Biomedical subjects

P Zou

Publications and source records attributed to P Zou.

At least 19 recordsLinked to original sources

PubMed2006

Diffusion tensor imaging of tract involvement in children with pontine tumors.

BACKGROUND AND PURPOSE: Conventional MR imaging permits subcategorization of brain stem tumors by location and focality; however, assessment of white matter tract involvement by tumor is limited. Diffusion tensor imaging (DTI) is a promising method for visualizing white matter tract tumor involvement supratentorially. We investigated the ability of DTI to visualize and quantify white matter tract involvement in pontine tumors. METHODS AND MATERIALS: DTI data (echo-planar, 1.5T) were retrospectively analyzed in 7 patients with pontine tumors (6 diffuse, 1 focal), 4 patient controls, and 5 normal volunteers. Fractional anisotropy (FA) and apparent diffusion coefficient (ADC) were calculated from the diffusion tensor in 6 regions of interest: bilateral corticospinal tracts, transverse pontine fibers, and medial lemnisci. Relationships between FA and ADC values and results of the neurologic examinations were evaluated. RESULTS: The corticospinal tracts and transverse pontine fibers were affected more often than the medial lemnisci. The DTI parameters (FA and ADC) were significantly altered in all tracts of patients with pontine tumors (P < .05), compared with those values in the control groups. A marginally significant (P = .057) association was seen between the severity of cranial nerve deficit and decreased FA. CONCLUSION: DTI provided superior visualization and quantification of tumor involvement in motor, sensory, and transverse pontine tracts, compared with information provided by conventional MR imaging. Thus, DTI may be a sensitive measure of tract invasion. Further prospective studies are warranted to assess the ability of DTI to delineate tumor focality and improve risk stratification in children with pontine tumors.

Adolescent↗

PubMed2005

Chemical fingerprinting of Isatis indigotica root by RP-HPLC and hierarchical clustering analysis.

The aim was to establish a method for extraction and chemical fingerprinting of extracts of Isatis indigotica roots ("Ban-Lan-Gen") and to apply the method developed to 18 Ban-Lan-Gen samples. RP-HPLC with gradient elution was performed on authentic reference standards of powdered I. indigotica roots, indigotin and indirubin purchased from the National Institute for the Control of Pharmaceutical and Biological Products (NICPBP) of China. Eighteen "Ban-Lan-Gen" samples (including the reference powdered herb) were bought from Singapore and different regions in China. Comparisons of the chromatograms showed that the samples can be divided into three groups. The chromatograms of the extracts of five samples were found to be similar to that of the extract of the authentic sample. Eight other samples had similar peaks as the authentic sample but the intensities of the peaks were generally lower, except for the peaks between retention times of 10-40 min. Peaks in these regions were more intense than those found in the extract of the authentic sample. Forty-five characteristic peaks could be found in the extracts of all the above samples. Peaks at retention times 52 and 53 min were determined to be indigotin and indirubin, respectively. The remaining four samples had similar chemical fingerprints to each other but were different from that of the authentic sample. Hierarchical clustering analysis gave similar results as the visual comparison. The RP-HPLC method developed allows simple identification and comparisons of I. indigotica roots. This is the first report of hierarchical clustering analysis of I. indigotica root.

Chromatography, High Pressure Liquid↗

PubMed2003

Kaposi's sarcoma-associated herpesvirus (KSHV)-encoded vMIP-I and vMIP-II induce signal transduction and chemotaxis in monocytic cells.

Kaposi's sarcoma-associated herpesvirus (KSHV)/ Human herpesvirus 8 encodes three chemokines, which are called viral macrophage inflammatory protein (vMIP)-I, -II, and -III. Here, we expressed the KSHV vMIP-I and vMIP-II proteins and analyzed their biological functions. Both vMIP-I and vMIP-II had an apparent molecular mass of 7.8 kDa and were localized to the cytoplasm in a body cavity-based lymphoma cell line BC-3, stimulated with phorbol ester. We next treated a human monocytic leukemia cell line, THP-1, with purified recombinant vMIP-I and vMIP-II, or vMIP-I and vMIP-II fused with alkaline phosphatase to study Ca(2+) signalling and in vitro chemotaxis in response to these proteins. Calcium mobilization was induced by both vMIP-I and vMIP-II. Furthermore, vMIP-I and vMIP-II induced Ca(2+) mobilization in K562 cells expressing the CC chemokine receptor 5 (CCR5), suggesting that both may be agonistic for CCR5. Additionally, vMIP-I induced Ca(2+) mobilization through the intermediary of CCR8. These viral MIPs were also capable of chemotactically activating the THP-1 cells. These results imply that vMIP-I and vMIP-II may play important roles in the propagation of KS and primary effusion lymphoma by inducing the chemotaxis of CCR5-expressing monocytes.

Calcium↗

PubMed2001

Application of CD45/SSC gating multiparameter flow cytometry in the classification of acute leukemia--an analysis of 139 cases.

In order to study the significance of flow cytometry immunophenotyping in the diagnosis of acute leukemia, CD45/SSC gating multiparameter flow cytometry (FCM) was utilized to analyze the immunophenotypes of 139 cases of acute leukemia. 139 cases of acute leukemia were enrolled in our hospital from April 1998 to April 2000. Morphological analysis and FCM immunophenotypic tests were conducted on all cases. Our results showed that CD45/SSC gating multiparameter flow cytometry immunophenotyping could reflect the origin of leukemic cells specifically. It is one of the important methods for the diagnosis of ALL, AML, and HAL. CD45/SSC gating multiparameter FCM analysis is a good technique for immunophenotyping. FCM immunophenotypic analysis can help improve the diagnosis and classification of acute leukemia, and extend the use of FCM in clinical practice.

Adolescent↗

PubMed2001

The effect of the Fas/FasL pathway during chemotherapeutic drug-induced apoptosis of leukaemeic cells.

The mechanism of chemotherapeutic drug-induced apoptosis in leukaemic cells was studied to further investigate whether Fas/FasL system was involved in apoptosis induced by chemotherapeutic drugs and assess their effects when used in combination with soluble FasL (sFasL). The expression of Fas on human leukaemic cell lines K562, HL-60 and U937 treated with daunorubicin (DNR) or cytosine arabinoside (Ara-C) was detected by using flow cytometry. The activities of sFasL, DNR and Ara-C inducing apoptosis of leukaemic cells, in the absence or presence of neutralizing anti-Fas IgG antibody, were detected by using flow cytometry and TUNEL. The results showed that flow cytometric profiles of K562, HL-60 and U937 cells treated with DNR or Ara-C failed to show any significant increase in Fas expression over 18 h (P > 0.05). Anti-Fas monoclonal antibody (IgG) could not block the apoptosis in leukaemic cells induced by DNR or Ara-C, but could block the apoptosis induced by sFasL. A role of sFasL in a cytotoxic synergistic effect when used in combination with chemotherapeutic drugs was revealed. It was concluded that chemotherapeutic drug-induced apoptosis in human leukaemic cells (UG37, HL-60) is independent of the Fas/FasL system, but combination of sFasL and drug treatment produces a synergistic cytotoxic effect on human leukaemic cells.

Apoptosis↗

PubMed2001

Bioactivities of culture supernatants from retroviral packaging cells carrying the mouse Fas ligand gene.

The bioactivities of culture supernatants from retroviral packaging cells carrying the mouse Fas ligand (mFasL) gene was investigated. FasLcDNA was cloned into PLXIN with an internal ribosome entry site to link two cistrons through gene recombination technology, PLXIN and the recombinant vector PLFIN were separately transfected into PA317 retrovirus packing cell line by lipofectamine 2000, and the resistant clones were selected with G418 selective medium. The integration of genome DNA was assayed by genomic DNA PCR. NIH3T3 cells were transduced by the culture supernatants from PA317 carrying the mFasLcDNA gene, and were selected with G418 selective medium, so as to select the PLFIN-PA317 clone capable of producing higher titer of supernatants. The levels of mFasL protein on NIH3T3 cells membrane were assayed by flow cytometry (FCM). The biological activity of mFasL on NIH3T3 cells membrane was investigated by the inducing apoptosis of Fas+ Yac-1 cells co-cultured with NIH3T3 cells expressing Fas ligand. To explore the direct mFasL cytotoxicity of culture supernatants from retroviral packaging cells carrying the mFasL gene, the culture supernatants from PLFIN-PA317 and PLXIN-PA317 were separately co-cultured with Yac-1 cells in parallel. The recombinant PLFIN was successfully constructed. The highest titer of supernatants from twelve resistant clones was 8.5 x 10(5) colony-forming-unit (CFU)/ml. The NIH3T3 cells transfected by above supernatants had a higher level of mFasL (53.81 +/- 6.9%), and significantly induced the apoptosis of Fas+ Yac-1 cells (56.78 +/- 4.5%), as both were cocultured for 5 h at 1:1 ratio, whereas it is 7.08 +/- 3.4% in control group (P < 0.01). Supernatant from PLFIN-PA317 could also directly induce the apoptosis of Yac-1 within 5 h of incubation. Thus, the culture supernatants from PLFIN-PA317 possessed both infectivity and cytotoxicity of mFasL.

3T3 Cells↗

PubMed2001

Effect of antisense oligodeoxynucleotide directed to NF-kappa B-RelA on Bcl-XL mRNA in extended drug resistance leukemia cell line HL-60/E6.

To explore the effect of NF-kappa B on bcl-x gene transcription in extended drug resistance leukemia cell line HL-60/E6, drug-resistant subline HL-60/E6 was derived by intermittently exposing HL-60 cells to 6 ng/ml epirubicin. Indirect immunofluorescence was used to demonstrate the location of NF-kappa B-RelA in HL-60/E6 cells. FCM analysis and RT-PCR were used to detect the efficiency of liposome-mediated ODN transfection and the change of bcl-XL mRNA levels after 5 mumol/L phosphorothioate (PS)-derivatized antisense (AS) oligodeoxynucleotide (ODN) directed to RelA was transferred into HL-60/E6 cells. The results showed that RelA remained persistently active and located at the nuclei of HL-60/E6 cells, but in the cytoplasm of HL-60 cells, the efficiency of liposome-mediated ODN transfection was significantly higher than that of null ODN (P < 0.01 in 4 h, 6 h, 12 h, 24 h). Exposure of HL-60/E6 cells to 5 mumol/L AS-PS-ODN directed to RelA led to a maximal 40% decline of bcl-XL mRNA levels within 8 h. The inhibition rate of bcl-XL mRNA was (15 +/- 1.79)%, (28 +/- 2.34)%, (40 +/- 3.47)%, (20 +/- 1.54)%, in 4 h, 6 h, 8 h, 15 h, respectively, but it was less than 15% in control group. It was concluded that NF-kappa B was involved in regulating bcl-x transcription. It was suggested that NF-kappa B was an important factor for drug resistance in leukemia cells.

Apoptosis↗

PubMed2001

Biology, life table and host specificity of the mushroom pest, Brennandania lambi (Acari: Pygmephoroidea).

Biology and life table parameters of Brennandania lambi (Krczal) were studied at different temperatures while feeding on white mushroom (Agaricus bisporus) mycelium cultured on mushroom compost. The duration of egg and larva development, preoviposition and oviposition period, female longevity, and the time to 50% mortality declined as temperature increased from 16 to 28 degrees C. The threshold temperature of development (female) was 9 degrees C and the thermal constant for completion of development (female) was 195 day-degrees. At 16, 20. 24 and 28 degrees C, the total fecundity (eggs/female) was 71, 67, 66 and 57, respectively and the daily fecundity rate (eggs/female/day) was 5.6, 8.7, 8.7 and 9.1, respectively. The sex ratio (female/male) ranged from 1.9 to 2.1 at 16-28 degrees C. At 16, 20, 24 and 28 degrees C, the intrinsic rate of natural increase (rm) was 0.11, 0.18, 0.22 and 0.27, respectively, and the population doubling time was 6.1. 3.9. 3.2 and 2.5 days, respectively. All life stages of the mite died when exposed to 35 degrees C constant temperature for 24h. or to 32 degrees C constant temperature for 12 days or to 31-35 degrees C (average 32.9 degrees C) ambient temperature for 4 days. Brennandania lambi completed development only when fed on Ag. bisporus mycelium growing on mushroom compost. It could not survive on mushroom mycelia of Auricularia auricula. Au. polytricha, Ganoderma lucidum, Hericium erinaceus, Lentinus edodes, Pleurotus ostreatus, P. sajor-caju and Tremella juciformis.

Agaricales↗

PubMed2001

The therapeutic effects of Sheng Jing Zhong Zi Tang in treating male infertility.

Eight-seven cases of male infertility due to spermatopathy were treated with Sheng Jing Zhong Zi Tang (SJZZT [symbol: see text]) for 1-3 courses. The total effective rate was 95.40% (83/87). 56.32% (49/87) of their spouses got pregnant and the semen quality was markedly improved (P < 0.01). The results showed that the decoction could dual-directionally regulate the levels of follicle-stimulating hormone (FSH), prolan B luteinizing hormone (LH), testosterone (T), and cortisol (C).

Adult↗

PubMed2001

[The expression of human telomerase reverse transcriptase gene in cord blood hematopoietic stem cells and its significance].

OBJECTIVE: To investigate the expression and significance of human telomerase reverse transcriptase (hTERT) gene in cord blood hematopoietic stem cells. METHODS: Using in situ hybridization techniques, we detect the expression of hTERT gene in cord blood hematopoietic stem cells in different condition during different culture time. RESULTS: hTERT gene was lowly expressed in freshly isolated cord blood CD34+ cells; the positive rate was 13%. It could be increased in 5-7 days when the cells were cultured in vitro, especially in the presence of stem cell factor, interleukin-3(IL-3), IL-6 and Flt-3 Ligand together; the positive rate reached 48%. Transform growth factor-beta 1 and all-trans retinoic acid could repress hTERT gene. CONCLUSION: hTERT gene was lowly expressed in the cord blood CD34+ cells; it could be upregulated in the culture in vitro along with optimal cytokines, but was downregulated by negative regulator and induction differentiation.

Antigens, CD34↗

PubMed2000

Methodological study of cell separation with domestic immunomagnetic beads.

To establish the method of cell separation with domestic immuomagnetic beads, three methods were investigated. Direct method, SPA method and Biotin-Avidin method were applied to separate cell strain Hut-78 and CD4 positive cells. Separation rate of strain Hut-78 was more than 90% in direct method. Detachment rate with papain was over 95%. Cell activity was well retained. SPA method and Biotin-Avidin methods were also effective, but the direct method was superior to the other two techniques. Before separated by the direct method, CD4 positive cells constituted 46.4% +/- 6.4% of mononuclear cells (MNC), but in eliminated suspension there was only 6.2% +/- 2.3% CD4 positive cells left. In the separated part, 80.6% +/- 7.2% of the cells combined with the beads. It is concluded that the direct method in separating cells had high sensitivity and specificity.

CD4-Positive T-Lymphocytes↗

PubMed2000

Bcl-1 rearrangement and cyclin D1 protein expression in multiple myeloma precursor cells.

The rearrangement of Bcl-1 gene (Bcl-1/IgH rearrangement) and expression of cyclin D1 in multiple myeloma (MM) precursor cells were studied and the role of cyclin D1 in the pathogenesis of MM was investigated. The BCL-1 rearrangement and cyclin D1 protein expression in 15 cases of MM were detected. By using hemi-nested polymerase chain reaction (PCR) the genomic DNA from fresh peripheral blood and bone marrow was amplified and the expression of cyclin D1 in the smears was detected by using immunohistochemical method. Ten volunteer with normal bone marrow served as control group. The results showed Bcl-1 rearrangement was detectable in 3/15 (20%) MM patients and cyclin D, expression in 4/15 (27%) MM patients. Bcl-1 rearrangement and cyclin D1 protein expression were also detected in MM precursor cells. No overexpression of cyclin D1 or the rearrangement of the Bcl-1 gene was found in the 10 volunteers. It was concluded that Bcl-1 rearrangement and cyclin D1 protein overexpression were detected in MM precursor cells, speculating that overexpression of cyclin D1 protein may play an initial (critical) role in the pathogenesis of MM.

Adult↗

PubMed2000

Separation of CD34 positive cells and determination of surface homing antigen.

To study the differences in homing potential between bone marrow cells and umbilical blood cells, CD34 positive cells were obtained from bone marrow (BM) and umbilical blood (UB) by the direct cell separation with domestic immunomagnetic beads. The expression of the two adhesion molecules CD11a/CD18 and CD44 were examined. After separation, CD34 positive cells accounted for 51%-82% of the harvested cells and dye-resistance rate was 82%-88%. The expression of CD11a/CD18 and CD44 on the surfaces of UB cells was 49.6% +/- 10.2% and 37.7% +/- 10.3% respectively. On BM cells they were 50.2% +/- 6.2% and 34% +/- 13.3% respectively. There were no significant differences in the expression of these two molecules. It was concluded that the cell separation method with domestic immunomagnetic beads was effective and the stem cells from UB could serve as an alternative source for transplantation.

Antigens, CD34↗

PubMed2000

The heme-independent manganese-peroxidase activity depends on the presence of the C-terminal domain within the Streptomyces reticuli catalase-peroxidase CpeB.

Streptomyces reticuli produces a heme-containing homodimeric enzyme (160 kDa), the catalase-peroxidase CpeB, which is processed to the enzyme CpeC during prolonged growth. CpeC contains four subunits of 60 kDa each that do not include the C-terminal portion of the progenitor subunits. A genetically engineered cpeB gene encodes a truncated subunit lacking 195 of the C-terminal amino acids; four of these subunits assemble to form the enzyme CpeD. Heme binds most strongly in CpeB, least in CpeD. The catalase-peroxidase CpeB and its apo-form (obtained after extraction of heme) catalyze the peroxidation of Mn(II) to Mn(III), independent of the presence or absence of the heme inhibitor KCN. CpeC and CpeD, in contrast, do not exhibit manganese-peroxidase activity. The data show for the first time that a bacterial catalase-peroxidase has a heme-independent manganese-peroxidase activity, which depends on the presence of the C-terminal domain.

Amino Acid Sequence↗

PubMed2000

A variable resolution x-ray detector for computed tomography: II. Imaging theory and performance.

A computed tomography (CT) imaging technique called variable resolution x-ray (VRX) detection provides variable image resolution ranging from that of clinical body scanning (1 cy/mm) to that of microscopy (100 cy/mm). In this paper, an experimental VRX CT scanner based on a rotating subject table and an angulated storage phosphor screen detector is described and tested. The measured projection resolution of the scanner is > or = 20 lp/mm. Using this scanner, 4.8-s CT scans are made of specimens of human extremities and of in vivo hamsters. In addition, the system's projected spatial resolution is calculated to exceed 100 cy/mm for a future on-line CT scanner incorporating smaller focal spots (0.1 mm) than those currently used and a 1008-channel VRX detector with 0.6-mm cell spacing.

Algorithms↗

PubMed1999

Multidrug resistance P-glycoprotein function of bone marrow hematopoietic cells and the reversal agent effect.

The multidrug resistance P-glycoprotein (P-gp) expression and function in hematopoietic stem/progenitor cells were studied to investigate whether the inhibition of hematopoietic cell P-gp function by multidrug resistance reversal agent increases the cytotoxicity of chemotherapy drugs on the hematopoietic cells. The expression of P-gp on the surface of CD34+ cells from healthy human marrow was examined by flow cytometry. The multidrug resistance reversal agent MS-209 was used to measure the effects of MS-209 on the Rhodamin-123 uptaking of CD34+ hematopoietic cells. By using methylcellulose semi-solid culture, normal human granulocyte-macrophage clonal formation unit (CFU-GM) was cultured. The changes in CFU-GM inhibitory rate caused by daunorubicin were determined in the presence or absence of MS-209. The results showed that the P-gp expression rate of bone marrow CD34+ cells was 13.3%. MS-209 obviously increased the Rhodamin-123 uptake of CD34+ positive cells. The mean inhibitory rate of daunorubicin for CFU-GM was 29.6%, but it was increased to 43.3% in the presence of MS-209 with the difference being significant (P < 0.05). It was concluded that hematopoietic cells expressed P-gp protein and possessed active function. MS-209 could inhibit the membrane efflux pump and increase the cytotoxicity of chemotherapy drugs to the clonal growth of hematopoetic stem cells, suggesting the side effects of these drugs on the hematopoietic system should be taken into consideration in the clinical use.

ATP Binding Cassette Transporter, Subfamily B↗

PubMed1999

Measurement of the activation of IL-2 on bone marrow by flow cytometry.

The changes of cell surface markers before and after activation by IL-2 were detected by flow cytometry (FCM) to establish a more convenient and precise criterion for the judgment of the activation of bone marrow. By using the measurement of the release of lactate dehydrogenase (LDH) the cytotoxicity of mononuclear cells (MNCs) from bone marrow, activated or inactivated, on tumor cell line K562 was evaluated, and at the same time the changes of surface markers on MNCs before and after activation were examined by using FCM. The results showed that the cytotoxicity of MNCs from bone marrow activated by IL-2 on tumor cell line K562 was increased obviously and the number of CD25+ and CD70+ positive cells in bone marrow MNCs was higher than before activation. The enhanced cytotoxicity of MNCs on tumor cell line K562 was synchronous with the increase of the number of CD25+ and CD70+ positive cells in 48 to 72 h. It is more direct, simple and precise to demonstrate the activation of IL-2 on bone marrow by detecting the changes of the amount of the CD25+ and CD70+ positive cells in bone marrow by FCM.

Bone Marrow Cells↗

PubMed1999

Clonal growth of human acute leukemia cells in serum-free methylcellulose medium.

The clonal growth of human acute leukemia cell line (K562) and acute myeloid leukemia cells in the serum-free culture (SFC) was studied in order to establish a SFC system which could replace the effects of serum by using semi-solid methylcellulose culture technique. Our results showed that the clonal growth of K562 cells in semi-solid culture was dependent on exogenous serum. The K562 could be grown in SFC supplemented with 4 major replacing substances. The multifactor and multilevel orthogonal experiment demonstrated that the colony formation was statistically influenced by the 4 replacing substances at various concentrations (P < 0.01). Among them, bovine serum albumin had greatest effect on clonal growth of K562 cells with the optimal concentration being 15 mg/L, followed by transferring, cholesterol and insulin with their optimal concentrations being of 150 mg/L, 7.8 mg/L and 7.0 mg/L respectively. SFC system was formed with the 4 substances at their optimal concentrations. Colony formation of the blast cells in 10 patients with acute myeloid leukemia was observed in this SFC system. There was a heterogeneity of acute myeloid leukemia cells among the 10 patients in response to the growth substances. In SFC system, there was a linear relationship between the number of the clonal formation and the count of the added cells, indicating the colony growth of the cells. Primary acute leukemia cells maintained in SFC system in 10 cases could completely form clones. The colony formation number in some cases in SFC system was more than that of the serum-containing culture. The SFC system could partially replace the serum for study of the clonal formation of human leukemia cells.

Cell Division↗