Biomedical subjects

Z Zou

Publications and source records attributed to Z Zou.

At least 37 records · Page 2Linked to original sources

PubMed1999

In vivo analysis of plastid psbA, rbcL and rpl32 UTR elements by chloroplast transformation: tobacco plastid gene expression is controlled by modulation of transcript levels and translation efficiency

5' and 3' untranslated regions (UTRs) of plastid RNAs act as regulatory elements for post-transcriptional control of gene expression. Polyethylene glycol-mediated plastid transformation with UTR-GUS reporter gene fusions was used to study the function of the psbA, rbcL and rpl32 UTRs in vivo. All gene fusions were expressed from the same promoter, i.e. the promoter of the 16S-rRNA gene, such that variations in RNA and protein levels would be due to the involved UTR elements alone. Transgenic tobacco lines containing different combinations of UTRs showed fivefold variation in the uidA-mRNA level (RNA stability) and approximately 100-fold differences in GUS activity, a measure of translation activity. The rbcL 5'-UTR conferred greater mRNA stability than the psbA 5'-UTR on uidA transcripts. In contrast, the psbA 5'-UTR enhanced translation of GUS to a much greater extent compared to the rbcL 5'-UTR. The psbA 5'-UTR also mediated light-induced activation of translation which was not observed with other constructs. Deletion mutagenesis of an unanalysed terminal sequence element of the psbA 5'-UTR resulted in a twofold drop in uidA-mRNA level and a fourfold decrease in translation efficiency. Exchange of 3'-UTRs results in up to fivefold changes of mRNA levels and does not significantly influence translation efficiency. The mechanical impacts of these results on plastid translation regulation are discussed.

Journal Article↗

PubMed1998

Zonal and regional differences identified from precision mapping of vitamin A-storing lipid droplets of the hepatic stellate cells in pig liver: a novel concept of addressing the intralobular area of heterogeneity.

Knowledge of hepatic heterogeneity has been strikingly increased, while an accurate means for addressing intralobular positions is still lacking. We examined pig liver preparations of the gold impregnation method for vitamin A-storing lipid droplets in hepatic stellate cells. Droplet morphometry was performed under oil immersion, and the calculated volumes plotted on computerized maps. The heterogeneous results were assessed with five concentric zones and five radial regions; the latter were determined based on midseptum visualized by portal injection. Zonation and regionation thus subdivided lobules into 5-zone/5-region (5Z/5R) compartmentalization. Distribution of values exhibited a distinct zonal gradient, heightened at peripheral zones 1 and 2, decreased over intermediate zone 3 toward centrilobular zones 4 and 5; peak was always found at zone 2. Within a single zone, variations were obvious, forming a regional gradient. Values were significantly higher at periportal than midseptal regions. Digitized mapping showed that low values filled up centrilobular zones, whereas high values concentrated in periportal regions. Along the periphery, inlet venules were quantified, revealing an occurrence rate of 60% at periportal, and 5% at midseptal regions, closely compatible with the regional gradient of vitamin A-storing capacity. The interweaving between zonal and regional gradients results in a vitamin A-low territory, a compound area composed of centrilobular zones plus extensions into midseptal regions. Because the results could account for physiological and pathological events, we regard the 5Z/5R compartmentalization a model worth routine adoption for a precise description of any morphofunctionally demonstrable heterogeneity of the liver lobules.

Adipocytes↗

PubMed1998

[Purification of recombinant erythropoietin by reversed-phase high performance liquid chromatography (RP-HPLC)].

Recombinant erythropoietin is a glycoprotein which is strongly hydrophobic. We purified recombinant erythropoietin by RP-HPLC. The results showed that 30 nm Spherisorb C4 reversed-phase column and acetonitrile-TFA mobile phase with gradient elution, could readily isolate recombinant erythropoietin from crude samples with high speed and efficiency. Erythropoietin could be eluted at the concentration of about 50% acetonitrile with appropriate sample purity and elution gradient. When RP-HPLC is used as a final step of purification, the purity of sample should be at least 60%. The purity of the product tested by SDS-PAGE was nearly 100%. And the specific activity of the product was about 1.96 x 10(3) IU/g protein.

Chromatography, High Pressure Liquid↗

PubMed1998

[Experimental study of parotid gland injected with gentian violet].

OBJECTIVE: The Gentian Violet was used for treating the chronic parotitis since 1960's, but the dosage and the histologic changes of the tissues were undefined until now. We try to study the histologic changes of the salivary glands, heart, liver and kidneys after large volume of gentian violet was injected into the parotid gland through the duct. METHODS: 5 ml of Gentian Violet was injected to each side of 6 dogs. The macropathologic and histologic examination of the salivary glands, heart, liver and kidneys were performed at 30 min, 60 min, 120 min, 21 days and 9 months separately after the perfusion. RESULTS: Local swelling was obvious in two or three days after infusion and subsided in one week in most of the dogs. Degeneration of the gland took place after 20 days. After 9 months, the parotid gland tissues were replaced by the connective tissues. On the other hand, no histologic change was observed in heart, liver and kidney in the investigation. CONCLUSION: The Gentian Violet can cause degeneration of the parotid gland including the duct and replaced by connective tissues later. There is no obvious changes were noted in other organs.

Animals↗

PubMed1998

[Subclinical Sjögren's syndrome].

OBJECTIVE: To investigate various manifestations and treatment of subclinical Sjögren's syndrome (SS). METHODS: A long term clinical, laboratory and sialographic observations were performed in 24 patients with subclinical SS. Injectin of thymosin intramusularly was used to treat the patients and clinical effect of this treatment was evaluated. RESULTS: All of 24 cases had experienced recurrent parotid swellings (RPS) for 2-17 years (mean 7 years) before dry mouth and dry eyes occurred and all of them were misdiagnosed as chronic suppurative parotitis or sialadenitis. Follow-up showed that all of these patients developed SS. Vasculitis was found in 8 cases, purpura in 2 cases. The vascular involvement was relatively common in subclinical SS. Main sialographic findings was sialectasis of terminal ducts with irregular dilation of main duct. Frequency of RPS was markedly decreased in the patients treated with thymosin. CONCLUSION: The proposal of subclinical SS has theoretical value for understanding the entity and reclassification of chronic suppurative parotitis, and has guide value for diagnosis and treatment of SS in the early stage. Injection of thymosin is considered an effective therapy to reduce RPS in subclinical SS.

Adolescent↗

PubMed1998

[The effect of pressure on the morphology of superior mesenteric vein in rabbits].

The effect of pressure on the morphology of the superior mesenteric vein of rabbits (SMV) was researched with the method of constant pressure fixation. The results indicate the morphology of SMV is similar to human umbilical cord vein. It looks like the structure of femoral artery of vein in many ways. Under constant pressure fixation (4 kPa), the internal elastic membrane of SMV is straightened, and the wall of SMV becomes thin, with its media thinning from 51.680 microns to 32.3260 microns. The long diameter of nucleus of the smooth muscles decreases from 1.9146 microns to 3.4980 microns, the short diameter of nucleus of the smooth muscles becomes from 0.7884 micron to 0.5228 micron. The direction of the tension on the smooth muscles is mainly longitudinal.

Animals↗

PubMed1998

[The effect of activity of smooth muscles on the relationship of circumferential stress-strain of superior mesenteric veins in rabbits].

The superior mesenteric veins (SMV) of 14 rabbits were divided into two groups for experiment of inflation pressure, namely the normal group and the inactivated smooth muscles group. The results showed that the relationship of circumferential stress-strain of SMV could be expressed with the exponential equation. Constant X2 is effected by the active condition of smooth muscles. The difference of the material constant X2 between the two groups was statistically significant (P < 0.05), but the difference of the material constant X1 between the two groups was not statistically significant (P > 0.05). These suggest that X2 is the parameter concerning the activity of smooth muscles.

Animals↗

PubMed1997

Repair effect of phenylpropanoid glycosides on thymine radical anion induced by pulse radiolysis.

Repair effects on thymine radical anion by six phenylpropanoid glycosides (PPGs), isolated from Pedicularis species, were studied using pulse radiolysis method. The thymine radical anion was produced by the reaction of hydrated electron with thymine. PPGs were added into the thymine solution saturated with N(2). Kinetic analysis showed that transient absorption spectrum of thymine radical anion formed at first, and then after several microseconds of pulse radiolysis changed to that of PPG radical anion. The evidence indicated that thymine radical anion was repaired through one-electron transfer between the radical anion and PPG. Electrophilic phenyl-substituted unsaturated carboxylic group containing in PPGs' structure was able to capture electron from thymine radical anion before it undergo reversible protonation. The reaction rate constants of electron transfer from thymine radical anion to PPGs were within 1.16-2.29 x 10(9) dm(3) mol(-1) s(-1).

Journal Article↗

PubMed1997

t(8;20)(q22;p13): a novel variant translocation of t(8;21) in acute myeloblastic leukaemia.

A novel variant translocation t(8;20)(q22;p13) detected by karyotype analysis of bone marrow cells using R- and G-banding techniques, is reported in a case of M2-acute myeloid leukaemia (AML). The leukaemic cells were indistinguishable morphologically from that of M2-AML with t(8;21)translocation. RT-PCR revealed no AML1/ETO fusion transcript, but the wild-type ETO-3' was expressed in the bone marrow cells suggesting that t(8;20) is a true simple variant translocation of t(8;21), and that a fusion gene consisting of ETO and an unidentified gene located in band 20p13 may exist in our case. Further study is required to clarify the entity of the assumed fusion gene.

Aged↗

PubMed1997

[Plasma and skin tissue endothelin in patients with psoriasis vulgaris].

The levels of plasma endothelin in 46 patients with psoriasis vulgaris and the levels of endothelin in skin tissue of 25 cases were determined by RIA. The results showed that: (1) The plasma levels of endothelin in patients with psoriasis vulgaris was significantly increased compared with that of the controls (P < 0.01), so was the active stage group compared with the stable stage group (P < 0.01); (2) The level of endothelin in skin lesions of patients was significantly higher than that of the uninvolved skin. These findings suggest that endothelin might play a role in the pathogenesis of psoriasis vulgaris.

Adolescent↗

PubMed1997

[Clinical and pathological study on liver fibrosis in viral hepatitis].

49 patients with viral hepatitis were studied on the correlationship between liver fibrosis and the level of serum precollagen type III (PC III), pre-collagen III pre-peptide (P III P), Laminin (LN), hyaluronic acid (HA) and collagen type IV (IV-C), as well as relationship between them and the expression of LN, IV-C, a-smooth muscle actin (a-SMA) and cytokeration (CK) in the liver tissues examined by immunohistochemistry. Results showed that the level of PC III, P III P, LN, HA and IV-C in the groups of liver cirrhosis and chronic severe hepatitis were higher than that in the groups of acute and chronic hepatitis. High correlation was found between the level of these markers (especially the level of the IV-C) and the degree of fibrosis in the group of chronic hepatitis. So were the expression of LN, IV-C, a-SMA and CK in the liver tissue. The results also showed that the liver fibrosis correlated with inflammatory reaction in the liver. So the authors suggested that more attention should be paid to the inflammatory reaction of the liver for prevention and treatment of liver fibrosis.

Adolescent↗

PubMed1997

[In vitro expansion of human umbilical cord blood hematopiotic cells and its subpopulation].

OBJECTIVE: To study the effect of expansion of cord blood stem cells in vitro. METHODS: The mononuclear cells of human umbilical cord blood was cultured in vitro and the cell cycle and CD34+ subset analysis was performed on these cell preparations using flow cytometry. RESULTS: After 35 days, the number of nucleated cells showed over a comulative 252 fold expansion. CD34+ cells increased 50-fold in 7-21 days. CD33+ cells increased 280-fold during 7-28 days. CD19+ and CD34+ cells disappared after 14 days. The cells remained in G0/G1 phase and increased in the S phase. CONCLUSION: Single umbilical cord blood would be enough to transplant to adults if suitable time and a novel expansion strategies are set.

Antigens, CD↗

PubMed1996

Transformation by human papillomavirus 16 E6 and E7: role of the insulin-like growth factor 1 receptor.

Human papillomavirus-16 E6 and E7 inactivate the tumor suppressors p53 and pRB, respectively, and cooperate during malignant transformation, but the downstream molecular events remain incompletely understood. Using fibroblast cell lines derived from mice with a homozygous disruption of the insulin-like growth factor-1 receptor (IGF-1R) gene (R- cells) and their wild-type (WT) littermates, we have stably transfected plasmids encoding E6 and E7 proteins and examined their transforming potential in these cells. Consistent with previous studies using NIH3T3 cells, pooled cultures of E7-transfected WT cells readily formed colonies after suspension in soft agar. In contrast, R- cells were not transformed by E7. E6 had little transforming activity in WT (WT/E6) or R- (R-/E6) cells. However, transfection of R- cells with E6 plus E7 resulted in extensive colony formation. Because IGF-1R and E6 appear to be functionally equivalent in this transformation assay and both have been implicated in antiapoptotic responses, we investigated the apoptotic responses of the cells after exposure to the potent protein kinase C inhibitor, staurosporine. Compared to WT cells, R- cells were relatively resistant to staurosporine-induced apoptosis, but susceptibility to staurosporine was decreased in both WT/E6 and R-/E6 cells relative to WT and R- cells transfected with mock vector, respectively. In fibroblast cells from p53 gene knockout mice, transfection with E6 also conferred relative resistance to staurosporine-induced apoptosis. Our data suggest that transformation by E7 requires the participation of the IGF-1R and that E6 may assist E7 in transforming R- cells by functionally substituting for the IGF-1R. Because IGF-1R activated by its ligands (IGF-1 and IGF-2) protects cells from apoptosis, the role of the IGF-1R and E6 in transformation by E7 is probably related to the recruitment of survival pathways. In addition, because E6 suppressed apoptosis in p53 knockout cells, our data also suggest that E6 may participate in a p53-independent process that protects cells from apoptosis.

Animals↗

PubMed1996

Overexpression of the insulin-like growth factor-1 receptor and autocrine stimulation in human cervical cancer cells.

We characterized mechanisms of growth control involving insulin-like growth factor-1 (IGF-1), IGF-2, and IGF-1 receptor (IGF-1R) by investigating their expression in human cervical cancer cell lines, primary cervical tumor cell cultures, and normal ectocervical epithelial cells maintained in short-term culture. By reverse transcription followed by PCR, IGF-1 mRNA was not detected in any of the cell lines, whereas IGF-2 mRNA transcripts were detected in all of them. Using the RNase protection assay, low levels of IGF-2 mRNA were also detected in all of the cervical cancer cell lines, primary cervical tumor cell cultures, and normal ectocervical cultures tested, but no IGF-1 transcripts were detected. Scatchard analysis revealed 3- and 5-fold increases in IGF-1R expression by the primary cervical cancer cell cultures and cervical cancer cell lines, respectively, compared with the normal ectocervical cells. In proliferation assays, epidermal growth factor (EGF) consistently enhanced cervical cancer cell growth, but an antisense oligonucleotide to IGF-2 uniformly inhibited the EGF-induced mitogenic effect. These studies suggest that autocrine production of IGF-2 and overexpression of the IGF-1R are important components controlling the proliferation of cervical carcinoma cells, and that autocrine IGF-2 production in cervical cancer cells may participate in the mitogenic signaling of EGF.

Base Sequence↗

PubMed1996

Isolation and characterization of retinoic acid-inducible cDNA clones in F9 cells: a novel cDNA family encodes cell surface proteins sharing partial homology with MHC class I molecules.

Rae-1 cDNA is one of the retinoic acid (RA) inducible cDNA clones in mouse embryonal carcinoma F9 cells. Rae-1 mRNAs were detected in mouse early embryos, but not in various tissues of adult mice. RAE-1 protein apparently consists of 253 amino acids and is likely to be a glycoprotein consisting of a leader sequence, an extracellular domain, a serine, threonine, proline-rich domain, and a transmembrane domain. Interestingly, it has a weak, but significant homology with major histocompatibility complex (MHC) class I molecules and was immunocytochemically identified as a cell surface protein. By determining partial nucleotide sequences of 17 Rae-1 cDNAs isolated from the RA-induced F9 cells, at least three different kinds of Rae-1 cDNAs were identified and were named Rae-1 alpha, Rae-1 beta, and Rae-1 gamma cDNAs, respectively. As the overall nucleotide sequence homology among these three cDNAs was about 98%, they constitute a novel gene family which is likely to be involved in early mammalian embryogenesis.

Amino Acid Sequence↗

PubMed1996

A catalogue of genes in mouse embryonal carcinoma F9 cells identified with expressed sequence tags.

We used expressed sequence tags (ESTs) to identify genes expressed in mouse embryonal carcinoma F9 cells and prepared 2132 ESTs from undifferentiated F9 cDNA libraries: 1026 were prepared after randomly selecting clones from one of the libraries and the remaining 1106 ESTs were prepared after classifying 2896 clones of the libraries into four classes, according to the levels and patterns of expression. Among the former 1026 ESTs, 797 (78%) matched known genes, 61 (6%) matched database sequences of uncharacterized cDNAs, and 168 (16%) represented novel genes. The ESTs matching known genes were catalogued according to putative structural and cellular functions. As many as 53% were related to transcription and translation, and 19% were related to energy metabolism, including transcripts of mitochondrial DNA. These percentages were significantly higher in F9 cells than in the human heart and brain, and a human liver cell line, HepG2. We found that approximately 7% of the ESTs corresponding to low-abundance mRNAs are either related to retinoic acid-regulated genes or mammalian development- and/or differentiation-related genes. Cataloguing of the genes expressed in the F9 cells paves the way for isolating genes involved in early mammalian development.

Adult↗

PubMed1996

Genomic structures and characterization of Rae1 family members encoding GPI-anchored cell surface proteins and expressed predominantly in embryonic mouse brain.

Rae1 alpha, Rae1 beta, and Rae1 gamma cDNAs isolated from retinoic acid-treated mouse embryonal carcinoma F9 cells encode cell surface proteins sharing partial homology with MHC class I molecules, and mRNAs corresponding to these cDNAs were detected exclusively in early mouse embryos, especially in the head region. To initiate studies on their roles, the rae1 alpha gene and the genomic DNAs covering the complete coding regions of the rae1 beta and rae1 gamma genes were isolated and their structures were analyzed. Although the coding regions of the three rae1 genes were highly homologous, the restriction map of the 5'-end region of the rae1 alpha gene differed from that of the rae1 beta and rae1 gamma genes. The rae1 family members were mapped by FISH on mouse chromosome 10A4 region. Genomic DNAs hybridizable with a Rae1 cDNA were not detected in rat and human. Rae1 genes were preferentially expressed in early mouse embryos, preferentially in the brain, and RAE1 proteins were anchored on the cell surface by a glycosyl phosphatidylinositol (GPI)-tail, a feature shared by important cell surface ligands.

Animals↗

PubMed1996

Chronic suppurative parotitis: a proposed classification.

OBJECTIVE: To propose a practical and reasonable classification of chronic suppurative parotitis (CSP) on the basis of the various entities. MATERIAL AND METHODS: Clinical, laboratory, sialographic, scintigraphic, histopathologic (including ultrastructural) study of recurrent parotid swellings (RPS) was performed in 291 patients over a 10-year period. RESULTS: It is suggested that CSP should be classified into recurrent parotitis in childhood (RPC), recurrent parotitis in adults (RPA), chronic obstructive parotitis (COP) and should be differentiated from other subdivisions including subclinical Sjögren's syndrome (SCSS), chronic parotid swelling of Sjögren's syndrome and sialadenosis with retrograde infection. RPA is a continuation of recurrent parotid swelling from childhood (RPC) to adulthood. Remission can take place spontaneously in RPC and RPA so that self-conservative therapy is mainly used for reducing the parotid swellings. COP is recurrent parotid swellings and/or purulent discharge resulting from various obstructive factors. Mild COP can recover completely with the use of conservative methods, severe COP is often resistant to conservative treatment and should be treated with surgical modality or injection of methyl violet into the diseased gland. Treatment with methyl violet is considered as a convenient and practical method with a definite effect. SCSS is an autoimmune disease and should be treated as systemic disease. CONCLUSIONS: Because there exists confusion in the nomenclature of RPS this revised classification is based on the various entities and can be used as a guide in the diagnosis and treatment of RPS.

Adolescent↗