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91.
A Sebacinales species was recovered from a clone library made from a pooled rhizosphere sample of Nicotiana attenuata plants from 14 native populations. Axenic cultures of the related species, Piriformospora indica and Sebacina vermifera, were used to examine their effects on plant performance. Inoculation of N. attenuata seeds with either fungus species stimulated seed germination and increased growth and stalk elongation. S. vermifera inoculated plants flowered earlier, produced more flowers and matured more seed capsules than did non-inoculated plants. Jasmonate treatment during rosette-stage growth, which slows growth and elicits herbivore resistance traits, erased differences in vegetative, but not reproductive performance resulting from S. vermifera inoculation. Total nitrogen and phosphorous contents did not differ between inoculated and control plants, suggesting that the performance benefits of fungal inoculation did not result from improvements in nutritional status. Since the expression of trypsin proteinase inhibitors (TPI), defensive proteins which confer resistance to attack from Manduca sexta larvae, incur significant growth and fitness costs for the plant, we examined the effect of S. vermifera inoculation on herbivore resistance and TPI activity. After 10 days of feeding on S. vermifera-inoculated plants, larval mass was 46% higher and TPI activity was 48% lower than that on non-inoculated plants. These results suggest that Sebacina spp. may interfere with defense signaling and allow plants to increase growth rates at the expense of herbivore resistance mediated by TPIs.  相似文献   
92.
The effects of saturated long-chain (C: 16-22) N-acylethanolamines and a series of saturated fatty acids with the same length of carbon chains were investigated on depolarization-induced (45)Ca(2+) fluxes mediated by voltage-dependent Ca(2+) channels in transverse tubule membrane vesicles from rabbit skeletal muscle. Vesicles were loaded with (45)Ca(2+) and membrane potentials were generated by establishing potassium gradients across the vesicle using the ionophore valinomycin. Arachidonoylethanolamide and docosaenoylethanolamide but not palmitoylethanolamide and stearoylethanolamide (all 10 microM) caused a significant inhibition of depolarization-induced (45)Ca(2+) fluxes and specific binding of [(3)H]Isradipine to transverse tubule membranes. On the other hand, saturated fatty acids including palmitic, stearic, arachidic, and docosanoic acids (all 10 microM) were ineffective in functional and radioligand binding experiments. Additional experiments using endocannabinoid metabolites suggested that whereas ethanolamine and arachidic acids were ineffective, arachidonoylethanolamide inhibited Ca(2+) effluxes and specific binding of [(3)H]Isradipine. Further studies indicated that only those fatty acids containing ethanolamine as a head group and having a chain length of more than 18 carbons were effective in inhibiting depolarization-induced Ca(2+) effluxes and specific binding of [(3)H]Isradipine. In conclusion, results indicate that depending on the chain length and the head group of fatty acid, N-acylethanolamines have differential effects on the function of voltage-dependent Ca(2+) channels and on the specific binding of [(3)H]Isradipine in skeletal muscle membranes.  相似文献   
93.
In surgical treatment of head and neck cancer, when local tumor recurrence or failure of the previous reconstruction method occurs, reoperation for reconstruction of complicated soft-tissue defects can become a challenge for the plastic surgeon. This article describes the authors' experience with the extended vertical trapezius myocutaneous flap for head and neck complicated soft-tissue defects in nine patients ranging in age from 17 to 72 years. The causes of the defects were squamous cell carcinoma of the external ear (n = 2), lip (n = 2), larynx (n = 1), and oral cavity floor (n = 1); congenital hemifacial atrophy-temporomandibular joint ankylosis (n = 1); synovial sarcoma at the mandibular ramus (n = 1); and malignant fibrous histiocytoma at the posterior cranial fossa (n = 1). Eight of the nine patients had previously been operated on using other flap procedures, including free flaps and/or distant pedicled flaps (pectoralis major and deltopectoral flaps). One patient had been operated on using a graft procedure. After failure of the previous flap procedures in four patients and tumor recurrence in five patients, the extended vertical trapezius myocutaneous pedicled flap was used as a salvage procedure. The mean flap size was 7 x 34 cm. The flap was based solely on the transverse cervical artery. Superior muscle fibers of the trapezius were preserved and the caudal end of the flap was extended from 10 to 13 cm beyond the caudal end of the trapezius muscle. Three weeks postoperatively, the pedicle was separated. No flap failure occurred. The donor sites were closed primarily. There were no disabilities with regard to shoulder motion. Tumor recurrence was observed in two patients. In conclusion, for complicated soft-tissue defects of the head and neck, the extended vertical trapezius flap can be preferred as a salvage procedure because it is a simple, reliable, large flap that is located far enough from the damaged area.  相似文献   
94.
Inoue T  Oz HS  Wiland D  Gharib S  Deshpande R  Hill RJ  Katz WS  Sternberg PW 《Cell》2004,118(6):795-806
Wnt proteins are intercellular signals that regulate various aspects of animal development. In Caenorhabditis elegans, mutations in lin-17, a Frizzled-class Wnt receptor, and in lin-18 affect cell fate patterning in the P7.p vulval lineage. We found that lin-18 encodes a member of the Ryk/Derailed family of tyrosine kinase-related receptors, recently found to function as Wnt receptors. Members of this family have nonactive kinase domains. The LIN-18 kinase domain is dispensable for LIN-18 function, while the Wnt binding WIF domain is required. We also found that Wnt proteins LIN-44, MOM-2, and CWN-2 redundantly regulate P7.p patterning. Genetic interactions indicate that LIN-17 and LIN-18 function independently of each other in parallel pathways, and different ligands display different receptor specificities. Thus, two independent Wnt signaling pathways, one employing a Ryk receptor and the other a Frizzled receptor, function in parallel to regulate cell fate patterning in the C. elegans vulva.  相似文献   
95.
The aim of this study was to evaluate the protective effect of Ginkgo biloba extract on CCl4-induced hepatic damage in rats. Hepatic malondialdehyde, glutathione and hydroxyproline levels and histopathologic alterations in liver specimens were assessed. 200 mg/kg/day Ginkgo biloba extract were given orally to the animals for 10 days, then a single dose of 2 ml/kg b.w. carbon tetrachloride was, administered intraperitoneally. Ginkgo biloba extract treatment reduced hepatic malondialdehyde levels significantly (p < 0.05), but did not alter glutathione (p > 0.05) and hydroxyproline levels (p > 0.05). The light and electron microscopic findings showed that Ginkgo biloba extract limited the CCl4-induced hepatocyte necrosis and atrophy. These results suggest that this extract may protect the hepatocytes from carbon tetrachloride-induced liver injury.  相似文献   
96.
97.
We investigated the effects of different implant biomaterials on cultured canine bone marrow stromal cells (BMSC) undergoing differentiation into osteoblasts (dBMSC). BMSC were isolated from canine humerus by marrow aspiration, cultured and differentiated on calcium phosphate scaffold (CPS), hydroxyapatite, hydroxyapatite in gel form and titanium mesh. We used the MTT method to determine the effects of osteogenic media on proliferation. The characteristics of dBMSC were assessed using alizarin red (AR), immunocytochemistry and osteoblastic markers including alkaline phosphatase/von Kossa (ALP/VK), osteocalcin (OC) and osteonectin (ON), and ELISA. The morphology of dBMSC on the biomaterials was investigated using inverted phase contrast microscopy and scanning electron microscopy. We detected expression of ALP/VK, AR, OC and ON by day 7 of culture; expression increased from day 14 until day 21. CPS supported the best adhesion, cell spreading, proliferation and differentiation of BMSCs. The effects of the biomaterials depended on their surface properties. Expression of osteoblastic markers showed that canine dBMSCs became functional osteoblasts. Tissue engineered stem cells can be useful clinically for autologous implants for treating bone wounds.  相似文献   
98.

In this study, the distribution, morphology and relative abundance of Sulfate Reducing Bacterial (SRB) and Methanogenic Archaeal (MA) populations in the Black Sea sediments were investigated by using in situ hybridization with fluorescently labeled rRNA-targeted oligonucleotide probes. Results were discussed with respect to the characteristics of sampling points. MA and SRB showed a great diversity in all sediment samples. Higher abundance of MA (20–30%) and SRB (30–35%) populations were observed within the sediments from deeper parts of the Black Sea than the shallower parts (10–11% MA and 13–14% SRB). Desulfobotulus, Desulfosarcina and Desulfococcus groups were the most commonly detected SRB groups in the Black Sea sediments. Relative percentage of these SRB groups within sediments from deeper parts of the Black Sea was in a range of 17–21% whereas that of was in a range of 4–5% within the sediments from the shallower parts. Order Methanococcales were the dominant methanogenic group in all samples. Relative percentages of order Methanococcales were in a range of 8–12% and 4–5% within sediments from deeper parts and the coastal parts of the Black Sea, respectively.  相似文献   
99.
The dopamine D4 receptor gene (DRD4) encodes a receptor for dopamine, a chemical messenger used in the brain. One variant of the DRD4 gene, the 7R allele, is believed to be associated with attention deficit hyperactivity disorder (ADHD). The aim of this study was to investigate the relationships between repeat polymorphisms in dopamine DRD4 and second language learning styles such as visual (seeing), tactile (touching), auditory (hearing), kinesthetic (moving) and group/individual learning styles, as well as the relationships among DRD4 gene polymorphisms and ADHD in undergraduate students. A total of 227 students between the ages of 17–21 years were evaluated using the wender utah rating scale and DSM-IV diagnostic criteria for ADHD. Additionally, Reid's perceptual learning style questionnaire for second language learning style was applied. In addition, these students were evaluated for social distress factors using the list of Threatening Events (TLE); having had no TLE, having had just one TLE or having had two or more TLEs within the previous 6 months before the interview. For DRD4 gene polymorphisms, DNA was extracted from whole blood using the standard phenol/chloroform method and genotyped using polymerase chain reaction. Second language learners with the DRD4.7+ repeats showed kinaesthetic and auditory learning styles, while students with DRD4.7-repeats showed visual, tactile and group learning, and also preferred the more visual learning styles \(\left( {\bar{X}:{ 3}. 70} \right)\) . We also demonstrated that the DRD4 polymorphism significantly affected the risk effect conferred by an increasing level of exposure to TLE.  相似文献   
100.
The Anaphase Promoting Complex (APC) controls CDK activity by targeting the ubiquitin-dependent proteolysis of S-phase and mitosis-promoting cyclins. Here, we report that the ectopic expression of the Arabidopsis CDC27a, an APC subunit, accelerates plant growth and results in plants with increased biomass production. CDC27a overexpression was associated to apical meristem restructuration, protoplasts with higher 3H-thimidine incorporation and altered cell-cycle marker expression. Total protein extracts immunoprecipitated with a CDC27a antibody showed ubiquitin ligase activity, indicating that the Arabidopsis CDC27a gets incorporated into APC complexes. These results indicate a role of AtCDC27a in regulation of plant growth and raise the possibility that the activity of the APC and the rates of plant cell division could be regulated by the concentration of the CDC27a subunit. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users. Cristian Antonio Rojas and Nubia Barbosa Eloy contributed equally to this work.  相似文献   
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