERCC1 C118T, test for heterogeneity was done (χ(2) = 13.41, P = 0.1), and the odds ratio (OR) for the wild-type C/C genotype versus the heterozygous C/T and T/T genotypes was 1.50 (95% CI 1.09 - 2.06, P = 0.01). In four studies evaluating MDR1 polymorphism, test for heterogeneity was also done (χ(2) = 3.22, P = 0.36), and the OR for the wild-type C/C genotype versus the heterozygous C/T and T/T genotypes was 2.30 (95% CI 1.44 - 3.68, P = 0.0005). CONCLUSIONS: The results indicated that platinum-based chemotherapy sensitivity was significantly associated with polymorphism of ERCC1 C118T and MDR1 C3435T SNP. In further perspective studies, the ERCC1/MDR1 SNPs might serve as simple and less invasive biomarkers for personalized chemotherapy with platinum-based anticancer drugs.
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Membro 1 da Subfamília B de Cassetes de Ligação de ATP/genética , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/genética , Proteínas de Ligação a DNA/genética , Endonucleases/genética , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/genética , Platina/uso terapêutico , Polimorfismo Genético/genética , HumanosRESUMO
OBJECTIVE: To study the relationship between pulmonary surfactant-associated protein B (SP-B) gene polymorphisms and their susceptibility to neonatal respiratory distress syndrome (RDS). METHODS: Eighty-eight preterm infants with RDS (RDS group) and 103 infants without RDS (control group) were enrolled. The genomic DNA was isolated using DNA kits. Polymerase chain reaction with restriction fragment length polymorphism technique was used to detect the genotype and allele frequency of the SP-B -18A/C and SP-B 1580C/T single nucleotide polymorphisms. The association between the polymorphisms and RDS was analyzed. RESULTS: SP-B -18A/C and SP-B 1580C/T were found to be polymorphic in both RDS and control groups. The frequencies of CC genotype (X2=12.26, P<0.01) and C allele (X2=11.97, P<0.01) of SP-B 1580C/T were significantly higher in the RDS group than in the control group. The C allele significantly increased the risk of RDS (OR=2.26, 95%CI: 1.42-3.60). The frequencies of genotype and allele of SP-B -18A/C showed no significant difference between the two groups. CONCLUSIONS: SP-B 1580C/T polymorphism contributes to the etiology of RDS and may serve as the susceptibility gene for RDS. The C allele increases the risk of RDS. SP-B -18A/C shows no association with the etiology of RDS.
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Predisposição Genética para Doença , Polimorfismo de Nucleotídeo Único , Proteína B Associada a Surfactante Pulmonar/genética , Síndrome do Desconforto Respiratório do Recém-Nascido/genética , Genótipo , Humanos , Recém-Nascido , Síndrome do Desconforto Respiratório do Recém-Nascido/etiologiaRESUMO
BACKGROUND AND AIMS: With great progress made in individualized chemotherapy, pharmacogenetics is gradually put on the agenda. We performed this meta-analysis to compare outcome to platinum-based chemotherapies in advanced non-small cell lung cancer (NSCLC) with different ERCC1 C118T/C8092A and MDR1 C3435T polymorphisms. METHODS: Relevant studies were identified according to search strategy in this meta-analysis. Inclusion criteria were patients with advanced NSCLC who were receiving platinum-based chemotherapies. We evaluated the relationship between single nucleotide polymorphisms (SNP) and outcome of platinum-based chemotherapies. RevMan and STATA package were used for the comprehensive quantitative analyses. RESULTS: Twenty studies were included in the meta-analysis. There was no significant association between SNPs and objective response or overall survival of platinum-based chemotherapies with CC vs. CT/TT: ERCC1 C118T (OR 1.21, 95% CI 0.81-1.82 for objective response; HR 1.09, 95% CI 0.79-1.51 for overall survival); ERCC1 C8092A SNP (OR 0.84, 95% CI 0.59-1.18; HR 1.26, 95% CI 0.68-2.36) and MDR1 C3435T SNP (HR 1.11, 95% CI 0.78-1.56). Ethnic stratification provided the same results. We found a significant difference for MDR1 C3435T (OR 2.22, 95% CI 1.46-3.37; OR 2.63, 95% CI 1.56-4.45 for Asians; OR 1.61, 95% CI 0.79-3.28 for Caucasians). CONCLUSIONS: We found no evidence to support the use of ERCC1 C118T/C8092A polymorphisms as prognostic predictors of platinum-based chemotherapies in NSCLC. For the MDR1 C3435T SNP, a significant association with objective response was detected for CC genotype in overall and Asian populations stratified. Multiple and large-scale studies with ethnic stratification are required for the correlation between biomarkers and tumor prognosis.
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Membro 1 da Subfamília B de Cassetes de Ligação de ATP/genética , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Proteínas de Ligação a DNA/genética , Endonucleases/genética , Neoplasias Pulmonares/tratamento farmacológico , Polimorfismo de Nucleotídeo Único , Subfamília B de Transportador de Cassetes de Ligação de ATP , Carcinoma Pulmonar de Células não Pequenas/genética , Humanos , Neoplasias Pulmonares/genética , Resultado do TratamentoRESUMO
In an attempt to synthesize novel zirconium phosphate materials, a series of syntheses have been performed in a deep eutectic solvent (DES), composed of tetrapropylammonium bromide (TPABr) and oxalic acid. As a result, this DES does not act as a template provider in reaction probably owing to the steric effects of the longer chains of the TPA cation, and only the α-Zr(HPO(4))(2)·H(2)O (α-ZrP) phase has been achieved. However, after organic amine was added to the initial reaction mixture in a normal way, the additives did act as a template to induce the zirconium phosphate framework. For example, with 1,4-dimethylpiperazine as an additive, a novel layered compound, [C(6)H(16)N(2)](0.5)Zr(H(0.5)PO(4))(2)·H(2)O (denoted as ZrPO(4)-DES8) was obtained. Its structure was determined from single-crystal X-ray diffraction (XRD) data and consists of zirconium phosphate layers with the protonated 1,4-dimethylpiperazine and water molecules in between. Interestingly, the two layered materials as additives in a liquid lubricant exhibit excellent friction behavior with higher load-carrying and antiwear capacities in comparison to typical lubricant additives such as MoS(2) and graphite, increase the P(B) value of the base oil by 27.2% and 8.5%, and decrease the wear scar diameter of the base oil by 43% and 36%, respectively. Scanning electron microscopy, XRD, and energy-dispersive X-ray spectrometry are used to investigate the lubricant behavior of those materials.