Biomedical subjects

J Ye

Publications and source records attributed to J Ye.

At least 127 records · Page 7Linked to original sources

PubMed2000

On the role of hydroxyl radical and the effect of tetrandrine on nuclear factor--kappaB activation by phorbol 12-myristate 13-acetate.

Nuclear factor kappaB (NF-kappaB) is considered to be an important target for therapeutic intervention because of its role in the regulation of proinflammatory and profibrotic mediators. The present study examined the role of hydroxyl (*OH) radical and the effect of tetrandrine, an alkaloid extracted from the Chinese medicinal herb Stephania tetrandra, on NF-kappaB activation by a tumor promoter, phorbol 12-myristate 13-acetate (PMA) in human lymphoid T cells (ie, Jurkat cells). Exogenous superoxide dismutase (SOD) enhanced the NF-kappaB activation by PMA, while catalase blocked it. Formate, a scavenger of *OH radical, also was inhibitory, as was deferoxamine, a metal chelator. These data suggest an important role of *OH radical in PMA-induced NF-kappaB activation. Incubation of the cells with tetrandrine prior to the stimulation of the cells was found to inhibit PMA-induced NF-kappaB activation. Tetrandrine activity was so potent that 50 microM of tetrandrine was sufficient to inhibit activation of NF-kappaB completely. Electron spin resonance (ESR) spin trapping was used to investigate the antioxidant action of tetrandrine using 5,5-dimethyl-1-pyrroline N-oxide (DMPO) as a spin trap. Tetrandrine is an antioxidant for both *OH and superoxide (O2-)radicals. The reaction rate constant of tetrandrine with *OH is 1.4 x 10(10) M(-1)sec(-1), which is comparable with several well established antioxidants, such as ascorbate, glutathione, and cysteine. The Fenton reaction (Fe(II) + H2O2-->Fe(III) + *OH + OH-) and xanthine/xanthine oxidase were used as sources of *OH and O2- radicals. The free radical scavenging activity of tetrandrine is responsible for its inhibition of PMA-induced NF-kappaB activation.

Alkaloids↗

PubMed2000

[The development of an extracting method for high frequency components of abnormal intra-QRS of exercise ECG signal].

This article introduces a method of extracting high frequency components of abnormal intra-QRS of exercise ECG signal by using spline function interpolation algorithm, and defines QRSe of the residual signal as quantitative index. Some expected results have been obtained. This method is an effective measuring approach to further researches on the high frequency components of exercise and other ECG signals.

Electrocardiography↗

PubMed2000

Hepatitis B virus X protein activates expression of IGF-IR and VEGF in hepatocellular carcinoma cells.

OBJECTIVE: The expression of insulin-like growth factor I receptor (IGF-IR) and the vascular endothelial growth factor (VEGF) in HepG(2) cells transfected with a hepatitis B virus X (HBx) expression vector was investigated in an attempt to study their possible relationship to the growth of HBx-induced hepatocellular carcinoma (HCC). METHODS: The eucaryotic expression vector of HBx gene was constructed and introduced into HepG(2) cells. The modified cell HepaG(2)-X was synchronized in a quiescent state by culture of serum deprivation. The IGF-IR and VEGF were analyzed by immunohistochemical and Western blot technique. RESULTS: The positive rate of IGF-IR expression was 84%A3% in the transfected HBx gene cells, 26%A4% in X(0) control cells. The positive rate of VEGF expressed x cells was 83%A5%, X(0) cells was 28%A6% (P<0.001). The level of IGF-IR and VEGF in serum-starved x modified cells was 1.5 times higher than that of synchronized X(0) modified cells. CONCLUSION: Since the IGF-IR is a very important growth factor in sustaining the tumor abnormal growth and the VEGF has a crucial role in inducting tumor angiogenesis, our findings indicate that HBx may play an important role in the processes of HCC by activating IGF-IR and VEGF gene expression.

Carcinoma, Hepatocellular↗

PubMed2000

Activation of androgen response element by cadmium: a potential mechanism for a carcinogenic effect of cadmium in the prostate.

Cadmium is a transition metal that has been widely used in industry. Epidemiological and animal studies have demonstrated a carcinogenic effect of cadmium on the prostate. Although it has been established that androgen is required for this cancer-inducing process, it is not clear how cadmium interacts with androgen. In this study, the carcinogenic mechanism of cadmium was explored with a focus on interaction of androgen and cadmium at the gene transcription level. An androgen response luciferase reporter was used for analysis of the cadmium activity in the transient transfection assay. Human prostate epithelial cells (LNCap) and liver cells (HepG2) were transfected by the reporter. The result showed that cadmium was able to activate the reporter in the absence of androgen, and that this activation was dependent on the presence of androgen receptor. Cadmium could enhance the androgen response when both androgen and cadmium were applied together to the reporter-transfected cells. Activation of the reporter by cadmium was not associated with cell proliferation or interleukin 6 (IL-6) production, which was proposed to be involved in cadmium-induced carcinogenesis in other experimental systems. Cadmium exhibited a weak ability to induce AP-1. The results demonstrate that cadmium has an androgen-like activity in prostate epithelial cells, and this activity implies a new mechanism for the carcinogenic effect of cadmium in the prostate.

Androgens↗

PubMed2000

[Screening for 6-pyruvoyl-tetrahydrobiopterin synthase (PTPS) deficiency: clinical analysis of 9 patients with PTPS deficiency].

OBJECTIVE: To show the incidence of 6-Pyruvoyl-tetrahydrobiopterin synthase (PTPS) deficiency among hyperphenylalaninemia and conclude the clinical outcome of patients with PTPS deficiency. METHODS: The urinary neopterin (N) and biopterin (B) were determined by HPLC in 69 PKU cases. BH(4) loading test and mutation analysis of PTPS were performed in patients who had abnormal urinary pterin patterns. Three patients with PTPS deficiency were placed on treatment with combined synthetic BH(4) and neurotransmitter precursors such as Dopa and 5-hydroxytryptophan. RESULTS: 9 out of 69 patients, whose urinary N/B exceed 38 [normal: 1.17 (1.4)] and B% were less than 5% [normal: 55.9 (18.6)], were diagnosed as having PTPS deficiency. Four kinds of PTPS gene mutations (P87S, N52S, D96N and G144R) were detected from 4 out of 9 cases with PTPS deficiency. The last mutation was a new mutation. The three typical PTPS-deficient patients had satisfactory physical development, their intelligence quotient (IQ) were 70 approximately 80 after treatment and one partial PTPSD had normal growth and mental development. CONCLUSION: The screening for BH(4) deficiency should be carried out among all patients with hyperphenylalaninemia in order to avoid misdiagnosis.

Biopterins↗

PubMed2000

[Lymph node metastasis and the extent of lymph node dissection for gastric cancer: report of 326 cases].

OBJECTIVE: To investigate the pattern of lymph node metastasis and the extent of lymph node dissection for gastric cancer. METHODS: 326 patients with gastric cancer admitted from 1990 to 1999 were analyzed retrospectively after D(2), D(3) or D(3) plus para-aortic lymphadenectomy (D(3) + PAL). RESULTS: The total incidence of lymph node metastasis was 69.9%; node involvement was 15.4% and 77.4% respectively for early gastric cancer and advanced gastric cancer. Depth of invasion, tumor size and histology affected lymph node metastasis significantly (P < 0.05). For T(1) patients, node involvement was mainly confined to N(1) and one patient had N(2) metastasis; 8.1% of T(2) patients and 28.7% of T(3), T(4) patients had N(3), M(1) lymph node metastasis. Among 107 patients who received D(3) + PAL, 16a2b1 lymph node metastasis was found in 15.0%. The patients who had 16a2b1 node involvement were all suffered from advanced gastric cancer and N(1)-N(2) node metastasis. In the patients with serosal invasion-positive tumors or tumors size over 5 cm, the incidence of 16a2b1 metastasis was high, and that of entire stomach cancer was up to 38.5%. The 3-year and 5-year survival rates for D(3) + PAL group were 60.7% and 50.0% respectively. After D(3) + PAL, the 1-and 2-year survival rate, of patients with 16a2b1 metastasis were 60.0%, 50.0% respectively. CONCLUSIONS: D(2) lymphadenectomy should be taken for patients with early gastric cancer and D(3) lymphadenectomy for those with relatively early' advanced gastric cancer. For advanced gastric cancer with suspect or confirmed N(1)-N(2) node metastasis, tumor size over 5 cm and/or serosa invasion, D(3) plus para-aortic lymphadenectomy appears to be a necessary surgical procedure.

Adult↗

PubMed2000

[A cost-benefit evaluation of neonatal screening for phenylketonuria and congenital hypothyroidism].

OBJECTIVE: In order to make the best use of health care resources, to achieve the maximal social and economic benefits and to lay a foundation for popularizing neonatal screening for phenylketonuria (PKU) and congenital hypothyroidism (CH), a cost-benefit analysis of the screening program was conducted. METHODS: Cost for and benefit gained from screening were calculated according to the average incidence of two diseases recommended by the Ministry of Health, mean charge for neonatal screening, sampling extraction of medical history and data published in national economic statistics. RESULTS: The cost of neonatal screening, treatment for PKU with low phenylalanine milk powder and follow up, the total add up to 128 793 Yuan However the direct and indirect financial benefits is 481 263 Yuan, ratio of cost to benefit was 1:3.7. The cost of neonatal screening for CH is 129 175 Yuan. However the financial benefits including the money saved in treatment, nursing care, special education and the loss of income avoided is 468 470 Yuan, ratio of cost to benefit was 1:3.6. CONCLUSION: Neonatal screening for PKU and CH in this country reflects a better economic and social benefit and merits further popularization.

Congenital Hypothyroidism↗

PubMed2000

[DNA typing of old skeletons and teeth with fluorescence tagged short tandem repeats].

In order to identify the individual status of old human skeletons and teeth, studies were conducted on DNA extraction. The extracted DNA was then amplified and automatic typed with 373A sequence's gene scan system (made by PE Company) and fluorescence tagged Hum vWA, Hum LPL kit. This is a rapid, convenient and effective method in DNA typing of old skeletons and teeth in forensic investigation.

Alleles↗

PubMed2000

[Animal experimental study on endocrine factors affecting alveolar repair].

OBJECTIVE: To investigate the endocrine effects on activities of alkaline phosphatase (ALP) and acid phosphatase (ACP) and to obtain the mechanism of the resorption and regeneration of the alveolar bone. METHODS: 24 dog models with two-side osseous infrabony pocket were divided into 4 groups randomly and were studied by histologic examination, enzyme cytochemistry and image analysis system. RESULTS: The activities of ALP and ACP, except ACP in the sixth month significantly decreased in the group of thyroidism comparing with that of the control group (P < 0.01), but only the activities of ALP significantly decreased in groups of ovariectomy and diabetes (P < 0.05, P < 0.01), and there was close relationship between enzyme activities and histopathologic variations. CONCLUSION: Alveolar bone repair was regulated by systemic endocrine factors and was associated with the activities of ALP and ACP osteoblasts of and osteoclasts.

Acid Phosphatase↗

PubMed2000

[Producing characterization of constitutive-form laccase by Basidiomycete].

A constitutive-laccase-producing fungus was gained from 20 strains of different sources with plate method. Laccase activity reached 0.58 IU/mL when the strain grew on DC medium with shaking cultivation, which was superior to stationary method by 4 times. The enzyme production paralleled with biomass in early 8 days, subsequently activities declined slightly though its biomass continued upward. Tyrosine and tryptone at the concentration of 4 g/L improved the enzyme production, reaching 2.49 and 2.0 IU/mL respectively. Some tested chemical agents seemed not to contribute to the increase of the enzyme production effectively except for syringaldazine and o-tolidine. Heatshock at 40 degrees C for 1 h made 1.3 times more enzyme expression.

Basidiomycota↗

PubMed2000

[Observation of anterior chamber angle after phacoemulsification and extra capsule cataract extraction and intraocular lens implantation].

OBJECTIVE: To observe and compare the difference of anterior chamber angle after Phacoemulsification and Intraocular Lens Implantation (Phaco & IOL) through a tunnel incision and Extra Capsule Cataract Extraction and Intraocular Lens Implantation (ECCE & IOL). METHODS: The changes of internal incision, the peripheral iris and the fixation of lens intracapsular of 36 eyes were individually observed after the operation. RESULTS: Desemet's membrane detachments occurred in three eyes (8.35%) in the group of Phaco & IOL and four eyes (11.1%) in the group of ECCE & IOL. The difference was not significant. (P > 0.05) Peripheral anterior synechiae occured in three eyes (8.35%) of Phaco & IOL group and in 17 eyes (47.27%) of ECCE & IOL group. The difference was significant (P < 0.05). Intracapsular lens account for 31 eyes (86.1%) of Phaco & IOL group and ten eyes (22.5%) in ECCE & IOL group. The difference was statistically significant. (P < 0.05) CONCLUSION: Phaco & IOL can decrease the incidence of peripheral iris anterior synechiae and increase the chance of intracapsular placement of IOL.

Aged↗

PubMed2000

[The study about the characteristics of upper airway in obstructive sleep apnea syndrome].

OBJECTIVE: To investigate the upper airway (UA) characteristics of the patient's with obstructive sleep apnea syndrome (OSAS) and analyses the value of computer assisting fiberoptic pharyngoscopy with müller's maneuver (CFPMM) in topodiagnosis of OSAS. METHODS: The pharyngxes of 30 cases with OSAS and 30 controls were examined by CFPMM. The cross-section area at velo- and tongue-pharyngeal, pharyngeal collapsibility, sites of UA obstructive and their anatomical factors were measured and calculated and the correlation between the anatomical abnormalities of UA and outcomes of polysomnography (PSG) were analysed. RESULTS: 1. CFPMM can accurately measure and calculate the cross-section area of the upper airway. 2. mean areas of velopharyngeal and tongue-pharyngeal were significantly less than those in control subjects (all P < 0.05). OSAS patient's also showed relatively much larger collapsibility at sach site of the UA than controls. 3. At müller's maneuver, all the areas of OSAS patient's were below 40 mm2 and 60% cases appeared complete occlusion in pharyngeal. 4. All patient's had obstruction at velopharymx and airway collapses at multiple sites in 40% of cases. 5. At velopharyngeal the anatomical factors causing obstruction mainly were posterior displacement of soft palate, thicken and collapse of the pharyngeal wall. Besides the redundant lymph tissue at tongue base and posterior displacement of the tongue base, enlarged inferior pole of tonsil and collapse of pharyngeal wall played an important role at tongue-pharyngeal obstruction. 6. Diminished pharyngeal apertures and collapsibility were associated with increased rates of apnea and hypopnea index (P < 0.05). CONCLUSION: 1. CFPMM is able to measure and calculate UA's cross-section area and collapsibility, determine the site of obstruction, and helping the treatment. 2. Complete occlusion of UA at müller's maneuver is the criterion to determine site of UA obstruction in OSAS patient's during waking hours. 3. The anatomical abnormalities of UA of patients is reflects the severity of the OSAS.

Adult↗

PubMed2000

[Value of preservation of uvula in uvulopalatopharyngoplasty].

OBJECTIVE: To explore the effect of the modified Uvulopalatopharyngoplasty (UPPP) where uvula is preserved in the operation, and whether the postoperative complications are diminished. METHODS: Thirty consecutive patients with the obstructive sleep apnea syndrome (29 men, 1 woman) were analyzed by questionnaire, polysomnography and oral cavity measurement before and 6 months after uvulopalatopharyngoplasty to assess the surgical outcome and value of preservation of uvula in the operation. RESULTS: Eighty-seven percent of patients reported improvement of snoring and daytime sleepiness. Fifty-three percent of patients showed a decrease of at least 50% in the apnea and hypopnea indices. Among the mild and moderate obstructive sleep apnea (AHI < 50), 73.3% of them showed a decrease of at least 50% in the AHI. No velopalatal insufficiency occurred. The result of oral cavity measurement showed that the uvula, which was preserved completely during the operation, began to contract 2 weeks after the operation. Three to six month after operation, uvula contracted to the normal length and the anatomical shape of the pharyngeal cavity became normal. CONCLUSIONS: The results of the uvula preserving UPPP indicate that this approach not only improves the effect of the UPPP, but also avoids the postoperative complications. The uvula that preserved completely during the operation will contract to the normal length progressively.

Adult↗

PubMed1999

Role of reactive oxygen species and p53 in chromium(VI)-induced apoptosis.

Apoptosis is a programmed cell death mechanism to control cell number in tissues and to eliminate individual cells that may lead to disease states. The present study investigates chromium(VI) (Cr(VI))-induced apoptosis and the role of reactive oxygen species (ROS) and p53 in this response. Treatment of human lung epithelial cells (A549) with Cr(VI) caused apoptosis as measured by DNA fragmentation, mitochondria damage, and cell morphology. Cr(VI)-induced apoptosis is contributed to ROS generation, resulting from cellular reduction of Cr(VI) as measured by flow cytometric analysis of the stained cells, oxygen consumption, and electron spin resonance spin trapping. Scavengers of ROS, such as catalase, aspirin, and N-acetyl-L-cysteine, decreased Cr(VI)-induced apoptosis, whereas NADPH and glutathione reductase, enhancers of Cr(VI)-induced ROS generation, increased it. p53 is activated by Cr(VI), mostly by ROS-mediated free radical reactions. Cr(VI)-induced ROS generation occurred within a few minutes after Cr(VI) treatment of the cells, whereas p53 induction took at least 5 h. The level of Cr(VI)-induced apoptosis was similar in both p53-positive cells and p53-negative cells independent of p53 status in the early stage (0-3 h) of Cr(VI) treatment. However, at the later stage (3-24 h), the level of the apoptosis is higher in p53-positive cells than in p53-negative cells. These results suggest that ROS generated through Cr(VI) reduction is responsible to the early stage of apoptosis, whereas p53 contributes to the late stage of apoptosis and is responsible for the enhancement of Cr(VI)-induced apoptosis at this stage.

Apoptosis↗

PubMed1999

Unilateral antegrade cerebral perfusion through the right axillary artery provides uniform flow distribution to both hemispheres of the brain: A magnetic resonance and histopathological study in pigs.

BACKGROUND: Bilateral antegrade cerebral perfusion (ACP) has decreased in popularity over the past decade because of its complexity and the risk of cerebral embolism. We used magnetic resonance (MR) perfusion imaging to assess flow distribution in both hemispheres of the brain during unilateral ACP through the right carotid artery via a cannula placed in the right axillary artery in conjunction with hypothermic circulatory arrest. METHODS AND RESULTS: Twelve pigs were randomly exposed to 120 minutes of either bilateral ACP through both carotid arteries (n=6) or unilateral ACP through the right axillary artery (n=6) at pressures of 60 to 65 mm Hg at 15 degrees C, followed by 60 minutes of cardiopulmonary bypass at 37 degrees C. MR perfusion images were acquired every 30 minutes before, during, and after ACP. The brain was perfusion fixed for histopathology. During initial normothermic cardiopulmonary bypass, MR perfusion imaging showed a uniform distribution of flow in the brain. In both the bilateral and unilateral ACP groups, the same pattern was maintained, with an increase in regional cerebral blood volume during ACP and reperfusion. The changes in regional cerebral blood volume and mean transit time were similar in both hemispheres during and after unilateral ACP. No difference was observed between the 2 groups. Histopathology showed normal morphology in all regions of the brain in both groups. CONCLUSIONS: Both bilateral ACP and unilateral ACP provide uniform blood distribution to both hemispheres of the brain and preserve normal morphology of the neurons after prolonged hypothermic circulatory arrest.

Animals↗

PubMed1999

Selection at multiple checkpoints focuses V(H)12 B cell differentiation toward a single B-1 cell specificity.

Phosphatidyl choline (PtC)-specific B cells segregate to the B-1 subset, where they comprise up to 10% of the B-1 repertoire. About half express V(H)12 and Vkappa4/5H and are restricted in V(H)CDR3. We have previously reported that anti-PtC V(H)CDR3 is enriched among V(H)12-expressing cells by selective elimination of pre-B cells. We report here a bias for Vkappa4/5H expression among V(H)12-expressing B cells, even among those that do not bind PtC and are not B-1. This is due in part to an inability of V(H)12 to associate with many light (L) chains but must also be due to a selective advantage in survival or clonal expansion in the periphery for Vkappa4/5H-expressing cells. Thus, the bias for Vkappa4/5H expression is independent of PtC binding, and, as segregation to B-1 occurs after Ig gene expression, it precedes segregation to the B-1 subset. In 6-1 mice, splenic B-1 cells reside in follicles but segregate to follicles distinct from those that contain B-2 cells. These data indicate that selection at multiple developmental checkpoints ensures the co-expression of an anti-PtC V(H)CDR3 and L chain in a high frequency of V(H)12 B cells. This focus toward specificity for PtC facilitates the development of a large anti-PtC B-1 repertoire.

Amino Acid Sequence↗

PubMed1999

Regulation of a cell type-specific silencer in the human interleukin-3 gene promoter by the transcription factor YY1 and an AP2 sequence-recognizing factor.

Negative regulation of cytokine gene transcription is an important mechanism in maintaining homeostasis of immune function. In this study, we characterized a silencer element in the human interleukin-3 gene promoter that is responsible for the cell-specific expression of interleukin-3. This silencer activity was proposed to be mediated by an unidentified nuclear inhibitory protein (NIP). In this study, we have identified two nuclear factors that are responsible for the silencer activity in T cells. The NIP element forms four specific DNA-protein complexes (designated as complexes A-D) with the Jurkat nuclear proteins. Complex A contains a nuclear protein that shares DNA-binding specificity with the transcription factor AP2 (designated as an AP2 sequence-recognizing factor (ASRF)). Formation of this ASRF complex is required for the NIP silencer function, as mutation of the ASRF-binding site abrogated the silencer activity. Complex B contains the nuclear factor YY1 (Yin-Yang 1), whose function is to down-regulate ASRF activity in the silencer. YY1 activity is supported by data from mutation and cotransfection analyses. Complexes C and D are formed by nonspecific binding proteins and do not express any regulatory activity in the NIP element. These data indicate that a cell type-specific silencer activity might be determined by a unique profile of ubiquitous transcription factors.

DNA-Binding Proteins↗

PubMed1999

Postexposure immunoprophylaxis of primary isolates by an antibody to HIV receptor complex.

mAb B4 is a monoclonal antibody directed against HIV receptor complex. The antibody had broad neutralizing activity against HIV and provided postexposure prophylaxis to hu-peripheral blood leukocyte (PBL)-severe combined immunodeficient mice and chimpanzees. B4 recognized a complex receptor site for HIV on the T cell surface that includes CD4 and also may be influenced by interaction with HIV coreceptors. mAb B4 preferentially neutralized primary HIV-1 isolates compared with T cell line-adapted strains, including syncytium-inducing and non-syncytium-inducing phenotypes, representatives from HIV-1 subtypes A-G, as well as HIV-2, simian immunodeficiency virus, and chimeric simian/human immunodeficiency virus (SHIV). Neutralization was demonstrated in both pre- and postinfection models. The administration of mAb B4 after infectious challenge totally interrupted the infection of hu-PBL-severe combined immunodeficient mice by PBL-grown HIV-1 and the infection of chimpanzees by chimp-adapted HIV-1. This mode of protection suggested that the anti-HIV receptor antibody is efficacious for prophylaxis after exposure to HIV and for prevention of maternal transmission and may be an effective antiretroviral agent for treatment.

Animals↗