Search PubMed⌕ Search

Biomedical subjects

X Fu

Publications and source records attributed to X Fu.

At least 181 records · Page 10Linked to original sources
PubMed1993

Nude mouse metastatic models of human stomach cancer constructed using orthotopic implantation of histologically intact tissue.

Nude mice have been used to develop s.c. growing human stomach tumors, but these rarely metastasize. Recently, I. J. Fidler and others have developed orthotopic implantation metastatic models using cell suspensions which are inoculated into the corresponding organ of nude mice from which the tumor cells were originally derived in the human. However, recent work has indicated that disaggregated cell suspensions may not always express their full metastatic potential. In this light, we have recently developed an orthotopic implant model utilizing intact tissue such as that obtained directly from surgery. This approach has yielded high take rates and frequent metastases in colon cancer, bladder cancer, lung cancer, pancreatic cancer, and prostate cancer. We report here the application of this intact tissue orthotopic implant technique to stomach cancer resulting in the formation of metastases in 100% of the mice with extensive primary growth to the regional lymph nodes, liver, and lung. In contrast, when cell suspensions were used to inject stomach cancer cells at the same site, metastases occurred in only 6.7% of the mice with local tumor formation, emphasizing the importance of using intact tissue to allow full expression of metastatic potential. Injuring the serosa similar to that occurring in intact tissue transplantation did not increase the metastatic rate after orthotopic injection of cell suspensions of stomach tumor cells. This intact tissue orthotopic implantation model should allow development of new treatment modalities and further study of the biology of human stomach cancer.

Animals↗
PubMed1993

Flavonone and chalcone derivatives from Cryptocarya kurzii.

Four complex flavanones, kurziflavolactones A [2], B [3], C [4], and D [5] and a complex chalcone 6 with an unprecedented carbon side chain on the flavanone or chalcone A ring have been isolated from a Malaysian plant, Cryptocarya kurzii (Lauraceae). Their structures were determined by extensive spectroscopic analysis, especially 2D nmr experiments. Compounds 3 and 6 showed slight cytotoxicity against KB cells, with IC50 values of 4 and 15 micrograms/ml, respectively. A biosynthetic pathway for the formation of these compounds is suggested.

Antineoplastic Agents, Phytogenic↗
PubMed1993

Antitachyphylactic effects of progesterone and oxytocin on term human myometrial contractile activity in vitro.

OBJECTIVE: To determine whether progesterone causes any changes in the action of oxytocin on the contractile activity of term human myometrium in vitro. METHODS: Myometrial biopsies from 13 term pregnant women undergoing cesarean delivery were immediately immersed in Hepes buffer or buffer containing 5 micrograms/mL progesterone. In the laboratory under a stereomicroscope, the specimens were dissected into 1 x 7.5-mm muscle strips. These were mounted into six tissue baths and superfused with Hepes buffer and buffer containing 5 micrograms/mL progesterone, 5 micrograms/mL progesterone plus 10 microU/mL oxytocin, 5 micrograms/mL progesterone plus 100 microU/mL oxytocin, 10 microU/mL oxytocin, and 100 microU/mL oxytocin. Isometric tension was recorded constantly for at least 3 hours. RESULTS: The frequency of myometrial contractions and tonus increased by superfusion with progesterone, progesterone plus oxytocin, and oxytocin alone compared to buffer. In addition, a gradual decrease in frequency was observed after 60 minutes of contractions with oxytocin alone, whereas progesterone plus oxytocin had no such decrease. The activity area of contractions was greater with 10 microU/mL oxytocin and decreased with progesterone, progesterone plus both concentrations of oxytocin, and 100 microU/mL oxytocin alone, compared to buffer. CONCLUSIONS: Progesterone stimulated the frequency of contractions and tonus of strips from the lower uterine segment of term human myometrium. A lasting increase in the frequency of contractions was observed with superfusion of progesterone plus oxytocin, suggesting that progesterone counteracted the reaction of tachyphylaxis to oxytocin.

Dose-Response Relationship, Drug↗
PubMed1993

Unexpected stimulatory effect of progesterone on human myometrial contractile activity in vitro.

OBJECTIVE: To investigate the effects of continuous exposure of progesterone on contractile activity of term human myometrium in vitro. METHODS: Myometrial biopsy specimens were obtained from 14 term pregnant women undergoing elective cesarean. The specimens were immediately immersed in Hepes buffer and buffer containing 0.33, 4.1, and 70 micrograms/mL progesterone. Muscle biopsies were dissected along the bundles of smooth muscle under stereomicroscope. These myometrial strips were mounted in tissue baths and superfused with Hepes buffer and buffer containing different concentrations of progesterone. RESULTS: The progesterone concentration of 0.33 microgram/mL had no significant effect on myometrial contractile activity. The concentrations of 4.1 and 70 micrograms/mL increased the frequency of contractions (P < .01 for each) and tonus (P < .01 for each), decreased the activity area of contractions (P < .01 for each), and delayed the onset of contractions (P < .01 and P < .05, respectively). CONCLUSION: When the myometrium is not deprived of progesterone, this hormone may have excitatory effects on the frequency of contractions and tonus of the lower uterine segment of term human myometrium.

Adult↗
PubMed1992

A metastatic nude-mouse model of human pancreatic cancer constructed orthotopically with histologically intact patient specimens.

Pancreatic cancer is one of the most intractable and least understood of all human cancers. Pancreatic cancers is the fourth-leading cause of cancer-related mortality in the United States with less than 2% of the patients surviving for 5 yr. In an effort to help develop more effective treatment modalities for pancreatic cancer and improve detection, we report an animal model for individual human pancreatic-cancer patients. The model involves orthotopic transplantation of histologically intact pancreatic-cancer specimens to the nude-mouse pancreas, which can result in models that resemble the clinical picture including (i) extensive local tumor growth, (ii) extension of the locally growing human pancreatic cancer to the nude-mouse stomach and duodenum, (iii) metastases of the human pancreatic tumor to the nude-mouse liver and regional lymph nodes, and (iv) distant metastases of the human pancreatic tumor to the nude-mouse adrenal gland, diaphragm, and mediastinal lymph nodes. In a series of five patient cases, a 100% take rate has been demonstrated, and of 17 mice transplanted, 15 supported tumor growth. Immunohistochemical analysis of the antigenic phenotype of the transplanted human pancreatic tumors showed a similar pattern of expression of two different human tumor-associated antigens, such as tumor-associated glycoprotein 72 and carcinoembryonic antigen in the transplanted tumors when compared with the original surgical biopsy, suggesting similarity between the two. This model should, therefore, prove valuable for treatment evaluation of individual cancer patients, as well as for evaluation of experimental treatment modalities for this disease.

Adenocarcinoma↗
PubMed1992

Scalarane-type bishomosester terpenes from the sponge Phyllospongia foliascens.

Five new 20,24-bishomoscalarane sesterterpenes, phyllactones A [1], B [2], C [3], D [4], and E [5], are reported from the sponge Phyllospongia foliascens collected in the waters of the Nansha Islands in the South China Sea. Structural elucidation of these compounds is based on spectral data and chemical conversions. Phyllactones A and B show moderate cytotoxicity against KB cells (IC50 20 micrograms/ml).

Acetylation↗
PubMed1992

Multiple organ injuries after abdominal high energy wounding in animals and the protective effect of antioxidants.

Multiple organ injuries caused by high energy abdominal wounds were studied in 8 pigs and 24 dogs, and at the same time the protective effect of antioxidants in 14 dogs with multiple organ injuries was also studied. The experimental results showed that: 1) more than two organs (six organs at most) were wounded in each of the animals studied; 2) the injuries were characterized by hemorrhaging, tissue rupture and hematoma, and the main pathologic changes were local edema and necrosis; 3) the marked increase of lipid peroxide (LPO) levels in the vital organs indicated that multiple organ injuries could also involve the molecular level; 4) the injuries were due to the direct effect of pressure waves and ischemic reperfusion and not to shock or infection; and 5) antioxidants (vitamin E and Salvia miltiorrhiza Bge.) exhibited significant protective effects against multiple organ injuries through a free radical mechanism.

Abdominal Injuries↗