Biomedical subjects

C Huang

Publications and source records attributed to C Huang.

At least 127 records · Page 7Linked to original sources

PubMed2001

Arsenic-induced NFkappaB transactivation through Erks- and JNKs-dependent pathways in mouse epidermal JB6 cells.

Tumor promoting effects of arsenic are believed to be associated with its transactivation activity on transcription factors, such as AP-1 and NFkappaB. However, the results from different groups studying the effects of arsenic on NFkappaB activation are contradictory in different cell models. Since arsenic is a strong skin carcinogen, we have investigated the activation of NFkappaB by arsenic in a mouse skin epidermal cell line, JB6 cells. Exposure of cells to arsenite or arsenate led to NFkappaB transactivation in mouse epidermal JB6 NFkappaB-luciferase reporter stable transfectants, C141 NFkappaB mass1. This induction of NFkappaB activity by arsenic was dose- and time-dependent. The transactivation of NFkappaB by arsenic appeared to be through activation of Erks and JNKs pathways because increased NFkappaB activity by arsenic could be dramatically inhibited by either pre-treatment of cells with PD98059 or overexpression of dominant negative JNK1. That Erks activation is required for arsenic-induced NFkappaB transactivation was further supported by the findings that arsenic-induced NFkappaB transactivation was impaired in JB6 30.7b cells, which were deficient in Erks.

Animals↗

PubMed2001

[Epidemiological features of injuries in middle and primary schools students of Hui and Han nationalities in Ningxia].

OBJECTIVE: To find out the present situation and causes of injuries and risk factors of accidental injuries among students and to provide evidence for prevention and reduction of accidental injuries. METHODS: A cluster sampling study on the situation of injuries was conducted in 21 civic middle and primary schools with 7,000 (6-19 years old) students during the December 1999 and November 2000 in Ningxia province. RESULTS: Results showed that the total rate of injuries was 20.40% with boys higher than girls (P < 0.01). Five kinds of injuries took the leading place: injuries from falls (9.27%), bumps (4.55%), knive-cutting (2.99%), traffic accidents (2.00%) burns and scalds (1.66%). The rate of injuries was 22.11% in students of Hui nationality, higher than the ones in Han nationality (19.6%, P < 0.025). The rate of injuries among junior middle school students was the highest (24.11%), followed by high school students 22.15%, and primary students 17.63%. Causes, times, places, parts of the bodies and the treatment regarding injuries were analysed. CONCLUSION: The challenge of accidental injuries in middle and primary school students was although serious but avoidable. Comprehensive preventive measures should be take actively and effectively.

Child↗

PubMed2001

Growth inhibition of epidermal growth factor-stimulated human glioblastoma cells by nicardipine in vitro.

BACKGROUND: The objective of this work was to observe and analyze the effects of epidermal growth factor (EGF) and the calcium channel antagonist nicardipine on the growth of U251MG, a human malignant glioma cell line, which have high-affinity EGF receptors. METHODS: The growth effects of EGF and nicardipine on U251MG cultured in serum-free and serum-supplemented (10% fetal bovine serum, FBS) medium respectively were observed by MTT colorimeritric analysis. RESULTS: EGF significantly enhanced the growth of U251MG cells in a dose-dependent manner in serum-free medium. The maximal effect was seen at 20 ng/ml. The effects of EGF approximated those obtained in 10% FBS. Nicardipine decreased U251MG cell proliferation, especially in serum-supplemented medium, and completely blocked the growth-stimulated effects of EGF. The combined effects of EGF (10 ng/ml) and nicardipine equaled those of nicardipine alone. CONCLUSIONS: When serum was absent, the U251MG cells showed a pronounced mitogenic response to EGF in a dose-dependent manner, which approximated that achieved with 10% FBS. The addition of serum obscured this effect. Nicardipine suppressed the growth of U251MG cells and completely blocked the growth-stimulated effects of EGF may suggest a possible role of this drug as adjuvant therapy for human malignant gliomas.

Calcium Channel Blockers↗

PubMed2001

Protective effect of ginsenoside Rg1 on dopamine-induced apoptosis in PC12 cells.

AIM: To explore the possible molecular mechanism of exogenous dopamine-induced apoptosis in PC12 cells and the protective effect of ginsenoside Rg1. METHODS: Flow cytometric assay was used to quantify the apoptotic cells and measure the percentage of cells with positive Bcl-2 and Bax proteins. The morphology of apoptotic cells was evaluated by transmission electron microscope. DNA fragmentation was observed by gel electrophoresis. Caspase-3 activity was determined by fluorescent spectrofluorometer and the expressive bcl-2 and bax mRNA by semiquantitative reverse transcription polymerase chain reaction (RT-PCR). RESULTS: Dopamine 0.15, 0.30, 0.45, and 0.60 mmol/L induced PC12 cell apoptosis from 1.1 % +/- 0.4 % (control) to 41 % +/- 3 %, 46.4 % +/ -2.7 %, 53 % +/ -3 %, and 64.5 % +/- 2.7 %, respectively. After treatment with dopamine 0.45 mmol/L following pretreatment with Rg1 10 micromol/L for 24 h, the percentage of apoptotic cells and caspase-3 activity decreased from 53 % +/- 3 % and 683 +/- 8 (mean fluorescence intensity, MFI) to 1.9 % +/- 0.6 % and 325 +/- 5, and the percentage of cells with positive Bcl-2 protein increased from 14.3 % +/- 1.1 % to 25.9 % +/- 1.6 %, however, the percentage of cells with positive Bax protein decreased from 48 % +/- 3 % to 35 % +/- 3 %, compared with group treated with DA 0.45 mmol/L alone. CONCLUSION: Ginsenoside Rg1 protected PC12 cells against apoptosis by inhibiting the activation of caspase-3 and regulating the ratio of Bcl-2 to Bax protein.

Animals↗

PubMed2001

[Syphilis in pregnancy women].

OBJECTIVE: To investigate obstetric treatment and pregnancy outcomes of syphilis infection during pregnancy. METHODS: 64 pregnant women diagnosed with syphilis by serological assays were divided into treated group and untreated group according to whether they accepted full-dose treatment against syphilis or not. Patients in the treated group accepted benzathine penicillin(2.4 million units once per week) intramuscular injection for three weeks. The outcome of pregnan after treatment was observed and compared between the two groups. RESULTS: There were 5 cases of primary syphilis (7.8%), 29 cases of secondary syphilis (45.3%), and 30 cases of latent syphilis (46.9%) among the 64 cases. The occurrences of premature birth, fetal intrauterine death, and stillbirth were 0, and 3 cases of congenital syphilis in total 13 cases who carried pregnancy to term in the treated group; while 4, 11, 3, and 10 in the untreated group respectively. In treated group, the 3 babies with congenital syphilis were born from 10 mothers received treatment after 24 gestational weeks, while no congenital syphilis in the 3 women started treatment before 24 weeks. CONCLUSIONS: Pregnant syphilis is prone to be misdiagnosed because of its slight symptom, so it is especially important to screen syphilis as a routine among high risk pregnant women. Premature, fetal death and congenital syphilis can be well controlled through regular and early treatment during pregnancy, yet congenital syphilis can not be avoided completely.

Adolescent↗

PubMed2001

[Causal factors of decline disease in exotic pine (Pinus taeda and P. elliottii) plantations].

Investigation on the cause of the decline of exotic pine plantations in Anhui Province was carried out from 1995 to 2000. The results showed that the cause might develop from the interaction of three or more sets of factors. The first group of factors called as predisposing factors were high and low temperature and rainfall, poor soil fertility, and excessive soil bulk density, soil moisture, and of stand density; the second group of factors called as inciting factors were insect defoliators, damaging diseases of needles, late spring frost, severe drought, and excessive resin-tapping, and the third group of factors called as contributing factors were several biotic agents such as shoot blight infected by Sphaeropsis sapinea, decay wood and root rot by fungi, and bark beetles and wood borers.

Causality↗

PubMed2001

[Relationship between decline disease of exotic pines(Pinus taeda and P. eliottii) and forest stand and environmental factors].

The relationship between decline disease of exotic pines(Pinus taeda and P. eliottii) plantations in Anhui Province and forest stand status and environmental factors was quantitatively analyzed. Among 18 variable factors from 4 types of factors(climate, soil, stand status, and other diseases and insect pests), 10 factors contributed greatly to the state of illness. These were tree age, stand density, resin-tapping, rainfall, temperature, clay soil, stone soil, soil depth, water-logging, and other diseases and insect pests. Of them soil depth and rainfall negatively, and others positively related with the severity of disease. Accordingly, a linear multiple regression model was derived, which might predict the developmental level of decline disease at any given conditions of exotic pine plantation. In addition, the spiral chart of decline disease was mapped based on the action size and time order of various nosogenetic factors during the incidence of decline disease, which was used to visually describe and quantitatively analyze the disease with complicated causes.

Causality↗

PubMed2001

[Effect of environmental factors on N and P uptake by Gracilaria tenuistipitata var. liui Zhang et Xia].

The effect of light intensity, pH, temperature, salinity on the uptake of nitrogen and phosphorus by Gracilaria tenuistipitata var. liui Zhang et Xia was were studied under laboratory conditions. The uptake rate of nitrogen reached as high as 0.32-0.36 mumol.g-1.h-1 at favorable light intensity of 800-2400 mumol photon.m-2.s-1, while that of phosphorus reached 0.017-0.018 mumol.g-1.h-1 at 320-1600 mumol photon.m-2.s-1. The nutrient uptake rate reached the maximum at pH 8.0. A significant difference of N uptake rate at different temperatures or salinities and that of P uptake rate at different temperatures were found. The N uptake rate was higher at 21-26 degrees C and 20@1000-28@1000, but P uptake was higher at 21-26 degrees C. There was no interaction between temperature and salinity.

Absorption↗

PubMed2001

[A community-based acquired immunodeficiency syndrome education intervention study in Kunshan county].

OBJECTIVE: To evaluate the effectiveness of a community-based acquired immunologic deficiency syndrome (AIDS) educational intervention in young adults. METHODS: A quasi-experimental design was used. Two townships in Kunshan county, matched by socioeconomic characteristics, were randomly assigned to intervention or control groups. Eight hundred young adults aged 18-30 were recruited from the two townships as study subjects. A 12-month comprehensive educational intervention on AIDS prevention was conducted in the intervention group through local family planning services. RESULTS: After intervention, subjects in intervention group significantly improved their knowledge on AIDS and attitudes related to AIDS prevention. Reported rate of condom use during the last episode of sexual intercourse increased from 8.5% at baseline to 14.4% after intervention (chi 2 = 4.66, P = 0.030 8). No obvious change was observed among subjects in control group. CONCLUSION: This study demonstrated the feasibility of integration of AIDS educational intervention into the existing family planning services. Integration of AIDS programs into family planning program should be considered as a realistic approach for AIDS control in China.

Acquired Immunodeficiency Syndrome↗

PubMed2001

Reuse of water treatment plant sludge and dam sediment in brick-making.

In this study, an attempt was made to use water treatment plant (WTP) sludge and dam sediment as raw materials for brick-making through the sintering process. The sinter of dam sediment fired at 1,050 degrees C had a less than 15% ratio water absorption, and its compressive strength and bulk density met the Chinese National Standard (CNS) for first level brick. The WTP sludge sinter made under the same operating condition exhibited higher water absorption, larger shrinkage, but poorer compressive strength. When fired at 1,100 degrees C, the shrinkage of the WTP sludge sinter was as high as 45%, although its compressive strength and water absorption of WTP sludge brick still met the standard for the first level brick. To reuse WTP sludge in an economical way, mixtures of various proportions of WTP sludge to dam sediment are used as raw materials. A satisfactory result was achieved when the ratio of the WTP sludge was less than 20% of the mixture. Results of tests indicated that the sinter of dam sediments which are fired at a temperature of 1000 to approximately 1100 degrees C has reached the requirement for tile brick.

Adsorption↗

PubMed2001

[The mechanism of percutaneous transluminal balloon angioplasty as assessed by intracoronary ultrasound].

OBJECTIVE: To elucidate the mechanism of coronary balloon angioplasty intracoronary ultrasound imaging. METHOD: Intracoronary ultrasound imaging was performed in 68 coronary arteries of 52 patients. Ultrasound images obtained at the treatment site before and after balloon angioplasty were analyzed quantitatively for cross-sectional lumen area, area enclosed by internal elastic lamina (IELA) and plaque area. Qualitative analysis included assessment of presence of dissection, plaque composition and plaque topography. RESULTS: The internal elastic lamina area was significantly enlarged after balloon angioplasty [(6.67 +/- 1.45) mm(2) vs (8.14 +/- 1.13) mm(2), P < 0.05]. The difference between IELA before and after balloon angioplasty DeltaIELA was different among different plaques (fatty plaque 1.84 mm(2), fibrous plaque 1.52 mm(2), calcified plaque 0.40 mm(2), mixed plaque 1.23 mm(2)). 85% of the lesions had dissection in some degree after PTCA. Severe dissections occurred mostly in calcified lesions. CONCLUSION: The improvement in lumen dimensions after coronary balloon angioplasty is a result of both vessel stretch, as demonstrated by a larger internal elastic lamina area at the treated site, and dissection. Calcified lesions will have less vessel stretch and severer dissection after balloon angioplasty.

Adult↗

PubMed2001

[Preliminary study of effect of antisense hsc70 effect on the stability of mutant p53 protein].

OBJECTIVE: To investigate the effect of antisense hsc70 RNA on the stability of mutant p53 protein. METHODS: Using DNA recombination technique, retroviral recombinant expressing antisense hsc70 RNA was constructed and transfected into MCF7/Adr cells. After the existence of foreign DNA had been identified by the polymerase chain reaction (PCR) method, the protein level of hsc70 was detected by Western blot. The half-life of mutant p53 was detected by p53 stability assay. RESULTS: With the stable expressive transfectant cell strains obtained through G418 selection, the foreign DNA in transfectant cells were confirmed by PCR method and the repression rate of hsc70 protein was 42%. The half-life of mutant p53 in MAc70 cell was 10 hours which was significantly lower than the control cells. CONCLUSION: Antisense hsc70 RNA is able to lower the hsc70 protein level and significantly increase the instability of mutant p53 protein in MCF7/Adr human breast cancer cells.

Blotting, Western↗

PubMed2001

[Microscopic and UV identification of Millettia pulchra Kurz var. Laxior(Dunn) Z. Wei].

OBJECTIVE: To provide evidences for the identification of Millettia pulchra Kurz var. Laxior (Dunn) Z. Wei. METHOD: Microscopic and UV identification. RESULT: Obvious identificational character was found, fox example, there are stone cell groups and fiber bundles arranging with ring uncontinously in cortex; there are fibers containing square crystals in the powder; the EtOH solution of the powder has absorbing peaks in 261, 216, 204 +/- 1 nm wave length, and the CHCl3 solution 262 +/- 1 nm wave length. CONCLUSION: The character provided evidences for the identification of Millettia pulchra Kurz var. Laxior(Dunn) Z. Wei.

Millettia↗

PubMed2001

[Clinical significance of c-myc oncogene amplification in primary hepatocellular carcinoma by interphase fluorescence in situ hybridization].

OBJECTIVE: To investigate the relationships between c-myc oncogene amplification in primary hepatocellular carcinoma (HCC) and its clinical prognosis. METHODS: To detect c-myc oncogene amplification in 100 cases with primary HCC and in 6 cases with satellite nodes by interphase fluorescence in situ hybridization (FISH). RESULTS: c-myc amplification was detected in 92 of 100 (92%) cases with HCC, 37 of which (37%) showed high copy amplification (HC), 55 (55%) low copy amplification (LC) and 8 (8%) single copy or no amplification (SC). There wasn't statistically different significance between the frequency of c-myc amplification and clinical stage and tumor size, and pathological types (P > 0.05), however, in the 90 follow-up resected cases, the one-year rates of recurrence in HC, LC and SC were 70.6% (24/34), 39.6% (19/48) and 12.5% (1/8) respectively (P < 0.05) but the recurrence rates after more than one year were 14.70% (5/34), 14.6% (7/48) and 0 (0/8) respectively (P > 0.05). Meanwhile, two-year survival rate of patients with HC was significantly lower in comparison with those with LC and SC (P = 0.001). CONCLUSIONS: There is a high frequency of c-myc oncogene amplification in primary HCC and the fact that the patients with HC showed poorer prognosis indicates that the level of c-myc oncogene amplification may be a sensitive index in the prognosis of HCC.

Adult↗

PubMed2001

[A comparative study of clinical application of two types appliances for maxillary molar distalization].

OBJECTIVE: The aim of this study is to evaluate advantages and disadvantages of two types of appliances for maxillary molar distalization. METHODS: Totally, 28 patients with class II malocclusion resulting from molars shifting mesially were treated using two different molar distalization methods, including using removable and fixed appliances. An intra-oral removable acrylic appliance with headgear for extra-oral traction resulted in tipping the maxillary first molars distally. The modified rapid helix expansion appliance (MRHEA), which consisted of bands, anchorage teeth, Nance palatine bases, helix bars and connecting rods, made the maxillary first molars move parallel distally. RESULTS: The desired efforts were gained in 7 or 9 months by using removable appliances, but only 2 or 2.5 months if using MRHEA. The treatment results of using removable appliances were dependent on patients' cooperation, however, the method of using fixed appliance overcame some shortcomings of other molar distalization techniques, and this appliance would not lead to the distal inclination of the crown of the shifted teeth. CONCLUSION: These two methods could convert the class II molar relationship to class I. The MRHEA can save much chair-side time, and shorten the period of treatment, move molars distally parallel.

Child↗

PubMed2001

[Possible mechanism of the protective effects of ginsenoside Rg1 on apoptosis in PC12 cells].

AIM: To explore the possible mechanism of the protective effect of ginsenoside Rg1 on dopamine-induced apoptosis in PC12 cells. METHODS: Flow cytometric assay was performed to quantify the apoptotic cells and detect the positive percentage of Bcl-2 and Bax proteins in PC12 cells. The expression of bcl-2 and bax mRNA was identified by reverse transcription polymerase chain reaction (RT-PCR). The CPP32 activity was measured by fluorescent spectrofluorometer. RESULTS: Dopamine-induced apoptosis in PC12 cells was inhibited by pretreatment with 10 mumol.L-1 Rg1. Simultaneously, the expression of Bcl-2 protein and mRNA were increased, and the Bax protein and mRNA were decreased. The activation of CPP32 was inhibited after pretreatment with Rg1. CONCLUSION: Rg1 protects against dopamine-induced apoptosis in PC12 cells and this effect might be attributed to its regulation of the ratio of Bcl-2 to Bax and its inhibition of the activation of CPP32.

Animals↗

PubMed2000

Induction of activator protein-1 through reactive oxygen species by crystalline silica in JB6 cells.

We reported previously that freshly fractured silica (FFSi) induces activator protein-1 (AP-1) activation through extracellular signal-regulated protein kinases (ERKs) and p38 kinase pathways. In the present study, the biologic activities of FFSi and aged silica (ASi) were compared by measuring their effects on the AP-1 activation and phosphorylation of ERKs and p38 kinase. The roles of reactive oxygen species (ROS) in this silica-induced AP-1 activation were also investigated. We found that FFSi-induced AP-1 activation was four times higher than that of ASi in JB6 cells. FFSi also caused greater phosphorylation of ERKs and p38 kinase than ASi. FFSi generated more ROS than ASi when incubated with the cells as measured by electron spin resonance (ESR). Studies using ROS-sensitive dyes and oxygen consumption support the conclusion that ROS are generated by silica-treated cells. N-Acetylcysteine (an antioxidant) and polyvinyl pyridine-N-oxide (an agent that binds to Si-OH groups on silica surfaces) decreased AP-1 activation and phosphorylation of ERKs and p38 kinase. Catalase inhibited phosphorylation of ERKs and p38 kinase, as well as AP-1 activation induced by FFSi, suggesting the involvement of H(2)O(2) in the mechanism of silica-induced AP-1 activation. Sodium formate (an ( small middle dot)OH scavenger) had no influence on silica-induced MAPKs or AP-1 activation. Superoxide dismutase enhanced both AP-1 and MAPKs activation, indicating that H(2)O(2), but not O(2), may play a critical role in silica-induced AP-1 activation. These studies indicate that freshly ground silica is more biologically active than aged silica and that ROS, in particular H(2)O(2), play a significant role in silica-induced AP-1 activation.

Animals↗

PubMed2000

Endomorphin and mu-opioid receptors in mouse brain mediate the analgesic effect induced by 2 Hz but not 100 Hz electroacupuncture stimulation.

This work was designed to examine whether brain endomorphins (EM1 and EM2), the endogenous mu-opioid ligands, are involved in electroacupuncture (EA)-induced analgesia in the mice. C57BL/6J mice were given EA for 30 min and the effect of EA-induced analgesia was assessed by radiant heat tail flick latency (TFL). Intracerebroventricular (i.c.v.) injection of mu-opioid receptor antagonist D-Phe-Cys-Tyr-D-Tyr-Orn-Thr-Pen-Thr-NH(2) (CTOP), or antiserum against EM1 or EM2 was performed to see whether EA analgesia could be blocked. The results showed that: (1) i.c.v. injection of CTOP at 25-100 ng dose-dependently antagonized the analgesia induced by EA of 2 Hz, but not 100 Hz. (2) Intracerebroventricular injection of EM1 antiserum (5 ml, 1:1 or 1:10 dilution) dose-dependently antagonized 2 Hz, but not 100 Hz EA analgesia. (3) EM2 antiserum showed similar effect at 1:1 dilution. The results are interpreted to mean that endogenously released EM1 and EM2 and the cerebral mu-receptors are involved in mediating 2 Hz but not 100 Hz EA analgesia in the mice.

Animals↗