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Biomedical subjects

Hong Zheng

Publications and source records attributed to Hong Zheng.

At least 73 records · Page 4Linked to original sources
PubMed2004

CpG oligodeoxynucleotide and Montanide ISA 51 adjuvant combination enhanced the protective efficacy of a subunit malaria vaccine.

Unmethylated CpG dinucleotide motifs present in bacterial genomes or synthetic oligodeoxynucleotides (ODNs) serve as strong immunostimulatory agents in mice, monkeys and humans. We determined the adjuvant effect of murine CpG ODN 1826 on the immunogenicity and protective efficacy of the Saccharomyces cerevisiae-expressed 19-kDa C-terminal region of merozoite surface protein 1 (yMSP1(19)) of the murine malaria parasite Plasmodium yoelii. We found that in C57BL/6 mice, following sporozoite challenge, the degree of protective immunity against malaria induced by yMSP1(19) in a formulation of Montanide ISA 51 (ISA) plus CpG ODN 1826 was similar or superior to that conferred by yMSP1(19) emulsified in complete Freund's adjuvant (CFA/incomplete Freund's adjuvant). In total, among mice immunized with yMSP1(19), 22 of 32 (68.7%) with ISA plus CpG 1826, 0 of 4 (0%) with CFA/incomplete Freund's adjuvant, 0 of 4 (0%) with CpG 1826 mixed with ISA (no yMSP1(19)), and 0 of 11 (0%) with CpG 1826 alone were completely protected against development of erythrocytic stage infection after sporozoite challenge. The adjuvant effect of CpG ODN 1826 was manifested as both significantly improved complete protection from malaria (defined as the absence of detectable erythrocytic form parasites) (P = 0.007, chi square) and reduced parasite burden in infected mice. In vivo depletions of interleukin-12 and gamma interferon cytokines and CD4+ and CD8+ T cells in vaccinated mice had no significant effect on immunity. On the other hand, immunoglobulin G (IgG) isotype levels appeared to correlate with protection. Inclusion of CpG ODN 1826 in the yMSP1(19) plus ISA vaccine contributed towards the induction of higher levels of IgG2a and IgG2b (Th1 type) antibodies, suggesting that CpG ODN 1826 caused a shift towards a Th1 type of immune response that could be responsible for the higher degree of protective immunity. Our results indicate that this potent adjuvant formulation should be further evaluated for use in clinical trials of recombinant malarial vaccine candidates.

Adjuvants, Immunologic↗
PubMed2004

The tumor suppressor p53 inhibits Net, an effector of Ras/extracellular signal-regulated kinase signaling.

The tumor suppressor function of p53 is linked to its ability to repress gene expression, but the mechanisms of specific gene repression are poorly understood. We report that wild-type p53 inhibits an effector of the Ras oncogene/mitogen-activated protein (MAP) kinase pathway, the transcription factor Net. Tumor-associated mutant p53s are less efficient inhibitors. p53 inhibits by preventing phosphorylation of Net by MAP kinases. Loss of p53 in vivo leads to increased Net phosphorylation in response to wound healing and UV irradiation of skin. Our results show that p53 can repress specific gene expression by inhibiting Net, a factor implicated in cell cycle entry.

Animals↗
PubMed2004

Silica-hemin composite nanoparticles as new biocatalyst to highly sensitive determination of glucose in human serum.

The preparation and utilization of a novel composite silica-hemin nanoparticles (CSHNs) as mimetic peroxidase are reported in this article. Experimental results showed that the composite nanoparticles had unique advantages over free hemin molecules in good stability and highly catalytic activity. By employing these nanoparticles as biocatalyst, we developed a new spectrofluorometric method for the determination of trace level glucose. The calibration graph for glucose was linear over the range 4.0 x 10(-7) mol/L - 7.0 x 10(-5) mol/L, with a detection limit of 1.0 x 10(-7) mol/L. The proposed method has been successfully applied to the determination of glucose in serum samples and offers the advantages of being rapid, stable, sensitive, and renewable.

Blood Glucose↗
PubMed2004

Determination of nucleic acids by near-infrared fluorescence quenching of hydrophobic thiacyanine dye in the presence of Triton X-100.

A near-infrared (near-IR) fluorescence quenching method was developed for the determination of nucleic acids in aqueous solution by using a cationic heptamethylene thiacyanine as a probe. The near-IR cationic cyanine showed maximum excitation and emission wavelengths at 800 and 825 nm, respectively, in the presence of Triton X-100; the fluorescence of the cyanine could be greatly quenched by DNA. The calibration graphs were linear over the range of 10-400 ng/mL for CT (calf thymus) DNA and over the range 5-400 ng/mL for FS (fish sperm) DNA under optimal conditions. The corresponding detection limits were 5.2 ng/mL for CT DNA and 2.5 ng/mL for FS DNA. The relative standard deviation (n = 8) was 3.1% for 75 ng/mL CT DNA and 2.2% for 75 ng/mL FS DNA, respectively. Preliminary research showed that the fluorescence quenching might be ascribed to the formation of dye aggregate facilitated by DNA.

Animals↗
PubMed2004

[Detection of GABAA alpha 2 mRNA in rat cochlear spiral neuron with in situ hybridization].

OBJECTIVE: To investigate the expression of gamma-aminobutyric acid (GABA)A receptor alpha 2 subunit mRNA on rat cochlear spiral neurons and its' significance. METHODS: In the rat cochlear paraffin slides, the GABAA alpha 2 receptor in spiral ganglion neuron was detected with in situ hybridization. Digoxigenin-GABAA alpha 2 cDNA probe (549 base pair), anti-digoxigenin-AP(Fab fragments) and BM purple substrate(precipitating) were used. RESULTS: Positive signals(GABAA alpha 2 mRNA) were seen in all cochlear spiral neurons and their nerves. GABAA alpha 2 mRNA was not found in other structure such as bony spiral lamina. As a positive control, GABAA alpha 2 mRNA was seen in Purkinje cells, granule cells and their axons in rat's cerebellum. GABAA alpha 2 mRNA was not found in OMP cDNA probe (olfactory membrane estrogen receptor probe) negative control, non-probe negative control and non-anti-digoxingenin control in cochlear spiral neuron and cerebellum. CONCLUSION: GABAA alpha 2 receptor has been found in type I spiral neurons and their nerves. It strongly indicates that GABA as a nerve transmitter plays an important role in inhibiting the excessive stimulation transmission of the inner hair cells.

Animals↗
PubMed2004

Relations of Budd-Chiari syndrome to prothrombin gene mutation.

BACKGROUND: Budd-Chiari syndrome (BCS) is a type of disease characterized by portal hypertension and/or hypertension of the inferior vena cava (IVC) due to the obstruction of the hepatic veins (HV) and/or intrahepatic IVC outlet. Being etiologically complicated and obscure, BCS can be acquired or idiopathic and several gene mutations may be contributable. This study was to explore whether prothrombin gene mutation (FII G20210A) takes part in the pathogenesis of BCS and to investigate their correlativity. METHODS: In 38 proven BCS patients and 70 controls, polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was used to find FII G20210A mutation. To detect whether there are any mutations, four steps were taken: purification of genome DNA from whole blood, amplification of special fragment by polymerase chain reaction, digestion of the fragment via restriction endonuclease, and analysis of results by polyacrylamide gel electrophoresis. RESULTS: FII G20210A mutation was not detected in all patients and controls. CONCLUSIONS: No FII G20210A mutation exists in Chinese patients with BCS, nor correlativity between the occurrence of BCS and FII G20210A mutation. The etiology of BCS in the Chinese needs further investigation.

Adolescent↗
PubMed2004

[Applying distortion product otoacoustic emission in testing human sensory hearing loss].

OBJECTIVE: To probe into the application of distortion product otoacoustic emission (DPOAE) test in human sensory hearing loss (SHL) research using lower stimulus parameter L1 = 65 dB, L2 = 50 dB. METHODS: Elicitation rate, size of DPOAE and correlation between DPOAE and pure tone auditory threshold were analyzed, and then the sensitivity and specificity were calculated. RESULTS: DPOAE was elicited in all of the hearing normal controls (25 subjects, 50 ears). In SHL cases (40 patients, 53 ears), DPOAE was elicited in 51 ears at 4 kHz and 6 kHz, and in 53 ears at 1 kHz and 2 kHz. The DPOAE size at each frequency in the normal group was higher than that in the SHL group (P < 0.05). A negative correlation between DPOAE size and pure tone auditory threshold was revealed by means of Spearman rank sum test. The sensitivity and specificity of DPOAE for testing SHL were better than those in literature reports. CONCLUSION: The DPOAE elicited by lower stimulus parameter mainly reflects the function of outer hair cells of inner ear, and thus it may provide some guidance or information for clinical diagnosis and treatment of SHL.

Adult↗
PubMed2004

[An experiment study and clinical observation of the testicle spermatogenesis after scrotum reconstruction].

OBJECTIVE: To explore the effect of scrotum reconstruction with a skin flap on spermatogenesis. METHODS: Two patients who underwent scrotum reconstruction with the skin flap were followed up for four years. Their sperm quality, sex function, sexual hormone, and testis biopsy were examined. To exclude the influential factors of testis and spermatic cord contusing, an experiment study was designed and performed in rabbits. The scrotal skin of the rabbits was stripped off and the scrotum was reconstructed with a hypogastric skin flap. RESULTS: The clinical follow-up indicated that in the early postoperative period, the reconstruction did not impede spermatogenesis, but the arrest of spermatogenesis happened with time. The experimental results showed that the sperm count of the rabbits decreased obviously and the rabbits became sterile two months after scrotum reconstruction. CONCLUSION: The thick skin flap is not recommended for scrotum reconstruction.

Adult↗
PubMed2004

[Changes of P-selectin and E-selectin in children with Kawasaki disease].

OBJECTIVE: Kawasaki disease (KD) is a kind of febrile disorder without definite etiology. The pathologic change of KD is characterized by nonspecific vasculitis, which mainly involves the coronary artery. Some patients may have coronary angioma formation, and some of them will result in the coronary narrowing or embolism. Notwithstanding that KD has been one of the most common causes for acquired heart diseases in childhood in addition to the rheumatic fever, the pathogenesis of the vascular damage remains unknown. This study was conducted to explore the pathophysiological role of cell adhesion molecules (P-selectin and E-selectin) on the endothelial lesions in KD, and to look for the evidence of direct relationship between the plasma levels of soluble cell adhesion molecules (P- and E-selectin) and the incidence of the coronary artery lesion (CAL). METHODS: Soluble P-selectin (PS), E-selectin (ES), thromboxane-B(2)(TXB(2)), 6-keto-PGF(1)alpha (6-KPGF(1)alpha) were measured in 36 patients with KD, 20 patients with febrile disease and 30 healthy children by using double antibody sandwich enzyme linked immunosorbent assay (ELISA) and radioimmunoassay. Patients with KD were separated into acute phase group, subacute phase group, recovery phase group, coronary artery lesion group (CAL), non-coronary artery lesion group (NCAL), intravenous immunoglobulin (IVIG) effective group (body temperature back to normal after 48 hours of using IVIG), and IVIG ineffective group. RESULTS: Plasma PS and ES levels in the acute phase group [(211 +/- 28 and 186 +/- 14) ng/ml], subacute phase group [(238 +/- 27 and 151 +/- 13) ng/ml] and recovery phase group [(198 +/- 21 and 1008 +/- 9) ng/ml] were significantly higher than those in the healthy group [(102 +/- 36 and 72 +/- 10) ng/ml, P < 0.01]. The plasma PS levels remained higher after the treatment, but in IVIG effective group, the PS and ES levels declined significantly (P < 0.01) compared with those in acute phase group. Plasma PS and ES levels of CAL group [(281 +/- 78 and 210 +/- 52) ng/ml] were significantly higher than those of NCAL group [(217 +/- 15 and 108 +/- 10) ng/ml, P < 0.01]. In contrast to 1 week after the treatment, the PS and ES in IVIG effective group at the time point of 2 weeks after the treatment decreased more significantly (P < 0.01). While the PS and ES in IVIG ineffective group remained higher at the time point of 2 weeks after the treatment, which showed no significant difference compared with those 1 week after the treatment (P > 0.05). One week after the treatment, the PS levels of IVIG effective and ineffective groups did not descend, and there was no significant difference in PS between these two groups at this time point. Two weeks after the treatment, the PS and ES in IVIG ineffective group remained higher than those in IVIG effective group, and there was a significant difference between them. The peak level of PS appeared in the subacute phase. TXB(2) levels of KD in acute phase group increased markedly, which were significantly higher than those of healthy group [(345 +/- 127 and 190 +/- 69) ng/L, P < 0.01]. There was no significant difference between subacute phase group and healthy group. No significant difference was found between CAL group and NCAL group (P > 0.05). The levels of TXB(2) declined quickly after the treatment. The 6-KPGF(1)alpha level in KD of acute phase group, subacute phase group and recovery phase group [(7.1 +/- 2.8, 10.8 +/- 3.7 and 11.3 +/- 4.0) ng/L, respectively] was significantly lower than that of healthy group [(17.7 +/- 5.8) ng/L, P < 0.01], and the levels did not recover to normal even 2 weeks after the treatment. There was no significant difference 6-KPGF(1)alpha levels between CAL group and NCAL group (P > 0.05). In the febrile group, PS and ES levels showed no significant differences compared with healthy children (P > 0.05). ES level of KD patients was significantly correlated with CRP levels (r = 0.79 P < 0.01). In febrile group, there was no significant correlation between ES and CRP. There was a significant correlation between PS and PLT levels in KD patients (r = 0.75 P < 0.01), and no significant correlation between PS and PLT levels in febrile patients. CONCLUSION: The increase of plasma PS and ES levels in KD acute phase and subacute phase might play an important role in the pathophysiology of the endothelial damage. E- and P-selectin may potentially be a predictor of CAL in patients with KD.

Child↗
PubMed2004

[Expression of EDAG-1 gene in human leukemia and lymphoma cell lines].

BACKGROUND & OBJECTIVE: Embryonic development associated gene 1 (EDAG-1), located at chromosome 9q22, is specially expressed in hematopoietic cells, and related to the regulation of hematopoietic system. This study was designed to explore relationship between pathogenesis of leukemia, lymphoma and EDAG-1 through analyzing the structure of EDAG-1 coding region, and its expression in these cell lines. METHODS: Fifteen leukemia and lymphoma cell lines, HEL, K562, HL-60, Namalwa, Raji, J111, Jurkat, HuT 78, MEG-01, U937, 6T-CEM, HPB-ALL, KG-1a, THP-1, and DAMI, were selected to observe the expression of EDAG-1 by reverse transcriptase-polymerase chain reaction (RT-PCR), EDAG-1 cDNA coding fragments (1.5 kb) were purified to construct the corresponding recombinant plasmid. Then, the plasmid was sequenced to analyze mutation of the coding region. The expression of EDAG-1 protein, and mRNA in these cell lines were detected by Western blot, and Northern blot; the rearrangement and amplification of EDAG-1 genome in these cell lines were detected by Southern blot. RESULTS: EDAG-1 mRNA and protein were highly expressed in erythroleukemia cell lines (K-562, HEL), megakaryoblast leukemia cell lines (DAMI, MEG-01), and T cell leukemia cell line (Jurkat), while no gene mutation was found in coding region, no amplification and rearrangement of genome was detected in these cell lines. EDAG-1 was absent in HL-60 cell line, and rearranged in HuT 78 cells. CONCLUSION: EDAG-1 may relate with pathogenesis of erythroleukemia and megakaryoblast leukemia; its coding region may have no relation with the mechanism of its activation.

Burkitt Lymphoma↗
PubMed2004

Diagnosis of isolated dextrocardia using angiocardiography or surgery.

BACKGROUND: Isolated dextrocardia is a rare phenomenon and usually associated with multiple cardiac anomalies. This study was to evaluate the accuracy of diagnosis of isolated dextrocardia by using angiocardiography and to compare it with the results of surgery. METHODS: The clinical data of 27 cases of congenital isolated dextrocardia were collected to understand the diagnostic approaches to the major cardiac anomalies. All cases underwent angiocardiography followed by palliative or curative surgery. The diagnosis was compared by angiocardiography relying on segmental analysis with the pathological features observed in surgery. RESULTS: The results of angiocardiography of 22 patients were the same as the pathological features observed during surgery, including one case with congenital left ventricular diverticulum was inadvertently omitted in angiocardiograhy. There were significantly dissimilar diagnoses between angiocardiograhy and post-operation in 5 patients, including anatomical corrected transposition of great arteries misinterpreted as corrected transposition of the great arteries in 1, complete transposition of great arteries misinterpreted as corrected transposition of the great arteries in 1, single ventricle misinterpreted as double-outlet right ventricle in 1, and anatomical double-outlet left ventricle misinterpreted as corrected transposition of the great arteries in 2. Misdiagnostic rate of angiocardiograhy was almost 20%. CONCLUSIONS: Angiocardiography is of great significance in the diagnosis and classification of isolated dextrocardia. However, because of the intricacy of cardiac anomalies of isolated dextrocardia, atrial angiography and double oblique projection are needed to improve the accuracy of diagnosis to support surgical treatments.

Adolescent↗
PubMed2004

[Clinical significance of progesterone receptors A and B expressions in endometrial carcinomas].

OBJECTIVE: To determine PRA and PRB expressions at mRNA and protein levels in endometrial carcinomas, and to correlate the PRA and PRB expressions in tumours with clinical features including grading, surgical stage, degree of myometrial invasion, and lymph node status. METHODS: Sixty-six endometrial carcinomas were investigated with Western blot assays and reverse-transcription polymerase chain reaction. The corresponding clinical information was collected. Spearman's rank correlation was used to test for association between expressions of total PR and PR isoforms in endometrial carcinomas and clinical features. RESULTS: At protein level, expressions of PRA and PRB were significantly inversely related to grade(r=-0.343, r=- 0.310, P<0.05), and only PRA was inversely related to surgical stage(r=-0.294, P<0.05). Lymph node metastasis was associated with reduced PRA: PRB ratio(r=-0.376, P=0.044), PRA:PRB ratio was lower in the cases with lymph node metastasis compared with that without lymph node metastasis(P=0.047). No correlation was found between protein levels of isoforms of progesterone receptor and degree of myometrial invasion. PR and PRB mRNA expressions were not related to any of the clinical features discussed above. CONCLUSION: PRA and PRB protein levels were correlated with grade, but were not correlated with degree of myometrial invasion. Only PRA protein level was related to surgical stage. Decreased ratio of PRA: PRB was related to lymph node metastasis. PR and PRB mRNA levels had no relationship with any of the clinical features discussed above.

Adult↗
PubMed2004

[Mode of delivery on urinary incontinence].

OBJECTIVE: To evaluate the association of route of delivery in primiparae with prevalence of urinary incontinence. METHODS: One thousand primiparae who had birth deliveries from March 2001 to March 2002 in our hospital were telephone interviewed through a questionnaire about symptoms of urinary incontinence before and during pregnancy, and after delivery. Totally 548 women answered the questionnaire based on International Consultant on Incontinence completely. The incidence and degrees of different kinds of urinary incontinence in connection with different ways of delivery and the associated factors were evaluated using SPSS software. RESULTS: (1) Among 548 cases, urinary incontinence was diagnosed in 167 (30.5%). (2) According to logistic regression, cesarean section and neonatal weight were associated factors with incontinence. If the odds ratio (OR) were taken as 1.0 for the incontinence women who had a normal vaginal delivery, then OR for cesarean section would be 0.326. OR for neonatal weight would be 1.633. Neonatal weight was the only high risk factor related with incontinence in women with vaginal delivery (P = 0.013, OR = 2.081). (3) The incidence of urinary incontinence in spontaneous vaginal delivery, forceps and cesarean section was 38.6% (105/272), 43.8% (21/48) and 18.0% (41/228) respectively. There was no difference in the incidence of urinary incontinence between spontaneous vaginal delivery and forceps (P > 0.05). A lower incidence of urinary incontinence was found in cesarean section than in other ways of delivery (P < 0.05). (4) The incidences of stress urinary incontinence, mixed incontinence and urgent incontinence were 33.8%, 4.4% and 0.4% respectively in spontaneous vaginal delivery; 35.4%, 8.3% and 0% in forceps delivery; and 14.5%, 3.1% and 0.4% in cesarean section. The incidence of stress urinary incontinence was higher in vaginal delivery women than in cesarean section women (P < 0.05). Severe cases of stress urinary incontinence were more in spontaneous vaginal delivery than in cesarean section (P < 0.05). (5) 1.2% (2/167) women reported urinary incontinence before pregnancy; 7.8% (13/167) during pregnancy; 44% (75/167) within one year after delivery; 40.7% (68/167) persisting for more than one year after delivery; and 2.4% (4/167) in recent time. CONCLUSIONS: (1) Cesarean section may decrease the risk of urinary incontinence compared with vaginal delivery. (2) Most patients have the symptoms of incontinence within one year after delivery, with some lasting for more than one year. (3) Heavy fetal weight increases the risk of stress incontinence.

Adult↗
PubMed2003

Cell surface expression of an endoplasmic reticulum resident heat shock protein gp96 triggers MyD88-dependent systemic autoimmune diseases.

Heat shock proteins have been implicated as endogenous activators for dendritic cells (DCs). Without tissue distress or death, these intracellular molecules are inaccessible to surface receptor(s) on DCs, possibly to avoid uncontrolled DC activation and breakdown of immunologic tolerance. We herein addressed this hypothesis in transgenic mice by enforcing cell surface expression of gp96, a ubiquitous heat shock protein of the endoplasmic reticulum. Although a pan-specific promoter is used for transgene expression, neither the expression level nor the tissue distribution of the endogenous gp96 was altered by this maneuver. However, cell surface gp96 induced significant DC activations and spontaneous lupus-like autoimmune diseases, even though the development/functions of lymphocytic compartments were unaltered. Using a bone marrow chimera approach, we further demonstrated that both DC activation and autoimmunity elicited by cell surface gp96 are dependent on the downstream adaptor protein MyD88 for signaling by Toll/IL-1 receptor family. Our study not only established the proinflammatory property of cell surface gp96 in vivo, but also suggested a chronic stimulation of DCs by gp96 as a pathway to initiate spontaneous autoimmune diseases.

Adaptor Proteins, Signal Transducing↗
PubMed2003

The transcription factor Net regulates the angiogenic switch.

Angiogenesis is fundamental to physiological and pathological processes. Despite intensive efforts, little is known about the intracellular circuits that regulate angiogenesis. The transcription factor Net is activated by phosphorylation induced by Ras, an indirect regulator of angiogenesis. Net is expressed at sites of vasculogenesis and angiogenesis during early mouse development, suggesting that it could have a role in blood vessel formation. We show here that down-regulation of Net inhibits angiogenesis and vascular endothelial growth factor (VEGF) expression in vivo, ex vivo, and in vitro. Ras-activated phosphorylated Net (P-Net) stimulates the mouse VEGF promoter through the -80 to -53 region that principally binds Sp1. P-Net and VEGF are coexpressed in angiogenic processes in wild-type mouse tissues and in human tumors. We conclude that Net is a regulator of angiogenesis that can switch to an activator following induction by pro-angiogenic molecules.

Animals↗
PubMed2003

Dye-binding protein assay using a long-wave-absorbing cyanine probe.

A simple and fast protein assay that involves the binding of water-soluble sulfonate heptamethylene cyanine to protein is described. The binding of the dye to protein causes a shift in the absorption maximum of the dye from 778 to 904 nm, and the increase in absorption at 904 nm is monitored. This assay is very reproducible, of good color stability for at least 80 min, and sensitive at the 100 ng/mL level of human serum albumin (HSA) when a spectrophotometer with near-infrared wavelength is used to measure absorbance. Few chemicals except ionic surfactants such as cetyltrimethylammonium bromide and sodium dodecyl sulfonate interfere with the assay. Purified proteins have different capacities to interact with the dye; under the experimental conditions, the linear ranges of bovine serum albumin (BSA), HSA and gamma-IgG were 200-2000, 100-2400, and 200-3000 ng/mL, respectively. The relative standard deviation for the five replicate determinations of 1200 ng/mL BSA is 2.1%.

Alkanesulfonic Acids↗