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Biomedical subjects

C Zhou

Publications and source records attributed to C Zhou.

At least 91 records · Page 5Linked to original sources
PubMed2000

[Clinical observation on effect of yixin yidu decoction in treating acute viral myocarditis].

OBJECTIVE: To observe the effect of Yixin Yidu Decoction (YXYDD, self-formulated according to the TCM therapeutic principle of supplementing Qi and Yin, clearing away evil Heat and toxic substances) in treating acute viral myocarditis (AVM). METHODS: Seventy-six patients of AVM were randomly divided into 2 groups, the 40 patients in the treated group were treated with YXYDD and the 36 patients in the control group treated with Qidong Yixin Oral Liquid (QDYX), the therapeutic course for both groups was 4 weeks. RESULTS: YXYDD was more effective than QDYX in improving clinical symptoms, adjusting the abnormal ECG, lowering the serum level of myocardial enzymes, improving the cardiac function of left ventricle and regulating the T-cell immunity (elevation of CD3, CD4 and CD4/CD8 ratio). CONCLUSION: YXYDD is an effective medicine in treating AVM.

Adolescent↗
PubMed2000

[CT anatomic measurement of the optic canal and its clinical significance].

OBJECTIVE: To probe into the normal anatomy of the optic canal and its clinical significance. METHODS: The optic canals of 200 normal subjects were examined by thin layer CT scan in axial nd coronal positions. The distance and anatomic relationship with circumferentral structure were measured. RESULTS: In average: (1) The transverse diameter of the optic canal was (3.57 +/- 0.61) mm, the longitudinal diameter was (4.82 +/- 0.38) mm, the length of the inner wall was (12.62 +/- 2.59) mm, the length of the outer wall was (10.18 +/- 2.19) mm, and the length of the optic canal was (11.46 +/- 2.35) mm. The angle between optic canal and the middle line of the skull was 34.34 degrees +/- 6.48 degrees, the angle between optic canal and the intraorbital optic was 10.69 degrees +/- 6.48 degrees. The thickness of the inner wall was (0.68 +/- 0.46) mm. It showed no significant difference between the two sides of the optic canal in diameters(P > 0.05). (2) The optic canal, the superior orbital fissure and the inferior orbital fissure were respectively shown as track, crack and gorge type in CT axial pictures, while in the coronal pictures, they were respectively shown as butterfly eyes, horizontal fissure and vertical fissure type. (3) The relationship of the posterior ethmoid sinus and the optic canal was: anterocanal(42.00%), semicanal(27.5%), whole-canal(18.75%), sella turcica(9.75%) and circumcanal(2.00%). (4) The relationship of the position of the sphenoidal sinus and the optic canal was: I degree sphenoidal sinus(20%), II degree (63%) and III degree (17%). (5) The incidence of the bony defect of the inner optic canal wall was 25.5%. The range of the defect was (5.07 +/- 2.52) mm. CONCLUSION: It's a reliable way to show the relation of the optic canal and circumcanal by CT, and it is of important value in operation.

Adolescent↗
PubMed2000

[Intracytoplasmic injection with sperm from ejaculation, epididymis and testis in treating different male infertility with oligo-asthenozoospermia or azoospermia ].

OBJECTIVE: To retrospectively study 400 intracytoplasmic sperm injection (ICSI) cycles by using three different sources of sperm. METHOD: Different male infertility with oligo-asthenozoospermia or azoospermia was treated by ICSI using sperm from ejaculation, epididymis and testis. RESULTS: In the ejaculation group (n = 277), the fertilization rate was 69.6% and the clinical pregnancy rate 28.9%. In the 104 cycles using epididymal sperm, the fertilization and clinical pregnancy rate was 65.9% and 37.5% respectively. And the fertilization and clinical pregnancy of testis sperm (n = 19) was 65.7% and 21.1%. The difference of fertilization and clinical pregnancy rate among the three groups were not significant. CONCLUSIONS: Male infertility of different causes can be treated by ICSI. The outcome has nothing to do with the common parameter of semen except that the sperm motility is 0, but the effectiveness of ICSI should be studied by long-term observation.

Adult↗
PubMed2000

[High temperature Raman spectra and micro-structure study of lithium metaborate and its melt].

Lithium metaborate (LiBO2) is studied by high temperature Raman spectroscopy from room temperature up to 1,673 K, and spectra drawing in different temperature are got. By analyzing, it focus on the phase transition, it is that the endless chains of BO3 triangles transform into rings of (B3O6)3- at about 1,123 K, and then the different kind of phase balance's motion occurs after 1,273 K which implies that both endless chain and ring have changed to CRN. In the drawing, the variation of peak's area rate implies the micro-structure information, and shows the process from order to disorder.

English Abstract↗
PubMed1999

Induction of apoptosis by cadmium and the adeno-associated virus Rep proteins.

The parvoviruses exert antiproliferative effects on transformed cells in culture. The development of cell lines that inducibly express the parvovirus nonstructural proteins have implicated these proteins in the limitation of cell growth. To study the host cell interactions of the nonstructural proteins we have developed a human 293 cell line that expresses the adeno-associated virus (AAV) rep gene upon induction with heavy metal salts. When induced with both Zn(2+) and Cd(2+), Rep protein expression correlates with a cell cycle block in S phase (Yang, Q., Chen, F., and Trempe, J. P. (1994). J. Virology 68,7169-7177). However when induced with Cd(2+) alone, the Rep proteins are expressed and the cells are killed. Production of a nucleosomal DNA repeat pattern and degradation of poly-ADP ribose polymerase (PARP) suggest that killing occurs by apoptosis. These results demonstrate that AAV Rep protein expression in chemically stressed cells is cytotoxic due to induction of apoptotic pathways.

Apoptosis↗
PubMed1999

A clinical trial of retroviral-mediated transfer of a rev-responsive element decoy gene into CD34(+) cells from the bone marrow of human immunodeficiency virus-1-infected children.

Genetic modification of hematopoietic stem cells with genes that inhibit replication of human immunodeficiency virus-1 (HIV-1) could lead to development of T lymphocytes and monocytic cells resistant to HIV-1 infection after transplantation. We performed a clinical trial to evaluate the safety and feasibility of this procedure, using bone marrow from four HIV-1-infected pediatric subjects (ages 8 to 17 years). We obtained bone marrow, isolated CD34(+) cells, performed in vitro transduction with a retroviral vector carrying a rev-responsive element (RRE) decoy gene, and reinfused the cells into these subjects with no evidence of adverse effects. The levels of gene-containing leukocytes in peripheral blood samples in the 1 year after gene transfer/cell infusion have been extremely low. These observations support the potential of performing gene therapy for HIV-1 using hematopoietic cells, but emphasize the need for improved gene transfer techniques.

Acquired Immunodeficiency Syndrome↗
PubMed1999

Molecular cloning and characterization of a novel developmentally regulated gene, Bdm1, showing predominant expression in postnatal rat brain.

Postnatal development, such as synapse refinement, is necessary for the establishment of a mature and functional central nervous system (CNS). Using differential display analysis, we identified a novel gene, termed Bdm1, that is more abundantly expressed in the adult brain than in the embryonic brain. The full-length Bdm1 cDNA is 2718 base pairs long and contains an open reading frame of 1059 base pairs encoding a 38-kDa protein. Northern blot analysis revealed that expression of Bdm1 mRNA in the brain was weak on embryonic days and increased in the early postnatal period. Bdm1 mRNA was significantly expressed in the brain and heart, but there was no or little expression in other tissues. During the differentiation of mouse carcinoma cells P19 to neuron-like cells by retinoic acid, Bdm1 mRNA was up-regulated almost parallel to neurofilament mRNA. Expression of Bdm1 mRNA was observed appreciably in PC12 cells after neuronal differentiation but not in the nonneural cell lines examined. In situ hybridization demonstrated that Bdm1 was expressed widely in the olfactory bulb, cerebral cortex, hippocampus, cerebellum, thalamus, and medulla oblongata. Taken together, these data suggest that Bdm1 gene plays a role in the early postnatal development and function of neuronal cells.

Amino Acid Sequence↗
PubMed1999

Enhancement of UV-induced cytotoxicity by the adeno-associated virus replication proteins.

Adeno-associated virus (AAV) normally requires co-infection of a helper virus to complete its life cycle. However, under conditions of cellular stress, such as treatment with carcinogens or ultraviolet (UV) light, a permissive intracellular environment is established and AAV completes its replicative cycle producing low levels of progeny virus. AAV DNA replication is dependent upon viral replication proteins, Rep78 and Rep68. The detailed mechanism by which these proteins interact with host cell factors is unknown. We have used a cell line (Neo6) that inducibly expresses the AAV Rep proteins to study their effects on cells that have undergone UV-induced DNA damage. Induction of Rep protein expression immediately after a sub-lethal dose of UV irradiation resulted in rapid cell killing. Those cells that die had chromatin condensation while cellular membranes remained intact, suggesting that concurrent Rep expression and UV damage induces an apoptosis-like response. However, we did not observe any DNA degradation. Thus we believe that the combination of Rep expression and UV irradiation induces cell death that shares some of the characteristics of apoptosis. UV irradiation and Rep expression induced an increase in the level of the CDK inhibitor, p21Cip, and the appearance of modified forms of both p21Cip and Bcl-2. Alteration of normal expression of these cytostatic/apoptotic proteins provides insight into the intracellular targets of the AAV replication proteins.

Apoptosis↗
PubMed1999

A 20-kDa domain is required for phosphatidic acid-induced allosteric activation of phospholipase D from Streptomyces chromofuscus.

Two phospholipase D (PLD) enzymes with both hydrolase and transferase activities were isolated from Streptomyces chromofuscus. There were substantial differences in the kinetic properties of the two PLD enzymes towards monomeric, micellar, and vesicle substrates. The most striking difference was that the higher molecular weight enzyme (PLD57 approximately 57 kDa) could be activated allosterically with a low mole fraction of phosphatidic acid (PA) incorporated into a PC bilayer (Geng et al., J. Biol. Chem. 273 (1998) 12195-12202). PLD42/20, a tightly associated complex of two peptides, one of 42 kDa and the other 20 kDa, had a 4-6-fold higher Vmax toward PC substrates than PLD57 and was not activated by PA. N-Terminal sequencing of both enzymes indicated that both components of PLD42/20 were cleavage products of PLD57. The larger component included the N-terminal segment of PLD57 and contained the active site. The N-terminus of the smaller peptide corresponded to the C-terminal region of PLD57; this peptide had no PLD activity by itself. Increasing the pH of PLD42/20 to 8.9, followed by chromatography of PLD42/20 on a HiTrap Q column at pH 8.5 separated the 42- and 20-kDa proteins. The 42-kDa complex had about the same specific activity with or without the 20-kDa fragment. The lack of PA activation for the 42-kDa protein and for PLD42/20 indicates that an intact C-terminal region of PLD57 is necessary for activation by PA. Furthermore, the mechanism for transmission of the allosteric signal requires an intact PLD57.

Allosteric Site↗
PubMed1999

Cytologic features of villoglandular adenocarcinoma of the uterine cervix: comparison with typical endocervical adenocarcinoma with a villoglandular component and papillary serous carcinoma.

BACKGROUND: To the authors' knowledge, the cytologic features of villoglandular adenocarcinoma (VGC) have been described in very few publications. The malignant cells are difficult to separate from reactive glandular cells and the majority of VGCs are missed on screening cytology. METHODS: The cytologic findings of a retrospective study of four cases of pure VGC are described and are contrasted with those of papillary serous adenocarcinoma and typical mucinous endocervical adenocarcinoma with a focal component of VGC. RESULTS: Although atypical glandular cells of endocervical origin were reported when the smears from the VGC cases were examined in the screening program, none of the cases was recognized as malignant prior to histologic diagnosis. The smears showed many groups of endocervical glandular cells. Important architectural features included large cohesive groups and sheets of cells showing nuclear crowding and loss of the normal honeycomb pattern. True papillary structures comprising stromal cores covered by well polarized columnar cells with a smooth surface were characteristic. It is important to note that a "feathered edge" appearance of the cell groups was absent. The neoplastic cells were mildly atypical, showing a slight increase in the nuclear-cytoplasmic ratio but minimal hyperchromatism. The cytology smears of four cases of typical adenocarcinoma of endocervical type that had a focal VGC pattern showed cell groups with irregular borders and "feathered" edges comprised of distinctly atypical columnar cells with elongated and irregular hyperchromatic nuclei. Free-lying atypical cells and ball-like clusters of atypical cells also were present in the latter cases but not in pure VGCs. The primary high grade papillary serous adenocarcinomas of the cervix exhibited extreme cytologic atypia that was interpreted readily as malignant. CONCLUSIONS: The diagnosis of VGC on cytology smears often is missed. Papillary fragments, nuclear crowding, and subtle atypia may suggest the diagnosis.

Adenocarcinoma, Papillary↗
PubMed1999

Action of phosphatidylinositol-specific phospholipase Cgamma1 on soluble and micellar substrates. Separating effects on catalysis from modulation of the surface.

The kinetics of PI-PLCgamma1 toward a water-soluble substrate (inositol 1,2-cyclic phosphate, cIP) and phosphatidylinositol (PI) in detergent mixed micelles were monitored by 31P NMR spectroscopy. That cIP is also a substrate (Km = approximately 15 mM) implies a two-step mechanism (intramolecular phosphotransferase reaction to form cIP followed by cyclic phosphodiesterase activity to form inositol-1-phosphate (I-1-P)). PI is cleaved by PI-PLCgamma1 to form cIP and I-1-P with the enzyme specific activity and ratio of products (cIP/I-1-P) regulated by assay temperature, pH, Ca2+, and other amphiphilic additives. Cleavage of both cIP and PI by the enzyme is optimal at pH 5. The effect of Ca2+ on PI-PLCgamma1 activity is unique compared with other isozymes enzymes: Ca2+ is necessary for the activity and low Ca2+ activates the enzyme; however, high Ca2+ inhibits PI-PLCgamma1 hydrolysis of phosphoinositides (but not cIP) with the extent of inhibition dependent on pH, substrate identity (cIP or PI), substrate presentation (e.g. detergent matrix), and substrate surface concentration. This inhibition of PI-PLCgamma1 by high Ca2+ is proposed to derive from the divalent metal ion-inducing clustering of the PI and reducing its accessibility to the enzyme. Amphiphilic additives such as phosphatidic acid, fatty acid, and sodium dodecylsulfate enhance PI cleavage in micelles at pH 7.5 but not at pH 5.0; they have no effect on cIP hydrolysis at either pH value. These different kinetic patterns are used to propose a model for regulation of the enzyme. A key hypothesis is that there is a pH-dependent conformational change in the enzyme that controls accessibility of the active site to both water-soluble cIP and interfacially organized PI. The low activity enzyme at pH 7.5 can be activated by PA (or phosphorylation by tyrosine kinase). However, this activation requires lipophilic substrate (PI) present because cIP hydrolysis is not enhanced in the presence of PA.

Animals↗
PubMed1999

Isolation, cloning, and characterization of a new mammalian coronin family member, coroninse, which is regulated within the protein kinase C signaling pathway.

In order to understand the regulatory role of protein kinase C (PKC) in secretory epithelia, it is necessary to identify and characterize specific downstream targets. We previously identified one such protein in studies of gastric parietal cells. This protein was referred to as pp66 because it migrated with an apparent molecular mass of 66 kDa on SDS-polyacrylamide gels. The phosphorylation of pp66 is increased by the cholinergic agonist, carbachol, and by the PKC activator, phorbol-12-myristate-13-acetate, in a calcium-independent manner. In this study, we have purified pp66 to homogeneity and cloned the complete open reading frame. GenBankTM searches revealed a 45% homology with the Dictyostelium actin-binding protein, coronin, and approximately 67% homology with the previously cloned human and bovine coronin-like homologue, p57. pp66 appears to be most highly expressed in the gastrointestinal mucosa and in kidney and lung. Confocal microscopic studies of an enhanced green fluorescent protein fusion construct of pp66 in cultured parietal cells and in Madin-Darby canine kidney cells indicate that pp66 preferentially localizes in F-actin-rich regions. On the basis of our findings, we propose that pp66 may play an important, PKC-dependent role in regulating membrane/cytoskeletal rearrangements in epithelial cells. We have tentatively named this protein coroninse, because it appears to be highly expressed in secretory epithelia.

Amino Acid Sequence↗
PubMed1999

Low-risk endometrial carcinoma: assessment of a treatment policy based on tumor ploidy and identification of additional prognostic indicators.

OBJECTIVES: The aims of this study were (1) to assess a treatment policy for patients with low-risk endometrioid endometrial carcinoma where adjuvant treatment decisions have been based on ploidy status of the tumor, and (2) to screen diploid, low-risk tumors for additional features of prognostic significance. METHODS: Between 01/1992 and 08/1996, 406 patients were referred to the B.C. Cancer Agency-Vancouver Clinic with typical endometrial adenocarcinomas limited to <50% myometrial invasion and no vascular space invasion or grade 3 disease on pathology review ("low-risk stage I endometrial carcinoma"). Patients were prospectively assigned to treatment groups based on tumor ploidy. Those patients with aneuploid tumors (n = 91) were treated with adjuvant vaginal vault radiotherapy while those with diploid tumors (n = 315) were followed and treated only at relapse. The hysterectomy specimens from all 14 patients in the untreated, diploid group who relapsed, as well as 28 stage- and grade-matched diploid controls who did not fail, were analyzed by immunohistochemical staining for estrogen receptor (ER), Bcl-2, and p53 proteins. RESULTS: There were no significant differences in the stage (Ia vs Ib) and grade (G1 vs G2) distribution for the diploid and aneuploid groups. Overall median age was 64 years (range 27-90 years) and was also not significantly different for the two groups. The median follow-up for the entire cohort is 45 months (range 1-76 months). There have been 14 failures in the diploid group and 4 failures in the aneuploid group with actuarial 5-year disease-free survival rates of 95.0 and 95.2%, respectively (P = NS). Eight of the failures in the diploid group occurred at the vaginal vault and were all subsequently salvaged with radiotherapy. All but 1 of the failures in the aneuploid group were considered incurable. Of the 14 diploid tumors from patients who failed, 7 stained positively for p53, compared to 4 of 28 diploid controls (P = 0.02). No significant differences were seen in the diploid tumors that recurred, compared to controls, with respect to Bcl-2 or ER expression. CONCLUSIONS: Patients with diploid, low-risk stage I endometrial cancers have excellent prospects for relapse-free and overall survival. Patients with aneuploid tumors treated with adjuvant radiotherapy have the same risk of relapse as untreated patients with diploid tumors; however, their ultimate survival may be lower as a smaller proportion of aneuploid failures are salvageable. While p53 expression in diploid tumors is associated with increased risk of relapse, Bcl-2 and ER are not useful prognostic indicators in this setting.

Adult↗
PubMed1999

The Electronic Structure and Spectrum of RhC: New Bands in the 400-500 nm Region, Interacting (2)Sigma(+) and (2)Pi States, and Deperturbation.

Rhodium monocarbide (RhC) molecules were generated using a laser ablation/supersonic molecular beam source. Laser-induced and dispersed-fluorescence (DF) techniques were used to study the visible spectrum between 400 and 530 nm. Rh(12)C/Rh(13)C isotope shifts, DF, and excited level lifetime measurements assisted in classifying the observed bands into three series: the known C(2)Sigma(+) <-- X(2)Sigma(+) system (short excited state lifetimes) and the two spin subsystems of a (2)Pi(i) <-- X(2)Sigma(+) transition (long excited state lifetimes). A time-filtering technique was employed to separate effectively emission from close-lying (2)Pi and C(2)Sigma levels. The C-X system is inherently strong; the (2)Pi(i) <-- (2)Sigma(+) system very weak. The (2)Pi(1/2) <-- (2)Sigma component is identified with the B-X system, previously taken to be of (2)Sigma(+) <-- (2)Sigma(+) symmetry. The (2)Pi(3/2) component gives rise to local perturbations in the C state. Many new bands in the (2)Pi(i) <-- X(2)Sigma(+) transition were recorded and analyzed and the interactions/perturbations among the (2)Sigma(+) and the newly established (2)Pi(i) states were examined in detail. We calculated many spectroscopic constants and other properties associated with the perturbed (mixed) levels of the (2)Pi(1/2) and (2)Sigma(+) states and compared them with the experimental data. In most of the comparisons, the calculated values are in quantitative agreement with the experimental ones. Calculations of the spin-rotation constants of the (2)Sigma(+) and the Lambda-doubling constants of the (2)Pi(1/2) suggest the involvement of remote perturbers. Theory and experiment suggest that the electronic state labels of Scullman and Kaving [J. Mol. Spectrosc. 32, 475 (1969)], i.e., A(2)Pi(r), B(2)Sigma(+), C(2)Sigma(+), and D(2)Sigma(-), should be relabeled B(2)Pi(r), D(2)Pi(3/2), E(2)Sigma(+), and D(2)Pi(1/2), respectively. Copyright 1999 Academic Press.

Journal Article↗
PubMed1999

Progress toward positional cloning of ovine neuronal ceroid lipofuscinosis, a model of the human late-infantile variant CLN6.

The neuronal ceroid lipofuscinoses (NCLs) are lysosomal storage diseases with severe neurodegenerative pathology. An ovine model (OCL) has well-defined parallels with the human disease at the biochemical and pathological levels. The gene for OCL is located in the chromosomal region OAR7q13-15. This region is syntenic with HAS15q21-23, suggesting that OCL and CLN6 represent mutations in orthologous genes. New microsatellite markers have been developed enabling further refinement of the OCL critical region.

Animals↗
PubMed1999

Blood-compatibility of polyurethane/liquid crystal composite membranes.

Polyurethane/liquid crystal composite membranes were first suggested to be used as biomaterials. In our work, three series of polyurethane/liquid crystal composite membranes based on three different kinds of liquid crystal compounds [N-(-4-methyoxybenzylidene)-4'-heptylaniline, 4-pentyl-4'-nitrile-biphenyl and cholesteryl oleyl carbonate] were prepared by casting on glass plates from a tetrahydrofuran (THF) solution of polymer and liquid crystal at room temperature. In our opinion, the formation of liquid crystal phase on the composite membrane surface is the basic requirement for getting better biomaterial. The result of this work is in accordance with our opinion. The effect of liquid crystal content on the formation of liquid crystal phase was identified by the observation of optical polarization microscopy (OPM). The results showed that the content of liquid crystal in composite membrane must be more than 30% (wt) in order to form liquid crystal phase on the composite membrane surface. The blood-compatibility of the composite membranes was assessed from SEM observation of the platelet's adhesion to membrane's surface, blood clotting time and haemolysis ratio. The observation of platelet's adhesion showed that the platelets gathered together on the pure polyurethane films, but the amount of platelets which were adherent on the surface covered by the liquid crystal phase was fewer than that of pure polyurethane film when platelet-rich plasma was allowed to be in contact with the membranes for 1 h at room temperature. The determination of blood clotting time and haemolysis ratio showed that these polyurethane/liquid crystal composite membranes, in which the content of liquid crystal was more than 30% (wt), appear to be beneficial in improving the blood compatibility and reducing the thrombogenicity.

Biocompatible Materials↗
PubMed1999

The nuclear orphan receptor COUP-TFI is required for differentiation of subplate neurons and guidance of thalamocortical axons.

Chicken ovalbumin upstream promotor-transcription factor I (COUP-TFI), an orphan member of the nuclear receptor superfamily, is highly expressed in the developing nervous systems. In the cerebral cortex of Coup-tfl mutants, cortical layer IV was absent due to excessive cell death, a consequence of the failure of thalamocortical projections. Moreover, subplate neurons underwent improper differentiation and premature cell death during corticogenesis. Our results indicate that the subplate neuron defects lead to the failure of guidance and innervation of thalamocortical projections. Thus, our findings demonstrate a critical role of the subplate in early corticothalamic connectivity and confirm the importance of afferent innervation for the survival of layer IV neurons. These results also substantiate COUP-TFI as an important regulator of neuronal development and differentiation.

Animals↗