PubMed Health⌕ Search

Biomedical subjects

D J Li

Publications and source records attributed to D J Li.

At least 55 records · Page 3Linked to original sources
PubMed1993

Human B cell lymphomas: in vitro and in vivo studies on growth factors and cell growth.

The B cell non-Hodgkin's lymphomas (NHL-B) are a common, but heterogeneous group of human lymphoid neoplasms, consisting of monoclonal populations of neoplastic B lymphocytes demonstrating non-random chromosomal abnormalities, often associated with proto-oncogene translocations. Clinically and pathologically, these lymphomas are classified as low, intermediate, or high grade, according to the clinical aggressiveness of the NHL-B subtype. The clinical behavior can also be correlated with biological function regarding proliferative capabilities of the tumor cells. Our studies have shown that the low grade B cell lymphomas have low constitutive proliferative capacity in vitro and do not respond to cytokine growth factors (CGF), while the high grade NHL-B respond to the B cell growth factor (BCGF) family of CGFs. The high grade NHL-B also secrete BCGFs both in vitro and in vivo, as autocrine growth factors that may provide a target for new therapeutic approaches to therapy.

Animals↗
PubMed1992

99Tcm and 111In leucocyte scintigraphy in inflammatory bowel disease.

A comparative study of 99Tcm-hexamethylpropyleneamine oxime (HMPAO) and 111In leucocyte scintigraphy was performed in inflammatory bowel disease. Two hundred and thirty-four patients were studied, 146 had 99Tcm-HMPAO, 82 had 111In and six had both. The sensitivity, specificity and accuracy of the 99Tcm leucocyte scan were 96, 97 and 97%, respectively, and 96, 97 and 97%, respectively, for the 111In leucocyte scan. 99Tcm-HMPAO leucocytes demonstrated similar diagnostic accuracy to 111In-labelled leucocytes with improved image quality and reduced radiation dose.

Adolescent↗
PubMed1990

The selective killing effect of special wavelength light in the treatment of human superficial cancer.

The authors discovered that 0.4-micron to 1.1-microns wavelength light can selectively kill superficial cancer tissue in the human body. Light at a density of integral power 1 to 6 W/cm2 will kill tumor but will affect normal tissues less. The model KS-1 phototherapeutic instrument was made according to these principles and used to treat 34 patients who had a variety of cancers, including carcinomas of the oral cavity, skin, and cervix. The 25 cured patients were then monitored for 1 to 4 years. No side effects were found. Currently there are several hospitals in China that use this instrument for the treatment of some kinds of carcinoma.

Female↗
PubMed1990

Improvement of cold tolerance by selective A1 adenosine receptor antagonists in rats.

Previously we have shown that the improvement of cold tolerance by theophylline is due to antagonism at adenosine receptors rather than inhibition of phosphodiesterase. Since theophylline is a nonselective adenosine receptor antagonist for both A1 and A2 receptors, the present study investigated the adenosine receptor subtype involved in theophylline's action. Acute systemic injection of selective A1 receptor antagonists (1,3-dialkyl-8-aryl or 1,3-dialkyl-8-cyclopentyl xanthine derivatives) significantly increased both the total and maximal heat production as well as cold tolerance. In contrast, injection of a relatively selective A2 receptor antagonist, 3,7-dimethyl-1-propargylxanthine (compound No. 19), failed to significantly alter the thermogenic response of the rat under cold exposure. Further, the relative effectiveness of these compounds in increasing total thermogenesis was positively correlated with their potency in blocking the A1 adenosine receptor (r = .52, p less than 0.01), but not in A2 adenosine receptor (r = .20, p less than 0.2). It is likely that the thermally beneficial effects of adenosine A1 antagonists are due to their attenuation of the inhibitory effects of endogenously released adenosine on lipolysis and glucose utilization, resulting in increased substrate mobilization and utilization for enhanced thermogenesis.

Animals↗
PubMed1990

Present status on treatment of esophageal cancer in China.

The treatment of carcinoma of the esophagus is a challenging problem to clinicians. The 5-year survival rate of surgery reported from large centers is about 25-30%, with resectability rate around 85-90% and operation mortality rate around 5%. However, this is based on highly selected cases. The 5-year survival rate of radiation therapy is about 9-16%, while the patients receiving radiation therapy were mostly the late cases. Pre-operative radiation seems to improve the results of surgery, but more randomized control clinical studies are needed. A combination of chemotherapy with radiation might improve the short-term response rates. Chemotherapy alone may provide some benefits for patients. Intracavitary microwave hyperthermia might open a possibility in the improvement of treatment results in combination with radiation and/or chemotherapy.

China↗
PubMed1990

Overexpression of the multidrug resistance gene mdr3 in spontaneous and chemically induced mouse hepatocellular carcinomas.

Overexpression of a family of plasma membrane glycoproteins, known as P-glycoproteins, is commonly associated with multidrug resistance in animal cells. In rodents, three multidrug resistance (mdr or pgp) genes have been identified, but only two can confer the multidrug resistance phenotype upon transfection into animal cells. Using the RNase protection method, we demonstrated that the levels of three mdr gene transcripts differ among mouse tissues, confirming a previous report that the expression of these genes is tissue specific (J.M. Croop, M. Raymond, D. Huber, A. DeVault, R. J. Arceci, P. Gros, and D. E. Housman, Mol. Cell. Biol. 9:1346-1350, 1989). The levels of mdr transcripts were determined for mouse liver tumors spontaneously arising in both C3H/HeN and transgenic animals containing the hepatitis B virus envelope gene and for tumors induced by two different carcinogenic regimens in C57BL/6N and B6C3-F1 mice. The mdr3 gene was overexpressed in all 22 tumors tested. Our results demonstrate that overexpression of the mdr3 gene in mouse liver tumors does not require exposure of the animals to carcinogenic agents and suggest that its overexpression is associated with a general pathway of hepatic tumor development. The overexpression of the mdr3 gene, which is the homolog of human mdr1 gene, in hepatocellular carcinomas may be responsible for the poor response of these tumors to cancer chemotherapeutic agents.

1,2-Dimethylhydrazine↗
PubMed1990

Cloning of the bacteriophage T7 lysozyme gene.

Plasmid pBR322 and its derivative containing strong promoter phi 10 of bacteriophage T7 RNA polymerase were used as vectors. A fragment of bacteriophage T7 DNA which was digested with two restriction endonucleases (AvaII and HaeIII) was cloned in the BamHI site of plasmid pBR322 and its derivative pAR951, respectively. The inserted DNA is a segment of 632 base pairs containing the complete coding sequence of both T7 gene 3.5 and weak promoter phi 3.8 for bacteriophage T7 RNA polymerase. The function of T7 gene 3.5 is known to code for bacteriophage T7 lysozyme. Transformants that carry the recombinant plasmid were tested for intracellular lysozyme by adding CHCl3. Both cloned strains produce active T7 lysozyme. The gene product, T7 3.5 protein, was analyzed by 10 -20% gradient polyacrylamide- SDS electrophoresis. The result showed that the expression of inserted T7 gene 3.5 in pBR322 derivative is stronger than that in pBR322.

Cloning, Molecular↗
PubMed1990

A new approach to the treatment of malignant effusion.

Lymphocytes isolated from malignant effusion were induced to become LAK cells after in vitro culture with rIL-2. 28 patients with malignant effusion were treated by i.p. or intrapleural administration of autologous LAK cells combined with rIL-2 or by rIL-2 alone. The effusion disappeared in 13 patients and significantly decreased in another 13. Two patients did not respond to the treatment. Tumor cells in effusion disappeared or significantly decreased and lymphocytes significantly increased in all responses. Except for transient fever in 9 patients, no serious side effects were found.

Adult↗
PubMed1989

Thermo-chemo-radiotherapy of esophageal cancer. A preliminary report of 34 cases.

Thirty-four cases of esophageal cancer were treated by radiation combined with chemotherapy and hyperthermia (triple therapy) from September 1985 to January 1986. Hyperthermia was performed by an intracavitary microwave applicator of 915 MHz. The temperature at the tumor margin was 43 degrees C to 44 degrees C, whereas at the middle luminal surface of tumor it reached at 44 degrees C to 48.5 degrees C. Chemotherapy was with bleomycin (PYM) 20 mg/session, intramuscularly (IM) and cisplatin (DDP) 1.0 to 1.5 mg/kg/session intravenously (IV). Hyperthermia and chemotherapy were given simultaneously within 30 minutes after 500 cGy of radiation. Three modalities were given on the same day once a week for six sessions. The total response rate (complete + partial response [CR + PR]) was 94% (32/34) and 1-year and 2-year survival rates were 74% (25/34) and 44% (15/34), respectively. Among them were 23 patients primarily treated by triple therapy with the 1-year and 2-year survival rates of 83% (19/23) and 48% (11/23), respectively. No serious side effects were seen. The average microwave power consumption during the hyperthermic treatment and its prognostic significance are discussed.

Adult↗
PubMed1989

[Intrapleural transfer of LAK cells combined with rIL-2 in the treatment of advanced lung cancer with malignant pleural effusion].

Ten patients with advanced lung cancer complicated by malignant pleural effusion were treated by intrapleural transfer of autologous LAK cells induced from lymphocytes of malignant effusions in the presence of rIL-2 and by administration of rIL-2 10 days before and after the transfer of LAK cells. The pleural effusions disappeared in 8 patients and significantly reduced in the other two. The number of tumor cells in the pleural effusion was obviously decreased while the number of lymphocytes was significantly increased. No changes were found in 4 responders during 4 months follow-up after treatment. No serious side effects were observed in all these 10 patients. The results indicated that transfer of LAK cells combined with rIL-2 in the treatment of patients with malignant pleural effusion due to advanced lung cancer is effective, safe and feasible.

Adult↗
PubMed1989

[In vitro experimental expansion and induction of LAK cell of lymphocytes from human carcinomatous ascites].

Investigation on the in vitro expansion and induction of LAK cell activity of peritoneal exudate lymphocytes (PEL) from malignant ascites of advanced ovarian cancer patients is presented. The results indicated that to isolate PEL from malignant ascites was much more simple and economic than to isolate tumor infiltrating lymphocytes (TIL). PEL could be in vitro expanded 17-fold and induced to acquire LAK cell activity in the presence of rIL-2. Thus, PEL can be used as LAK cell precursor for adoptive immunotherapy of cancer.

Adenocarcinoma↗
PubMed1988

Biological characterization and oncogene expression in human colorectal carcinoma cell lines.

To establish well-characterized cellular reagents for the study of colon carcinoma, we have examined 19 human colorectal carcinoma cell lines with regard to morphology, ultrastructure, expression of tumor-associated antigens, proliferative capacity in vitro, anchorage-independent growth, oncogene expression, tumorigenicity and malignant potential. Cell lines examined were cultured under identical conditions, and in vitro and in vivo analyses were performed in parallel on replicate cultures. Three classes of colorectal cell lines were defined according to their tumorigenicity in nude mice. Class-1 lines formed rapidly progressing tumors in nearly all mice at an inoculum of 10(6) cells. Cell lines belonging to class-2 were less tumorigenic, producing tumors later and at a slower growth rate. Class-3 lines were non-tumorigenic under all experimental conditions tested. By Northern analysis, the oncogenes c-myc, H-ras, K-ras, N-ras, myb, fos and p53 were expressed in nearly all cell lines examined. In contrast, transcripts for abl, src and ros were not detected. The best in vitro predictor of tumorigenicity was colony formation in soft agar. There was no detectable correlation between tumorigenicity and metastatic potential, doubling time in vitro, production of tumor-associated markers, xenograft histology or expression of specific oncogenes.

Animals↗
PubMed1988

High-resolution electron microscopy of high-temperature superconductors.

We review recent results obtained at Northwestern using high-resolution electron microscopy to study high-temperature superconductors. While in general these materials form large, very perfect single crystal grains which display very few imperfections, there is also evidence of slip defects, amorphous regions, and order-disorder transformations. We also report that the gadolinium-based superconductors and in one case yttrium-based superconductors show evidence for some copper solid solubility in the form of copper-rich planar defects. The structure of a metastable trigonal polytype is also reported, as are the effects of electron beam and water vapor damage to the materials.

Crystallography↗
PubMed1987

Preliminary report on the treatment of esophageal cancer by intraluminal microwave hyperthermia and chemotherapy.

Thirty-two cases of esophageal cancer were treated with thermochemotherapy from August 1984 to June 1985. A combination of bleomycin (20 mg per session iv) and cisplatin (0.5-0.9 mg/kg per session as low dose and 1.0-2.0 mg/kg per session as high dose), or of bleomycin, cisplatin (high dose), and cyclophosphamide (400-600 mg per session) were the treatment regimens. A 915-MHz microwave applicator was inserted into the lumen of the esophagus for heating. The temperature at normal adjacent tissue to the cancer was at 43-44 degrees C, while the temperature of the cancer was at 45 degrees C-50 degrees C. Chemotherapy and hyperthermia were administered simultaneously, once a week for six to eight sessions. The response rate in the low-dose group was 36.4% (four of 11) and 81% (17 of 21) in the high-dose group. The complete response rate in the low-dose group was zero of 11 patients, with 38.1% (eight of 21) in the latter group. The relationship between power output and tumor response is also discussed.

Adult↗
PubMed1984

Design and thermometry of an intracavitary microwave applicator suitable for treatment of some vaginal and rectal cancers.

The construction of a modified coaxial cable as an intracavitary microwave applicator suitable for use in some vaginal and rectal cancers is presented. Thermometry was performed for microwave frequencies of 300, 400, 650, and 915 MHz. Temperature profiles in tissue phantoms were obtained with non-perturbing temperature probes and thermography, and the data were compared with those obtained in dogs. The temperature profiles were dependent on the frequency of the microwaves and the insertion depth of the applicator. In addition, an acrylic cylindrical spacer external to the applicator also altered the heating pattern. Therefore, with proper combinations of frequency, insertion depth and spacer, the applicator can be used for heating tumors in some clinical situations.

Animals↗