Biomedical subjects

J Cao

Publications and source records attributed to J Cao.

At least 163 records · Page 9Linked to original sources

PubMed1999

beta-hydroxyisovalerylshikonin inhibits the cell growth of various cancer cell lines and induces apoptosis in leukemia HL-60 cells through a mechanism different from those of Fas and etoposide.

beta-Hydroxyisovalerylshikonin (beta-HIVS), which was isolated from the plant, Lithospermium radix, inhibited the growth of various lines of cancer cells derived from human solid tumors at low concentrations between 10(-8) and 10(-6) M. When HL-60 cells were treated with 10(-6) M beta-HIVS for 3 h, characteristic features of apoptosis, such as DNA fragmentation, nuclear fragmentation, and activation of caspase-3-like activity, were observed. The most characteristic features of the effect of beta-HIVS were the remarkable morphological changes induced upon treatment of HL-60 cells with beta-HIVS, as visualized on the staining of actin filaments with phalloidin labeled with tetramethylrhodamine B isothiocyanate. Moreover, activation of MAP kinases, such as ERK2, JNK and p38, was detected after treatment with 10(-6) M beta-HIVS preceding the appearance of the characteristics of apoptosis, and the features of the activation of these MAP kinases were quite different from those of Fas and anticancer drug-induced apoptosis. The activation of JNK by beta-HIVS was not inhibited by inhibitors of caspases, suggesting that JNK is located either upstream or independent of the caspase signaling pathway. beta-HIVS did not inhibit the activity of topoisomerase II. These results indicate that beta-HIVS induces apoptosis in HL-60 cells through a mechanism unlike those reported for anti-Fas antibodies and etoposide.

Antineoplastic Agents↗

PubMed1999

Global stability analysis in delayed cellular neural networks.

In this paper, the author analyzes further problems of global stability for a class of cellular neural networks with delays by means of the Lyapunov functional method, inequalities a(2)+b(2)> or =2ab and a(3)+b(3)+c(3)> or =3abc (a,b,c > or =0) analysis technique, some stability criteria are obtained under more general conditions. These criteria can be applied to design globally stable networks and thus have important significance in both theory and applications.

Biophysical Phenomena↗

PubMed1999

Periodic solutions and exponential stability in delayed cellular neural networks.

Some simple sufficient conditions are given ensuring global exponential stability and the existence of periodic solutions of delayed cellular neural networks (DCNNs) by constructing suitable Lyapunov functionals and some analysis techniques. These conditions are easy to check in terms of system parameters and have important leading significance in the design and applications of globally stable DCNNs and periodic oscillatory DCNNs. In addition, two examples are given to illustrate the theory.

Animals↗

PubMed1999

Role of Th1 and Th2 cytokines in regulating the liver injury induced by delayed-type hypersensitivity to picryl chloride.

AIMS/BACKGROUND: We have previously reported that a new model of liver injury induced in mice by delayed-type hypersensitivity (DTH) to picryl chloride (PCl) mimicks the pathogenesis of human hepatitis. This liver injury is mediated by CD4+ T cells. The interaction between lymphocyte function associated antigen 1 (LFA-1) and intercellular adhesion molecule 1 (ICAM-1) is an essential process for hepatocyte (HC) damage. The present study was undertaken to reveal the role of Th1 and Th2-like cytokines in regulating the liver injury. METHODS: The kinetics of cytokine production were examined by ELISA and RT-PCR after the elicitation of liver injury for both serum protein and liver mRNA expression, respectively. A co-culture assay between liver nonparenchymal cells (NPC) and HC was conducted to evaluate the cytokine regulation on the cell-cell interaction. Expression of LFA-1 on NPC and ICAM-1 on HC were examined by FACScan and ELISA, respectively. RESULTS: Serum IL-2 and IFN-gamma showed a peak production at 6 and 12 h, while IL-5 and IL-4 reached their maximum levels at 18 and 24 h after induction of liver injury, respectively. Liver mRNA expression of IFN-gamma and IL-4 had a similar time course to their corresponding products. Both recombinant murine IFN-gamma and IL-2 triggered the hepatotoxicity of NPC or spleen cells at 0 h. In this case, an increased expression of both LFA-1 on NPC and ICAM-1 on HC was also observed. In contrast, IL-4 and IL-5 completely abolished the hepatotoxicity of NPC at 12 h without influencing the adhesion molecules. CONCLUSION: Th1 and Th2 may be involved in regulating liver injury. Th1/Th2 balance may critically contribute to the production of the liver injury or recovery from it.

Animals↗

PubMed1999

Individual hydrogen bonds play a critical role in MHC class II: peptide interactions: implications for the dynamic aspects of class II trafficking and DM-mediated peptide exchange.

Determination of the crystal structure of class II: peptide complexes has shown that in addition to pocket interactions involving the side chains of the peptide, peptide binding to MHC class II molecules is characterized by a series of hydrogen bonds which are contributed by genetically conserved amino acid residues in the class II molecule to the main chain of the peptide. Our experiments have revealed an unexpectedly large contribution of hydrogen bonds at the periphery of the MHC peptide binding pocket to MHC class II function. Kinetic studies have shown that peptide dissociation rates are profoundly accelerated by loss of a single hydrogen bonding residue. The magnitude of the effects seen with the loss in potential for a single hydrogen bond support a co-operative model in which individual bonds between class II and peptide are dependent on the integrity of neighboring interactions. Collectively our studies have revealed that MHC class II structure, peptide binding and intracellular trafficking events are critically dependent on the integrity of the hydrogen bonding network between class II molecules and its bound peptide.

Animals↗

PubMed1999

Angiogenic factors in human proliferative sickle cell retinopathy.

BACKGROUND/AIMS: Preretinal neovascular formations called sea fans develop at the border of non-perfused peripheral retina in sickle cell retinopathy. Angiogenic factors which could contribute to their development, however, have not been examined previously. The objective of this study was to determine immunohistochemically if vascular endothelial growth factor (VEGF) or basic fibroblast growth factor (bFGF) were associated with sea fan formations. METHODS: Immunohistochemistry on cryosections was used to localise bFGF, VEGF, heparan sulphate proteoglycan, human serum albumin, collagens IV and II, and von Willebrand factor in tissue from five sickle cell and one control subject. RESULTS: The greatest immunoreactivity for VEGF and bFGF was in the feeder and preretinal vessels of sea fans (p<0.01). The most prominent reaction product was localised to vascular endothelial cells. In retinal vessels, VEGF and bFGF immunoreactivities were greater in sickle cell subjects (both proliferative and non-proliferative) than in the control subject (p<0.01 and p<0.02 respectively). In the sickle cell retina, no angiogenic factor immunoreactivity was detected in non-perfused periphery and there was no significant difference in bFGF or VEGF immunoreactivity between perfused retina and the border of perfused and non-perfused areas. CONCLUSION: Our results demonstrate for the first time that VEGF and bFGF are associated with sea fan formations in sickle cell retinopathy. Both factors may function in an autocrine manner because immunoreactivity for these factors was greater within the neovascularisation than in adjacent retina.

Adolescent↗

PubMed1999

Regulation of gelatinases in human airway smooth muscle cells: mechanism of progelatinase A activation.

Matrix metalloproteinases (MMPs) play an important role in tumor metastasis and invasion, inflammatory tissue destruction and remodeling, wound healing, and angiogenesis. The 72-kDa gelatinase A is the most widely distributed of all the MMPs, and along with the 92-kDa gelatinase B, both play an important role in the turnover of basement membrane. The role of MMPs in chronic airway inflammation and remodeling has received scant attention. In this study, we sought to examine the release and activation of gelatinases from human airway smooth muscle (ASM) cells and the effect of tumor necrosis factor-alpha and phorbol 12-myristate 13-acetate (PMA) on this release and activation. The role of membrane type 1 MMP (MT1-MMP) and tissue inhibitor of MMP (TIMP)-2 in activating progelatinase A has been explored. We have demonstrated, using human airway smooth muscle cells in culture, that 1) ASM releases gelatinase A constitutively and when stimulated with PMA and tumor necrosis factor-alpha releases gelatinase B, and the release of gelatinase B is protein kinase C dependent because it is blocked by H-7 and staurosporin; 2) treatment of ASM cells with PMA or concanavalin A failed to activate progelatinase A despite these agents increasing cell expression of MT1-MMP; and 3) the inability of ASM cell membranes to activate progelatinase A is most likely secondary to the high levels of TIMP-2 on the cell membrane. In conclusion, our results demonstrate that human ASM cells constitutively secrete progelatinase A and when stimulated with proinflammatory mediators secrete gelatinase B. The released gelatinases A and B may be important factors in the airway remodeling that occurs in asthma.

Cell Membrane↗

PubMed1999

[Screening for mitochondrial 1555(G) mutation in patients with aminoglycoside antibiotic-induced deafness].

OBJECTIVE: To identify the incidence of the 1555(G) mutation in pedigrees and sporadic patients with aminoglycoside antibiotic- induced deafness so as, to privide the theoretical evidence for establishing the method of diagnosis of this disease. METHODS: Blood samples were obtained from two pedigrees and seven sporadic patients with aminoglycoside antibiotic-induced deafness, and five mothers of the sporadic patients. DNA was extracted from the isolated leukocytes. The mitochondrial DNA fragments were amplified by PCR; 1555(G) mutation was detected by Alw26 I restriction endonuclease digestion. RESULTS: Fourteen individuals from two pedigrees carried homoplasmic 1555(G) mutation. Seven sporadic patients and the five mothers did not have 1555(G) mutation. CONCLUSION: The incidence of the 1555(G) mutation in pedigrees with aminoglycoside antibiotic-induced deafness is fairly high, while in sporadic patients is low. Screening for mitochondrial 1555(G) mutation is of potential value to clinical use.

Adolescent↗

PubMed1999

[Cloning the 5 ' end fragment of ST13 cDNA by nested PCR].

OBJECTIVE: To clone and sequence the 5' -end fragment of ST13 cDNA. METHODS: The 5' -end fragment of the ST13cDNA was amplified directly from cDNA library by nested PCR method, and cloned into pGEM-T. easy vector, then the sequencing of the inserted PCR product was performed. RESULTS: After primary and secondary PCR, two PCR products obtained with the size of about 550bp and 480bp, respectively, were both proved to be the 5' -end of ST13 cDNA by sequencing. CONCLUSION: the method presented is very simple and effective for cloning and sequencing the 5'-end of a target gene.

Cloning, Molecular↗

PubMed1999

Gene polymorphisms of the renin-angiotensin system in essential hypertension.

OBJECTIVE: To determine whether angiotensin-converting enzyme (ACE) gene, angiotensinogen (AGT) gene and angiotensin II receptor 1 (AT1R) gene are implicated in Chinese essential hypertension (EH). METHODS: The case-control and haplotype-based haplotype relative risk (HHRR) study consisted of 169 essential hypertensive subjects (HT), 152 normotensive controls (NT) and 62 families. The polymorphisms of insertion/deletion (I/D) allele of ACE gene and the microsatellite allele of AT1R gene were determined in DNA extracted from peripheral blood leukocytes by polymerase chain reaction (PCR). The variants of AGT gene were screened by PCR-single strand conformation polymorphism (PCR-SSCP) analysis and further identified by cloning and sequencing. RESULTS: The significant association between EH and D allele of ACE gene was found (P < 0.05). The difference of the microsatellite allele distribution of AT1R gene between HT and NT groups was statistically significant (P < 0.005). By contrast, the distribution of A-20C genotype of AGT gene was almost identical in HT and NT groups. No significant linkage disequilibrium was observed between A-20C and M235T in AGT gene. CONCLUSIONS: D allele of ACE gene might correlate with a predisposing factor for EH. The microsatellite allele of AT1R gene might be linkage disequilibrium with an unidentified variant that contributes to the development of EH. A-20C of AGT gene is not a major genetic determinant of EH.

Adult↗

PubMed1999

Comparison of some antineoplastic drugs on inhibiting thrombin catalizing fibrinogen clotting in vitro.

OBJECTIVE: To classify the effect of thrombin, the key enzyme which enables fibrinogen to form fibrin (fibrinogen clotting) on the formation of metastasis by comparing the inhibition of some antineoplastic drugs on fibrinogen clotting in vitro. METHODS: Time intervals of different drugs to reach a maximum OD (340 nm) data in fibrinogen solution added with thrombin were used in this work. RESULTS: It was found that L-4-oxalysine (8-40 micrograms/ml) and arabinosyl cytosine (10-50 micrograms/ml) could inhibit the effect of thrombin by extending the fibrinogen clotting time to 100%-150% (P < 0.001) and 61%-100% (P < 0.001) while the other antimetastatic drugs razoxane, probimane, adriamycin, harringtonine homoharringtonine and alpha-anordrin at the treatment concentrations showed no such activity. The positive rate of drugs to thrombin activity was approximately 25%. CONCLUSION: It suggests that L-4-oxalysine and arabinosyl cytosine may even exhibit antimetastatic effect through thrombin-fibrinogen pathway, and thrombin might operate in tumor metastasis for only limited step but crucial to fibrin formation in tumor nodules.

Amino Acids, Dicarboxylic↗

PubMed1999

[An approach to the cytologic diagnostic criteria of hepatocellular carcinoma by fine needle aspiration biopsy].

OBJECTIVE: To identify useful cytologic features for diagnosis of hepatocellular carcinoma (HCC). METHODS: Fine needle aspiration(FNA) smears from 61 patients with proven HCC, 19 patients with metastatic tumors in the liver and 16 patients with non-neoplastic lesion of the liver were reviewed in order to detect the relevant cytologic changes associated with HCC. Step-wise logistic regression analysis was done to select useful cytologic features in discriminating HCC from metastatic tumors and non-neoplastic lesions of liver. RESULTS: Nine cytologic features observed were significantly associated with HCC: abundant tissue fragments(91.8%); trabecular pattern(91.8%); sinusoidal endothelial cells (47.5%); polygonal cells with centrally placed nuclei(82.0%); increased nuclear to cytoplasmic ratio(95.1%); large nucleoli(55.7%); bile granules(31.1%); cytoplasmic vacuoles(27.9%) and atypical naked hepatocyte nuclei(88.5%). In distinquishing HCC from metastatic tumors, polygonal cells with centrally placed nuclei, bile granules and trabecular pattern were useful cytologic features. Of the 61 patients with HCC, the logistic model correctly predicted 60(98.4%) as having HCC, while of the 19 patients with metastatic tumors, 18(94.7%) were correctly predicted. In distinquishing HCC from non-neoplastic liver disease, abundant tissue fragments, trebecular pattern, increased nuclear to cytoplasmic ratio and atypical naked hepatocyte nuclei were selected. When the four criteria were used, the sensitivity of diagnosing HCC was 100% and the specificity was 93.8%. CONCLUSION: Abundant tissue fragments, polygonal cells with centrally placed nuclei, increased nuclear to cytoplasmic ratio, trebecular pattern, atypical naked hepatocyte nuclei and bile granules are useful features for identifying HCC by FNA biopsy.

Biopsy, Needle↗

PubMed1999

[Combined TIPSS with modified Sugiura operation for portal hypertension].

OBJECTIVE: To evaluate the clinical results of combined TIPSS with modified Sugiura operation for portal hypertension. METHODS: 24 patients with portal hypertension associated with variceal bleeding and ascites were treated with TIPSS and then modified Sugiura operation two weeks later. RESULTS: After combined TIPSS with modified Sugiura operation, variceal bleeding ceased and ascites subsided. The portal pressure significantly decreased (P < 0.01) and the portal blood flowed quickly (P < 0.01). The blood velocity of intrahepatic shunts was (132.64 +/- 41.42) cm/s. Direct portal venography showed that coronary vein had disappeared. No rebleeding was noted in varices and stenosis in intrahepatic shunts. CONCLUSIONS: Combined TIPSS with modified Sugiura operation not only can reduce portal pressure and improve portal circulation, but also completely interrupt coronary vein and maintain liver function.

Adult↗

PubMed1999

[Development of plasmid-based transgenic mice carrying with target gene xylE].

OBJECTIVE: To develop a transgenic mouse model carrying with plasmid pUC118NX integrated into its genomic DNA for detecting mutagenesis. METHODS: DNA of plasmid UC118NX in target gene xy1E was injected microscopically into male protonucleus of 376 mouse spermatova, and 225 survival spermatova were transferred into the oviducts in both sides of 11 pseudopregnant female mice to develop their offspring. The genomic DNA in survival young mice were analyzed with polymerase chain reaction (PCR)-Southern blot, plasmid transformation test and endonuclease-digestion. RESULTS: Seven pseudopregnant mice got pregnant, and 29 offspring were delivered and 25 survived of which 18 were identified with positive for PCR-Southern blot (72%). The two stout male mice with intact integration of plasmid pUC118NX in their genome were finally chosen as founders to detect gene mutation in vivo and establish transgenic mouse lineages. CONCLUSION: Transgenic C57BL/6J mice integrated with plasmid pUC118NX into their genomic DNA have been successfully developed.

Animals↗

PubMed1999

[Chemoembolization of primary hepatic carcinoma with portal vein tumor thrombus].

Forty cases of primary hepatic carcinoma(PHC) with portal vein tumor thrombus(PTT) underwent chemoembolization twice or more. The total effective rate was 67.5%. The survival rates of half, one, and three years were 75.0%, 12.5%, and 2.5% respectively after the treatment. The mean survival time was 9 months. The effective rate of the cases with the branch PTT was higher than other cases(P < 0.05). The influence caused by the average treatment interval had no significant difference(P > 0.05). It is suggested that (1) in case of controlling the applications, TAI + TAE is an effective therapy of PHC with PTT; (2) no matter where PTT is, an active management must be adopted; (3) the average treatment interval shall be decided according to conditions of the patients.

Adult↗

PubMed1999

[Rhinitis and maxillary sinuitis caseosa].

OBJECTIVE: To investigate the effect of surgical procedures on patients with rhinitis caseosa and maxillary sinusitis caseosa. METHOD: The clinical analysis for 21 cases (24 sides) were reported in this paper, there were 6 rhinitis caseosa, 13 maxillary sinusitis caseosa, 5 rhinitis and sinusitis caseosa, all patients had caseation material in the nasal cavity or sinus cavity. All patients were treated successfully by surgery, transmaxillary sinus microsurgery and the middle meatal antrostomy were performed for 12 cases. RESULT: 21 cases who were followed-up 3-5 years after surgery were disappearance for symptoms, and did not recurring. CONCLUSION: The key of surgery is to allow free drainage for sinus ostium.

Adult↗

PubMed1999

[Preliminary examination of a LB-H2O2 substance that inhibit Neisseria gonorrhea growth].

OBJECTIVE: To study the possible mechanism of H2O2-producing lactobacilli inhibited neisseria gonorrhoeae growth. METHODS: H2O2-producing lactobacilli were coincubated with neisseria gonorrhoeae in vitro, LB+ cell were disrupted by sonication, the protein in the lactobacilli lysate was separated by filtration through different MW sizes membranes and was examined for the ability to inhibit N. gonorrhoeae catalase activity. RESULTS: When coincubation medium was at pH 5.0, there was a significant decrease in the gonococcal catalase activity, the lysates of LB+ also effectively inhibited gonococcal catalase activity. This inhibition was retained upon heating of lysate to 100 degrees C for 15 minutes but was lost with proteinase K treatment. CONCLUSIONS: The LB+ may inhibit growth of gonococci by production of catalase inhibitors.

Catalase↗

PubMed1999

[Clinical study on keratoplasty with corneal cryopreservation].

PURPOSE: To evaluate the clinical application value of the corneal cryopreservation in keratonosus. METHODS: 32 patients with keratonosus treated by corneal transplantation were clinically observed. RESULTS: In 32 keratonosus cases, 59.37% (19 cases) of the grafts remained transparant; in 24 corneal ulcer preforation cases, 45.83% (11 cases) of the grafts were transparent, all eyeballs(100%) were remained. CONCLUSION: Corneal cryopreservation can be a practical, effective method in the treatment of keratonosus in district hospitals.

Adolescent↗