Interactions between CD44 and hyaluronic acid: their role in tumor growth and metastasis.
Explore the source record for details and available documents.
Animals↗
Biomedical subjects
Y Guo
Publications and source records attributed to Y Guo.
Study of the antioxidant enzymes in human brain tumors.
The activities of antioxidant enzymes i.e. Cu, Zn-SOD, Mn-SOD, CAT, and GSH-Px in the normal brain and brain tumors, as well as the two varieties of SOD in the mitochondria were examined and correlated to the histopathological diagnosis and the degree of malignancy of tumors. It was found that these scavenging enzymes of oxygen free radicals were expressed with great regularity in brain tumors. Both Cu, Zn-SOD and Mn-SOD were decreased in descending order in meningiomas, low grade astrocytomas, high grade astrocytomas and medulloblastomas. Furthermore, the reduction of Mn-SOD in mitochondria was proportionate to that of the whole tissues. While in contrast to the SODs, the CAT levels were significantly increased in ascending order in high grade astrocytomas, low grade astrocytomas and meningiomas. GSH-Px increased in meningiomas but not in gliomas.
Antioxidants↗
Microcalorimetric study of metabolic inhibition by humic acids in mitochondria from Oryctolagus cuniculus domestica liver cells.
The metabolic thermogenesis curves of mitochondria isolated from Oryctolagus cuniculus domestica liver tissue have been determined by using an LKB-2277 bioactivity monitor. After isolation, mitochondria maintain activity when stored in appropriate nutrients. The thermokinetic equation: [formula: see text] was established for the activity recovery phase of metabolism. For these studies, the order of metabolism was found to be zero. The metabolic activity of mitochondria was inhibited by humic acid, a potential toxicant in Kashin-Beck and Keshan diseases. Experimental results indicate that humic acid will effect the heat output and lag time of mitochondrial metabolism.
Animals↗
Immediate early gene expression in cat visual cortex during and after the critical period: differences between EGR-1 and Fos proteins.
Immediate early gene (IEG) expression in the cat visual cortex is highly responsive to visual input and may initiate genetic mechanisms responsible for neuronal plasticity. The present study used immunohistochemical methods to address two issues regarding IEG expression in response to visual input. One was to define the differential response of distinct IEG families by comparing EGR-1 (also termed zif-268, NGFI-A, and Krox-24) and Fos proteins. The second was to determine whether IEG expression, in addition to reflecting neural activity, is related to the state of plasticity by comparing young and adult visual cortex. Immunoreactivity of the two IEG proteins was compared between 5-week-old and adult cats under three conditions of visual input: ambient light to assess basal levels of expression, 1 week of darkness to assess the effect of reduced activity, and exposure to light after 1 week of darkness to determine rapid changes in expression as a result of visual input. At both ages, there were marked differences in the expression of the two IEG proteins. EGR-1 responded to visual input with sustained changes in its level of expression. It showed high basal levels, reduced expression in darkness, and a rapid return to high constitutive levels with the introduction of light. Fos showed a markedly different profile. It had very low basal expression which was not demonstrably affected by darkness and its principal response was a marked transient induction upon exposure to light after darkness. These unique changes in expression highlight the complex response across IEGs to environmental input and suggest a genetic "on/off' signaling mechanism. There were marked differences in the laminar distribution of EGR-1 and Fos proteins between young and adult cats. In young animals, cells in all visual cortical layers showed high levels of EGR-1 and Fos proteins. In adults, immunostaining was largely specific to cells located above and below layer IV and only very faint labeling occurred within layer IV. These differences in laminar distribution between ages are inconsistent with a simple explanation of IEG expression in terms of neural activity level; rather, they suggest a relation between IEG expression and the state of plasticity in visual cortex.
Animals↗
Bombesin-mediated AP-1 activation in a human gastric cancer (SIIA).
BACKGROUND: Bombesin, a gut tetradecapeptide homologous to the mammalian gastrin-releasing peptide (GRP), stimulates the growth of the human gastric cancer line SIIA through specific GRP receptors (GRP-Rs); the cellular mechanisms are not known. The purpose of our study was to (1) confirm functional GRP-R in SIIA and (2) determine whether bombesin alters the expression and binding activity of the AP-1 transcription factors, c-jun and jun-B. METHODS: SIIA cells were treated with bombesin, and intracellular calcium mobilization was measured by means of fura-2 spectrofluorometry. To assess changes in c-jun and jun-B, RNA and protein were extracted for Northern and Western blots, respectively; nuclear protein was extracted for gel mobility shifts to determine AP-1 binding activity. RESULTS: SIIA cells mobilized intracellular calcium in response to bombesin, exhibiting a functional cell-surface GRP-R. Bombesin treatment increased expression of both c-jun and jun-B mRNA by 0.5 hours, with maximal expression at 1 hour; concomitant increases in steady-state levels of c-Jun and JunB protein were identified. Moreover, bombesin increased binding of the AP-1 proteins as shown by gel shifts. CONCLUSIONS: The SIIA human gastric cancer possesses functional GRP-R coupled to the calcium second messenger pathway. Further, bombesin stimulates expression of c-jun and jun-B mRNA and protein and increases binding activity of AP-1 proteins. Delineating the cellular pathways involved in bombesin-mediated gene activation will provide important insights into the mechanisms responsible for normal and neoplastic gut growth.
Adenocarcinoma↗
Tetraploid or near-tetraploid clones characterized by two 8;21 translocations and other chromosomal abnormalities in two patients with acute myeloblastic leukemia.
Acute myeloblastic leukemia (AML) with tetraploidy is rare. There have been only six such cases studied with banding techniques in the literature. Two were diagnosed as having AML-M2 and found to have similar near-tetraploid karyotypes with t(8;21) and missing Y chromosomes. We report two further cases of AML with tetraploid or near-tetraploid clones characterized by two t(8;21) and other chromosomal changes. Their cytogenetic findings were compatible with the diagnosis of AML-M2. Giant and bizarre blasts were seen on bone marrow (BM) smears from both cases. Immunologically, the blasts express CD2, CD15, and HLA-DR in case 1 and CD2 and CD65 in case 2. Cytogenetic studies on BM cells at diagnosis revealed that both cases had three related abnormal clones besides a normal one: 46,XY,t(8;21) (2%)/46,idem,add(7)(q31)(6.8%)/92, idem x 2 (80.6%) for case 1; and 46,XX,t(8;21)(13.4%)/47, idem,+4 (46.3%)/94,idem x 2 (39.1%) for case 2. Flow cytometric analysis displayed two cell populations in the former: one was in the diploid range and the other was in the tetraploid range. The patients did not obtain complete remissions and survived four and six months, respectively. These results indicate that tetraploid or near-tetraploid clones are secondary events which are associated with t(8;21) leukemia and may be associated with poor prognostic significance.
Adult↗
Karyotype conversion in two patients with chronic myeloid leukaemia after busulphan-induced marrow hypoplasia.
SUMMARY: We report two patients with chronic myeloid leukaemia (CML) developing hypoplasia and karyotype conversion after conventional busulphan therapy. Initially, the percentage of Ph-positive metaphases in marrow for both patients was 100%, which steadily diminished up to a complete disappearance in case 1 and decreased dramatically in case 2 following hypoplasia. Thereafter Southern blot and RT-PCR assays revealed no abnormalities. Both patients have survived 9 years and remained in good clinical and haematological remission without any treatment until recently. We believe that the high sensitivity to busulphan therapy result in hypoplasia and karyotype conversion, which contributed to prolonged survival.
Adult↗
Costimulatory signalling potential of murine MHC class II-positive T-clone cells.
Activated human and rat T cells as well as mouse T-cell clones have been reported to synthesize and express major histocompatibility complex (MHC) class II molecules. However, the capacity of class II+ antigen (Ag) presenting T cells to induce proliferation of Ag-specific cloned T cells has been controversial. We analysed whether the failure of some T-cell clones to proliferate in response to Ag presented by class II+ T cells is because of a lack of costimulatory cytokine production by the antigen-presenting cells (APC). As a model system the mouse class II+ cloned BI/O4.1 T cells were used as APC in order to activate the T cell clone KIII5. This T-helper 1 (Th1) type, GAT (synthetic copolymer of L-glutamic acid, L-alanine and L-tyrosine)-specific clone is characterized by an efficient downregulation of interleukin-2 receptor (IL-2R) with time following antigenic stimulation. KIII5 cells respond to GAT-presenting splenic antigen-presenting cells (APC) by IL-2 production, IL-2R upregulation and proliferation. When BI/O4.1 T cells were used as APC, KIII5 cells produced IL-2, but did not proliferate. Reverse transcriptase-polymerase chain reaction (RT-PCR) revealed a lack of IL-12 production by BI/O4.1 cells. Addition of IL-12 to a coculture of Ag-presenting BI/O4.1 cells and KIII5 cells fully reconstituted a proliferative response. IL-12 in synergy with IL-2 upregulated IL-2R alpha chain expression and enhanced proliferation of KIII5 cells. Our data suggest, that class II+ T cells are not functional in inducing Ag-mediated expansion of resting Th1 cells owing to their failure to produce IL-12, but rather that they play a role in amplification loops during an ongoing immune response.
Animals↗
Site-selected mutagenesis of the Drosophila second chromosome via plasmid rescue of lethal P-element insertions.
This paper describes a fast and efficient approach to correlating cloned genes with mutant phenotypes in Drosophila. We make use of a large collection D. melanogaster lines with recessive lethal insertions of a P[lacW] transposon on their second chromosome. Within this collection there clearly must be many insertions corresponding to Drosophila genes that have been cloned and characterized, e.g., via homology with cloned mammalian genes, but for which mutant phenotypes have yet to be identified. We have made use of the fact that P[lacW] contains a plasmid replicon to establish a collection of rescued plasmids containing genomic DNA flanking the sites of transposon insertion. Plasmids representing a total of 1836 lines were independently rescued and pooled in batches of 10 and 100. Pools of 100 plasmids were screened by hybridization with cDNAs corresponding to cloned second chromosome loci. Hybridizing pools were then narrowed down to single plasmids by a process of subdivision and rehybridization, and corresponding mutant lines were obtained. The success rate was better than one in four. This rate would undoubtedly be improved by the use of genomic DNA probes.
Animals↗
HOCl effects on the tight junctions of rabbit tracheal epithelium.
We previously found that HOCl, produced from neutrophil products in infected airways, decreases electrical resistance (R) of rabbit tracheal epithelium. Interestingly, HOCl at 6 mM, a reasonable concentration in diseased airways, decreased R without apparent cell damage. This study sought to determine whether this noncytotoxic dose of HOCl causes morphological changes that correlate with the decrease in R. Excised rabbit tracheas were treated with 6 mM HOCl for 15 min, before and after which epithelial R was determined. Epithelial tissue was then fixed and prepared for transmission electron microscopy, immunofluorescent labeling of F-actin or the tight junction protein ZO-1, or freeze fracture to examine tight junction strands. HOCl treatment caused a 50% decrease in R. Electron micrographs showed no cell, cell membrane, or tight junction changes. By laser confocal microscopy, 6 mM HOCl did not affect the distribution of F-actin or ZO-1. However, morphometric analysis of freeze-fracture replicas showed that tight junction strand number was significantly decreased from 7.06 +/- 0.09 to 4.79 +/- 0.11 and junctional width was significantly decreased from 0.306 +/- 0.007 to 0.214 +/- 0.006 microns. These latter changes may have contributed to the observed decrease in epithelial R.
Actins↗
Deficiency of protein phosphatase 2A uncouples the nuclear and centrosome cycles and prevents attachment of microtubules to the kinetochore in Drosophila microtubule star (mts) embryos.
A Drosophila strain, carrying a P[lacW] element in the promoter of the protein phosphatase 2A (PP2A) catalytic subunit gene at chromosomal location 28D, has been identified using plasmid rescue of the P element and adjoining genomic DNA in Escherichia coli. Reversion mutagenesis was employed to demonstrate that the observed phenotype of the Drosophila strain was due to a single P[lacW] element insertion at 28D and to create three deficiency strains at this locus. Drosophila heterozygous for P[lacW]28D have reduced levels of PP2A mRNA and reduced PP2A catalytic activity against four different substrates compared to wild type, while homozygotes are deduced to have approximately 20% of wild-type PP2A activity. P[lacW]28D homozygotes, termed microtubule star (mts), die in embryo-genesis around the time of cellularisation, exhibiting over-condensed chromatin and a block in mitosis between prophase and the initiation of anaphase. Multiple centrosomes are visible in cellularised embryos, suggesting that PP2A may play a role in coupling the nuclear and centrosome cycles. When embryos arrest just prior to cellularisation, disorganised elongated arrays of microtubules radiate from centrosomes in all directions, but they are rarely associated with any DNA, suggesting that PP2A is required for the attachment of microtubules to chromosomal DNA at the kinetochore.
Animals↗
In vivo effect of high energy shock waves on growth and metastasis of the heterografted tumors of nude mice.
OBJECTIVES: To examine whether high energy shock waves (HESW) can inhibit tumor growth in vivo and whether it can promote the metastasis of the heterografted tumors of nude mice. MATERIALS AND METHODS: Observations were made on the effect of HESW on tumor growth, histological and ultrastructural (transmission electron microscope, TEM) variations and metastasis to lymph nodes and viscera in the nude mice with heterografted tumors. The Dornier HM3 lithotripter was used under the working voltage of 15 kV, the impulse number being 0, 400 and 800 respectively, the temperature of waterbath, 35-37 degrees C and the impulse rate, 60/min. RESULTS: HESW did have cytotoxic effect on tumors in vivo, including acute and chronic lethal effects and growth inhibitory effect, and it could act on levels of cell membrane, cytoplasmic organelles and nuclear chromatin. At a definite working voltage, this effect was positively proportional to the impulse number. The action mechanism of HESW in vivo might be direct mechanical damage and indirect inhibition of tumor growth as a result of causing damage to the blood supply. Histological examination showed no metastatic foci to the lymph nodes and viscera of the nude mice with the heterografted tumors. CONCLUSIONS: HESW do inhibit tumor growth in vivo, but temporarily. This observation showed no tumor metastasis in the nude mice after the impulsion of HESW, but further studies on this topic are needed. It can be predicted that HESW will become a clinical method to treat the tumors after further investigation on its mechanism of action.
Animals↗
[Immunotherapy of tumors expressing IGF-I].
Recently we demonstrated that rat glioma cells when transfected with a vector encoding antisense IGF-I c-DNA lost tumorigenicity and induced a tumor specific immune response involving CD8+ lymphocytes. Here we showed, using immunostaining flow cytometry analysis, that the transfected cell lines, rat C-6 glioma and rat LF hepatoma, expressed an increase level of MHC-class I, and even the amount of MHC-I was found to be higher in the transfected hepatoma, than in the transfected glioma cells. This increased expression of MHC-I could contribute to the final immune recognition of tumour immunogenicity.
Animals↗
[Effect of the T4 on the viscera and embryo of perinatal mice].
58 Female Kun Ming mice of perinatal stage (from the 15th day of pregnacy to the 21th day after birth) were fed with Tripcholorolide (T4) isolated from multiglycosides of Tripterygium wilfordii (GTW) at a doze of 0.6 mg/kg for group 1 or 0.3 mg/kg for group 2 per day for 4 weeks. Lactation was decreased in some females and some F1 off spring died. The succinic dehydrogenase (SDH) activity of the mice liver were increased due to the destruction of its mitocondian. Liver cells degenerated and glycogen decreased. Distal tubules of kidney degenerated. Heart and spleen were normal. T4 was also fed to 10 female mice from the 5th to 17th day of pregnacy. However, neither the absorbed fetus nor dead fetus increased.
Animals↗
[The antifertility effect of gossypol plus testosterone and estrogen].
In order to reduce the side effect of gossypol, gossypol was used in combination with steroid hormones so that the dose of both drugs can be reduced. Silastic capsules containing testosterone (T) + estradiol (E) were implanted under the skin male wister rats for 8 weeks. After removing the implants, testosterone was given orally at the dose of 15 mg.kg-1 which is only 50% of the usual antifertility dose. Mating tests showed that the male rats became infertile. Microscopic examination of the heart, liver and kidneys showed no pathologic changes. The treated rats gained body weight as well as the controls. The fertility of the treated rats recovered four to five weeks after treatment. Thus, gossypol in combination with testosterone and estrogen exhibited a low degree of side effect and high antifertility activity.
Animals↗
[Magnetic resonance imaging of laryngeal cancer].
MRI data of twenty-four cases of laryngeal cancer were analysed and compared with the findings of postsurgical pathology. The results revealed that MRI could clearly demonstrate the three dimensional representations of tumor pathology, and correctly depict invasion of paraglottic space (PGS), and preepiglottic space (PES), and precisely display involvement of laryngeal cartilage by cancer. It was considered that MRI was of great importance in determining appropriate therapy for laryngeal cancer.
Adult↗
[Aneurysmal bone cyst: imaging diagnosis and evaluation of therapeutic methods].
OBJECTIVE: To determine the imaging features and useful therapeutic methods of aneurysmal bone cyst (ABC). METHODS: The radiographs, CT, and MR scans of 82 cases of pathologically proved ABC were retrospectively analyzed. Post-therapeutic follow-up of 45 cases was carried out for 3 months to 24 years. RESULTS: Plain radiographs showed eccentric expansile osteolysis in most cases. Fluid-fluid level was seen in 21/27 cases on CT scans, and calcification or ossification in 11/27 cases. MR images showed a hypointense rim in 7/7 cases, multilocular hyperintense cysts with hypointense septae on T2WI in 6/7 cases, and fluid-fluid levels in 5/7 cases. CONCLUSION: CT and MR scans are superior to plain radiographs in the diagnosis of ABC in the osteolytic phase and in the axial skeleton. Curettage combined with bone graft surgery is the most effective therapeutic method for ABC of the extremities. Arterial embolization with or without surgery is valuble for the treatment of ABC arising from the axial skeleton.
Adolescent↗
[Progresses in urology in China, 1996].
Explore the source record for details and available documents.
Animals↗