首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
H Fukamachi  T Mizuno  Y S Kim 《Experientia》1986,42(3):312-315
The morphogenesis and cytodifferentiation of human colon cancer cells (LS174T and HT29) were examined by combining cancer cells with fetal rat digestive-tract mesenchyme in organ culture. LS174T cells migrated into the mesenchyme to form glandular structures composed of single columnar cells with their nuclei oriented basally, while HT29 cells formed cell masses with little lumen formation. Immunohistochemical studies with antibodies against carcinoembryonic antigen and secretory components showed that the composition of cell surface glycoproteins was not necessarily reversed to the normal type, even when neoplastic cells exhibited normal glandular structures.  相似文献   

2.
Summary Epithelial-mesenchymal interaction in the differentiation of duodenal epithelium of fetal rats was investigated by recombination experiments in vitro. The proportion of goblet cells in duodenal epithelium was significantly greater on recombination of developing duodenal epithelium with mesenchyme of the glandular stomach than on recombination with that of the duodenum. Mesenchyme of the glandular stomach or forestomach was better than duodenal mesenchyme in supporting morphogenesis of duodenal epithelium. Treatment of tissues with N-methyl-N-nitro-N-nitrosoguanidine (MNNG) did not affect these tissue interactions.This work was supported by grants-in-aid for cancer research from the Ministry of Education, Science and Culture, Japan.Acknowledgment. The authors wish to express their gratitude to Prof. T. Mizuno of the University of Tokyo for valuable suggestions.  相似文献   

3.
Summary In addition to several anomalous structures, other general forms of definitely rod-shaped microorganisms have been found by scanning and transmission electron microscopy in the lung tissue taken at autopsy from a patient who succumbed to confirmed Legionnaires' disease with extensive necrotizing lobar pneumonia. The microorganisms were greatly varied in size and shape. They were micrographed in the act of fission. These forms have been found to some extent throughout the tissue. No nickel was demonstrated, either in the lung tissue or in the microorganisms.This work has been supported in part by a Henry Ford Hospital institutional grant from the Ford Foundation and in part by the Veterans Administration Medical Center Research Funds.  相似文献   

4.
Summary Human polymorphonuclear neutrophil chemotaxis under agarose was assessed following in vitro treatment of cells with colchicine. No inhibition of random migration or chemotaxis was detected. The discrepancy between these results and reports utilizing micropore filter assays could be due to the need for cell deformability in the latter.Supported by a grant from the Veterans Administration and Research grant AM 19349 from the NIAMDD, NIH.  相似文献   

5.
Summary Visual pigment regeneration in the frog requires apposition between the retina and retinal pigment epithelium. However, regeneration occurs nearly as well with the retina upside down (i.e. with the inner limiting membrane facing the pigment epithelium) as right side up.Acknowledgments. Supported in part by the Medical Research Service of the Veterans Administration and National Eye Institute Grant EY-01678.  相似文献   

6.
Summary A simple and time-saving method for intraportal acute or chronic infusion in the rat by the insertion of a catheter into the spleen is described. This method has proved to be especially useful for performing chronic infusions in conscious animals.The author thanks Providencia Cruz for excellent secretarial assistance. Present address: Veterans Administration Center, Medical Research Division, San Juan, Puerto Rico.  相似文献   

7.
Summary Small intestinal explants from pre- and post-natal rats were incubated in an organ culture system in the absence and presence of epidermal growth factor (EGF). The rate of synthesis of small intestinal DNA and protein as well as the activity of lactase and alkaline phosphatase increased rapidly between 17 and 20-day gestational age, whereafter they declined. The maximal incorporation of3H-thymidine and14C-alanine into DNA and protein, respectively, was significantly stimulated by EGF (100 ng/ml). EGF had no effect on the activity of either lactase or alkaline phosphatase in the small intestinal explants.Acknowledgment. The project was supported by grants from the Veterans Administration Research Service. The authors wish to thank Dr. M. C. Geokas, Chief, Department of Medicine, Veterans Administration Medical Center, Martinez, CA, for providing us with excellent laboratory facilities and for his encouragement in this study.  相似文献   

8.
Summary I125 insulin binding and the uptake of oxygen and 2-deoxyglucose are increased in skeletal muscle after denervation, suggesting an increase in insulin receptors (IR). Sustained increases in the number of affinity of IR molecules may account for some properties of denervated muscle fibres.Supported by the Medical Research Service of the Veterans Administration.  相似文献   

9.
The kinesin-related protein HsEg5 plays essential roles in mitotic spindle dynamics. Although inhibition of HsEg5 has been suggested as an aid in cancer treatment, the effects of such inhibition on human cells have not been characterized. Here we studied the effects of monastrol, an allosteric HsEg5 inhibitor, on AGS and HT29 cell lines and compared them to those of taxol. While both cell lines were similarly sensitive to taxol, AGS cells were more sensitive to monastrol. The differences in sensitivity were determined by the degree of inhibitory effect on cell proliferation, reversibility of monastrol-induced G2/M arrest, intracellular phenotypes and induction of apoptosis. In both cell lines, monastrol-induced apoptosis was accompanied by mitochondrial membrane depolarization and poly-ADP-ribose polymerase 1 cleavage. In AGS, but not HT29 cells, monastrol-induced apoptosis involved a prominent cleavage of procaspases 8 and 3. While in AGS cells, monastrol induced the formation of symmetric microtubule asters only, in HT29 cells, asymmetric asters were also formed, which may be related to specific HsEg5 functions in HT29 cells.Received 18 February 2004; received after revision 30 May 2004; accepted 16 June 2004  相似文献   

10.
Summary The role of neural mechanisms in gastrin stimulated H+ secretion was studied using amphibian gastric fundic mucosa. Spontaneously secreting mucosae were converted to resting state (zero H+ secretory rate) using Burimamide. Following removal of burimamide, 3×10–6 M tetrodotoxin did not block gastrin stimulation of H+ secretion indicating that neural mechanisms are not required.This work was supported by U.S. Public Health Service NIH Grant AM17315 and by the Medical Research Service of the Veterans Administration.  相似文献   

11.
目的探索人结直肠癌细胞系形成肿瘤细胞球的培养方法及球体内间质化标志物的表达检测。方法结直肠癌细胞系SW480、SW620、LOVO、HT29及HCT116在添加了不同细胞生长因子的无血清培养基(SFM)中悬浮培养,传代更新,诱导分化。免疫荧光技术和RT-PCR分别检测细胞球中间质化标志物N—cadherin及Vimentin的表迭情况。结果5种细胞系均能在特制的SFM中形成细胞球,并稳定的传代增殖。在用血清诱导分化后,又重新贴壁生长,且与亲代细胞保持一致的细胞形态。细胞球中间质化标志物N—cadherin、Vimentin表达均上调。结论结直肠癌细胞系在低黏附及添加了细胞生长因子R—Spondin 1、Noggin的无血清环境中更容易形成悬浮生长的肿瘤细胞球,细胞球细胞比亲代细胞更具有转移侵袭能力。  相似文献   

12.
Summary The release of14C-serotonin by ADP, epinephrine and arachidonic acid and the release of ADP by kaolin were measured in normal platelets in the presence and absence of carbon monoxide and in smokers' platelets. It is shown that carbon monoxide inhibits significantly the platelet release reaction. This function is also decreased in platelets obtained from heavy cigarette smokers.This work was supported by Veterans Administration Research Fund 8073-01.  相似文献   

13.
Summary Arg-Pro-Pro-Gly-Phe, the N-terminal pentapeptide of bradykinin, is not an inhibitor of angiotensin-converting enzyme and is not hydrolyzed by the enzyme. Arg-Pro-Pro, the N-terminal tripeptide is a relatively potent (IC50=2.3×106 M) inhibitor but its higher homolog, Gly-Arg-Met-Lys-Arg-Pro-Pro is not an inhibitor of angiotensin-converting enzyme.This work was supported in part by grants from the US Public Health Service (HL 18415, HL 15691, HL 19764) and the John A. Hartford Foundation, Inc., and by the Medical Research Service of the Veterans Administration.  相似文献   

14.
Summary A characteristic and reproducible sign of narcotic withdrawal is the naloxone induced increase in arterial pressure. In morphine-dependent rats allowed to undergo spontaneous withdrawal (6–24 h) and then transected at the spinal C-1 level, arterial pressure was maintained at a significantly higher level than either spinal-transected nondependent controls or morphine-dependent, spinal-transected rats pithed from C-1 to L-4. These findings indicate that the morphine-dependent spinal cord, independent of supraspinal influences, is able to exhibit an autonomic component of spontaneous withdrawal.This study was supported by the Medical Research Service of the Veterans Administration. A preliminary report of aspects of this work appeared in Soc. Neurosci. Abs.10 (1984) 1113.  相似文献   

15.
Summary Two min of intraluminal perfusion of the rat proximal tubules with autologous serum induced marked ultrastructural alterations including extensive cytoplasmic vesiculation due to swelling of rough endoplasmic reticulum cisternae and occasional extrusion of nuclei and cytoplasm into the lumen. Within 4 min pronounced vesiculation of mitochondria was observed. These findings are consistent with the notion that serum-induced inhibition of proximal tubular fluid absorption is due to cell lysis, presumably mediated by complement activation.Acknowledgment. This study was supported by NIH grants AM16258, AM27857, a New York Health Council grant, and a Veterans Administration Research grant.  相似文献   

16.
Summary A simple and rapid technique for cannulating the portal vein in the rat is described. Multiple blood samples can be obtained or alternatively substrate may be infused through the cannula.Supported by the Clayton Foundation for Research, Houston, Texas. Common resource support was also provided by the Research Service of the Veterans Administration. To whom reprint requests should be addressed as follows.  相似文献   

17.
Summary Oral administration to man of 20 mg 11-tetrahydrocannabinol (THC) together with placebo or 40 mg cannabinol (CBN) or 40 mg cannabidiol (CBD) gave evidence of a possible limited interaction of THC with CBN but not with CBD as indicated by average plasma THC levels. Peak CBD and CBN concentrations were similar to that of THC, viz. about 5–8 ng/ml.Supported by the Swedish Medical Research Council and grant MH-00424 from the Veterans Administration.  相似文献   

18.
The recent approvals of anticancer therapeutic agents targeting the histone deacetylases and DNA methyltransferases have highlighted the important role that epigenetics plays in human diseases, and suggested that the factors controlling gene expression are novel drug targets. Protein arginine deiminase 4 (PAD4) is one such target because its effects on gene expression parallel those observed for the histone deacetylases. We demonstrated that F- and Cl-amidine, two potent PAD4 inhibitors, display micromolar cytotoxic effects towards several cancerous cell lines (HL-60, MCF7 and HT-29); no effect was observed in noncancerous lines (NIH 3T3 and HL-60 granulocytes). These compounds also induced the differentiation of HL-60 and HT29 cells. Finally, these compounds synergistically potentiated the cell killing effects of doxorubicin. Taken together, these findings suggest PAD4 inhibition as a novel epigenetic approach for the treatment of cancer, and suggest that F- and Cl-amidine are candidate therapeutic agents for this disease.  相似文献   

19.
Summary A good correlation was shown between the presence of ergastoplasmic granules in the glandular cells of the locusts corpora cardiaca and the flight activity of these insects.Research supported by grants A.T.P. No. 1831 and E.R.A. No. 620 from the Centre National de la Recherche Scientifique, French Ministry.  相似文献   

20.
目的 探讨人子宫颈癌中负性协同刺激分子PD-L1的表达和它与肿瘤浸润淋巴细胞的关系以及PD-L1融合蛋白促宫颈癌患者外周血活化T细胞凋亡的作用.方法 采用免疫组化S-P法检测67例宫颈癌组织及20例正常宫颈组织中PD-L1的表达,分析PD-L1同临床病理特征的相关性,免疫荧光观察肿瘤浸润淋巴细胞数量,TUNEL法检测T细胞凋亡,体外实验将PD-L1融合蛋白细胞加入PHA刺激活化的宫颈癌患者外周血T细胞中共同培养,流式细胞术分析T细胞凋亡率和CD8+/CD4+T细胞比例.结论 正常子宫颈组织不表达PD-L1;宫颈癌组织中PD-L1的表达率为70%.宫颈癌PD-L1的表达与宫颈癌浸润深度相关(P<0.05).PD-L1阳性病例肿瘤局部浸润淋巴细胞存在凋亡且CD8+T细胞数量明显减少;PD-L1融合蛋白组T细胞凋亡率明显高于抗PD-1组和空白对照组T细胞,分别为32.7%、18.3%和17.9%;CD8+T/CD4+T细胞的比值低于加入抗PD-1组和空白对照组,分别为0.864、0.894和0 907.结论 PD-L1在子宫颈癌中高表达且与肿瘤浸润程度及肿瘤浸润淋巴细胞数量减少有关,PD-L1能促进活化的T细胞尤其是CD8+T细胞的凋亡.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号