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Biomedical subjects

B Fu

Publications and source records attributed to B Fu.

At least 55 records · Page 3Linked to original sources
PubMed1999

Induction of gastritis and gastric ulcer in Mongolian gerbils infected with Helicobacter pylori.

OBJECTIVE: To induce the model of Mongolian gerbil infected by Helicobacter pylori (HP) and to observe the changes of the infiltration and the proliferation of inflammatory cells before and after the bactericidal treatment. METHODS: The animal model of HP infection was induced by inoculating the HP strain (American Type Culture Collection) to male Mongolian gerbil MGS/Sea (SPF). Half a month, 1 month and 3 months after inoculation, kill the animals and make HE staining and immunohistochemistry staining of the stomach to observe the pathological changes. RESULTS: The infiltration of a great number of inflammatory cells was observed with the center of the mucosa of pylorus at the second week of HP infection. At the 3rd month of infection, ulcer appeared near the lesser curvature side of the pylorus. On the early stage of infection, the lesion was acute inflammation characterized by the neutrophilic infiltration, and then transformed into the chronic inflammation characterized by the lymphatic infiltration and the wide formation of lymphatic follicles. CONCLUSION: Mongolian gerbil is an ideal and standard animal model of HP infection.

Animals↗
PubMed1999

[Expression of GST-pi gene in human esophageal carcinogenesis].

OBJECTIVE: To investigate the possible role of GST-pi in esophageal carcinogenesis. METHODS: GST-pi expression at mRNA level was studied by in situ hybridization (ISH) and at protein level by immunohistochemistry (IHC). GST-pi expression of the esophagus in normal epithelial cells (NC), hyperplastic cells (HC), dysplastic cells (DC) from grade I to III, carcinoma in-situ (CIS) and invasive carcinoma (IC) was examined in the same esophageal cancer specimens (n = 48) which provided a model reflecting the process of esophageal carcinogenesis. RESULTS: The positive rate of IHC staining was 87.5% for NC, 95.3% for HC, 55.9% for DC (grade I: 73.9%, grade II: 47.4%, grade III: 41.2%), 36.4% for CIS and 45.8% for IC. The positive rate of GST-pi mRNA expression was 81.2% for NC, 94.4% for HC, 61.9% for DC (grade I: 76.5%, grade II: 61.5%, grade III: 41.7%), 44.4% for CIS and 83.3% for grade I IC, 30.0% for grade II IC and 0% for grade III IC. There was no statistically significant difference in GST-pi expression at the mRNA and the protein level. CONCLUSION: There is a decreasing tendency of GST-pi expression from dysplasia to CIS and IC. The decrease in GST-pi expression is an early event in esophageal carcinogenesis.

Esophageal Neoplasms↗
PubMed1999

[Effect of plasminogen activator inhibitor 1 gene transfer into mesangial cells on Extracellular matrix accumulation].

OBJECTIVE: To observe the influence of plasminogen activator inhibitor 1 (PAI-1) overexpression on extracellular matrix (ECM) accumulation of rat mesangial cells. METHODS: PAI-1/GFP green fluorescent protein fusion gene eukaryotic expression vector pCMX-PAI-1-GFP was constructed and delivered into cultured rat mesangial cells by liposome. PAI-1/GFP expression was observed by fluorescent microscope. FN, LN and Type IV collagen levels were measured by Northern blot analysis and ELISA method. RESULTS: Northern blot analysis, SDS-PAGE analysis and Western blot analysis demonstrated that PAI-1/GFP gene can be transcripted and translated in rat mesangial cells. PAI-1/GFP gene can express a specific protein. The recombinant PAI-1/GFP had significant inhibition activity on urokinase-type plasminogen activator and displayed autonomous fluorescence. The PA activity of cell supernatants decreased markedly in gene transfer group. FN, LN and Type IV collagen levels were higher than in a control group. CONCLUSION: Over-expression of PAI-1 gene leads to mesangial ECM accumulation. The changes of PA/PAI-1 activity in supernatants of cultured rat mesangial cells might be the key factor in ECM accumulation regulation.

Animals↗
PubMed1998

Genetic deletion of AT2 receptor antagonizes angiotensin II-induced apoptosis in fibroblasts of the mouse embryo.

To examine whether angiotensin II (Ang II) can trigger apoptosis via Ang II type 2 (AT2) receptor, two genotypes of skin fibroblasts cultured from the AT2 receptor gene targeting homozygous (AT2-/-) and wild-type (AT2+/+) mouse embryos, respectively, were studied when exposed to Ang II. In the AT2+/+ fibroblasts, mRNA expression of the AT2 receptor was modulated by Ang II in a dose-dependent manner and apoptosis appeared with the convincing features of internucleosomal DNA fragmentation and DNA content decrease after stimulation with Ang II, whereas Ang II had no significant impact on the AT2-/- fibroblasts due to the AT2 receptor gene deletion. This is the first report using a gene targeting study to demonstrate that Ang II induces apoptosis through the AT2 receptor in the fibroblasts of the mouse embryo.

Angiotensin II↗
PubMed1998

Linkage of Gordon's syndrome to the long arm of chromosome 17 in a region recently linked to familial essential hypertension.

Gordon's syndrome (GS) is a salt-sensitive, hyperkalaemic, familial hypertension syndrome which may masquerade in milder forms as essential hypertension. The response of hyperakalaemia to dietary salt restriction and to mineralocorticoids is heterogeneous, suggesting genetic heterogeneity. In a recently published study using small pedigrees, possible linkage of GS to chromosomes 1 and 17 was described. Studying the largest pedigree so far reported with GS, and using fluorescent-labelled microsatellite markers, we sought evidence of linkage to chromosomes 1 and 17. In this family there was no segregation of GS with any of the markers for chromosome 1. On chromosome 17, however, evidence of linkage was found with a maximum multipoint LOD score of 2.4 (the maximum LOD possible from the pedigree) over markers D17S250 and D17S934. This represents strong evidence in this pedigree for a responsible gene mutation on the long arm of chromosome 17. Recent reports of linkage for essential hypertension and, especially, familial essential hypertension within the same area of chromosome 17 containing the D17S934 marker raise the possibility that the same gene may be responsible for familial essential hypertension and for Gordon's syndrome.

Chromosomes, Human, Pair 1↗
PubMed1998

[Effects of Arg-Gly-Asp-Ser (RGDS) tetrapeptide on apoptosis-related genes in glomerular mesangial cells].

OBJECTIVE: To investigate the effects of Arg-Gly-Asp-Ser (RGDS) tetrapeptide on the expressions of apoptosis-related genes interleukin-1 beta-converting enzyme (ICE) and bcl-2 in human glomerular mesangial cells, so as to provide experimental evidence for regulating proliferation and apoptosis of mesangial cells with RGD-containing polypeptide. METHODS: Propidium iodide staining was used to observe the condensation and fragmentation of apoptotic nuclei. The internucleosomal DNA fragmentation was detected by DNA electrophoresis on agarose gel. The expressions of ICE and Bcl-2 were determined by reverse transcription-polymerase chain reaction (RT-PCR). RESULTS: After ten hours of incubation, the glomerular mesangial cells treated with RGDS peptide displayed features consistent with apoptosis, such as nuclear condensation and fragmentation, and a regularly spaced "ladder" shape of genomic DNA electrophoresed. And RT-PCR showed that expressions of both ICE and Bcl-2 mRNAs were apparently increased in RGDS treated group, compared with that of the control group. CONCLUSION: These results demonstrated for the first time that RGDS peptide was able to induce apoptosis in human glomerular mesangial cells, during the process ICE and bcl-2 genes may have an important regulating role.

Apoptosis↗
PubMed1998

Detection of filarial larvae in mosquitoes with oligonucleotide probe.

OBJECTIVE: To investigate a new way to detect filarial larvae in mosquitoes and apply it to the surveillance of filariasis. METHODS: An oligonucleotide probe that was species-specific to W. malayi was synthesized and marked with 32P using molecular biological technique. Then the probe was tested with dot hybridization in detection of W. malayi filarial larvae from mosquitoes. RESULTS: The minimal detectable limit was found to be 2 ng DNA of filarial larvae or microfilaria (Mf.), with no cross reaction with other animal filariae. A single larva can be detected when infected mosquitoes were tested one by one. One infected mosquito can be detected from a group of 20 mosquitoes tested together. CONCLUSIONS: Our probe is sensitive and specific. It is practical to apply our probe to mosquito surveillance in Brug's filariasis endemic areas.

Animals↗
PubMed1998

[Three-dimensional volumetric display--a new application of frequency up-conversion].

This paper discusses the present research situation and the application prospect of 3-D volumetric display technology. The possible usability and science significance of frequency up-conversion in 3-D volumetric display field are also demonstrated systematically. In ZBLAN: Pr, Yb glasses, we primarily demonstrated and achieved a new application of frequency up-conversion three dimensional volumetric display, using the two-frequency up-conversion of the rare earth ions. The efficiency of luminescence of Pr was enhanced much by the energy transfer between Pr and Yb ions.

English Abstract↗
PubMed1997

RGD-containing peptides trigger apoptosis in glomerular mesangial cells of adult human kidneys.

Substantial evidence was given that different Arg-Gly-Asp (RGD)-containing peptides, linear Arg-Gly-Asp-Ser (RGDS) and cyclic Arg-Gly-Asp-Phe (RGDF), which are sequences present in fibronectin and vitronectin and which can bind alpha5beta1 and alpha(v)beta3 integrins, respectively, both induced apoptosis and expression of interleukin-1beta-converting enzyme (ICE) in cultured glomerular mesangial cells from adult human kidneys, with consistent apoptosis features appearing as nuclei condensation and fragmentation, internucleosomal DNA fragmentation, and DNA content decrease. These results indicated that both fibronectin and vitronectin may be important in the survival of human glomerular mesangial cells and that stable cyclic RGD(D)FV peptide may be a candidate to be used for regulating apoptosis in vivo.

Adult↗
PubMed1997

[Mechanisms of thrombin induced proliferation and detachment of glomerular endothelial cells].

To clarify the mechanisms of thrombin contributing to the progression of glomerular diseases by injuring glomerular endothelial cells (GECs), we studied the effects of thrombin on GECs in vitro. Cell proliferation was detected with MTT incorporation, total plasminogen activator (PA) and tissue type PA (t-PA) activities were detected with fibrin plate and chromatogenic substrate methods and fibronectin was detected with ELISA as well as indirect immunofluore scence. 0.4-3.2 NIH U/ml thrombin promoted GEC proliferation significantly (P < 0.05). Thrombin promoted cell detachment, which can be inhibited by hirudin or aprotinin. Thrombin enhanced total PA and t-PA activities of GECs significantly (P < 0.01). Fibronectin in the supernatants of thrombin-stimulated GECs decreased significantly (P < 0.01) and in the extracellular compartment also decreased. The decrease was inhibited by hirudin and aprotinin. In conclusion, thrombin can induce GEC proliferation and GEC detachment. The latter is probably related to PA-mediated over-degradation of extracellular matrices such as fibronectin, which are needed for cell attachment.

Cell Division↗
PubMed1997

[Hyperosmotic glucose and antibiotics induce production of plasminogen activator inhibitor and expression of TGF beta mRNA by rat peritoneal mesothelial cells].

To investigate the mechanism of fibrosis in peritoneal dialysis, we observed the effects of the hyperosmotic glucose and antibiotics such as gentamicin and cefazolin on rat peritoneal mesothelial cells with cell culture, fibrin-plate lyzing and Northern blotting analysis method. The peritoneal mesothelial cells may express PAI-1 mRNA. The expression of PAI-1 mRNA in peritoneal mesothelial cells and activities of PAI in the supernatants were enhanced by 11.2 mmol/L glucose, gentamicin and cefazolin at 12 hr. By 24 hr, the activity of PAI-1 also increased in the supernatants with 11.2 mmol/L glucose. The expression of PAI-1 mRNA and production of PAI activities by the peritoneal mesothelial cells were increased by gentamicin, and the TGF-beta mRNA increased in the peritoneal mesothelial cells was induced by 11.2 mmol/L glucose, gentamicin and cefazolin. The results suggested that 11.2 mmol/L glucose, gentamicin and cefazolin may increase the expressions or productions of PAI and TGF-beta in peritoneal mesothelial cells. So by perosmotic glucose, cefazolin and gentamicin promote the peritoneal fibrosis in patients with CAPD.

Animals↗
PubMed1996

Processing of nutritious, safe and acceptable foods from CELSS candidate crops.

A controlled ecological life-support system (CELSS) is required to sustain life for long-duration space missions. The challenge is preparing a wide variety of tasty, familiar, and nutritious foods from CELSS candidate crops under space environmental conditions. Conventional food processing technologies will have to be modified to adapt to the space environment. Extrusion is one of the processes being examined as a means of converting raw plant biomass into familiar foods. A nutrition-improved pasta has been developed using cowpea as a replacement for a portion of the durum semolina. A freeze-drying system that simulates the space conditions has also been developed. Other technologies that would fulfill the requirements of a CELSS will also be addressed.

Biomass↗
PubMed1996

A new method of measuring heparin levels in whole blood by protamine titration using a heparin-responsive electrochemical sensor.

OBJECTIVE: To determine the ability of a new electrochemical sensor to determine heparin levels in whole blood and to correlate the heparin levels as determined by this heparin-responsive sensor (HRS) with heparin levels as determined by the Hepcon assay system (Medtronic Hemotec, Parker, CO). DESIGN: Methods comparison study. SETTING: A large academic medical center. INTERVENTIONS: The heparin levels of 162 samples from 24 patients undergoing cardiopulmonary bypass were determined by the HRS system and by the Hepcon system. In 21 samples, heparin levels as measured by anti-Xa activity were determined as well. MEASUREMENTS AND MAIN RESULTS: HRS-determined values correlated highly with Hepcon-determined values (r = 0.942) and with anti-Xa determined values (r = 0.905). Bias +/- precision comparing the HRS and Hepcon methods was 0.211 +/- 0.478 U/mL. CONCLUSIONS: HRS determined that whole blood heparin levels correlate well with Hepcon-determined levels. These limited results indicate that further development and testing of this new technology are warranted.

Anticoagulants↗
PubMed1995

Teaching microbiology with hypertext: first steps towards a virtual textbook.

Computer-assisted learning materials for medical microbiology were developed using hypertext-authoring software (Folio 3.1). Two versions of a text-only introductory tutorial (detailed, read only, and read-write noteform) were then evaluated in a prospective, randomized trial. Evaluation was by pre- and post-exposure multiple choice questions, and by self-administered questionnaire. There was a small difference in outcome between the two groups; the read-write group scoring higher, and students who used either software performed better than those who did not (P = 0.014). Responses to the post-test questionnaires showed that many students regarded the read-only software as an electronic handout, more frequent users requesting the addition of illustrations, self-assessment questions, and greater interactivity. A small group of students made use of the read-write version of the tutorial as a 'virtual textbook' by adding extra material to the starter file. Our experience suggests that the low-cost option of text-only hypermedia produces only modest learning gains for medical undergraduates.

Computer-Assisted Instruction↗
PubMed1995

The food-process subsystem for CELSS: a conceptual analysis.

A controlled ecological life support system (CELSS) is required to sustain life for future long-duration space missions. Food processing is an important subsystem component of a CELSS. Factors for designing the food-process subsystem are identified and characterized in this analysis. Interactions of the subsystem with other subsystems in a CELSS are also discussed.

Crops, Agricultural↗
PubMed1994

Response mechanism of polymer membrane-based potentiometric polyion sensors.

The potentiometric response mechanism of a previously reported polymer membrane-based electrode sensitive to the polyanion heparin is established. Based on transport and extraction studies, the heparin response is attributed to a nonequilibrium change in the phase boundary potential at the sample/membrane interface. While true equilibrium polyion response, obtained for low heparin concentrations only after very long equilibration times (> 20 h), yields the expected Nernstian response slope of < 1 mV/decade, the observed large and reproducible EMF response to clinically relevant heparin concentrations (approximately 10(-7) M) during typical measurement periods (2-5 min) is ascribed to a steady-state kinetic process defined by the flux of the polyion both to the surface and into the bulk of the polymer membrane. A model describing this nonequilibrium response is presented. With this model, the uniqueness of the polymer membrane composition (e.g., very low plasticizer content, strictly controlled cationic site concentration, etc.) required to achieve analytically useful heparin response becomes clear. Practical working conditions and limitations of the sensor are discussed. To support the generality of the steady-state model proposed, corresponding EMF response data for a newly developed membrane electrode sensitive to a polycationic protein (protamine) are also presented. It is shown that the protamine-responsive membrane electrode appears to operate via the exact same kinetic mechanism as the heparin sensing system.

Biosensing Techniques↗