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诱导分化（Induction of differentiation，IOD）是指恶性肿瘤细胞在体内外分化诱导剂的作用下，向成熟或接近成熟的细胞分化。目前，恶性肿瘤的诱导分化治疗已成为肿瘤生物学和肿瘤治疗学的研究热点和前沿领域，其中，寻找低毒高效的分化诱导剂是肿瘤诱导分化治疗的关键。人参皂苷Rh2是人参所含活性成分之一，具有较强的抗肿瘤活性。各国学者先后通过多种体内外试验证实，Rh2通过诱导肿瘤细胞分化或凋亡，抑制多种肿瘤细胞的生长，而对正常细胞的毒性甚低。笔者仅对人参皂苷Rh2诱导肿瘤细胞分化的研究做一综述。 相似文献
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以不同质量浓度的人参皂苷Rh2与马立克氏病肿瘤细胞系MSB-1细胞共同作用,利用改良MTT法测定了人参皂苷Rh2对MSB-1细胞的增殖抑制作用,并通过流式细胞术、荧光检测和电镜形态学观察等方法探讨其抑制机理.结果显示:人参皂苷Rh2对MSB-1细胞的增殖存在押制作用,并呈剂量依赖性,人参皂苷Rh2与MSB-1细胞培养72 h后的半敷抑制质量浓度为0.65 mg/L;流式细胞术测定表明,人参皂苷Rh2可阻滞MSB-1细胞于S期;荧光检测和透射电镜观察表明,人参皂苷Rh2可以诱导部分MSB-1细胞发生凋亡. 相似文献
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抗肿瘤中药及其有效成分的作用研究现状 总被引：7，自引：2，他引：7
中药是祖国医学理论中重要的组成部分,几千年来为保障我国人民和动物的机体健康做出了巨大的贡献。近年来,肿瘤的发病率不断增高,逐渐成为人类和动物健康的大敌。由于中药与化学合成药物相比有着取材方便、价格低廉和毒副作用小等优点,中药及其有效成分抗肿瘤的机理研究已成为当今医学研究的热点。中药及其有效成分防治肿瘤是通过多靶点、多途径、多环节来实现的,其抗肿瘤的作用机理主要包括调节机体免疫功能、抑制肿瘤血管生长、诱导肿瘤细胞凋亡、诱导肿瘤细胞分化、逆转肿瘤细胞多重耐药性、调节肿瘤细胞信号传导、抑制端粒酶活性和细胞毒作用等。中药及其有效成分必将为人类和动物肿瘤的治疗开辟新的途径。 相似文献
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新牛蛙抗肿瘤肽RGD-T-La(FS)嵌合体的设计及其抗肿瘤作用 总被引：1，自引：0，他引：1
为了研究新牛蛙抗肿瘤肽RGD-嵌合体的抗肿瘤作用及其对肿瘤细胞的作用机制。本研究以新牛蛙抗菌肽Temporin-La(T-La)为基序,通过生物信息学分析,改变特定氨基酸残基设计合成新的抗肿瘤肽Temporin-La(S)(TLa(S))和Temporin-La(FS)(T-La(FS)),氨基端偶联RGD肽成RGD-T-La、RGD-T-La(S)和RGD-T-La(FS)抗肿瘤肽,通过圆二色谱检测多肽二级结构,MTT法体外筛选抗肿瘤细胞活性多肽。使用流式细胞仪测定不同肿瘤细胞对不同多肽的吸收量,筛选对抗肿瘤肽敏感的肿瘤细胞。利用激光共聚焦显微镜实时观察抗肿瘤活性强的抗肿瘤肽对敏感肿瘤细胞的杀伤作用,并用扫描电镜观察抗肿瘤肽及其RGD嵌合体肽对肿瘤细胞的作用机制。在新牛蛙抗菌肽Temporin-La基序上设计T-La(S)和T-La(FS)2种抗肿瘤活性肽,圆二色谱仪测定其二级结构均呈α螺旋型,MTT结果显示黑色素瘤细胞(B16)对几种多肽的敏感性最强,10 mg/L质量浓度时,RGD-T-La(FS)对B16的毒性作用最强,细胞存活率为24.65%。激光共聚焦显微镜实时观察到,RGD-La(FS)和RGD-La(S)对肿瘤细胞都有较强的杀伤作用。扫描电镜结果显示,RGD嵌合体多肽对肿瘤细胞的杀伤作用具有位点靶向性。流式细胞仪检测HepG2对FITC-RGD-T-La(FS)的吸收量最大,检测到荧光强度为800 950.70。经改造的多肽T-La(FS)可以增加其对肿瘤细胞的杀伤作用,且偶联RGD的嵌合体RGD-T-La(FS)对肿瘤细胞的杀伤作用更具有靶向专一性,为抗肿瘤肽作为抗肿瘤药物的临床应用提供科学依据。 相似文献
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虽然旋毛虫抗肿瘤的分子机制仍不清楚,但旋毛虫具有抗肿瘤的效应却已被许多实验所证实。小鼠感染旋毛虫后对肿瘤细胞在体内的增殖或对移植进体内的肿瘤生长的抑制作用,其可能的机理是旋毛虫感染机体后激发宿主免疫网络系统促使机体产生多种免疫活性细胞因子,发挥特异性和非特异性抗肿瘤免疫功能;或者是由于寄生虫本身就具有能够分泌排泄一些抗肿瘤活性物质而发挥抗肿瘤效应;或者是由于寄生虫感染诱导肿瘤的基因表达发生变化而产生了抗肿瘤的效应。 相似文献
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蜂毒肽是蜂毒中主要的活性成分,具有广泛的抗肿瘤、抗炎症、镇痛、抗病毒等生理活性,极具潜在的临床药用价值.对蜂毒肽的抗肿瘤作用机制,主要包括对肿瘤细胞的直接杀伤效应,诱导肿瘤细胞发生损伤和凋亡,影响肿瘤细胞的生物学行为,改变肿瘤细胞生存环境和免疫调节作用等进行了综述,并简要分析了蜂毒肽在实际应用中所面临的挑战. 相似文献
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Rassnick KM Gieger TL Williams LE Ruslander DM Northrup NC Kristal O Myers NC Moore AS 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2001,15(3):196-199
1-(2-Chloroethyl)3-cyclohexyl-1-nitrosourea (CCNU) is an alkylating agent in the nitrosourea subclass. A prospective evaluation of CCNU was done to determine the maximally tolerated dosage of CCNU in tumor-bearing cats. Response data were obtained when available. Twenty-five cats were treated with CCNU at a dosage of 50-60 mg/m3 body surface area. Complete hematologic data were available for 13 cats. Neutropenia was the acute dose-limiting toxicity. The median neutrophil count at the nadir was 1,000 cells/microL (mean, 2,433 cells/microL; range, 0-9,694 cells/microL). The time of neutrophil nadir was variable, occurring 7-28 days after treatment, and counts sometimes did not return to normal for up to 14 days after the nadir. Based on these findings, a 6-week dosing interval and weekly hematologic monitoring after the 1st treatment with CCNU are recommended. The nadir of the platelet count may occur 14-21 days after treatment. The median platelet count at the nadir was 43,500 cells/microL. No gastrointestinal, renal, or hepatic toxicities were observed after a single CCNU treatment, and additional studies to evaluate the potential for cumulative toxicity should be performed. Five cats with lymphoma and 1 cat with mast cell tumor had measurable responses to CCNU. Phase II studies to evaluate antitumor activity should be completed with a dosing regimen of 50-60 mg/m3 every 6 weeks. 相似文献
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Davis MS Willard MD Nelson SL Mandsager RE McKiernan BS Mansell JK Lehenbauer TW 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2003,17(3):311-314
Human and equine athletes are reported to have a high prevalence of gastric disease, and anecdotal evidence suggests a similar phenomenon applies to racing sled dogs. To investigate the prevalence of gastric disease in racing sled dogs, we conducted 2 gastroscopy studies on dogs competing in the annual Iditarod Sled Dog Race. A pilot study of dogs that were either dropped from the 2000 Iditarod Sled Dog Race because of illness or that finished the race indicated that, approximately 5 days after competing, 10 of 28 dogs (35%) had endoscopic evidence of gastric ulceration, erosion, or hemorrhage. The next year, an endoscopic study of 73 dogs participating in the 2001 Iditarod race was performed in order to evaluate a larger population of dogs. Data from 70 of these dogs could be used; 34 (48.5%) had ulceration, erosion, gastric hemorrhage, or some combination of these findings. When this group of 70 dogs was compared retrospectively to a control group of 87 dogs presented to the Texas A&M University (TAMU) Veterinary Medical Teaching Hospital, the Iditarod sled dogs had a significantly higher prevalence (P = .049) of gastric lesions. These findings suggest that, similar to athletes of other species, elite canine athletes have an increased prevalence of gastric disease compared to the canine population at large. 相似文献
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Furosemide continuous rate infusion in the horse: evaluation of enhanced efficacy and reduced side effects 总被引：1，自引：0，他引：1
Johansson AM Gardner SY Levine JF Papich MG LaFevers DH Fuquay LR Reagan VH Atkins CE 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2003,17(6):887-895
Continuous rate infusion (CRI) of furosemide in humans is considered superior to intermittent administration (IA). This study examined whether furosemide CRI, compared with IA, would increase diuretic efficacy with decreased fluid and electrolyte fluctuations and activation of the renin-angiotensin-aldosterone system (RAAS) in the horse. Five mares were used in a crossover-design study. During a 24-hour period, each horse received a total of 3 mg/kg furosemide by either CRI (0.12 mg/kg/h preceded by a loading dose of 0.12 mg/kg IV) or IA (1 mg/kg IV q8h). There was not a statistically significant difference in urine volume over 24 hours between methods; however, urine volume was significantly greater after CRI compared with IA during the first 8 hours ([median 25th percentile, 75th percentile]: 9.6 L [8.9, 14.4] for CRI versus 5.9 L [5.3, 6.0] for IA). CRI produced a more uniform urine flow, decreased fluctuations in plasma volume, and suppressed renal concentrating ability throughout the infusion period. Potassium, Ca, and Cl excretion was greater during CRI than IA (1,133 mmol [1.110, 1,229] versus 764 mmol [709, 904], 102.7 mmol [96.0, 117.2] versus 73.3 mmol [65.0, 73.5], and 1,776 mmol [1,657, 2.378] versus 1,596 mmol [1,457, 1,767], respectively). Elimination half-lives of furosemide were 1.35 and 0.47 hours for CRI and IA, respectively. The area under the excretion rate curve was 1,285.7 and 184.2 mL x mg/mL for CRI and IA, respectively. Furosemide CRI (0.12 mg/kg/h) for 8 hours, preceded by a loading dose (0.12 mg/kg), is recommended when profound diuresis is needed acutely in horses. 相似文献
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Tropical Animal Health and Production - 相似文献
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Waruiru RM Thamsborg SM Nansen P Kyvsgaard NC Bogh HO Munyua WK Gathuma JM 《Tropical animal health and production》2001,33(3):173-187
The epidemiology of H. placei and of other gastrointestinal nematodes in yearling dairy cattle was examined on two farms in Kiambu District, central Kenya during each of 13 one-month periods from April 1993 to April 1994. On each farm, 32 newly weaned dairy calves were given a single dose of albendazole and then placed on experimental pastures. Twelve of the animals were designated for bi-monthly slaughter (n = 2) and analysis of worm population characteristics and 20 were designated for blood and faecal collection and for weighing. Two parasite-free tracer calves were grazed alongside the weaner calves each month throughout the study period and were also slaughtered for analysis of worm populations. Faecal egg counts, haematological and serum pepsinogen determinations, herbage larval counts, and animal live weight changes were recorded monthly. The study revealed that Haemonchus placei, Trichostrongylus axei, Cooperia spp. and Oesophagostomum radiatum were responsible for parasitic gastroenteritis and that H. placei was the predominant nematode present in the young cattle on both farms. Faecal egg counts from resident cattle and necropsy worm counts revealed that pasture larval levels were directly related to the amount of rainfall. The total worm burdens in the animals were highest during the rainy season (March–June and October–December) and lowest during the dry seasons (July–September and January–February). The very low recovery of immature larvae of H. placei from the tracer calves indicated that arrested development is not a feature of the life cycle of this parasite in central Kenya. The maintenance of the parasite population depended on continuous cycling of infection between the host and the pasture. The agroclimatic conditions of the study area were such that, in general, favourable weather conditions for the development and survival of the free-living stages of gastrointestinal nematodes existed all year round. 相似文献
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The occurrence of ectoparasites in sheep flocks is frequently reported but seldom quantified. Sheep production used to be a predominantly family activity in the state of Sa~o Paulo (Brazil), but it began to become a commercial activity in the past decade. Thus, information about the ectoparasites existing in sheep flocks has become necessary. The present data were obtained by means of questionnaires sent to all sheep breeders belonging to the `Associaça~o Paulista de Criadores de Ovinos' (ASPACO; Sa~o Paulo State Association of Sheep Breeders). Response reliability was tested by means of random visits paid to 10.6% of the respondents. Most of the properties (89.5%) reported the presence of one or more ectoparasites. Screw-worm (Cochliomyia hominivorax) was the most frequent ectoparasite (72.5%), followed by bot fly larvae (Dermatobia hominis, 45.0%), ticks (Amblyomma cajennense) and Boophilus microplus, 31.3%) and finally lice (Damalinia ovis, 13.8%). Combined infestations also occurred, the most common one being screw-worm with bot fly larvae (36.0%) followed by bot fly larvae with ticks (13.9%), screw-worm with ticks (9.3%), bot fly larvae with lice (6.9%), and ticks with lice (5.0%). The most common triple combination was screw-worm, bot fly larvae and ticks (12.8%). Breeds raised for meat or wool were attacked by bot fly larvae and ticks more often than other breeds. Lice were only absent from animals of indigenous breeds. The relationships among these ectoparasites are discussed in terms of sheep breeds, flock size, seasonality and the ectoparasitic combinations on the host. 相似文献
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H Hayashi T Yoshimura J Y Chen 《Comparative immunology, microbiology and infectious diseases》1985,8(2):73-87
Our particular attention in this article was given to natural mediators for macrophages isolated from the sites of tissue injury. A number of chemotactic factors, which may satisfy many criteria making them acceptable as inflammatory leucocyte chemotactic factors, has been separated. Among them, our laboratory has isolated three macrophage (monocyte) chemotactic factors (MCF-a, -b and -c). Their purification, characterization and functional specificity are discussed. 相似文献
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Evaluation of biohydrogenation rate of canola vs. soya bean seeds as unsaturated fatty acids sources for ruminants in situ 
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下载免费PDF全文 S. Pashaei T. Ghoorchi A. Yamchi 《Journal of animal physiology and animal nutrition》2016,100(2):211-216
An experiment was conducted to study disappearance of C14 to C18 fatty acids, lag times and biohydrogenation (BH) rates of C18 fatty acids of ground soya bean and canola seeds in situ. Three ruminally fistulated Dallagh sheep were used to determine ruminal BH of unsaturated fatty acids (UFAs). Differences in the disappearance of fatty acids through the bags and lag times were observed between the oilseeds. We saw that the longer the incubation time of the oilseeds in the rumen, the lower the content of C18:2 and C18:3. Significantly higher lag times for both C18:2 and C18:3 were observed in ground canola compared to ground soya bean. BH rates of C18:2 and C18:3 fatty acids in soya bean were three times higher than those of canola. These results suggest that the fatty acid profile of fat source can affect the BH of UFAs by rumen micro‐organisms. So that UFAs of canola had higher ability to escape from ruminal BH. It seems that fatty acid profile of ruminant products is more affected by canola seed compared to soya bean seed. 相似文献
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Serum biochemical values and the wet weight to dry weight ratios of tissues were determined in yaks in Shandan county of Gansu province. The liver, kidney, heart and muscle contents of seven elements in yaks were also analysed. Most serum biochemical values were similar to those of cattle, camels and sheep, but the calcium concentration was considerably above the normal range for other ruminants. The liver contained the highest concentrations of copper, manganese and cobalt and the kidney of selenium, iron and calcium.Abbreviations Alb
albumin
- ALT
alanine aminotransferase
- AST
aspartate aminotransferase
- BUN
blood urea nitrogen
- Chol
cholesterol
- Glob
globulin
- -GT
-glutamyl transpeptidase
- IP
inorganic phosphorus
- TP
total protein 相似文献