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Biomedical subjects

Y J He

Publications and source records attributed to Y J He.

At least 37 records · Page 2Linked to original sources

Development of a two color immunofluorescence stain and immunolocalization method for N-myc and c-myc oncoproteins with a newly generated mouse IgM anti N-myc antibody.

A new mouse monoclonal antibody specific for N-myc oncoprotein was generated and used in combination with an anti-c-myc antibody to develop two color immunofluorescence staining and ultrastructural immunolocalization of N-myc and c-myc in well established (SK-N-SH; CHP 126) and in newly established neuroblastoma (NB) cell lines. Analysis and quantitation of c-myc and N-myc in dually stained cells was done by flow cytometry. Immunolocalization was done by staining with immunogold secondary antibodies and transmission electron microscopy. The results obtained from analysis of 13 newly established NB cell lines revealed, great heterogeneity in the expression of N-myc oncoprotein with 10/13 cell lines over expressing the protein. C-myc oncoprotein was also expressed in all cell lines, however, the level of expression was 4-10-fold lower than the N-myc oncoprotein. Localization studies of c-myc and N-myc oncoproteins on the level of light microscopy and electron microscopy revealed exclusive nuclear localization of c-myc whereas N-myc was localized to the nucleus and to the cytoplasm.

Antibodies, Monoclonal↗

A novel methodology for the establishment of neuroblastoma cell lines from metastatic marrow. Expression of surface markers, neurofilaments, MDR-1 and myc proteins.

A methodology for rapid isolation of neuroblastoma (NB) cells from marrow with metastatic NB cells was developed using a cocktail of five antibodies and magnetic microspheres coated with secondary antibodies. Cells bound to microspheres were released by brief exposure to chymopapain, followed by repeated culture of released cells in serum supplemented DMEM medium and selection for adherent cells. Using this methodology, over 35 primary cell lines were obtained free of contaminating normal cells. Detailed analyses of over 14 cell lines revealed gross differences in cell phenotype, size, morphology development of neurite processes, and doubling time (40h-80 h). All cell lines expressed the 145 kDa neurofilament (NF) and a few expressed the 200 kDa NF, with very little or no expression of the 68 kDa NF. DNA analyses revealed 80% near diploid cell lines. High expression of the MDR-1 protein was detected in 6/22 of the cell lines tested.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

Down regulation of stem cell colony formation by purified CD8 lymphocytes and CD8 conditioned medium: potential importance for bone marrow transplantation in leukemia.

A methodology for selection of the CD8 cell subset from the peripheral blood and bone marrow mononuclear cells was developed using anti-T8 (CD8) antibody and magnetic microspheres coated with anti-mouse IgG. Following optimization of antibody:cell binding ratio and microsphere:cell ratios, CD8(+)-cells in the peripheral blood and bone marrow were effectively removed, with an overall final recovery of 34.9% +/- 8.6%, and 56% +/- 8.5% respectively with complete recovery of stem cells and very little contamination with effector cells. CD8(+)-depleted cell preparations demonstrated a 3-4 fold increase in CFU-C and CFU-E colony formation over non-depleted preparations when stimulated with G-CSF, GM-CSF or IL-3 and erythropoietin. The largest increase in colony formation was evident when IL-3 was used to stimulate colony formation. Purified autologous CD8+ T-cells or culture supernatant from in vitro cultures of purified autologous CD8+ T-cells added back to CD8 depleted preparations, induced 20%-90% suppression of CFU-C and CFU-E colony formation in a dose dependent manner. Colony formation by CD34+ cells, purified by anti CD34 antibodies and magnetic microspheres, were also inhibited by either pure CD8(+)-cell populations or CD8-culture supernatant. Preliminary fractionation studies indicate that the inhibitory factor is a protein of > 50 kd. In contrast, when purified autologous CD4+ cells were added to purified CD34+ stem cells, an increase (< 50%) in colony formation was observed. These results, taken together, suggest that CD8+ T-cells are negative effectors of normal hematopoiesis whereas CD4+ T-cells function as positive effectors.

Animals↗

[A clinical study of primary lipoma and liposarcoma of the orbit].

3 cases of primary lipoma and 2 cases of liposarcoma originating from the orbit were confirmed histopathologically. The clinical features, pathologic findings, ultrasonography, computed tomography, and nuclear magnetic resonance imaging of the tumours and the differential diagnoses were discussed.

Adult↗

[Dissolution rate and bioavailability of famotidine tablets].

An automated dissolution test system was used for the determination of the dissolution rate of famotidine tablets, and a mean cumulative dissolution rate of 97.40 +/- 0.31% in 15 min was obtained. To each of six healthy volunteers, 40 mg of famotidine tablets were administered orally, then an automated HPLC with switching column system was used to analyze famotidine in plasma. Variation of drug concentration vs time were fitted to curves. By comparison of calculated values with observed ones, the results could be described as one-compartment model in human. According to a statistic moment algorithm, the results of calculation showed that T1/2 = 2.92 h and Frel = 118.8%.

Biological Availability↗

[Surgical treatment of lid retraction in Graves' ophthalmopathy].

Surgical treatment of lid retraction in Graves' ophthalmopathy consisted of resection of Müller's muscle and myotomy of Müller's muscle combined with intraoperative guided disinsertion of the levator palpebrae superioris from the tarsus. Among 10 eyes of 9 patients treated by the authors, 9 eyes achieved good cosmetic effect and corneal exposure was prevented during a follow-up of 3-42 months.

Adult↗

Cultured cell lines from human breast cancer biopsies and xenografts.

Eighty-five breast cancer specimens were processed as part of a program in tumor acquisition, propagation, and preservation for biotherapy. Nine long-term culture cell lines were developed. Four cell lines were from solid tumor metastases, two lines were from pleural fluid specimens, and three were from xenograft tumors grown in nude mice. Two of the xenograft-derived cell lines were from biopsies which produced tumor cell lines as well. Success in establishing cultures did not correlate with the viability of the biopsy received. Poor tumor cell attachment to culture plastic was the most common problem. For certain specimens, attachment and growth were enhanced on collagen and extracellular matrix substrates. Collagen was beneficial in the development of one cell line. The cell lines were characterized and each of the lines contained more nuclear DNA than found in normal cells. Four of five lines tested were tumorigenic in nude mice. Five of nine were clonogenic in soft agar. Each of the cell lines tested reacted with at least two anti-tumor monoclonal antibodies. Xenograft and biopsy-derived cell lines from the same tumor were similar in their characteristics. While breast cancers are indeed difficult to establish and propagate in culture, the use of xenografts and special substrates appears to be beneficial in the development of cell lines from some tumors.

Animals↗

[Direct injection of plasma to determine famotidine in plasma using HPLC column switching technique].

An automated high performance liquid chromatographic switching system is described for the analysis of famotidine, an H2-receptor antagonist in plasma. The system used YWG-C18 short precolumn for on-line sample clean-up and a Shimpack CLC-ODS analytical column for separation. A solution of 0.2 mol/L acetic acid was used as pretreatment mobile phase and 14% (v/v) methanol in ammonium acetate (0.2 mol/L) was used as analytical mobile phase. The detection was at 267 nm and the detection limit was 12 ng/ml plasma. Plasma sample was diluted with acetic acid (0.2 mol/L) and injected directly on the HPLC system. The procedure of clean-up is simple and automatic. The recovery of clean-up is 84.1%.

Adult↗

Tumor acquisition, propagation, and preservation. The culture of human colorectal cancer.

Fourteen new colorectal cancer cell lines were developed as part of a tumor acquisition, propagation, and preservation program for biotherapy. Fifty-six specimens were received. Nine cell lines were generated from biopsies; seven of these cell lines were from metastatic lesions. Five additional cell lines were developed from xenografts grown in nude mice. Biopsies that produced three of these xenografts gave rise to parallel culture cell lines. Biopsy-derived and xenograft-derived cell lines from the same tumor behaved similarly in culture and exhibited similar markers when assessed immunohistochemically. Collagen substrate was beneficial in the primary culture of 50% of the specimens tested. Collagen was required for the successful propagation of two cell lines.

Animals↗

Establishment and characterization of a malignant lymphoid cell line from a chronic lymphocytic leukemia patient.

A long-term culture Epstein-Barr virus (EBV)-negative malignant lymphoid cell line (NAK) was established from a lymph node biopsy of a chronic lymphocytic leukemia patient. This cell line is of particular interest because it grows as an adherent cell line and depends on the presence of autologous conditioned medium for growth. After 6 months of growth in vitro, doubling time and cell cycle parameters were derived. Doubling time was 48 hours with over 45% cycling cells. Cell viability was over 90%. Expression of B-cell markers (CD19 and CD20) and surface immunoglobulin of the original tumor cell biopsy were roughly the same as in passage 14 (3 months in culture), including the expression of the original patient idiotype and IgM-lambda. Furthermore, binding of antiidiotypic antibodies was only slightly decreased at passage 14. Cytogenetic studies of chromosomal abnormalities in the primary tumor tissue and in later passages indicated similar abnormalities, with no translocations t(8;14), t(14;22), or t(2;8). However, frequent trisomies, deletions, and t(1;4) translocations were observed. Negative results for EBV nuclear antigen indicate that this cell line is an EBV-negative cell line.

Antigens, Differentiation, B-Lymphocyte↗

[Influence of radix Astragali on noise-caused changes in hepatic glycogen content in the rat].

It has been found that in rats exposed to a noise of 2kHz (mai frequency) and 103 dB(A) (potency) for 60 minutes, the hepatic glycogen content (HGC) is significantly higher than that of the control group unexposed to the noise (P less than 0.05), whereas in those treated with a prior ip Radix Astragali plus noise the HGC appears apparently lower than that of the noise group (P less than 0.05), very close to the control group (P greater than 0.2). This indicates that Radix Astragali might have some antinoise effect.

Animals↗

Circadian rhythm of rat liver dihydropyrimidine dehydrogenase. Possible relevance to fluoropyrimidine chemotherapy.

The activity of dihydropyrimidine dehydrogenase (DPD), the initial, rate-limiting enzyme in pyrimidine catabolism, was measured at various times over a 24-hr period in the livers of rats housed under standardized conditions of light and dark. Under "normal" conditions, i.e. lights on from 6:00 a.m. to 6:00 p.m. and off from 6:00 p.m. to 6:00 a.m., a circadian rhythm of DPD activity was observed (P less than 0.0001, Cosinor analysis) with the peak of activity at 4:00 p.m. (2.96 nmol catabolites/min/mg) and the trough at 4:00 a.m. (0.40 nmol catabolites/min/mg). Maximum enzyme activity exceeded minimum activity by more than 7-fold. Reversing the light-dark cycle (i.e. lights on from 6:00 p.m. to 6:00 a.m. and off from 6:00 a.m. to 6:00 p.m.) resulted in a corresponding shift in enzyme activity. Under these "reverse" conditions, a circadian rhythm was observed (P less than 0.0001, Cosinor analysis) with the peak of activity at 6:00 a.m. (2.87 nmol catabolites/min/mg) and the trough at 6:00 p.m. (0.92 nmol catabolites/min/mg). These studies demonstrated that DPD activity in rat liver varies over a 24-hr period in association with the light-dark cycle.

Animals↗

Treatment of advanced malignancies with ifosfamide under protection with mesna.

Fifty-seven patients with advanced malignant tumours were treated with ifosfamide (Holoxan) and mesna (Uromitexan) in our department from November 1979 to December 1984. This series comprised eight cases of soft tissue sarcoma, nine cases of ovarian carcinoma, five cases of non-seminomatous testicular tumour, 11 cases of bronchogenic carcinoma, three cases of renal carcinoma, seven cases of non-Hodgkin's lymphoma, two cases of skeletal fibrosarcoma, two cases of breast carcinoma, one case each of Ewing's tumour, prostatic carcinoma, seminoma, plasma cell tumour, multiple myeloma, malignant teratoma, nasopharyngeal carcinoma, Wilms's tumour, neuroblastoma and mycosis fungoides. Out of these 57 cases, 53 were evaluable. There were five complete remissions and 20 partial remissions, corresponding to a total response rate of 47%. The overall median survival time (MST) of the 53 evaluable patients was 7.5 months. The responders had a longer survival time (MST 10 months) than the non-responders (MST 4.75 months) (p greater than 0.05). Analysis of the results according to sex, age, dosage of ifosfamide and degree of histological differentiation of the tumour cells failed to show any influence of these factors on the therapeutic results. The response rate to ifosfamide found in this study might be related to the histological origin of the tumours and to whether the primary tumours had been resected. The non-seminomatous testicular tumours, non-Hodgkin's lymphomas and ovarian carcinomas showed a high response rate. The response rate was higher in the group in which the primary tumour had been resected (61%) than in the non-resected group (12%) (except the non-Hodgkin's lymphoma). The side-effects of this regimen were moderate. Dyspepsia, nausea, vomiting, myelodepression, dizziness, and alopecia were common. Cystitis could be prevented nearly completely by concomitant administration of mesna, when given correctly, for preventing side-effects of ifosfamide on the urinary system (haemorrhagic cystitis, etc.).

Adult↗

The effects of ischemia on estrogen and progesterone receptor profiles in the rodent uterus.

Ischemia is considered to invalidate the estrogen receptor (ER) and progesterone receptor (PR) values of tissues available for steroid hormonal analysis. To evaluate the temporal effect of devascularization on steroid receptors, complete uterine ischemia was induced in vivo in 64 female Buffalo rats (80-154 g). Animals were assigned to varying intervals of ischemia (0-90 min) and were maintained at a constant ambient (75 degrees F) and core-body temperature (100-102 degrees F). Following tissue preservation at -80 degrees C, multipoint titration of steroid binding capacity (SBC) was performed with [3H]estradiol 17-beta (3-0.15 nM) or [3H] R5020 (8-0.4 nM) in the presence or absence of a 200-fold excess of an unlabeled ligand. Applying nonlinear regression analysis, ischemia was observed to decrease the binding capacitance for both ER and PR profiles of rodent uterine tissues at 30 min with significant decay over the 90-min interval of devascularization (ER, P less than 0.01; PR, P less than 0.1). Significant reduction in SBC was evident after 80 min of ischemia for PR (P less than 0.05) and 90 min of tissue ischemia for ER (P less than 0.05) comparative to control (t0) valves. The detrimental effect of progressive ischemia on ER and PR values was such that it appears essential to assure rapid and reliable tissue aliquot preservation techniques when organ ischemia greater than or equal to 90 min is anticipated.

Animals↗