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Biomedical subjects

B He

Publications and source records attributed to B He.

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

[Magnetic drug delivery system--adriamycin-carboxymethyl dextran magnetic nanoparticles].

A novel magnetic drug carrier-carboxymethyl dextran magnetic nanoparticles(CMD MNPs) was prepared. Adriamycin (ADR) was coupled with two types of carrier-neutral dextran MNPs and anionic CMD MNPs, by periodate oxidation. The physico-chemical characteristics and the magnetic guidance effects in vitro and in vivo of ADR-CMD MNPs were studied. The distribution profiles of liver and spleen in mice were studied for both ADR-dextran conjugate MNPs and ADR-CMD conjugate MNPs. The results showed ADR-CMD conjugate MNPs possessed superparamagnetism, the mean diameter was 56 nm, the mass magnetic susceptibility was 1.06 x 10(-4) emu.g-1, and the drug loading was 12.4%. The distribution profiles in liver and spleen revealed that conjugation with neutral dextran MNPs, excessive accumulation of loaded ADR was found in liver and spleen after intravenous administration, while conjugation with CMD MNPs gave a markedly lower concentration in these organs, which indicated less uptake of ADR-CMD conjugate MNPs by reticuloendothelial system(RES) and the advantage of delivering loaded drug to sites other than the RES; thus it opens a new perspective for the active delivery of drug.

Animals↗
PubMed2000

A network inversion technique for estimating equivalent dipole description of visual evoked potential.

For the activation study of the brain, dipole localization from the scalp potential is one of the most promising techniques to realize a reasonable temporal resolution which cannot be realized in functional MR and PET. The goal of our study is to estimate inversely the electrical brain activity in the form of several dipoles from the scalp potential, using a network inversion technique. As a basic approach, we have inversely estimated several dipoles from the potential distribution on a spherical surface, in the homogeneous sphere model. In the training phase, by expanding the neural network input dimensions being redundant, the network can easily learn the forward mapping. In the inversion phase, the space of the expanded-network-input-vector can be narrowed by introducing a penalty term. Additionally, a consensus term was used to force several dipoles to have a similar orientation. We estimate that this is applicable to the localization of several dipoles that reflect the actual brain activity, especially in the visual evoked potentials.

Brain Mapping↗
PubMed2000

Simulation of body surface Laplacian maps during ventricular pacing in a 3D inhomogeneous heart-torso model.

A computer simulation study has been conducted to investigate the performance of body surface Laplacian maps (BSLMs) in localizing and imaging spatially separated myocardial electrical events. A cellular automaton model of ventricles simulates cardiac electrical activity using a two-site pacing protocol to induce dual simultaneously active myocardial electrical events. The heart model is embedded in a realistically shaped inhomogeneous volume conductor. The BSLMs are numerically computed from the induced electrical activity in the heart model. The present computer simulation results show that the BSLM can provide better separation and localization of two regional myocardial electrical events as compared with the body surface potential map (BSPM).

Artifacts↗
PubMed2000

[The role of membrane-type 1 matrix metalloproteinase in the invasion and metastasis of hepatocellular carcinoma].

OBJECTIVE: To study the role of membrane-type 1 matrix metalloproteinase (MT(1)-MMP) in the invasion and metastasis of hepatocellular carcinoma (HCC), and find a method to judge the invasion and metastasis of HCC through MT(1)-MMP. METHODS: RT-PCR was used to study the expression of MT(1)-MMP mRNA in the HCC and in HCC nude mice model with higher metastasis potential (LCI-D20) and lower metastasis potential (LCI-35), and statistical methods were used to analyse the association between the expression of MT(1)-MMP mRNA and the pathological indexes of HCC. RESULTS: MT(1)-MMP mRNA was expressed by all the normal liver tissue (1.12 +/- 0.73), HCC (3.51 +/- 0.97), surrounding liver parenchyma (1.19 +/- 0.57), tumor embolus, and HCC nude mice model with LCI-D20, LCI-D35. The overexpression of MT(1)-MMP mRNA in HCC, embolus, LCI-D20 was related to the invasion and metastasis of HCC. The expression of MT(1)-MMP mRNA in HCC being higher than that in surrounding liver parenchyma was an important index to judge the invasion and metastasis of the HCC. CONCLUSION: MT(1)-MMP is related to the invasion and metastasis of HCC. The expression of MT(1)-MMP mRNA in HCC being higher than that in surrounding liver parenchyma could be acted as an important index to judge the invasion and metastasis of HCC.

Animals↗
PubMed2000

Arsenic speciation based on ion exchange high-performance liquid chromatography hyphenated with hydride generation atomic fluorescence and on-line UV photo oxidation.

An on-line method capable of the separation of arsenic species was developed for the speciation of arsenite As(III), arsenate As(V), monomethylarsenic (MMA) and dimethylarsenic acid (DMA) in biological samples. The method is based on the combination of high-performance liquid chromatograph (HPLC) for separation, UV photo oxidation for sample digestion and hydride generation atomic fluorescence spectrometry (HGAFS) for sensitive detection. The best separation results were obtained with an anion-exchange AS11 column protected by an AG11 guard column, and gradient elution with NaH2PO4 and water as mobile phase. The on-line UV photo oxidation with 1.5% K2S2O8 in 0.2 mol L(-1) NaOH in an 8 m PTFE coil for 40 s ensures the digestion of organoarsenic compounds. Detection limits for the four species were in the range of 0.11-0.15 ng (20 microL injected). Procedures were validated by analysis of the certified reference materials GBW09103 freeze-dried human urine and the results were in good agreement with the certified values of total arsenic concentration. The method has been successfully applied to speciation studies of blood arsenic species with no need of sample pretreatment. Speciation of arsenic in blood samples collected from two patients after the ingestion of realgar-containing drug reveals slight increase of arsenite and DMA, resulting from the digestion of realgar.

Arsenates↗
PubMed2000

[E-selectin mediates early adhesion of HepG2 hepatoma cells to endothelial cells].

OBJECTIVE: To study the role of E-selectin and sLe(x) in the adhesion between hepatoma cells (HepG2) and endothelial cells, and to select drugs capable of inhibiting such adhesion. METHODS: HepG2 cells were vitally stained with fluorescent dye BCECF-AM. Adhesion between the fluorescent HepG2 cells and human umbilical vein endothelial cells (HUVEC) was examined by solid phase adhesion assay in vitro. A number of agents were tested for their effect on the tumor cell-endothelial adhesion. RESULTS: sLe(x) on the surface of HepG2 cells and E-selectin expressed on the surface of HUVEC were necessary for early adhesion. HepG2 cells could activate HUVEC to increase their adhesiveness to HepG2 cells. Dexamethasone, phenylarsenic oxide, levamisole and actinomycin D were able to block the adhesion between HepG2 to HUVEC at low concentrations. CONCLUSION: sLe(x) and E-selectin are important molecules in the early adhesion of hepatoma cells to HUVEC. Cytokine-like factors of HepG2 origin are likely involved in the activation of endothelial cells in the target tissue. Agents capable of inhibiting NF kappa B can be hopefuly used as anti-adhesion drugs to inhibit metastasis of liver cancer.

Animals↗
PubMed2000

[Photochemical immobilization--a new approach to surface modification of medical polymer materials].

The present paper reviews the approach of surface modification of medical polymer materials-photochemical immobilization. The approach is dramatically different from any other surface modification process available for medical materials. The topics include the principle of photochemical immobilization, the fundamental classification photoreactive groups and the typical applications of photochemical surface modification.

Biocompatible Materials↗
PubMed2000

[Clinical application of the first metacarpal fasciocutaneous flap].

OBJECTIVE: To report the application of the first metacarpal fasciocutaneous flap in repairing digital soft tissue defects. METHODS: The first metacarpal fasciocutaneous flap was designed to repair the lesions of the thumb, index, middle and ring fingers in 14 cases. The blood supply of the flap originates from the branches of the radial pollicis artery at the metacarpophalangeal joint and the venous drainage is to the cephalic vein through the deep pollicis vein and dorsal pollicis vein. RESULTS: All the flaps survived successfully except that one survived partly, two had cyanosis and blister. Followed-up for 3 to 12 months showed the flaps had sensation with good texture and thickness. CONCLUSIONS: The first metacarpal fasciocutaneous flap can be used to repair the lesions of the thumb, index, middle and ring fingers. It has following advantages: 1. reliable blood supply; 2. convenient dissection and 3. less damage of the donor site.

Adolescent↗
PubMed2000

[Experimental study on effect of folium Ginkgo biloba in treating pulmonary interstitial fibrosis in rats].

OBJECTIVE: To evaluate the therapeutic effect and mechanism of folium Ginkgo biloba (FGB) in treating pulmonary interstitial fibrosis (PIF) induced by bleomycin in rats. METHODS: PIF models of bleomycin-A5-induced pulmonary fibrosis were established in rats, they were treated by Bailuda, a preparation of FGB, and the pathological changes, collagen protein level, nuclear factor kB(NF-kB) activity, transforming growth factor beta (TGF-beta) mRNA expression and protein level of the lung tissue were measured. RESULTS: In the Bailuda treated group after treatment, amelioration of the pulmonary alveolitis and fibrosis were shown in pathological section (P < 0.05) and collagen protein content was lesser (P < 0.01) as compared with those in the model control group. After 1 week of Bailuda treatment, the NF-kB activity of pulmonary alveola macrophage lowered by 47.3%, and levels of TGF-beta mRNA expression and protein were all decreased (P < 0.05). CONCLUSIONS: Bailuda has definite effect in treating PIF. The mechanism may be through inhibiting the activity of NF-kB, decreasing TGF-beta mRNA expression and protein, so as to ameliorate the inflammation and fibrosis.

Animals↗
PubMed2000

[Simultaneous pancreas-kidney transplantation for the treatment of type I diabetes with end-stage renal disease].

OBJECTIVE: To demonstrate whether simultaneous pancreas-kidney transplantation is practical for the treatment of Type I diabetes with end-stage renal disease. METHODS: Eight cases of combined pancreas-kidney transplantation were performed in our institute. The age ranged from 35 years to 48 years (average 43.46 years). All cases were diagnosed as type I diabetes with end-stage nephropathy, two cases with blindness due to retinopathy. The case history ranged from 2 years to 22 years. Pancreas allograft was placed in the right iliac fossa with pancreas exocrine drainage to bladder, whereas renal allograft the in left iliac fossa. Initial immunosuppression regimen is quadruple. RESULTS: Seven patient could be insulin free after transplantation, with normal fasting blood glucose. One patient received insulin treatment for 40 days after operation. One patient survived 1 year and 9 months after transplantation with normal functioning pancreas allograft and kidney allograft. Four patient survived 2 months with normal allograft function. Fasting blood glucose was between 4.5 and 6.2 mmol/L; Cr was between 53 and 106 micromol/L. Diet control was not necessary. Two patient died of encephalorrhagia, and 1 pancreatic vascular thrombosis and necrotic pancreatitis. CONCLUSIONS: Combined pancreas-kidney transplantation is feasible to treat type I diabetes with end-stage nephropathy. Functional pancreas allograft could be procured in the present condition. Pancreatic exocrine is drained to bladder. The diagnosis of acute rejection could be made earlier by detecting urine amylase. Heparin should be added in order to prevent pancreatic thrombosis.

Adult↗
PubMed2000

[MMF and CyA in the prevention of early acute rejection after renal transplantation].

OBJECTIVE: To investigate the effect of MMF and low dose CyA on the prevention of early acute rejection after renal transplantation. METHODS: 146 patients with kidney transplantation were analyzed retrospectively from December 1997 to January 1999. These patients were divided into two groups according to the immunosuppressive regimen: Aza group (78 patients) and MMF group (68 patients). All patients met the following criteria: HLA mismatch </= 3 loci, lymphocytes toxicity test < 10%, PRA < 20% for second or third transplantation, warm ischemia time 5-11 minutes, and cold ischemia time 3-24 hours. RESULTS: There were 24 patients with acute rejection episodes (30.77%) in the Aza group; and 10 patients (14.71%) in the MMF group, (P < 0.05). The dosage of CyA and blood concentration of CyA were significantly different; 6.00 +/- 1.21 mg x kg(-1) x d(-1) and 286.00 +/- 20.02 microg/L in the Aza group; 4.00 +/- 1.14 mg x kg(-1) x d(-1) and 204.00 +/- 20.18 microg/L in the MMF group (P < 0.001). CONCLUSIONS: MMF with low dose CyA based triple regimen could prevent the acute rejection episodes effectively at the early period of post transplantation. This triple regimen can reduce the acute rejection episodes by 50%. To some extent, low dose CyA may avoid nephrotoxicity. The long-term effect of this regimen on allograft is still needed to observe.

Adolescent↗
PubMed2000

[The modulating effect of panax pseudoginseng wall saponins on the DAG-PKC signal pathway and TNF secretion of macrophages].

OBJECTIVE: To explore the roles of panax pseudoginseng wall saponins on the DAG-PKC signal pathway and TNF secretion of macrophages. METHODS: The changes of the activities of postburn inositol lipid signal system factors such as PLC, DAG, cytomembrane PKC, cytoplasma PKC, and intracellular calcium concentration and the secretory amount of macrophage TNF were observed. RESULTS: Panax pseudoginseng wall saponins could reduce the increased PLC activity from 57.58 +/- 8.19 to 27.00 +/- 2.31 and the intracellular calcium concentration from 393.18 +/- 392.62 to 90.56 +/- 7.21. With the role of panax pseudoginseng wall saponins, DAG activity reduced from 488.10 +/- 40.20 to 288.30 +/- 30.00, cytomembrane PKC activity decreased from 3081.50 +/- 698.50 to 1699.50 +/- 218.50, and cytoplasmic PKC activity from 2 188.60 +/- 258.30 to 848.40 +/- 138.30. The secretory TNF amount of macrophage decreased by 55%. CONCLUSION: Panax pseudoginseng wall saponins might play an very important role in the modulating of the DAG-PKC signal pathway and decreased TNF secretion of macrophage.

Animals↗
PubMed2000

[A case control study on the levels of lipid, fasting glucose, fasting insulin and sex hormones of hypertension in among elderly Uighur people in Hetian, Xinjiang].

OBJECTIVE: To detect the relationship between the levels of lipid, fasting glucose, fasting insulin, sex hormones and hypertension in the elderly Uighur people in Hetian, Xinjiang. METHODS: A case control study on 105 cases of hypertension was performed, including 58 males and 47 females, aged 60 - 106. RESULTS: Among the lipid analysis items, the decrease of high density lipoprotein-cholesterol (HDL-C) was the important factor related to the occurrence of the complications of hypertension (OR = 5.6214). The increases of both fasting glucose and fasting insulin levels were also risk factors of hypertension in the elderly Uighur people (OR = 2.4474 and OR = 2.5318). CONCLUSION: The risk factors of hypertension in the elderly Uighur people included decrease of HDL-C, high-level fasting glucose and fasting insulin.

Aged↗
PubMed2000

[Mutation of hepatitis B virus DNA pre-C region in patients with primary hepatocellular carcinoma in Guangxi].

OBJECTIVE: To study the association between mutation of hepatitis B virus (HBV) pre-C gene and HBV infection in patients with primary hepatocellular carcinoma (PHC) but negative hepatitis B e antigen (HBeAg) in Guangxi Province, China. METHODS: Nested polymerase chain reaction (nPCR) was used for amplification of HBV DNA Pre C region in sera collected from 16 patients with PHC in Guangxi, and then their HBV DNA nPCR products were sequenced by Sanger method. RESULTS: Sera in fourteen of 16 patients showed positive HBV DNA, with a positive proportion of 87.5% (14/16). One (C23) of them was positive for HBeAg; one (C24) was negative HBeAg, but with normal sequence in his Pre C region; two (C7, C14) were co-infected with HBV wild and mutant strains; and the remainder eight cases (C3, C4, C5, C8, C10, C11, C12, C13) were infected with mutant virus strains, but stop codon at codon 28 was only found in C4, C5 and C12. One case (C8) was co-infected with both HBV stop codon mutant and non-stop codon strains. CONCLUSION: It is uncommon for patients with PHC in Guangxi infected with HBV mutant strain with classical mutation at nt 1 896, which suggests that maybe there exist other types of mutation other than that in pre-C region causing HBV infection without HBeAg.

Base Sequence↗
PubMed2000

[An adenosine triphosphate bioluminescence assay for detecting the number of living cells].

The method for detecting the number of living cells was studied. Using an adenosine triphosphate (ATP) bioluminescence assay, the present authors reported a perfect linear relationship between lg ATP concentrations and lg luminescence counts (r = 0.9963) as well as a relationship between lg number of cells and lg ATP luminescence counts (r = 0.9922). The detectable cells ranged from 10(2) to 10(6) cells/ml, the coefficients of variation 1-3%. This method is simple, accurate and sensitive and has a high reproducibility.

Adenosine Triphosphate↗
PubMed2000

[An evaluation of adenosine triphosphate bioluminescence assay for tumor in vitro chemosensitivity testing].

This study was aimed at the feasibility of using ATP-bioluminescence assay for tumor in vitro chemosensitivity testing. With the use of this assay, the authors determined dose-response curve in mouse fibroma cell line L929 treated with chemotherapeutic agents, and investigated the different in vitro responses of 6 ovarian carcinomas (5 from fresh tumor tissues, 1 from ascites) treated with etopside, cis-plating, 5-fluorouracil and adriamycin. The results showed that the coefficients of variation for triplicate assays ranged from 1.2% to 15.8% which means high reproducibility of the assay. The single cell suspension (including < 30 cells clusters) could be separated from tissue fragments by means of enzyme cocktail (collagenase, Dnase, pronase). The viable cells were over 90%. This study demonstrates that ATP-bioluminescence assay is a sensitive, reliable and efficient method for tumor chemosensitivity testing. In this connection, the correlation between in vitro drug sensitivity and in vivo patient response is worth further studying.

Adenosine Triphosphate↗