New measurements of 2H( gamma
Explore the source record for details and available documents.
Journal Article↗
Biomedical subjects
X Zhao
Publications and source records attributed to X Zhao.
DNA sequence and characterization of Haemophilus influenzae dprA+, a gene required for chromosomal but not plasmid DNA transformation.
Natural genetic transformation in Haemophilus influenzae involves DNA binding, uptake, translocation, and recombination. In this study, we cloned and sequenced a 3.8-kbp H. influenzae DNA segment capable of complementing in trans the transformation defect of an H. influenzae strain carrying the tfo-37 mutation. We used subcloning, deletion analysis, and in vivo protein labeling experiments to more precisely define the gene required for efficient DNA transformation on the cloned DNA. A novel gene, which we called dprA+, was shown to encode a 41.6-kDa polypeptide that was required for efficient chromosomal but not plasmid DNA transformation. Analysis of the deduced amino acid sequence of DprA suggested that it may be an inner membrane protein, which is consistent with its apparent role in DNA processing during transformation. Four other open reading frames (ORFs) on the cloned DNA segment were identified. Two ORFs were homologous to the phosphofructokinase A (pfkA) and alpha-isopropyl malate synthase (leuA) genes of Escherichia coli and Salmonella typhimurium, respectively. Homologs for the two other ORFs could not be identified.
Amino Acid Sequence↗
Cloning and characterization of the majority of repetitive DNA in cotton (Gossypium L.).
Repetitive DNA elements representing 60-70% of the total repetitive DNA in tetraploid cotton (Gossypium barbadense L.) and comprising 30-36% of the tetraploid cotton genome were isolated from a genomic library of DNA digested with a mixture of four blunt-end cutting restriction enzymes. A total of 313 clones putatively containing nuclear repetitive sequences were classified into 1103 families, based on cross hybridization and Southern blot analysis. The 103 families were characterized in terms of genome organization, methylation pattern, abundance, and DNA variation. As in many other eukaryotic genomes, interspersed repetitive elements are the most abundant class of repetitive DNA in the cotton genome. Paucity of tandem repeat families with high copy numbers (>10(4)) may be a unique feature of the cotton genome as compared with other higher plant genomes. Interspersed repeats tend to be methylated, while tandem repeats seem to be largely unmethylated in the cotton genome. Minimal variation in repertoire and overall copy number of repetitive DNA elements among different tetraploid cotton species is consistent with the hypothesis of a relatively recent origin of tetraploid cottons.
Base Sequence↗
Use of electric-field-mediated cell fusion to produce hybridomas secreting monoclonal antibodies.
Explore the source record for details and available documents.
Animals↗
Accumulation of gamma/delta T cells in human dysgerminoma and seminoma: roles in autologous tumor killing and granuloma formation.
The precise biological function of a subset of T cells bearing gamma/delta T cell receptor (TCR) remains poorly understood. The present study demonstrated the presence of gamma/delta T cells in tumor-infiltrating lymphocytes (TIL) and peripheral blood lymphocytes (PBL) of human patients with dysgerminoma and seminoma when determined by flow cytometry and in situ immunohistochemical staining. TIL contained a high percentage of gamma/delta T cells, ranging from 17.3 to 35.1%. gamma/delta T cells often accumulated within the granulomatous inflammation of tumor tissues. The majority of gamma/delta T cells were V gamma 9/V delta 2+ cells. Freshly isolated PBL, TIL and purified gamma/delta T cells showed autologous tumor killing (ATK) activity, which could be inhibited by monoclonal antibodies (mAb) against V delta 2. Furthermore, two gamma/delta T cell clones established from TIL showed cytotoxicity against autologous and allogeneic dysgerminoma, while they had low or no lytic effects on other cell types including carcinomas of ovary and tumor cell lines such as K562, Daudi and Molt-4. Lysis of autologous tumor cells by the clone was inhibited completely by anti-V delta 2 mAb and partially by mAb against CD3, LFA-1 alpha and ICAM-1 molecules, while it was resistant to anti-CD8, anti-HLA-ABC and anti-HLA-DR mAb. Supernatants produced by gamma/delta T cell clones induced adhesion, aggregation and increased DNA synthesis of monocytes and some characteristics of activated macrophages or epithelioid cells. Tumor necrosis factor (TNF)-alpha, granulocyte-macrophage colony stimulating factor (GM-CSF) and interferon (IFN)-gamma were detected in the supernatants of gamma/delta T cell clone. These results suggest that gamma/delta T cells accumulating in dysgerminoma and seminoma exhibit ATK activity through V gamma 9/delta 2 TCR and these gamma/delta T cells also play a role in the formation of granulomatous inflammation, which is associated with human dysgerminoma and seminoma.
Adult↗
Immunogold localization of high-affinity glucose transporter isoforms in normal rat kidney.
BACKGROUND: Facilitative glucose transporters (GLUT) have unique kinetic characteristics and distributions suited to the functions of the tissues in which they reside. However, little is known about their individual roles in renal glucose metabolism, and previous investigations of renal GLUT expression have been extensive only with respect to their mRNA levels. We provide here a complete analysis of three GLUT isoforms along the nephron using a sensitive immunodetection method. EXPERIMENTAL DESIGN: Normal rat kidneys were harvested, fixed in paraformaldehyde, and embedded in either paraffin or resin as required for immunogold labeling of individual GLUT Isoforms 1, 3, and 4. Samples were evaluated by light microscopy and selected regions analyzed by high resolution optical scanning with computer-assisted detection of immunogold-labeled GLUT at the subcellular level. We describe, compare, and related to the local patterns of glucose metabolism the cellular and subcellular expression patterns of these GLUT along the nephron. RESULTS: GLUT1 was most intensely labeled in the medullary thick ascending limbs of Henle, cortical collecting ducts, and inner medullary collecting ducts. In contrast, GLUT3 was most prominent in the inner medullary collecting ducts and GLUT4 in medullary thick ascending limbs of Henle. All three GLUT were detected in glomerular tufts, and GLUT1 was also detected in parietal epithelial cells. The predominant subcellular distributions in tubule cells were: basolateral and basolateral/cytoplasmic for GLUT1; basolateral and cytoplasmic for GLUT3; and perinuclear/cytoplasmic for GLUT4. GLUT 1 and 3 expressions were confirmed in specific regions by immunoblotting. CONCLUSIONS: 1) GLUT 1, 3, and 4 are expressed in both glomeruli and renal tubules. 2) The unique GLUT expression patterns along the renal tubules suggests unique functional roles for these isoforms. 3) The renal cortex demonstrates lesser labeling intensity for the high-affinity GLUT compared with the medulla, where higher rates of glucose oxidation and glycolytic metabolism are paralleled by higher GLUT labeling intensities.
Animals↗
The effects of transplantation of hepatocytes cultured with insulin on acute liver failure induced by 90% hepatectomy in the rat.
OBJECTIVE: To evaluate the influence of transplantation of hepatocytes either not cultured or cultured with or without insulin on survival in rats with acute liver failure induced by 90% hepatectomy. DESIGN: Randomized laboratory experiment. SETTING: University department, Sweden. MATERIAL: 60 Adult male Sprague-Dawley rats, not including donors. INTERVENTIONS: 90% hepatectomy without hepatocyte transplantation, or with intrasplenic transplantation of: uncultured hepatocytes immediately after resection, or uncultured hepatocytes one or three days before resection, or hepatocytes cultured with or without insulin immediately after resection (n = 10 in each group). MAIN OUTCOME MEASURES: Cell viability, attachment ability, survival, liver function, and body weight. RESULTS: Transplantation of hepatocytes cultured for 3 days without insulin or of uncultured hepatocytes one day prior to hepatectomy did not significantly improve 30-day survival compared with uncultured hepatocyte transplantation immediately after hepatectomy. Hepatocytes cultured with insulin for 3 days and transplanted immediately after hepatectomy significantly improved survival compared with animals in which hepatocytes were transplanted either uncultured or cultured for 3 days without insulin immediately after hepatectomy. Hepatocyte transplantation 3 days before hepatectomy further increased survival compared with the other groups in which transplantation was done immediately after hepatectomy. Acute failure, acute compensatory, and late 'enhanced' phases were defined within 30 days of hepatectomy. CONCLUSION: Transplantation of hepatocytes that are cultured with hepatocellular trophic factors (for example insulin) before transplantation may have the potential to increase the effectiveness of transplanted hepatocytes in the treatment of acute liver failure.
Analysis of Variance↗
Hemocyte alterations during melanotic encapsulation of Brugia malayi in the mosquito Armigeres subalbatus.
The involvement of hemocytes in melanotic encapsulation reactions against Brugia malayi was assessed in Armigeres subalbatus. Hemocyte populations, epitope changes, phenol oxidase (PO) activity, and the presence of an 84-kDa polypeptide were investigated in mosquitoes exposed to a B. malayi-infective bloodmeal (= immune-activated), in mosquitoes given a noninfective bloodmeal (= controls), in nonbloodfed mosquitoes (= naive), or in some combination of these. Total hemocyte populations in immune-activated mosquitoes significantly decreased at 24 hr postbloodmeal (PB) as compared with controls. At 48 and 72 hr PB, hemocyte population levels in immune-activated mosquitoes increased to control levels. Epitope changes, as indicated by wheat germ agglutinin (WGA) binding, also were observed. There was a significant increase in the percentage of hemocytes binding WGA in immune-activated mosquitoes at 24 hr PB as compared with controls. Furthermore, the activity of hemocyte PO, an enzyme involved in the melanotic encapsulation pathway, was significantly elevated at 12 hr PB in immune-activated mosquitoes as compared with controls. Analysis for the presence of an 84-kDa polypeptide in A. subalbatus indicates that a 2.0-kb message in total RNA hybridized to D6.12, an Aedes aegypti cDNA encoding an 84-kDa polypeptide that is associated with melanotic encapsulation responses. The hybridization of D6.12 to RNA was not greater in immune-activated as compared to control A. subalbatus, as has been observed in A. aegypti. Results indicate that these hemocyte changes correspond in time with the melanotic encapsulation reactions of A. subalbatus against filarial worms.
Animals↗
[Dynamic observation of alpha-granule membrane protein 140 during the treatment of thrombolytic and anticoagulant therapy in patients with acute myocardial infarction].
The degree of platelet activation and damage in 15 cases with acute myocardial infarction (AMI) receiving thrombolytic therapy and 15 cases with AMI receiving anticoagulant therapy were studied in vivo and in vitro by using specific monoclonal antibodies (SZ-51 & S12) against alpha-granule membrane protein 140 (GMP-140). Clinical indexes and myocardial enzyme changes in the two groups of patients were also observed. The results showed that the number of GMP-140 molecules on platelet surface and the concentration of GMP-140 in plasma were increased before treatment. The number of GMP-140 molecules on platelet surface began to decrease on the 1st day and returned to baseline on the 7th day after treatment. The concentration of GMP-140 in plasma reached a peak on the 1st day, began to fall on the 2nd day and returned to baseline on the 3rd day after treatment. There were no significant differences in the dynamic changes of number of GMP-140 molecules on platelet surface and the concentration of GMP-140 in plasma between groups of thrombolytic therapy and anticoagulant therapy. In vitro experiment showed that the thrombolytic medicine urokinase neither activated platelets nor inhibited platelet activation induced by thrombin. Significantly greater reperfusion rate and earlier appearance of CK and CK-MB peaks were found in the thrombolytic than in the anticoagulant group. LVEF determined by echocardiography, rate of return of ST segments to baseline and alleviation rate of chest pain were significantly greater and complications of AMI (ventricular fibrillation, left ventricular failure and angina) were less in the group receiving thrombolytic therapy.(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗
Interaction between intercalation type anticancer drugs and DNA studied by ultraviolet resonance Raman spectroscopy.
The interaction of typical intercalation type anticancer drugs, adriamycin (ADM) and aclacinomycin (ACM), with calf thymus DNA was studied first with ultraviolet resonance Raman spectroscopy (UVRRS). The results demonstrate that the important information such as intercalation sites of drugs, the electronic interaction and the hydrogen bonds between drugs and DNA can be obtained by UVRRS. The method can also show the influence of drugs on DNA conformation and hydrogen bonds between bases of DNA.
Aclarubicin↗
Abrupt reduction of c-myc expression by antisense RNA inducing terminal differentiation and apoptosis of a human esophageal cancer cell line.
A human esophageal cancer cell line (EC8712) expressing high-level Myc protein was infected with recombinant retroviral particles (pA-BD9) at a multiplicity of infection (MOI) 1:1. This viral particle contains a neomycin-resistant gene and a 1.53-kb antisense RNA spanning the 2nd exon and its flanking sequences of the human c-myc oncogene. The G418-resistant EC8712 clones showed an 86% inhibition of growth rate and morphological changes characteristic of terminal differentiation and apoptosis. A decrease of about 80% of Myc protein was also observed in these infected cells by ABC-ELISA assay. 12-24 h after the infection of EC8712 cells with pA-BD9 at a high viral particle concentration (MOI = 1:10), the integration of the extrinsic 1.53-kb antisense c-myc fragment into the cancer cell genome was evidenced by the Southern blot analysis. Northern blot analyses showed the expression of this antisense fragment and a decrease of the intrinsic c-myc expression by 74% in comparison with that of the parental EC8712 cells. Heterotransplants of the infected EC8712 cells into the nude mice revealed a substantial decrease in tumorigenicity and morphological changes characteristic of terminal differentiation and apoptosis. Primary monolayer cell cultures of normal epithelia derived from the fetal and adult esophagus mucosa were set as controls. No noticeable increase in c-myc expression was found in these cultures. Infection of these cells with the same recombinant viral particles neither affected the growth rate of the cells nor their normal morphology. Our experiments indicate that the drastic decrease of the over-expressed Myc protein in cancer cells may also be an entrance to one of many pathways leading to the terminal differentiation and programmed cell death.
Animals↗
[The role of sympathetic mechanism in the effect of electroacupuncture on immunoregulation].
1. In normal control mice (only injected SRBC) after EA the lymphocyte transformation test (LTT, P < 0.05) and interlukin-2 (IL-2) activity (P < 0.05) were significantly increased, but the serum lysozyme (IZM, P < 0.01) was apparantly decreased. 2. After injection of 6-OHDA in mice, the spleen weight, spleen index, thymus weight, thymusindex, spleen lymphocyte population and serum IZM, igG contents were markedly decreased, whereas LTT, IL-2 and plaque forming cell (PFC) were umchanged, In contrast, the thymus lymphocyte population was markedly increased. 3. After EA of mice axotomized sympathetic nerve with 6-OHDA the above mentioned immune parameters deceased by 6-OHDA could be returned to normal or nearing normal levels. However, the unchanged LTT, IL-2 and the increased thymus lymphocyte population could be enhanced further, especially IL-2. These results suggest that peripheral sympathetic nerve may be participation in the EA-mediating immunological responses.
Animals↗
[The effect of low engengy laser on the repair of osseous defect in the mandible of rabbitis].
Explore the source record for details and available documents.
Animals↗
Treatment of primary thrombocytopenic purpura by modified minor decoction of bupleurum.
Explore the source record for details and available documents.
Adolescent↗
[The distribution of abnormal hemoglobins in the silk road region of China].
215,785 individuals living in the Silk Road region of China were surveyed for abnormal hemoglobins (Hbs). Among them, 695 carriers were detected. The average incidence of abnormal Hbs was 3/22 and the frequencies of abnormal Hbs among 12 nationalities reached 0.15/1000-12.17/1000. The primary structural analyses were made in 271 persons, and 24 variants [13 alpha-chain variants and 11 beta-chain variants] were identified. HbJ Tashikuergan and Hb Tianshui were discovered the first time in the world. HbS, Hb Bunbury, Hb Setif and HbI Philadelphia were not found previously in the Chinese population. Three variants, i.e. HbD Punjab, HbG Taipei and HbG Coushatta occurred at the highest frequencies and showed a gradient distribution along the Silk Road, suggesting that they may originate from Caucasians in Central Asia, Han in the Yellow River valley, and the ancient nomadic minorities of China in Mongolia Plateau respectively. The frequencies of other variants were quite low. Some were probably imported from other countries and areas, and some arose from independent mutations. The data from many variants support the movements of various populations in this area, as reported in numerous historical documents. It is indicated that the Silk Road promoted the national fusion among the Chinese nationalities, Mongolian and Caucasian races.
Adolescent↗
[The DNA damage by photodynamic effects of hematoporphyrin derivatives (HPD)].
Photodynamic effects of HPD has been used for cancer therapy (PDT) successfuly. The biological mechanism of the PDT was studied by using DNA as a target in this work. After treatment of phage M13 DNA with HPD + light the molecule of the DNA kept intact in TE buffer. But the smear bands by puting DNA in 0.1 mol/L NaOH at 90 degrees C and separating with electrophoresis denoted the degradation of DNA at the alkali-labile sites of phosphodiester bond in which the groups of the bases were photooxydized. The primer extension experiment showed the aggregation of DNA template by photooxydation. The DNA sequencing results showed that some of the wrong sequences appeared both at the site of A,G,C,T bases. The mouse Ehrlich ascetes carcinoma cell DNA was treated as above then degraded by Bgl II and BamH I respectively. It was found that the restriction fragments became larger than the controls. It also meant the alteration of the bases of DNA by the photooxydation. So the four bases of A,G,C,T of DNA were altered by photodynamic effects of HPD.
Animals↗
[On the diagnosis of multiple myeloma an analysis of 2,547 domestic cases].
Analysis of 2,547 cases of multiple myeloma (MM) reported in China in 1980s showed that the clinical manifestations are characterized by multipliey. High misdiagnosis rate (69%) and multiple complications. While the monoclonal protein had more than 25 immunological type, IgG myeloma was the commonest (43.1%). Light chain subgroup trended to have higher incidence of renal damage (76.9%). Plasma cell leukemia eventually developed in 30 cases. In order to improve diagnosis and avoid misdiagnosis, the key points are 1, to better the recognition of clinical features of MM. 2. patient should receive urine Bence-Jones protein, immunoglobulins, immunoeletrophresis, bone X-ray and multiple site bone marrow puncture whenever one of such manifestations as unexplained anemia, skeletal pain, proteinuria, elevation of ESR, hyperviscosity syndrome, hypercalcemia, hyperuricemia, elevation of alkaline phosphatase, pathological fractures and diffuse osteoporosis. 3. immuno-binding electrophoresis and immunofluorence antibody detection should be done for suspected cases with normal immunoglobulin level.
Adolescent↗
[The effect of retinoic acid on cell membrane and metastatic ability of mouse forestomach carcinoma cells].
We studied the effect of all-trans-retinoic acid (RA) on the expression of several surface lectin receptors and cell membrane fluidity of mouse forestomach carcinoma cell line (MFC) in vitro. The results showed that cells treated with RA manifested decreased expression of lectin receptors, increased membrane fludity and reduced spontanous metastasis. These rusults suggest that the effect of RA on tumor cell membrane may be one of the mechanisms involved in the alternation of cell metastatic phenotype.
Animals↗