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Y H Zhao

Publications and source records attributed to Y H Zhao.

At least 37 records · Page 2Linked to original sources
PubMed1996

Inhibition of TGF-alpha gene expression by vitamin A in airway epithelium.

The autocrine/paracrine growth mechanism has been implicated in the regulation of bronchial epithelial cell proliferation. By inhibiting the expression of the transforming growth factor-alpha (TGF-alpha) gene product, vitamin A is able to suppress the proliferation of tracheobronchial epithelial cells in culture. Similar repressions in TGF-alpha mRNA levels by retinol were observed in airway explant cultures and in a cell line immortalized from normal human bronchial epithelial cells. Both the nuclear run-on transcriptional assay and the transfection study with the chimeric construct of the TGF-alpha promoter and chloramphenicol acetyltransferase reporter gene partly suggest a transcriptional downregulation mechanism of TGF-alpha gene expression by the retinol treatment; however, this inhibition at the transcriptional level cannot account for the total inhibition at the mRNA level. These results suggest that a downregulation of the expression of the TGF-alpha gene at the transcriptional and post-transcriptional levels by vitamin A may precede the essential event associated with the homeostasis of normal conducting airway epithelium.

Animals↗
PubMed1996

Isolation and characterization of nucleolin gene as one of the vitamin A-responsive genes in airway epithelium by a palindromic primer-based mRNA differential display method.

A palindromic primer-based mRNA differential display method has been used to isolate various vitamin A-responsive genes from primary cultures of monkey tracheobronchial epithelial cells. This method, as compared with the original mRNA differential display (mDD) method described by Liang and Pardee, used only one arbitrarily designed primer instead of two in the polymerase chain reaction. The single-primer mDD method has several advantages over the two-primer mDD system, especially in the reamplification and the selection of 5'-end cDNA clone. To verify the usefulness of this approach, one of these differential display bands, M34, was initially chosen for further amplification and cloning. The clone derived from the M34 band has a DNA sequence with > 90% homology to the human nucleolin gene. Furthermore, DNA sequencing confirms that both 5' and 3' ends of the insert of M34 contain the invertly repetitive nucleotide sequence that was used to direct this cloning. Nucleolin is a multifunctional phosphoprotein that plays an important role in ribosome biogenesis and mRNA stability. Northern blot analysis demonstrated that in addition to the elevation by vitamin A, the level of nucleolin message is significantly higher in fetal than in adult tracheobronchial epithelial cultures. Furthermore, in situ hybridization demonstrated that the amount of nucleolin message is significantly higher in both basal and ciliated cell types than in mucous and intermediary cell types. These results support the feasibility that the single-primer mDD technique can be used to isolate vitamin A-responsive genes with a palindromic nature.

Animals↗
PubMed1995

Inheritance and chromosomal locations of male fertility restoring gene transferred from Aegilops umbellulata Zhuk. to Triticum aestivum L.

Restriction fragment length polymorphism (RFLP) markers were used to map male fertility restoring gene that was transferred from chromosome 6U of Aegilops umbellulata Zhuk. to wheat. Segments of chromosome 6U bearing the gene that restore fertility to T. timopheevi Zhuk. male sterile cytoplasm were identified in all four translocation lines by two probes, BCD21 and BCD342. Lines 040-5, 061-1 and 061-4 are T6BL.6BS-6U translocations, while line 2114 is a T6AL.6AS-6U translocation. Line 2114 has a much larger 6U chromosomal segment and lower frequency of transmission of male gametes with the alien segment than the other three lines. The restoring gene carried by the 6U segment in 2114 showed high expressivity and complete penetrance. This restoring gene is designated Rf6. A homoeologous chromosome recombination mechanism is discussed for the alien gene transfer.

Chromosome Mapping↗
PubMed1994

[Clinical research on the treatment of acute leukemia with autologous bone marrow transplantation].

38 cases of acute leukemia were treated with autologous bone marrow transplantation (ABMT). The marrow was purged with hyperthermia of 42 degrees C in vitro for one hour in microwave. Twenty-two among them were AML (CR1). Sixteen were ALL (CR1). The mean age was 26 (10-43) years. All the patients were engrafted successfully after ABMT. Mean DFS was 21 (3-69) months. Four cases relapsed at 3 to 8 months after ABMT. Two patients with ALL developed central nervous system leukemia at 12 and 15 months respectively after ABMT. The DFS and probability of relapse at 5 years were 67.8% and 16.8% respectively for all patients.

Adolescent↗
PubMed1993

Neuronal localization of the tyrosine-specific protein kinase p62c-yes in rat basal ganglia.

The cellular localization of the tyrosine-specific protein kinase p62c-yes, the product of the proto-oncogene c-yes, has been examined in the striatonigral neurons which interconnect the rat neostriatum and substantia nigra. Although p62c-yes was more enriched in the neostriatum than in the substantia nigra, excitotoxin-induced necrosis of nerve cells in the neostriatum led to 50-60% decreases of p62c-yes both in the lesioned neostriatum and in the ipsilateral substantia nigra. Hence, the p62c-yes tyrosine kinase is present both in the cell body region and in the axonal and nerve terminal region of the striatonigral neurons. This localization indicates that the enzyme may be involved in both presynaptic and postsynaptic functions in mammalian forebrain neurons.

Animals↗
PubMed1992

A study of RBC aggregation-sedimentation phenomenon with conductivity method.

In this paper, we present a conductivity method for measuring the RBC (red blood cell) aggregation-sedimentation phenomenon and the theoretical analysis of this phenomenon. A theory describing the RBC aggregation-sedimentation phenomenon with the conductivity method is proposed and the formula of the l-t function which depicts the RBC aggregation-sedimentation process is given. We put forward the aggregation index and sedimentation factor describing the RBC aggregation-sedimentation phenomenon for the first time.

Animals↗
PubMed1991

Blood supply and structural changes of canine intact tibia following plate fixation with different rigidities.

To study the causes of osteopenia after plate fixation in the treatment of fractures and bone diseases, intact tibiae of 26 dogs were fixed by 3 different plates at various rigidities. The dogs were killed at 24 hours 3, 6, 12, 20 weeks. Disulphine blue was injected intravenously before killing. The results showed that in addition to stress shielding the disturbance of blood supply was the main cause of osteopenia in the early stage. Reaction to the implant might be another cause in the middle stage. The disuse of the affected limb was the most important factor in the late stage. Osteopenia can be treated by active exercises and normal weight-bearing before plate removal.

Animals↗
PubMed1991

Localization of p62c-yes protein in mammalian neural tissues.

Expression of the c-yes proto-oncogene in mammalian brain, retina and adrenal gland was studied by immunohistochemistry and immune assays with affinity-purified anti-yes IgG. Immunohistochemical staining with anti-yes IgG showed that in the central nervous system p62c-yes is highly expressed in mitral cells of the olfactory bulb, Purkinje cells of the cerebellum, hippocampal neurons and granule neurons of the dentate gyrus and ependymal cells lining central nervous system ventricles. Less intense labeling by anti-yes IgG was observed in most neuronal cell bodies in the brain. In addition, we observed intense c-yes immunoreactivity in the ganglion cells of the retina, the inner segment layer of rods and cones and medullary cells of the adrenal gland. Mapping p62c-yes expression to specific areas of mammalian neural tissues points to attractive experimental systems which could be used to investigate the function of the proto-oncogene product in neural processes.

Adrenal Glands↗
PubMed1991

Differential expression of p62c-yes in normal, hyperplastic and neoplastic human epidermis.

The protein product of the c-yes proto-oncogene, p62c-yes, is highly expressed in a variety of mammalian cell types, including neurons, spermatozoa, platelets, and epithelial cells. In order to understand the function of p62c-yes in epithelial cells, the expression and localization of p62c-yes was studied in cultured human epidermal keratinocytes and in normal, hyperplastic, and neoplastic human epidermis. Human keratinocytes in culture produce a single 4kb c-yes mRNA and a 62kd protein product, p62c-yes, which is active as a protein tyrosine kinase. Using affinity-purified antibodies generated to the amino-terminus of the human c-yes protein, the expression of p62c-yes was localized to keratinocytes in the basal epidermal layer of normal neonatal and adult epidermis. There was a marked reduction in expression of p62c-yes by suprabasal keratinocytes undergoing progressive differentiation. By immunofluorescence microscopy, p62c-yes was localized to the plasma membrane and to a perinuclear cytoplasmic area in cultured keratinocytes. The apparent association of p62c-yes with plasma membranes was particularly evident in suprabasal keratinocytes from hyperplastic epidermis. Neoplastic keratinocytes in basal cell carcinomas showed a marked reduction in p62c-yes expression compared to normal basal keratinocytes in epidermis or to proliferating cultured keratinocytes. Thus the expression of p62c-yes by one epithelial cell type, the keratinocyte, is altered by cellular differentiation and neoplastic transformation. Keratinocytes provide a normal epithelial cell model in which the biochemical function of p62c-yes can be studied.

Cell Transformation, Neoplastic↗
PubMed1990

Microvascular decompression by retrosigmoid approach for trigeminal neuralgia: experience in 200 patients.

Trigeminal neuralgia is often seen in elderly persons. Two hundred patients with trigeminal neuralgia were submitted to microvascular decompression by a retrosigmoid approach. The surgical procedure is described. Vascular compression of the nerves was noticed in all these patients at operation. One hundred ninety-seven had relief of symptoms postoperatively, for a 98.5% cure rate. In addition, we suggest that another important cause is arteriosclerosis.

Adult↗
PubMed1990

Determinants of elevated blood lead during pregnancy in a population surrounding a lead smelter in Kosovo, Yugoslavia.

We are prospectively examining the relation between environmental lead exposure and pregnancy outcome in cohorts of women exposed to a wide range of air lead concentrations. Titova Mitrovica, Yugoslavia, is the site of a large lead smelter, refinery, and battery factory. At midpregnancy, 602 women in T. Mitrovica and 900 women in Pristina, a non-lead-exposed control town, were interviewed. Blood was obtained for blood lead (PbB), hemoglobin, erythrocyte protoporphyrin, and serum ferritin measurements. Women were seen again at delivery, at which time maternal and umbilical cord blood samples were obtained. While many demographic and social characteristics were similar across the two towns, women in Pristina were more likely to report employment outside the home, cigarette smoking, and alcohol use during pregnancy. As expected, PbB levels were substantially higher in the smelter town. At midpregnancy, PbB geometric means were 17.1 micrograms/dL in T. Mitrovica and 5.1 micrograms/dL in Pristina; 86% of the pregnant women in T. Mitrovica, compared to 3.4% of those in Pristina, had PbB levels greater than 10 micrograms/dL. Within T. Mitrovica, distance between the home and the smelter was the most important predictor of PbB at mid-pregnancy and delivery. Husband's employment in the lead industry was associated with a significant increase in maternal PbB levels independent of place of residence. Higher maternal serum ferritin concentrations were associated with lower PbB levels, suggesting that dietary iron inhibits lead absorption. Overall, the placenta was a poor barrier to lead; the relationship between maternal PbB and umbilical cord PbB was linear across a wide range of PbB levels.

Adult↗
PubMed1990

Expression of cellular-yes protein in mammalian tissues.

Expression of the c-yes proto-oncogene in normal mammalian tissues was studied by immunohistochemistry and by immunoprecipitation assays using affinity purified anti-yes IgG. The antibody was raised against the amino-terminal domain of the human c-yes protein expressed in bacteria as a trpE-yes fusion protein. We detected p62c-yes in a variety of rat and human tissues but its relative level of expression varied significantly among different cell types. Certain epithelial cells, platelets and spermatid acrosomes showed the highest levels of p62c-yes. Intracellular localization of p62c-yes in epithelial cells differed among organs performing different physiological functions. The overall pattern of expression suggests that p62c-yes may be involved in numerous cellular pathways.

Acrosome↗
PubMed1989

[Determination of the contents of mineral elements in the soil where the jinin big-wild ginseng grows].

The element contents in the soil where the Jilin Big-Wild Ginseng grows were determined with plasma emission spectrometry. 23 elements in the soil were found, of which 12 are macro and trace elements indispensable to Ginseng growth. This study provides a scientific basis for selecting suitable soil for planting wild ginseng, or for creating optimum soil conditions for the bumper harvest and high quality of Ginseng.

Calcium↗
PubMed1989

[Urine-Cr assay with diphenylcarbazide].

Systemic investigations of chromium determination in urine with diphenylcarbazide were carried out and suitable analytic conditions for the determination established. Urine samples were first digested with nitric acid-hydrogen peroxide and then the chromium in the sample was oxidized to the hexavalent state by permanganate in acidic medium. After the excess oxidizing reagent was destroyed with sodium nitrite, chromium (VI) combined with diphenylcarbazide, forming a stable red color. The average recovery was 101.1%, ranging from 82.0% to 115.8%. Coefficients of variation were in the range from 2.0% to 8.4%. The method can be conveniently applied to the analysis of trace chromium in urine samples with satisfactory sensitivity and recovery. The method was applied to the measurement of 180 normal and 124 CHD (coronary heart disease) urine samples from Chengdu city. The mean of chromium level in normal urine was 6.1 micrograms/L and the range with 95% confidence of urine chromium was determined as 1.7-11 micrograms/L. The mean of chromium level in CHD urine samples was 4.2 micrograms/L. By statistical analysis, there was a significant difference between the means of the two groups (t' = 6.9, P less than 0.05).

Chromium↗