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Biomedical subjects

B He

Publications and source records attributed to B He.

At least 199 records · Page 11Linked to original sources
PubMed1997

[Effects of extract of Cortex Ilicis Rotundae on cardiovascular pharmacology].

In thes paper, the effects of Cortex Ilicis Rotundae (CIR) on Cardiovascular Pharmacology are studied. The results show that ethyl alcohol extract of CIR can reduce coronary blood flow, weaken myocardial contractility, slow down heart rates, prolong survival time of mice and prevent arrhythmias, the roles of CIR decoction are similar to ethyl alcohol extract, but it is not markable on heart rates and myocardial contractility.

Animals↗
PubMed1997

[Evaluation study on determination of ZPP in blood with hematofluorometer].

The authors studied the normalization and evaluation of the method detecting the zinc protoporphyrin (ZPP) by direct displaying blood fluorescent. The results revealed that this method was highly accurate and precise. The relative humidity not more than 90% had no influence to the results. The detection limit of this method was 0.1 microg/g. The linear range of standard curve was 0-15 microg/g, and the precision in batch RSD=0.27%-1.93%. On the accuracy side, the three concentration curving values of ZPP standard material in blood were all within the range of indefinition of given values. If the samples were not detected rapidly and the blood was diluted by heparin, it might be preserved at 4 degrees C for 3 days, at -8 degrees C for 8 days. The blank fluorescent value of glassy cover made in China is less than 3.5 microg/g, Hb can substitute KLI glassy cover. This method can analyse one sample per minute, has advantage of rapidity, convenience, accuracy and reliablity.

China↗
PubMed1997

Body surface Laplacian mapping of bioelectrical activity.

A method is described to process and interpret multi-channel bioelectrical signals. The bioelectrical signals were recorded noninvasively over the body surface of human subjects at 120 sites. The body surface Laplacian maps were then constructed from the multi-channel bioelectrical potential measurement. The method was evaluated by means of computer simulations, and applied to imaging cardiac electrical activity. The present investigation suggests body surface Laplacian mapping provides an important means in interpreting bioelectrical signals.

Body Surface Potential Mapping↗
PubMed1997

A comparison of body surface Laplacian and potential maps during paced ventricular activation.

The objective of this study is to evaluate the spatial resolution of body surface Laplacian maps (BSLMs) in localizing ventricular electrical activity by means of computer simulation. A 3-D computer heart-torso model was used to simulate cardiac electrical activity and the body surface maps. A two-site pacing protocol was used to generate two simultaneously activated myocardial events on the anterior epicardial wall and the anterior endocardial wall. Following the pacing, the BSLMs and the body surface potential maps (BSPMs) were calculated and compared with the known activation pattern. As a result, the BSLMs showed superior resolution than the BSPMs for localized initial ventricular activity. In summary, the present study suggests that body surface Laplacian mapping may provide a useful methodology for the clinical diagnosis of cardiac electrical abnormalities.

Body Surface Potential Mapping↗
PubMed1996

The application of genetically engineered herpes simplex viruses to the treatment of experimental brain tumors.

Due to lack of effective therapy, primary brain tumors are the focus of intense investigation of novel experimental approaches that use vectors and recombinant viruses. Therapeutic approaches have been both indirect, whereby vectors are used, or direct to allow for direct cell killing by the introduced virus. Genetically engineered herpes simplex viruses are currently being evaluated as an experimental approach to eradicate malignant human gliomas. Initial studies with gamma (1)34.5 mutants, R3616 (from which both copies of the gamma (1)34.5 gene have been deleted) and R4009 (a construct with two stop codons inserted into the gamma (1)34.5 gene), have been assessed. In a syngeneic scid mouse intracranial tumor model, recombinant herpes simplex virus can be experimentally used for the treatment of brain tumors. These viruses and additional engineered viruses were subsequently tested in human glioma cells both in vitro and in vivo. Using a xenogeneic scid mouse intracranial glioma model, R4009 therapy of established tumors significantly prolonged survival. Most importantly, long-term survival was achieved, with histologic evidence that R4009 eradicated intracranial tumors in this model. Furthermore, the opportunity to evaluate gamma (1)34.5 mutants that have enhanced oncolytic activity, e.g., R8309 where the carboxyl terminus of the gamma (1)34.5 gene has been replaced by the murine homologue, MyD116, are considered.

Adenoviridae↗
PubMed1996

Renal agenesis and the absence of enteric neurons in mice lacking GDNF.

Glial-cell-line-derived neurotrophic factor (GDNF) is a potent survival factor for dopaminergic neurons and motor neurons in culture. It also protects these neurons from degeneration in vitro, and improves symptoms like Parkinson's disease induced pharmacologically in rodents and monkeys. Thus GDNF might have beneficial effects in the treatment of Parkinson's disease and amyotrophic lateral sclerosis. To examine the physiological role of GDNF in the development of the mammalian nervous system, we have generated mice defective in GDNF expression by using homologous recombination in embryonic stem cells to delete each of its two coding exons. GDNF-null mice, regardless of their targeted mutation, display complete renal agencies owing to lack of induction of the ureteric bud, an early step in kidney development. These mice also have no enteric neurons, which probably explains the observed pyloric stenosis and dilation of their duodenum. However, ablation of the GDNF gene does not affect the differentiation and survival of dopaminergic neurons, at least during embryonic development.

Animals↗
PubMed1996

The structure-function relationship and reduction potentials of high oxidation states of myoglobin and peroxidase.

In these studies, we substitute electron-withdrawing (diacetyl) or -donating (diethyl) groups at the 2- and 4-positions of the heme in sperm whale Mb and HRP, and examine the structural and biochemical consequences. X-ray absorption spectroscopy shows that increased electron density at the heme results in an increased iron-pyrrole nitrogen average distance in both HRP and Mb, while decreased electron density results in shorter average distances. In HRP, the proximal ligand is constrained by a H-bonding network, and axial effects are manifested entirely at the distal site. Conversely, in Mb, where the proximal ligand is less constrained, axial effects are seen at the proximal side. In HRP, electron density at the heme iron depends linearly on pK3, a measure of the basicity of the porphyrin pyrrole nitrogens [Yamada, H., Makino, R., & Yamazaki, I. (1975) Arch. Biochem. Biophys. 169, 344-353]. Using diethyl substitution (pK3 = 5.8) and diacetyl substitution (pK3 = 3.3) in HRP and Mb, we measured the one-electron reduction potentials (E(O)') of HRP compounds I and II and ferryl Mb. Compound I showed a decreased E(O)' with increasing electron density at the heme (pK3), similar to E(O)' of ferric HRP. E(O)' of HRP compound II and ferryl Mb showed an opposite dependence. This behavior of E(O)', while initially surprising, can be explained by the apparent net positive charge on the iron porphyrin in each oxidation state of the hemoproteins.

Animals↗
PubMed1996

Constitutive expression of parathyroid hormone-related peptide (PTHrP) stimulates growth and inhibits differentiation of CFK2 chondrocytes.

We have examined the effects of constitutive expression of PTHrP on the growth and differentiation of populations of cells derived from a clonal chondrocytic cell line, CFK2. Cells were stably transfected with cDNA encoding either full-length, secretory PTHrP (CFK2P) or nonsecretory PTHrP (CFK2P-SS). In cultures of cells plated at low density, secretory PTHrP acted as a potent mitogen compared with nonsecretory PTHrP or exogenous PTHrP-(1-34), both of which stimulated only a minor increase in proliferation. In populations of control cells maintained postconfluent for several weeks, there was a dramatic increase in expression of mRNA for type II collagen, aggrecan, and link protein. Addition of exogenous PTHrP-(1-34) at a concentration of 10(-8) M to these cultures was ineffective in inhibiting this time-dependent increase in expression of matrix proteins. In contrast, populations of cells producing either secretory or nonsecretory forms of PTHrP, maintained over the same time period, demonstrated an almost complete inhibition of mRNA expression for matrix proteins. These observations demonstrate that PTHrP acts as a bifunctional modulator of chondrogenesis and that some of its biological activity is exerted via a mechanism distinct from the recognised signal transduction pathways linked to the PTH/PTHrP receptor.

Animals↗
PubMed1996

Analysis of the cellular origin of hepatocellular carcinoma by p53 genotype.

The polymerase chain reaction and HaeIII enzymatic digestion were used to study the seventh exon of the p53 gene in 29 primary and recurrent hepatomas in paraffin-embedded samples from 11 patients. The mutation rate of the p53 gene and its genotypes in samples of primary and recurrent tumours and multiple nodules were investigated. The cellular origins of hepatocellular carcinoma were analysed by p53 genotype. p53 mutation rates were found to be 69.0% (20/29) in the primary and recurrent tumours, 58.8% (10/17) in tumours with a single nodule and 83.3% (10/12) in tumours with multiple nodules. The p53 genotypes were found to be different in 6 pairs of primary and recurrent tumours, and another 5 pairs had the same p53 genotypes. The samples with multiple nodules in the same patients had the same p53 genotypes. Seven recurrences were of multicentric origin and four were of unicentric origin. It is suggested that the recurrent lesions developed from both unicentric and multicentric origins.

Adult↗
PubMed1996

Augmented expression of tumour necrosis factor-alpha and lymphotoxin in mononuclear cells in multiple sclerosis and optic neuritis.

The involvement of proinflammatory cytokines tumour necrosis factor-alpha (TNF-alpha) and lymphotoxin (LT) in multiple sclerosis is suggested by the parallel occurrence of these proinflammatory cytokines in acute and chronic active multiple sclerosis brain lesions. We describe the use of in situ hybridization with radiolabelled cDNA oligonucleotide probes to detect and enumerate TNF-alpha and LT mRNA expressing mononuclear cells without culture, and after culture in the presence of myelin basic protein (MBP), control antigens or without antigen. Compared with patients with aseptic meningo-encephalitis, non-inflammatory neurological diseases and healthy controls, the multiple sclerosis patients had elevated numbers of TNF-alpha and LT mRNA expressing mononuclear cells in blood when enumerated without previous culture, and also after culture with MBP. The MBP-induced upregulation of TNF-alpha and LT was major histocompatibility complex (MHC) class II molecule dependent. Tumour necrosis factor-alpha mRNA expressing mononuclear cells were further enriched in the multiple sclerosis patients' CSF. Positive correlations were observed in multiple sclerosis between TNF-alpha and LT mRNA expressing blood mononuclear cells, MBP-reactive TNF-alpha and LT mRNA expressing cells, and TNF-alpha and interferon-gamma (INF-gamma) mRNA expressing mononuclear cells. Upregulation of TNF-alpha correlated positively with exacerbation, enhanced disability and the secondary progressive phase of multiple sclerosis. Patients with optic neuritis, in many instances representing very early multiple sclerosis, had TNF-alpha and LT positive blood mononuclear cells that were elevated to the same extent as patients with clinically definite multiple sclerosis. The findings support the hypothesis that TNF-alpha and LT play a harmful role in the development of multiple sclerosis and suggest that TNF-alpha could be useful as a disease activity marker in multiple sclerosis.

Adult↗
PubMed1996

Induction of interleukin (IL)-8 gene expression by respiratory syncytial virus involves activation of nuclear factor (NF)-kappa B and NF-IL-6.

Respiratory syncytial virus (RSV) preferentially infects respiratory epithelium and is an important cause of lower respiratory tract infections in young children. RSV induces the production of interleukin (IL)-8 in airway epithelial cells; however, the mechanism of this induction is not known. To define the mechanism by which RSV induces IL-8 gene activation, A549 epithelial cells were transfected with plasmids containing serial deletions of the 5'-flanking region of the IL-8 gene and then exposed to RSV for 24 h. A positive cooperative effect of the binding sites for the transcription factors, nuclear factor (NF)-kappa B and NF-IL-6, was observed. Mutations in either region abates responsiveness of the promoter to RSV infection. RSV also increases activation of the NF-kappa B and NF-IL-6 transcription factors. These data suggest that RSV may increase IL-8 production in airway epithelium partly via activation of the transcription factors NF-kappa B and NF-IL-6.

Base Sequence↗
PubMed1996

The carboxyl terminus of the murine MyD116 gene substitutes for the corresponding domain of the gamma(1)34.5 gene of herpes simplex virus to preclude the premature shutoff of total protein synthesis in infected human cells.

The herpes simplex virus 1 mutants from which both copies of the gamma(1)34.5 gene had been deleted trigger total shutoff of protein synthesis in human neuroblastoma cells and human foreskin fibroblasts but not in African green monkey (Vero) cells. The carboxyl-terminal 64 amino acids of gamma(1)34.5 are homologous to the corresponding domain of MyD116, a murine myeloid differentiation primary responsive gene. The carboxyl-terminal domain of gamma(1)34.5 is required to preclude the shutoff of protein synthesis (J. Chou and B. Roizman, Proc. Natl. Acad. Sci. USA 91:5247-5251, 1994). We report that in-frame substitution of the carboxyl terminus of gamma(1)34.5 with the corresponding domain of MyD116 in the context of the viral genome restored the ability of gamma(1)34.5 to preclude premature shutoff of protein synthesis in both neuroblastoma cells and in human foreskin fibroblasts. The results suggest that (i) in the course of its evolution, the virus "borrowed" a gene fragment to preclude a cell response to infection and (ii) the carboxyl terminus of MyD116 and its family of genes known as GADD34 may have a similar function(s) in cells stressed by growth arrest, DNA damage, and differentiation and in herpes simplex virus infection.

Animals↗
PubMed1996

The chemical modification of E. coli L-asparaginase by N,O-carboxymethyl chitosan.

E. coli L-asparaginase was modified with N,O-carboxymethyl chitosan in the presence of normal product L-aspartic acid, which protected the active site of the enzyme. The modified enzyme remained high catalytic activity, showed greater stability against trypsin and alpha-chymotrypsin, but lost its activity more rapidly at high temperature (> 45 degrees C) than did the native enzyme. When tested in vivo, the plasma half-life of the modified enzyme (t1/2 = 40 hr) was over 33 times longer than that of the native enzyme (t1/2 = 1.6 hr). The results showed that the modified L-asparaginase may be much more useful than did the native enzyme for clinical treatments of tumors.

Animals↗
PubMed1996

Gallium-67 scanning for detection of alveolitis in idiopathic pulmonary fibrosis and sarcoidosis.

OBJECTIVE: To investigate 67Gallium scanning for the detection of alveolitis in idiopathic pulmonary fibrosis and sarcoidosis. PATIENTS AND METHODS: 67Ga scintigraphy was performed in 14 patients with IPF (age: mean +/- s = 58.3 +/- 10.3 years), 13 patients with sarcoidosis (age: mean +/- s = 46.9 +/- 9.0 years) and 11 controls (age: mean +/- s = 44.0 +/- 10.5 years). RESULTS: Lung/thigh ratio was respectively 3.18 +/- 0.07 in IPF, 3.12 +/- 0.94 in sarcoidosis and 2.11 +/- 0.26 in controls. IPF and sarcoidosis groups had a significantly higher lung/thigh ratio comparing with the control group (P < 0.05). Three patients received 67Ga scanning examination after corticosteroid therapy and the 67Ga uptake decreased. CONCLUSIONS: The 67Ga scintigraphy is useful in monitoring the activity and extent of alveolitis.

Aged↗
PubMed1996

Expression of TGF-beta 1, PDGF and IGF-1 mRNA in lung of bleomycin-A5-induced pulmonary fibrosis in rats.

OBJECTIVE: To investigate the influence of alveolar macrophages (AMs), fibroblasts and interstitial cells on development of lung fibrosis, and the interactions among TGF-beta 1 PDGF and IGF-1 and these cytokines-effects on lung fibrosis. MATERIAL AND METHODS: Expressions of TGF-beta 1, PDGF and IGF-1 mRNA in the lung cells and lung tissues in different stages of Bleomycin-A5-induced pulmonary fibrosis in rats were studied through Northern hybridization. RESULTS: The expressions of TGF-beta 1 and PDGF mRNA reached their peaks in AMs of pulmonary fibrosis in rats on the 7th day after Bleomycin-A5 instillation. It was similar with that in the lung tissues. IGF-1 mRNA remained relatively stable in AMs during the course. PDGF and IGF-1 mRNA increased gradually in fibroblasts, and reached the highest expressions in the interstitial cells. There was almost no TGF-beta 1 mRNA expression in all groups of fibroblasts. CONCLUSIONS: AMs are the main sources of TGF-beta 1 and PDGF in the lung tissues with fibrosis induced by Bleomycin-A5 AMs are activated in the first weekend and secrete TGF-beta 1 and PDGF to promote fibroblasts proliferation and fibrosis. As fibrosis developed, fibroblasts have established PDGF and IGF-1 autocrine and these three cytokines paracrine nets combined with the interstitial cells to promote lung fibrosis.

Animals↗
PubMed1996

[Analysis of cell origin of human hepatocellular carcinoma according to p53 gene mutation].

Paraffin-embedded hepatocellular carcinoma (HCC) samples were used to study point mutation of p53 gene at 249 codon in the exon 7 by polymerase chain reaction and gel electrophoresis under Hae III enzyme digestion. Fourteen primary tumor foci and 15 recurrent tumor foci from 11 patients were investigated. p53 gene point mutation was detected in 10 of 14 primary foci (71.4%), in 10 of 15 recurrent foci (66.7%) and in 10 of 12 multiple foci. The p53 genotype of the primary and recurrent tumor foci was the same in 5 patients but different in 6. The p53 genotype of the primary and recurrent tumor foci was identical in 5 patients with multiple tumor nodules. The results suggest that recurrent HCC was multi-centric in origin in 7 of the 11 patients but was mono-centric in the other 4 patients studied.

Adult↗
PubMed1996

[The value of urine cystein proteinase and serum CA125 measurement in monitoring the treatment of malignant ovarian tumor].

Urine cystein proteinase (UCP) and serum CA125 were measured in 40 patients with malignant ovarian tumor (malignant group), 40 patients with benign ovarian tumor (benign group), and 40 normal control (normal group). 28 patients in the malignant group underwent UCP and CA125 measurement pre-operation, post-operation, and during three courses of chemotherapy. The enzyme activity of UCP in the malignant group was significantly higher than that in the benign and normal groups (P < 0.05 or 0.01). The values of UCP in patients with malignant tumor of stages II-IV were significantly higher compared with those of stages I-II (P < 0.01, 0.05). The activity of UCP was elevated pre-operation, post-operation, and was much higher on the seventh day postoperation. After the seventh day, UCP activity decreased gradually. Serum CA125 was also detected pre-operation, at 7.30 and 60 days post-operation. The levels of UCP and CA125 pre-operation and 30, 60 days post-operation in the patients whose residual carcinoma lesions were > 2 cm in diameter were apparantly higher than those with no residual lesions (P < 0.05). UCP and CA125 values were measured in six patients before relaparotomy. The sensitivity, specificity, accuaracy, positive predictive value and negative predictive value for UCP assay are 980%, 100%, 83%, 100% and 50% and those for CA125 assay are 40%, 100%, 80%, 100%, and 25%, respectively.

Biomarkers, Tumor↗