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Biomedical subjects

P Huang

Publications and source records attributed to P Huang.

At least 91 records · Page 5Linked to original sources
PubMed2000

Genome-wide allelotype analysis of sporadic primary nasopharyngeal carcinoma from southern China.

Nasopharyngeal carcinoma (NPC) is one of the most common malignant tumors in Southern China, especially in the Guangdong area. To demonstrate a comprehensive profile of loss of heterozygosity (LOH) in NPC, we applied a large panel of 382 microsatellite polymorphism markers covering all the 22 autosomes in 98 cases of sporadic primary NPC. Of the 335 informative markers, 83 loci showed high level of LOH (presence in equal to or more than 30% cases) and most of the high frequent loci were clustered to chromosome 1p36 and 1p34, 3p14-p21, 3p24-p26, 3q25-q26 and 3q27, 4q31 and 4q35, 5q15-21 and 5q32-q33, 8p22-p23, 9p21-p23 and 9q33-q34, 11p12-p14, 13q14-q13 and 13q31-q32, 14q13-q11, 14q24-q23 and 14q32. High frequency of LOH was found in chromosomes 3, 5, 9 and 11 (>/=50%), while medium frequency of LOH was found in chromosomes 1, 4, 6, 14, 17 and 19 (40-49%). Several new regions showing high frequency of LOH were found in chromosome 1p36, 3q25-q26, 3q27, 5q15-q21, 8p22-p23 and 11p12-14. The relationship between LOH and TNM stage of NPC was evaluated. Regions 6p23 (D6S289), 8p23.1 (D8S549) and 9q34.2 (D9S1826) showed higher frequency of LOH in later stages (III and IV) than in earlier stages (I and II) (P<0.05). Thus, our study provides a global view on allelic loss in the development of NPC and should shed light on the way for localization of putative tumor suppressor genes associated with the pathogenesis of NPC.

Adult↗
PubMed2000

Comparison of action of paclitaxel and poly(L-glutamic acid)-paclitaxel conjugate in human breast cancer cells.

The new anticancer agent poly(L-glutamic acid)-paclitaxel (PG-TXL) is a conjugate of paclitaxel and the water-soluble polyglutamate carrier. The observation that PG-TXL appears to possess antitumor activity superior to free paclitaxel in preclinical studies suggests that PG-TXL might possess favorable pharmacokinetic properties and/or have a mechanism of action different from that of paclitaxel. The purpose of this study was to compare the pharmacological action of PG-TXL and free paclitaxel in a panel of breast cancer cell lines with emphasis on their ability to induce apoptosis, their effects on cell cycle progression, and their cellular uptake. Morphological analysis and biochemical characterizations demonstrated that both compounds have similar abilities to induce apoptosis in cells expressing wild-type p53 (MCF-7) or mutant p53 (MDA-MB435 and MDA-MB453). Although MCF-7 cells were less sensitive to each compound than MDA-MB435 and MDA-MB453 cells, transfection experiments demonstrated that p53 did not appear to play a significant role in drug-induced cell death with either agent. Flow cytometry analysis further revealed that both free paclitaxel and PG-TXL induced a characteristic G2/M arrest in the cell cycle, consistent with the disturbance of microtubule polymerization as their mechanism of action. Western blot analysis showed that paclitaxel and PG-TXL downregulated HER2/neu expression in a similar fashion. HPLC analysis revealed that paclitaxel was released from the PG-TXL conjugate in vitro. The released paclitaxel, not the glutamic acid polymer, was subsequently transported into the cells. These results suggest that PG-TXL exerts its anticancer activity by continuous release of free paclitaxel, and that the favorable pharmacokinetics and drug distribution of the PG-TXL conjugate in vivo are likely the main factors contributing to its superior anticancer activity.

Antineoplastic Agents, Phytogenic↗
PubMed2000

[The effects of smoking on pulmonary IgA and immune response to antigen in young smokers].

OBJECTIVE: To evaluate the influence of smoking on pulmonary immune function. METHODS: Twelve healthy volunteers, of them 5 smokers and another 7 nonsmokers, underwent right middle lobe bronchoalveolar lavage (BAL) and transbronchial instillation of KLH into lingula. Dimeric and monomeric IgA, albumin and cellular differential count in BALF were measured. Serum anti-KLH IgA was tested at various days after instillation of antigen. RESULTS: The level of monomeric IgA, counts of neutrophils and pulmonary macrophages in BALF of smokers were significantly higher than nonsmokers. Positive correlations were found between mIgA, and albumin and neutrophils counts. Serum anti-KLH IgA level in smokers increased slower and decreased earlier than in nonsmokers. CONCLUSIONS: Smoking causes inflammatory responses in lung and injures pulmonary immune response to antigen in young smokers.

Adult↗
PubMed2000

[Inhibition of the expression of Epstein-Barr virus antigens in vitro by Chinese medicine compound "Dongxia wan"].

OBJECTIVE: To investigate the effect of Chinese medicine "Dongxia wan" on the expression of Epstein-Barr virus (EBV) antigens in vitro. METHODS: Cell culture and indirect immunoenzyme methods were used. RESULTS: When Raji and B95-8 cells were cultured with 20-80 microg/'ml of "Dongxia wan", the expression of EBV early antigen (EBV-EA) and EBV capsid antigen (EBV-VCA) induced by croton oil and n-butyric acid and the natural expression of EBV-VCA were all inhibited significantly. The inhibition rates were 19.3% - 49.84%, 34.63% - 45.61% and 21.67% - 47.78%, respectively. When Raji and B95-8 cells were pretreated with "Dongxia wan" the expression of EBV-EA and EBV-VCA were also inhibited obviously. CONCLUSIONS: Chinese medicine "Dongxia wan" can inhibit the expression of EBV antigens in target cells, it may be used to the prevention and treatment of EBV related diseases.

Antigens, Viral↗
PubMed2000

[Effect of ligustrazine injection on vascular endothelial cell of the patients with arteriosclerosis obliterans].

OBJECTIVE: To study the effect of ligustrazine injection (LI) on vascular endothelial cell of the patients with arteriosclerosis obliterans (ASO) and explore the new pathway of investigating effective vascular protective agents in Chinese medicinal herbs. METHODS: Forty-six patients with ASO in the LI group treated by LI were observed, their circulating endothelial cells (CEC) were detected quantitatively before and after treatment. The results were compared with the CEC of 53 cases of healthy persons (control group) in the same period. RESULTS: In the LI group, the immediate cure rate was 45.7% (21 cases), markedly effective rate 36.9% (17 cases) and the effective rate 17.4% (8 cases). The CEC of patients before treatment was 4.39 +/- 1.76/0.9 microliter, which was significantly higher than that of the healthy persons (1.53 +/- 0.42/0.9 microliter). It could be reduced after treatment, along with the improvement of symptoms and signs, to 2.43 +/- 0.87/0.9 microliter, P < 0.01. CONCLUSION: LI in treating ASO not only displays extraordinary effect, but also has good effect in curing the damage of endothelial cells.

Aged↗
PubMed2000

[Glutamate in experimental acute elevated intraocular pressure models of rabbits].

OBJECTIVE: To measure the concentration of glutamate (Glu) in the retina of eyes with experimentally elevated intraocular pressure (IOP). METHODS: High-performance liquid chromatography (HPLC) was utilized to measure the Glu in the retina. 18 rabbits were divided into three groups, each group including 6 rabbits. In one eye of each rabbit in group 1, the IOP was elevated to 60 mm Hg (1 mm Hg = 0.133 kPa) by the anterior chamber perfusion with normal saline maintained for 4 hours, while the IOP of the other eye was maintained at 20 mm Hg by the same method. In group 2, the same experimental method was carried out, but the elevated IOP was maintained at 30 mm Hg. Group 3 was a normal control group without perfusion. RESULTS: High-IOP eyes (60 mm Hg and 30 mm Hg) had high glutamate concentration in the retinal tissue than that in low-IOP eyes (20 mm Hg) (P < 0.05). CONCLUSION: Elevated IOP induces higher content of glutamate in the retina.

Animals↗
PubMed2000

[An experimental study on cerulenin induced apoptosis of human colonic cancer cells].

OBJECTIVE: To investigate whether cerulenin could induce apoptosis and suppress the proliferation of human colonic cancer cells. METHODS: Cell morphology, microculture tetrazolium assay (MTT), agarose gel electrophoresis and flow cytometry assays were performed to identify the inhibitory effect on cell proliferation and the induction of apoptosis in human colonic cancer cells (LoVo). RESULTS: Cerulenin was able to induce LoVo cells death via apoptosis. Cerulenin also inhibited the proliferation of LoVo cells in vitro and was dose-dependent. Nuclear DNA of apoptotic cells displayed ladder bands characteristic of internucleosomal DNA fragmentation and apoptotic peak. The inhibitory effect of cerulenin on proliferation of LoVo cells was associated with cell cycle arrest from S to G(2)-M phase transition and with induction of apoptosis. In contrast, cerulenin could not affect the proliferation of human fibroblasts in vitro. CONCLUSION: The fatty acid synthase inhibitor, cerulenin, enables to induce cell apoptosis and to suppress the growth of human colonic cancer cells by inhibition of the synthesized fatty acids endogenously in the cancer cells.

Apoptosis↗
PubMed2000

[Cerulenin inhibits growth of human colonic carcinoma in nude mice].

OBJECTIVE: To determine the effects of fatty acid synthase inhibitor, cerulenin, on tumor growth of human colonic carcinoma (LoVo) in nude mice. METHODS: The transplantable colonic carcinoma cell line LoVo model was established in BALB/CA-nu/nu mice by subcutaneous implantation. Cerulenin was administrated by i.p. injection (80 mg/kg, 160 mg/kg each time) for 10 times. 17 days later the mice were killed and tumor size evaluated. RESULTS: The size of tumors in cerulenin-treated group were significantly smaller than in control group and were similar to that of the 5-Fu treated group. Transmission electronic microscopy (TEM) revealed that death of LoVo cells treated by cerulenin was associated with apoptosis characterized by cell shrinkage, condensation and chromosome fragmentation. bcl-2 oncoprotein expression rate was significantly lower in cerulenin-treated group in comparing with the control group. The expression rate of bax was the opposite to that of bcl-2. CONCLUSIONS: Cerulenin effectively suppresses the growth of human colonic carcinoma cells in vivo. The mechanism of cell death may be correlated with apoptosis, and bcl-2 and bax gene may play an important role in regulating cerulenin-induced apoptosis.

Animals↗
PubMed2000

[Proliferation inhibition and apoptosis induction of K562 cells by fatty acid synthase inhibitor--cerulenin].

OBJECTIVE: To investigate the effect of fatty acid synthase (FAS) inhibitor--cerulenin on K562 leukemia cells and its mechanism. METHODS: Inhibition rate of cerulenin on K562 leukemia cells was assayed by MTT method, cell apoptosis by flow cytometry (FCM) and agarose gel electrophoresis. RESULTS: When treated with 10(-9) - 10(-5) mol/L of cerulenin for 24 h, the proliferation of K562 cells was obviously inhibited with dose related effect. At the same concentrations, the inhibition rates of human skin fibroblasts were all lower than 30%. When K562 cells were treated for 12 h with 50 microg/ml and 60 microg/ml of cerulenin, the apoptosis rate revealed by FCM was 42.30% and 38.8%, respectively, and DNA agarose gel electrophoresis showed the typical DNA ladder of apoptosis. CONCLUSION: Fatty acid synthase inhibitor--cerulenin inhibits proliferation of K562 cells but not of human fibroblasts. Cerulenin mediated cytotoxity is due to apoptosis induction. Fatty acid synthase might be a potential target for anti-leukemia.

Apoptosis↗
PubMed2000

[Analysis of surface markers of expanded human umbilical cord blood cells in vitro].

OBJECTIVE: To explore the optimal timing for in vitro expansion and transplantation of umbilical cord blood hematopoietic cells. METHODS: Hematopoietic cells from human umbilical cord blood were cultured with G-CSF, GM-CSF, rIL-3, rIL-6, SCF and Epo in a long term culture system, the cell cycle and cellular markers were analysed dynamically. RESULTS: CD(3)(+), CD(4)(+)/CD(45RO)(+) and CD(8)(+)/CD(45RO)(+) cells increased at day 3, and reached the highest level at day 7, decreased at day 14, and remained lower level at day 21. CD(4)(+) and CD(8)(+) cells showed no change at day 7, decreased at day 14, and decreased further at day 21. CD(4)(+)/CD(45RA)(+) and CD(8)(+)/CD(45RA)(+) cells decreased after day 3, and decreased further at day 14. HLA-DR(+) cells increased from day 3 to day 7. CD(34)(+) cells increased at day , reached the highest level at day 7, and decreased at day 14. CD(34)(+), CD(34)(+) CD(38)(-), CD(34)(+) CD(38)(+) cells increased 8.8, 7.4 and 8.7 fold at day 7, respectively, as compared with that precultured. The cells in the S phase increased at day 21. CONCLUSIONS: This culture system is able to expand hematopoietic cells of human umbilical cord blood and keeps them intact. The number of hematopoietic cells reached the highest level in the culture from day 7 to day 14, which is the optimal time for transplantation.

Antigens, CD↗
PubMed2000

[Studies on chemical constituents of Peucedanum medium Dunn var. garcile Dunn ex Shan at Sheh].

OBJECTIVE: To study the chemical constitutents in Peucedanum medium var. gracile distributed in Guangxi. METHOD: Chromatography and spectral analysis were used to isolated and elucidate the constituents. RESULT: Eight compounds were isolated from the root of P. medium var. gracile and elucidated as isoimperatorin, phellopterin, bergapten, oxypeucedanin hydrate, byakangelicin beta-sitosterol, hamaudol and mannitol. CONCLUSION: Seven compounds were obtained from this plant for the first time.

5-Methoxypsoralen↗
PubMed2000

[The relationship between GPx activity in gingival fluid and clinical parameters of adult periodontitis].

OBJECTIVE: To study the relationship of glutathione peroxidase (a natural FR scavenger) in gingival cervical fluid (GCF) of patients with periodontitis. METHODS: GCF was collected from 44 sites of 23 patients with adult periodontitis. The volume of GCF was measured with Periotron 8000. GCF-GPx activity was determined by DTNB methods before and after treatment, and the periodontal parameters GI, PD and AL were recorded. RESULTS: GCF-GPx activity was negatively correlated with PD and AL (P < 0.01, P < 0.005), but was not correlated with GI (P > 0.05). After treatment, clinical parameters decreased while GCF-GPx activity increased (P < 0.001), but the increment of GCF-GPx activity showed no correlation with the base level and the changes of clinical parameters. CONCLUSION: The imbalance between FR's production and scavenging might be an important pathological factor of periodontal diseases, and GCF-GPx might be a promising indicator of periodontal status.

Adult↗
PubMed2000

[Study on inhibitory actions of san huang yi gan capsule (SHYGC) on HBeAg with seropharmacological method].

In this paper, the inhibitory actions of SHYGC on HBeAg in vitro were studied with the seropharmacological method. By Enzyme Linked Immuno Sorbent Assay (ELISA), it was found that the rabbit sera containing SHYGC have significant inhibitory effects on HBeAg, and they become stronger with the drug concentration in sera improved and the actions time prolonged, they decrease with the HBeAg concentration improved, and the effects of the sera containing hing-dose drugs equal those of Su Xiao Jing containing 250 micrograms/g effective chloric. The direct external inhibitory effects of SHYGC in original pharmaceutics are stronger than those of the sera containing drugs. It probably indicated that the active ingredients of SHYGC could not be digested and absorbed completely from gastrointestine, or were inactived by metabolism in vivo.

Animals↗
PubMed2000

[mRNA expression of keratoepithelin in cornea after photorefractive keratectomy in rabbits].

OBJECTIVE: To investigate the roles of keratoepithelin(KE) during healing after photorefractive keratectomy (PRK). METHODS: 20 of 24 rabbits underwent bilateral 193 nm excimer laser photorefractive keratectomy to correct 10 diopters of myopia, and the other 4 rabbits as normal group. The mRNA levels of KE in corneas of the rabbits were determined by the in situ hybridization technique with a Digoxigenin labled probe. RESULTS: In normal group, there was no mRNA expression of KE in cornea. on 7, 14 days after operation, mRNA expression of KE was observed in epithelium and stroma of operation group, while on 28 days mRNA expression of KE was observed only in epithelium. CONCLUSION: KE was involved in the synthesis of extracellular matrix during healing after PRK and may play an important role in the development of haze by maintaining proper spacing among collagen fibrils.

Animals↗
PubMed2000

[Multiple factors analysis of myopic regression after photorefractive keratectomy].

PURPOSE: To investigate myopic regression after excimer laser photorefractive keratectomy(PRK) in patients with myopia. METHODS: PRK was performed to correct myopia errors from 1.00 D to 16.00 D diopters on 214 myopia eyes(121 patients). All eyes were divided into two groups: group I--1.00 D(-)-6.00 D (124 eyes), group II--6.25 D(-)-16.00 D(90 eyes). All the patients were followed up for two years. RESULTS: A Significant positive correlation was found between the regression and the extents of attempted correction. The rate of regression in mild to moderate myopia group was 9.7% while in highter group it was 27.8% (P < 0.005). The rate of regression of older age group in lighter myopia group was highter than that in younger case (P < 0.005). Relatively severe haze under the corneal epithelium often accompanies the regression. CONCLUSION: The main factors which caused the myopia regression after PRK was the extent of attempted correction, patients' age and corneal haze.

Adolescent↗
PubMed2000

[Analysis of refractive state after excimer laser photorefractive keratectomy in myopia].

OBJECTIVE: To evaluate refractive state after excimer laser photorefractive keratectomy (PRK) in patients with myopia. METHODS: 234 cases(391 eyes) followed up for two years were divided into two groups, group I: mild and moderate myopia(< or = -6.00 D), 228 eyes; group II: High myopia(> -6.00 D), 163 eyes. The refractive state of patients at three, six, twelve and twenty-four months postoperatively were monitored. RESULTS: At two years after photorefractive keratectomy (PRK), refractive regression (> -0.5 D), overcorrection(> 1.00 D), undercorrection(> 1.00 D), postoperative residual astigmatism postoperative astigmatism and hyperopia shift in group I were 1.7%, 4.4%, 5.7%, 12.8%, 7.4% and 7.5% respectively, while in high myopia group were 15.9%, 4.9%, 23.3%, 29.7%, 31.1% and 6.7% respectively. CONCLUSION: The results prove that photorefractive keratectomy is an effective, precise, stable and safe method for correction of mild and moderate myopia, but insufficient for high myopia.

Adolescent↗
PubMed1999

Elimination of aggressive behavior in male mice lacking endothelial nitric oxide synthase.

Male mice with targeted deletion of the gene encoding the neuronal isoform of nitric oxide synthase (nNOS(-/-)) display increased aggressive behavior compared with wild-type (WT) mice. Specific pharmacological inhibition of nNOS with 7-nitroindazole also augments aggressive behavior. We report here that male mice with targeted deletion of the gene encoding endothelial NOS (eNOS(-/-)) display dramatic reductions in aggression. The effects are selective, because an extensive battery of behavioral tests reveals no other deficits. In the resident-intruder model of aggression, resident eNOS(-/-) males show virtually no aggression. Latency for aggression onset is 25-30 times longer in eNOS(-/-) males compared with WT males in the rare instances of aggressive behaviors. Similarly, a striking lack of aggression is noted in tests of aggression among groups of four mice monitored in neutral cages. Although eNOS(-/-) mice are hypertensive ( approximately 14 mmHg blood pressure elevation), hypertension does not appear responsible for the diminished aggression. Reduction of hypertension with hydralazine does not change the prevalence of aggression in eNOS(-/-) mice. Extensive examination of brains from eNOS(-/-) male mice reveals no obvious neural damage from chronic hypertension. In situ hybridization in WT animals reveals eNOS mRNA in the brain associated exclusively with blood vessels and no neuronal localizations. Accordingly, vascular eNOS in the brain appears capable of influencing behavior with considerable selectivity.

Aggression↗