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Biomedical subjects

Hui Li

Publications and source records attributed to Hui Li.

At least 343 records · Page 19Linked to original sources
PubMed2003

[Quantum chemistry study on fluorescence spectra of three kinds of amino acids].

Quantum chemistry calculation of fluorescence spectrum offers certain theoretical reference for designing and selecting fluorescent analysis methods of amino acids. A theoretical study on fluorescence spectra of three kinds of amino acids by semi-empirical AM1 is given in this paper. After geometries of the three compounds are optimized, it is known that the titled compounds have rigid planar construction and big unlocalized pi bond from structural parameters. For all optimal geometries, there is no imaginary frequency in vibrational analysis, which proves that the geometric configurations of the three compounds are stable. On this basis, the electronic spectra have been calculated by CIS method. All calculated results are basically consistent with experimental values.

Phenylalanine↗
PubMed2003

[The epidemiological survey of prevalence rate of hypertension in the countryside of Zhangwu county, Liaoning province].

OBJECTIVE: To investigate the prevalence state of essential hypertension in the countryside of Zhangwu county, Liaoning province to confirm whether this county is the high prevalence region of essential hypertension. METHODS: Five thousand, two hundred and eight 15-year olds or older were sampled by means of whole population random sampling. Blood pressure was measured and the related risk factors were investigated with the uniform questionnaire. SPSS 10.0 of statistical software was used for data analysis. RESULTS: The standardized prevalence rate of hypertension was 35.0% at this region, 40.0% in male, 32.0% in female. The prevalence rates of hypertension were increased with the increasing of the age in both males and females. There were significant statistically differences in the prevalence rates of hypertension between the different age groups, different countrysides and different villages. The standardized prevalence rate of hypertension were 43.0% the highest and 29.0% lowest respectively in the countryside, with prevalence rates, were 59.4% highest and 26.9% lowest respectively in the village. In all the patients with hypertension, 72.0% having hypertension II, III. CONCLUSION: The countryside of Zhangwu county was a high prevalence region of essential hypertension which was unusual in our country. The reason of this status was still unknown which called for further study.

Adolescent↗
PubMed2003

[Origin of Hakka and Hakkanese: a genetics analysis].

Hakka is a distinctive Han Chinese population in Southern China speaking Hakkanese. The origin of Hakka has been controversial. In this report, we analyzed Y chromosomal markers in 148 Hakka males. Principle component analysis of Y-SNP haplotype distribution shows Hakka is clusteed strongly with the Han in Northern China, and is also close to She, a Hmong-Mien-speaking population, while the general Southern Han is fairly close to Daic populations. Admixture analysis revealed that the relative genetic contribution 80.2% (Han), 13% (She) and 6.8% (Kam) in Hakka. The network of Y-STR haplotype of M7 individuals in all concerned populations suggested two possible origins of Hmong-Mien contribution in Hakka: One is from Hubei and the other is from Canton. The Kam contribution in Hakka is likely from Kan-Yue, the ancient aborigine of Kiangsi (Jiangxi). The frequency of 9bp-deletion in Region V of mitochondrial DNA of Hakka is 19.7%, which is quite close to She but far from Han. We therefore concluded that genetically the majority of Hakka gene pool shall come from North Han with She contributing the most among all non-Han groups. Regarding the Hmong-Mien character of Hakkanese, the genetic structure of Hakka shows their core may be Kim-man, the ancient Hmong-Mien. We hypothesized that a great number of Han people from North China join this population in succession. Southern Chinese dialects, such as Hakkanese may also be those languages of Southern aborigines at first, and turn to extant appearance under the continuance effect of Northern Chinese.

China↗
PubMed2003

[Identification on Herba Hedyotidis by X-ray diffraction Fourier fingerprint pattern method].

OBJECTIVE: To establish a new identification and analysis method of Herba Hedyotidis. METHOD: Powder X-Ray diffraction fourier fingerprint pattern method. RESULT: Experiment and analysis were carried out on eight samples. The standard X-Ray diffraction fourier fingerprint pattern method and characteristic diffraction peaks of Herba Hedyotidis were obtained. CONCLUSION: This method can be used for the identification of Herba Hedyotidis.

Drug Contamination↗
PubMed2003

[Comparison of composite grafting of autoskin with acellular dermal matrix from different sources].

OBJECTIVE: To compare the composite grafts of acellular dermal matrix (ADM) from different sources with autoskin. METHODS: Six local white mini pigs were employed for the experiment. The pigs were randomly divided into four groups according to different skin grafts, i.e. A (human ADM with razor thin autoskin), B (porcine ADM with razor thin autoskin), C (razor thin autoskin only), and D (split thickness autoskin) as control. The survival rate, the contraction degree of the grafts, and the histological changes in grafting area were observed at 2, 4, 8, 12 and 24 hours after the operation. RESULTS: The grafted area in both A and B groups appeared smooth and elastic with satisfactory graft survival. The in growth of the host reparative cells such as fibroblast and vascular endothelium could be induced by composite grafts of different ADMs with skin grafting. The contraction areas in A and B groups seemed bigger than those in C and D groups. The tissue structure of grafting areas was similar to that of split thickness skin grafting area at 24 post-operation weeks. CONCLUSION: Combination of the homogenous and heterogeneous ADMs with autografts exhibited similar biological function during the observation period (24 weeks after operation). Xenogenous ADMs might have broader clinical applications.

Animals↗
PubMed2003

[Emodin sensitizes HeLa cell to arsenic trioxide induced apoptosis via the reactive oxygen species-mediated signaling pathways].

Since reactive oxygen species(ROS) has been known to play an important role in apoptosis induced by arsenic trioxide, we attempt to elevate the cellular ROS level on HeLa cell by an natural anthraquinone-emodin, then to study its effect on apoptotic sensitivity to arsenic, and finally to investigate the mechanisms of the involved signaling pathway. The results showed that emodin 10 micromol/L could enhance arsenic induced apoptosis via generation of ROS, whereas rendered no detectable effect on normal fibroblast. Increased ROS promoted mitochondrial transmembrane potential collapse; inhibited the activation of transcription factors NF-kappa B. The study elucidated that emodin sensitize HeLa cells via generation of ROS which result in enhancement of apoptosis signaling pathway and inhibition of survival signaling pathway.

Apoptosis↗
PubMed2003

[Study on the relationship between activin A, follistatin and preeclampsia].

OBJECTIVE: The purpose of this study was to determine the relationship of maternal serum activin A, follistatin and their mRNA expression in placenta with preeclampsia at term. METHODS: Twenty women with preeclampsia were enrolled in this study. Twenty healthy pregnancies matched for gestational ages were recruited as control group. Maternal serum activin A and follistatin in two groups were compared by using enzyme linked immunosorbent assay (ELISA). Placental tissues were obtained from preeclampsia and healthy control groups for analysis of activin A mRNA and follistatin mRNA expression by using quantitative reverse transcriptase-polymerase chain reaction (RT-PCR). Linear correlation analysis was used to explore the relationship between placental avtivin A mRNA and maternal serum activin A concentrations. RESULTS: (1) Maternal serum concentrations of activin A are significantly increased in preeclampsia group (33.7 +/- 6.6) micro g/L compared with control group (9.9 +/- 2.1) micro g/L (P < 0.01). Maternal serum follistatin levels were not different between preeclampsia group (5.1 +/- 0.6) micro g/L and control group (4.7 +/- 0.3) micro g/L (P > 0.05). (2) The placentas of preeclampsia group expressed activin A mRNA levels at significantly higher levels 1.11 +/- 0.21 than that of control group 0.61 +/- 0.17 (P < 0.01). The expression of follistatin mRNA were not different between preeclampsia group 0.57 +/- 0.31 and control group 0.54 +/- 0.27 (P > 0.05). (3) In preeclampsia and control groups, maternal serum activin A concentrations had a significant positive correlation with activin A mRNA expression in placentas (r = 0.89, P < 0.01). CONCLUSION: These results suggest that activin A is increased in women with preeclampsia, the elevated levels of activin A due to increased placental production.

Activins↗
PubMed2003

[Clinical analysis of relevant factors causing laryngeal cancer postoperative recurrence].

OBJECTIVE: To investigate the clinical relevant factors causing laryngeal cancer postoperative recurrence and analysis the reasons of treatment failure. METHODS: Totally, 574 cases of laryngeal cancer from 1958 to 1999 treated in ENT department of PLA general hospital were retrospectively reviewed. All the patients were observed for 3 years postoperatively, and finally 56 cases of the recurrence were diagnosed. We analyzed the factors possibly causing the recurrence including age, sex, history, time in hospital, smoke, grade of pathology, combination, tumor stage, transfusion, radiotherapy, operation manners and cervical lymph metastasis node grade. RESULTS: By statistic analysis, tumor grade (P = 0.0002), operation (P = 0.0017), transfusion (P = 0.0001), radiotherapy (P = 0.0001) and cervical lymphatic metastasis node grade(P = 0.0228) have significant meaning with laryngeal cancer postoperative recurrence. CONCLUSION: Tumor grade, transfusion, radiotherapy, operation and cervical lymph metastasis node grade are main factors which may cause neoplasm postoperative recurring.

Adolescent↗
PubMed2003

[Expression and correlation of apoptosis-related gene c-IAP2 and caspase-4 in head and cervical undifferentiation squamous cell carcinoma].

OBJECTIVE: To examine the expression of apoptosis-related genes c-IAP2 and caspase-4 in head and cervical undifferentiation cell carcinoma, as well as to investigate the role and mechanism of the two apoptosis-related genes in head and cervical undifferentiation squamous cell carcinoma. METHOD: Sixty-six historily confirmed specimen of head and cervical undifferentiation squamous cell carcinoma were subjected for immunohistochemical staining to analyze the expression of c-IAP2 and caspase-4, in addition 5 cases of normal nasal mucosa tissue were selected as control. RESULT: 1. Higher level expression of c-IAP2 protein was detected in the head and cervical undifferentiation squamous cell carcinoma specimen compared with normal nasal mucosa(P < 0.05), and the expression of caspase-4 was more deletion in it than in normal nasal mucosa(P < 0.05). 2. The expression of c-IAP2 protein was positive correlation with clinical prognosis, not correlated with clinical staging. The expression of caspase-4 protein was negative correlated with clinical prognosis, not correlated with clinical staging, too. 3. The expression of c-IAP2 was negative correlated with the expression of caspase-4. CONCLUSION: It indicates that in tissue of head and cervical undifferentiation squamous cell carcinoma, c-IAP2 is activated while caspase-4 is restrained. The signal transduction pathway of apoptosis is arrested, leading to surviving of the tumor cells, which maybe directly associated with the developing of head and cervical undifferentiation squamous cell carcinoma, and also with the failure of tumor treatment.

Apoptosis↗
PubMed2002

Anti-DNA B cells in MRL/lpr mice show altered differentiation and editing pattern.

We have studied the regulation of anti-DNA B cells in transgenic mice with a heavy chain transgene (3H9H/56R). This transgene codes for a heavy chain that forms anti-double-stranded DNA (dsDNA) antibody when paired with most members of the endogenous Vkappa repertoire, but certain L chains, referred to as Vkappa editors, do not sustain dsDNA binding in combination with 3H9H/56R. In the nonautoimmune 3H9H/56R BALB/c, most B cells generated do not bind DNA because the transgene itself is edited or is associated with a Vkappa editor. A minor population of B cells (30%) bind dsDNA and express the lambda1 light chain (known to sustain 3H9H/56R DNA binding). These 3H9/56R/lambda1 B cells coexpress a kappa editor, and we propose that the down-regulation of the anti-DNA BCR caused by the dual L chain expression may prevent activation of this kappa/lambda population. These kappa/lambda B cells are sequestered in the marginal zone. Here, we studied the influence of autoimmunity on expression and regulation of 3H9H/56R. In 3H9H/56R MRL/lpr mice, the expression of anti-dsDNA is vastly accelerated. Anti-dsDNA B cells use noneditor kappas but, in addition, most anti-dsDNA B cells have edited the heavy chain transgene. lambda1 B cells (without the coexpression of a kappa editor) are found and the kappa/lambda1 MZ population is absent. Our results suggest that improper editing and failure to sequester autoreactive B cells may contribute to the breakdown of tolerance in MRL/lpr mice.

Amino Acid Sequence↗
PubMed2002

Selective protein extraction from Chlorobium tepidum chlorosomes using detergents. Evidence that CsmA forms multimers and binds bacteriochlorophyll a.

Chlorosomes of the photosynthetic green sulfur bacterium Chlorobium tepidum consist of bacteriochlorophyll (BChl) c aggregates that are surrounded by a lipid-protein monolayer envelope that contains ten different proteins. Chlorosomes also contain a small amount of BChl a, but the organization and location of this BChl a are not yet clearly understood. Chlorosomes were treated with sodium dodecyl sulfate (SDS), Lubrol PX, or Triton X-100, separately or in combination with 1-hexanol, and the extracted components were separated from the residual chlorosomes by ultrafiltration on centrifugal filters. When chlorosomes were treated with low concentrations of SDS, all proteins except CsmA were extracted. However, this treatment did not significantly alter the size and shape of the chlorosomes, did not extract the BChl a, and caused only minor changes in the absorption spectrum of the chlorosomes. Cross-linking studies with SDS-treated chlorosomes revealed the presence of multimers of the major chlorosome protein, CsmA, up to homooctamers. Extraction of chlorosomes with SDS and 1-hexanol solubilized all ten chlorosome envelope proteins as well as BChl a. Although the size and shape of these extracted chlorosomes did not initially differ significantly from untreated chlorosomes, the extracted chlorosomes gradually disintegrated, and rod-shaped BChl c aggregates were sometimes observed. These results strongly suggest that CsmA binds the BChl a in Chlorobium-type chlorosomes and further indicate that none of the nine other chlorosome envelope proteins are absolutely required for maintaining the shape and integrity of chlorosomes. Quantitative estimates suggest that chlorosomes contain approximately equimolar amounts of CsmA and BChl a and that roughly one-third of the surface of the chlorosome is covered by CsmA.

Bacterial Proteins↗
PubMed2002

Synthesis of a spacer-armed disulfated tetrasaccharide of SB1a, a carbohydrate hapten associated with human hepatocellular carcinoma.

A disulfated tetrasaccharide fragment with a spacer arm of human hepatocellular carcinoma carbohydrate antigen SB(1a), namely, 2-aminoethyl 3-O-sulfo-beta-D-galactopyranosyl-(1 --> 3)-2-acetamido-2-deoxy-beta-D-galactopyranosyl-(1 --> 4)-3-O-sulfo-beta-D-galactopyranosyl-(1 --> 4)-beta-D-glucopyranoside was synthesized via a [2 + 1 + 1] block building mode. In the last coupling step toward the trisaccharide acceptor 8, benzoyl protected galactosyl bromide donor 14 was found to be much more reactive than the acetyl-protected donors.

Antigens, Neoplasm↗
PubMed2002

Regulation of androgen receptor activity by the nuclear receptor corepressor SMRT.

Androgen receptor (AR) is a hormone-regulated transcription factor that mediates a wide array of biological processes including sexual differentiation, spermatogenesis, and prostate cancer progression. The transcriptional activity of AR and other members of the nuclear receptor superfamily are modulated by coregulatory proteins. In this study, we have investigated the regulation of AR transcriptional activity by the silencing mediator for retinoid and thyroid hormone receptors (SMRT). We found that AR possesses an intrinsic transcriptional repression activity, and AR interacts directly with SMRT. One interacting surface on AR is mapped to the ligand-binding domain, and the presence of a DNA binding/hinge region enhances this interaction. The binding surface on SMRT is mapped to the C-terminal ID2 region, and mutation in the ID2 corepressor motif inhibits the interaction. Overexpression of SMRT inhibits dihydrotestosterone-dependent transactivation by AR and further suppresses the antiandrogen flutamide-mediated inhibition of AR activity. We provide evidence to suggest that the mechanisms of SMRT-mediated inhibition of AR activity involves inhibition of AR N/C interaction and competition with the p160 coactivator. Our data establish a significant role of SMRT in modulating AR transcriptional activity.

DNA-Binding Proteins↗
PubMed2002

Serotonin potentiation of glycine-activated whole-cell currents in the superficial laminae neurons of the rat spinal dorsal horn is mediated by protein kinase C.

The modulatory effects of serotonin (5-HT) on glycine (Gly)-activated whole-cell currents were investigated in neurons acutely dissociated from the superficial laminae (I and II) of the rat spinal dorsal horn using the nystatin-perforated patch recording configuration under voltage-clamp conditions. Our results demonstrate that (1). Gly acted on strychnine (STR)-sensitive Gly receptors and elicited inward Cl(-) currents (I(Gly)) at a holding potential of -40 mV; (2). 5-HT potentiated I(Gly) without affecting the reversal potential of I(Gly); (3). the agonist (alpha-methyl-5-HT) and antagonist (ketanserine) of 5-HT(2) receptor mimicked and blocked the potentiating effect of 5-HT on I(Gly), respectively; (4). bisindolylmaleimide I (BIM), a selective inhibitor of protein kinase C (PKC), reduced the potentiating effect of 5-HT on I(Gly); and (5). 5-HT-induced enhancement of I(Gly) was not affected by pretreatment with 1,2-bis-(2-aminophenoxy) ethane-N,N,N',N'-tetraacetic acid tetrakis (acetoxy-methyl) ester (BAPTA AM), a Ca(2+) chelator. These results indicate that (1). the potentiation of 5-HT on I(Gly) is mediated by 5-HT(2) receptor and through Ca(2+)-independent PKC intracellular signal transduction pathway; and (2). the interactions between 5-HT and Gly might modulate the transmission of nociceptive information through the spinal cord.

Action Potentials↗
PubMed2002

Induction of specific CTL by MAGE-3/CEA peptide-pulsed dendritic cells from HLA-A2/A24(+) gastrointestinal cancer patients.

PURPOSE: In this study, we aimed to investigate whether MAGE3/CEA peptide-pulsed dendritic cells could induce specific cytotoxic T lymphocytes (CTL). METHODS: In this pilot study, we selected 25 patients expressing MAGE-3-HLA-A2/A24 or CEA-HLA-A24. Patients' dendritic cells (DCs) were expanded in vitro in the presence of recombined-human granular macrophage colony stimulating factor (rhGM-CSF) and recombined-human interleukin 4 (rhIL-4), pulsed with MAGE-3/CEA (HLA-A2/A24) peptide. The cytolytic cells' activity, induced by peptide-pulsed DCs and unpurified T cells as effector cells, and with Mel526, 803, Raji, and K562 as target cells, were measured using LDH-releasing assay. RESULTS: DCs were obtained by in vitro expansion in all cases although DC harvest rates varied among different patients (7.1+/-3.2%). Compared with T-IL-2 (IL-2-induced T cells), T-DC-P - which resulted from T-IL-2 co-cultured with DCs pulsed by MAGE3 or CEA peptides - exhibited an increase in cytolytic activity against Mel526 (expressing MAGE-3-HLA-A2) and 803 (expressing CEA-HLA-A24) cell lines by about 25-30% ( P<0.01). In contrast, there was no significant difference between the activity against Raji and K562 cells, which are negative for both peptides. CONCLUSIONS: This study showed that combined usage of rhGM-CSF and rhIL-4 in vitro could expand DCs, and that the DCs pulsed with specific peptides could induce MAGE- and CEA-specific CTL responses. The DC-based vaccine may provide an important method for the immunological treatment of gastrointestinal cancers.

Adult↗
PubMed2002

Autocorrelation of scattered laser light for ultrasound-modulated optical tomography in dense turbid media.

Based on measurement of the intensity autocorrelation function, a new method to determine the modulation depth of scattered laser light modulated by an ultrasonic wave in turbid media was applied to ultrasound-modulated optical tomography. Good signal-to-noise ratios and high sensitivities were demonstrated. Images of double optically absorbing objects buried in a highly optically scattering gel sample were obtained. The contrast was more than 10%, and the spatial resolution was approximately 2 mm.

Humans↗
PubMed2002

Reconstructed human skin produced in vitro and grafted on athymic mice.

BACKGROUND: The best alternative to a split-thickness graft for the wound coverage of patients with extensive burns should be in vitro reconstructed autologous skin made of both dermis and epidermis and devoid of exogenous extracellular matrix proteins and synthetic material. We have designed such a reconstructed human skin (rHS) and present here its first in vivo grafting on athymic mice. METHODS: The rHS was made by culturing newborn or adult keratinocytes on superimposed fibrous sheets obtained after culturing human fibroblasts with ascorbic acid. Ten days after keratinocyte seeding, reconstructed skins were either cultured at the air-liquid interface or grafted on athymic mice. We present the macroscopic, histologic, and phenotypic properties of such tissues in vitro and in vivo after grafting on nude mice. RESULTS: After maturation in vitro, the reconstructed skin exhibited a well-developed human epidermis that expressed differentiated markers and basement membrane proteins. Four days after grafting, a complete take of all grafts was obtained. Histological analysis revealed that the newly generated epidermis of newborn rHS was thicker than that of adult rHS after 4 days but similar 21 days after grafting. The basement membrane components (bullous pemphigoid antigens, laminin, and type IV and VII collagens) were detected at the dermo-epidermal junction, showing a continuous line 4 days after grafting. Ultrastructural studies revealed that the basement membrane was continuous and well organized 21 days after transplantation. The macroscopic aspect of the reconstructed skin revealed a resistant, supple, and elastic tissue. Elastin staining and elastic fibers were detected as a complex network in the rHS that contributes to the good elasticity of this new reconstructed tissue. CONCLUSIONS: This new rHS model gives supple and easy to handle skins while demonstrating an adequate wound healing on mice. These results are promising for the development of this skin substitute for permanent coverage of burn wounds.

Animals↗