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ISBN: (纸本)7040102927

关键词： nitric oxide   angiogenesis   metastasis   therapy   pancreas  

摘要： In this study, we report a metastatic model of Panc02 murine pancreatic adenocarcinoma. Parental Panc02 cells were orthotopically implanted into the pancreas of syngeneic C57BL/6 mice. Tumor cells were isolated from liver micrometastases 90 d after tumor implantation and established as a culture (Panc02-H1). The Panc02-H1 cells were then implanted into the pancreas of mice. Liver metastases were then collected and established as Panc02-H2 cells. This process was repeated until the Panc02-H7 cell line was established. These cells were extremely aggressive after implantation as manifested by progressive growth in the pancreas, peritoneal dissemination, and distant metastasis to multiple organs, including the liver and lungs. Moreover, Panc02-H7 cells expressed the inducible nitric oxide synthase gene at a very low level in culture and produced highly vascularized tumors having a large number of infiltrating macrophages. Collectively, this model system should be a valuable tool for investigating the molecular mechanisms governing pancreatic cancer growth and metastasis and exploring potential treatment modalities for this disease.

关键词： 规范   生物   生物学   医疗设备   动物  

标准号: GB/T 16886.2-2000

摘要： 本标准规定了生物学试验中动物适用的最低要求。 本标准的目标在于： a)为科学家提供尊重生命的通用性指南； b)选择最佳方式、减少动物实验次数和试验中的动物用量； C)将试验所用动物的痛苦降低至最低限度,保证动物的生存质量。 本标准适用于在脊椎动物体上的试验,不适用于在分化程度较低的动物体上以及在离体组织和器官上进行的试验。 本标准还建议,减少用于生物相容性试验的动物数量,如果有可能取消这一领域的动物试验。

关键词： desert rodent   Ctenomys fulvus   microclimate of burrows   evaporative water loss  

摘要： The Andean tuco-tuco, Ctenomys fulvus (Rodentia: Ctenomyidae) inhabits one of the most arid regions of the world, the Salar de Atacama, Northeast of Antofagasta, Chile (23 degrees 17'06 "S, 68 degrees 05'43 "W;2.240 m.a.s.l). We found that a stable microclimate in burrows, a low evaporative water loss (EWL), and a diet of roots (59% water content) are the main factors that permit the survival of this fossorial species in harsh desert conditions. Large circadian variation in T-a was observed above ground. Daily DeltaT(a) (T-a max - T-a min) = 37.9 +/- 0.2 degreesC in summer and in winter. In contrast, circadian variation of T-a inside the burrows was only 5.8 +/- 0.5 degreesC in the same seasons. Relative humidity (RH) was 1.9-3.1% during the day, increasing to maximum values of 27% at night and early morning. Inside the burrows RH was higher and quite stable, ranging between 53.1 and 65%, independent of the time of day and season. EWL, measured between 10 and 25 degreesC, was low (1.26 mg/g h), and a moderate increase of 13-20% was observed at higher temperatures. The low EWL may prevent dehydration. However, because of the low heat loss capability, animals became hyperthermic (0.8-1.6 degreesC) in dry air at T-a = 30-35 degreesC. As T-a during afternoon normally exceeded 35 degreesC, the microclimate of burrows provided the only way to avoid the lethal effects of hyperthermia. (C) 2000 Elsevier Science Ltd. All rights reserved.

关键词： Animals   Evolution   Forelimb/anatomy & histology   Fossils   Germany   Hindlimb/anatomy & histology   Locomotion   Posture   Reptiles/anatomy & histology   Reptiles/physiology   Running   Running   Tail/anatomy & histology  

关键词： COROPHIIDAE   AMPHIPODA   MARINE biology  

摘要： The population of Corophium multisetosum Stock, 1952 in Areao displayed a semiannual, iteroparous life history. Mean longevity was ==6 mo, with the estimated life span longer for overwintering individuals born in autumn than for individuals born in spring.

关键词： 抑郁症/遗传学   抑郁症/病理学   抑郁症/心理学   疾病模型   动物   动物   人类  

摘要： Development of drugs for the effective treatment of depressive disorders requires elucidation of factors that are critical for clinically antidepressant effects. During the past 4 years, we have studied in situ neurochemical alterations in the brain that may underlie depressive behavior. This was achieved using the genetically-selected Flinders Sensitive Line (FSL) of rats (a unique animal model of depression), before and after chronic antidepressant treatment. This line of rats exhibits behavioral features characteristic of depression, and responds to chronic, but not acute, antidepressant treatments. This review summarizes our findings concerning the local neuro-dynamics in the brain during manifestation of depressive behavior and effective antidepressant treatment in this animal model of depression. Understanding the abnormalities manifested in neurochemical pathways during depressive disorders and the dynamic effects of these abnormalities on the onset of action and efficacy of pharmacological treatments are crucial for the development of effective antidepresssant drugs and therapeutic strategies. (C) 2000 Elsevier Science Ltd. All rights reserved.

关键词： activation   gene expression   Kruppel-like factors   repression   transcription factors   zinc angers  

摘要： Recent advances in molecular cloning have led to the identification of a large number of mammalian zinc finger-containing transcription factors that exhibit homology to the Drosophila melanogaster protein, Kruppel. Although the amino acid sequences in the zinc finger domains of these Kruppel-like factors (KLFs) are closely related to one another, the regions outside the zinc fingers of the proteins are usually unique. KLFs display seemingly different and broad biological properties with each functioning as an activator of transcription, a repressor or both. This review article provides a current phylogenetic classification of the identified KLFs to date. More importantly, the currently known biological activities of the KLFs in regulating transcription, cell proliferation, differentiation and development are summarized and compared. Further characterization of this interesting protein family should provide additional insights into the their respective regulatory role in various important biological processes. (C) 2000 Elsevier Science Ltd. All rights reserved.

关键词： AMPHIPODA   SEA squirts   SPONGES (Invertebrates)   MARINE biology  

摘要： The population dynamics and reproductive biology of an ascidian- and a sponge-dwelling amphipod were examined. The two undescribed amphipod species, Leucothoe "ascidicola" and L. "spongicola", are closely related to each other, and occur in ascidians and sponges, respectively, along the Florida Atlantic coast. L. "ascidicola" was abundant in solitary ascidians during fall 1997, disappeared during spring/early summer, and became abundant again in September 1998. During the time when L. "ascidicola" were absent from their hosts, a copepod became a frequent inhabitant of the ascidians but disappeared again when L. "ascidicola" returned to the ascidians in September 1998. The numbers of L. "spongicola" in sponges increased substantially during spring, when high reproductive activity was observed. Following this reproductive peak, both adult and juvenile amphipods apparently left the sponges, and during the summer amphipod numbers in the sponges were very low. Another small amphipod species, which often co-occurred with L. "spongicola", showed less seasonal variation and was found in sponges throughout the whole study period. The percentage of ovigerous females per host unit was usually lower in the ascidian-dwelling than in the sponge-dwelling amphipods. In solitary ascidians, L. "ascidicola" amphipods usually occurred in groups of several adults, yet there never was more than one ovigerous female per ascidian. In contrast, several ovigerous L. "spongicola" females were found to cohabit in the same spongocoel. This suggests that intrasexual aggression may be stronger among reproductive amphipod females in the ascidians than in sponges. The size distributions of juvenile cohorts indicate that juvenile L. "ascidicola" remain for relatively long time periods in the parental ascidian, where they may reach sexual maturity. In contrast, in L. "spongicola", only cohorts of very small juveniles could be identified, indicating that juveniles disperse shortly after emerging from