Biomedical subjects
Publications and source records attributed to C Fan.
After growing area investigating which covered 10 Provinces (or Cities) of China, we gathered 11 types Zhiqiao and 6 types Zhishi which consistently came from 12 species (or varieties). Histological studies on them have been taken. microscopical characters including transverse section and powder were described. These studies will provide scientific basis for the identification of Zhiqiao and Zhishi.
The green fluorescent protein (GFP) is a widely used reporter in gene expression and protein localization studies. GFP is a stable protein; this property allows its accumulation and easy detection in cells. However, this stability also limits its application in studies that require rapid reporter turnover. We created a destabilized GFP for use in such studies by fusing amino acids 422-461 of the degradation domain of mouse ornithine decarboxylase (MODC) to the C-terminal end of an enhanced variant of GFP (EGFP). The fusion protein, unlike EGFP, was unstable in the presence of cycloheximide and had a fluorescence half-life of 2 h. Western blot analysis indicated that the fluorescence decay of EGFP-MODC-(422-461) was correlated with degradation of the fusion protein. We mutated key amino acids in the PEST sequence of EGFP-MODC-(422-461) and identified several mutants with variable half-lives. The suitability of destabilized EGFP as a transcription reporter was tested by linking it to NFkappaB binding sequences and monitoring tumor necrosis factor alpha-mediated NFkappaB activation. We obtained time course induction and dose response kinetics similar to secreted alkaline phosphatase obtained in transfected cells. This result did not occur when unmodified EGFP was used as the reporter. Because of its autofluorescence, destabilized EGFP can be used to directly correlate gene induction with biochemical change, such as NFkappaB translocation to the nucleus.
We investigated the effects of tumor necrosis factor (TNF) alpha on the human megakaryocytic leukemic cell lines Mo7e, Meg-01, and Dami/HEL. Our data show that both type I and type II TNF receptors (TNF-RI and TNF-RII) are expressed on all of these cells, and TNF-alpha significantly stimulates the proliferation of growth factor-dependent Mo7e cells but not of Meg-01 or Dami/HEL cells, which grow in a factor-independent manner. TNF-alpha serves predominantly as a mitogen for Mo7e cell proliferation and does not induce Mo7e cell differentiation. Coincubation with both TNF-alpha and anti-TNF-alpha neutralizing antibody completely abolishes the TNF-alpha-induced proliferation of Mo7e cells. In bioassays, there is no detectable level of other stimulatory cytokines in conditioned medium from Mo7e cells previously stimulated by TNF-alpha, implying that the stimulatory effect of TNF-alpha on Mo7e cells is derived from the direct action of TNF-alpha rather than via the induction of secondary cytokines by TNF-alpha. Flow cytometric studies demonstrated that TNF-alpha binds to Mo7e cells that have been pretreated with either anti-TNF-RI or anti-TNF-RII neutralizing antibody, but TNF-alpha does not bind to cells pre-exposed to both receptor antibodies. However, the incubation of Mo7e cells with either TNF-RI or TNF-RII neutralizing antibodies or with either soluble TNF-RI or TNF-RII inhibits TNF-alpha-induced cell proliferation, indicating the requirement of interactions with both TNF receptors for the mitogenic activity of TNF-alpha. Furthermore, our data suggest that an alternative signaling pathway may be involved in TNF-alpha-induced Mo7e cell proliferation, because the common mitogen-activated protein kinase (MAPK) and signal transducer and activator of transcription (STAT) signaling pathways activated by other cytokines that induce Mo7e cell proliferation are not activated by TNF-alpha.
This study investigated whether granisetron, a 5-HT3 receptor antagonist, can alter the Bezold-Jarisch reflex (i.e., hypotension and inappropriate heart rate slowing). A hemorrhagic rabbit model that has been shown to induce the Bezold-Jarisch reflex was used. In 11 rabbits (3.8 kg), catheters were placed in the carotid arteries one day before experimental hemorrhage. On the day of the study, the rabbits were given intravenous granisetron (50 micrograms/kg) or an equal volume of saline. Five minutes after administration of granisetron or saline, hemorrhage was induced by continuous blood withdrawal at 5 mL/min and blood pressure (BP) and heart rates were obtained at frequent intervals until systolic BP declined to 80 mmHg. Six rabbits received saline and five granisetron. An average of 77.6 mL +/- 16.4 mL of blood was removed in the group receiving granisetron (compared with 56.5 mL +/- 13.1 mL for the saline group) before achieving the target systolic BP of 80 mmHg. The group receiving granisetron demonstrated the same ability to increase their heart rate from baseline as the saline group. However, the granisetron group had a final heart rate that was closer to their maximal heart rate than the saline group. In this animal model, granisetron was significantly more effective at preventing inappropriate heart rate slowing and allowed significantly more blood to be removed before reaching the target blood pressure. This implies that granisetron may be effective in preventing vasovagal syncope, although further study should be carried out to verify these potentially interesting findings.
OBJECTIVES: We evaluated whether the reported difference in the ventricular defibrillation threshold (DFT) between short-term intravenous and oral amiodarone is due to the effect of amiodarone's active metabolite desethylamiodarone (DEA). BACKGROUND: Amiodarone is frequently used in patients with implantable cardioverter-defibrillator devices (ICD). Long-term oral amiodarone raises the DFT, but intravenous amiodarone has not been shown to have this effect. DEA, an active metabolite of amiodarone, has different electrophysiologic properties than its parent compound and may be responsible for the observed different effects of intravenous and oral amiodarone on DFT. METHODS: We ascertained the DFT in 24 pigs randomized to receive intravenous amiodarone, DEA or vehicle. Defibrillation was delivered through a transvenous lead system using a biphasic waveform. The DFT was determined using an up-down DFT algorithm and defined as the average minimal energies resulting in successful defibrillation delivered from ascending and descending serial shocks. RESULTS: Amiodarone caused a dose-response increase in DFT (mean +/- SD) from 22.7 +/- 4.1 (baseline) to 26.1 +/- 2.9 (10 mg/kg body weight), p = 0.11, to 34.9 +/- 8.2 J (after an additional 15 mg/kg), p = 0.035. DEA (10 mg/kg) caused an increase in DFT from 20.5 +/- 6.3 to 33.9 +/- 13.6 J, p < 0.01. Addition of 15 mg/kg of DEA resulted in hemodynamic instability and thus DFT was not obtained. In the control group, DFT decreased from 26.8 +/- 7.7 at baseline to 23.1 +/- 7.4 (dose 1), p = 0.19, to 22.8 +/- 6.2 J (dose 2), p = 0.18. CONCLUSIONS: DEA increases DFT by a greater amount than its parent drug amiodarone. There is an effect of intravenous amiodarone on DFT that is dose dependent.
Human cytomegalovirus (HCMV) genomes was detected by PCR in 51 patients' biopsy or operation specimens with gastrointestinal disease. The positive rate was 9.80%. At the same time, 41 patients' serum HCMV-IgM was detected by indirect immunofluorescence assay (IFA); the positive rate was 46.34%. Patients with cancer and colitis exhibited a higher HCMV infection rate than those without cancer and colitis. The results suggest that PCR is sensitive and specific in detection of gastrointestinal HCMV infection, and the examination of biopsy or surgical specimen is superior than that of IFA of serum HMCV-IgG.
OBJECTIVE: To investigate the ultrastructure of lens epithelial cells of normal eyes and cataractous eyes in rhesus monkeys. METHODS: Anterior capsules were taken from 4 normal lenses and 4 cataractous lenses of rhesus monkey eyes, and the samples were observed under transmission electron microscope. RESULTS: The ultrastructure of the cataractous lens epithelial cells changed obviously. Mitochondria with disappearance of crista were swollen, and vacuolar. Hollow cell with a single large vacuole in the cytoplasm could be seen. The cytoplasm presented dissolution. Cells were swollen and damaged, even cell membrane disruption could be seen. Karyopyknosis, nuclear deformity, disappearance of perinuclear cistern and nuclear pores could be found. The heterochromatin was concentrated and aggregated at the nuclear periphery. CONCLUSIONS: The ultrastructural changes of the lens epithelial cells in monkey cataractous lens are similar to that in human cataractous lens. Rhesus monkey cataract may be a suitable experimental model to investigate the formation of human cataract.
A strain, No. 90-1, is isolated from the oral cavity of a patient with periodontophthy. This strain is a Gram-positive, non-endospore-forming, facultative anaerobe with spherical cells, 0.9-1.5 microns in diameter, occuring in pairs and seldom in short chains of four cells, and motile by one flagellum per cell. The optimum growing temperature is 35-37 degrees C; appreciable growth is not found below 10 degrees C, but growth at 53 degrees and tolerance to 60 degrees C for 30 min. This strain is microhalophilous and grows best, well and poorly in the medium containing 2%, 10%-15% and 25% NaCl respectively. Catalase and urease are positive and nitrate is reduced. Acid is produced from many carbohydrates, but no gas. Gelatin can be hydrolyzed, but starch, cellulose and dextrin do not. G + C content in DNA is 41.34 mol%(Tm). The strain(90-1) is considered to be a new species belonging to a new genus because its some characteristics are different from those of the known coccus genuera and designated as Stomatostreptococcus microhalophilus Ping, Zhou, Sun et Fan gen. nov. sp. nov. according to its source and microhalophilic trait.
The research fields and advances of biomedical engineering have been reviewed in four aspects, biomedical material, biomedical engineering appliance, tele-diagnostic system and biomedical recovery engineering with 14 references.
The stability of omeprazole 2 mg/mL. in an extemporaneously prepared oral liquid was studied. The contents of five 20-mg omeprazole capsules were mixed with 50 mL of 8.4% sodium bicarbonate solution in a Luer-Lok syringe. Three vials of this liquid were prepared for storage at 24, 5, and -20 degrees C. A 3-mL. sample of each was taken initially and on days 1, 2, 3, 4, 6, 8, 10, 12, 14, 18, 22, 26, and 30 and assayed by high-performance liquid chromatography. The liquids stored at 5 degrees C and at -20 degrees C did not change color during the study period, but the color of the liquid stored at 24 degrees C changed from white to brown. There were no significant changes in the omeprazole concentrations of the liquids stored at 5 and -20 degrees C during the study period, but the omeprazole concentration of the liquid stored at 24 degrees C was < 90% of the initial concentration on day 18. Omeprazole 2 mg/mL in an oral liquid compounded extemporaneously from capsules and sodium bicarbonate injection was stable for up to 14 days at 24 degrees C and for up to 30 days at 5 and -20 degrees C.
The stability of granisetron 0.2 mg/mL (as the hydrochloride salt) in an extemporaneously prepared oral liquid was studied. Twelve 1-mg granisetron tablets were pulverized and suspended in 30 mL of distilled water. This mixture was then diluted with cherry syrup to produce a 60-mL oral liquid with a granisetron concentration of 0.2 mg/mL. Half of the preparation was stored at 5 degrees C, and half was stored at 24 degrees C. Samples were taken on days 0, 1, 2, 3, 4, 6, 8, 10, 12, and 14 and assayed by high-performance liquid chromatography. There was no change in the liquid's color, consistency, or pH, and the concentrations of granisetron ranged from 97% to 104% of initial concentration during the 14 days at 5 and 24 degrees C. Granisetron 0.2 mg/mL (as the hydrochloride salt) in an extemporaneously prepared oral liquid was stable for up to 14 days.
The crystallographic structure of the D-alanine:D-alanine ligase of the ddlB gene of Escherichia coli complexed with a D-Ala-D-alpha-hydroxybutyrate phosphonate and the structure of the Y216F mutant ligase complexed with a D-Ala-D-Ala phosphinate have been determined to 2.2 and 1.9 A resolution, respectively, and refined to R factors of 0.156 and 0.158. In each complex the inhibitor has reacted with ATP to produce ADP and a tight-binding phosphorylated transition state intermediate. Comparison of these two structures with the known crystal structure of the phosphinate intermediate of the wild-type ligase shows no major conformational changes, but B factors indicate differences in mobility of loops covering the binding site. The weaker inhibition of the Y216F mutant by both inhibitors is thought to be due in part to the loss of an interloop hydrogen bond. A similar mechanism may account for poor inhibition of VanA, the homologous D-Ala:D-lactate ligase produced by vancomycin-resistant enterococci.
Gebie Oral Liquid can increase the weight of thymus and spleen of the mouse, damaged by prednisone and cytoxan, enhance the phagocytosis of monocytes and DHT, and promote the blastogenesis of splenic lymphocytes as well as the activity of NK cells.
A transesophageal echocardiography (TEE) was used in monitoring the operation of tricuspid valvuloplasty. Nine patients with rheumatic heart disease were studied. The results showed that intraoperative TEE was important on the improving method of tricuspid annuloplasty, it help to determine surgical procedure, control annulus-reducing procedure and assess the result immediately after operation. The results suggested that intraoperative TEE can be widely used in valvuloplasty in future.
In this paper, separation of water soluble vitamins C (VC), B1 (VB1) and B6 (VB6) has been studied preliminarily by capillary zone electrophoresis (CZE) and micellar electrokinetic capillary chromatography (MECC) with a home-made amperometric electrochemical detector at the working electrode [carbon fiber (5 microm o.d.)] potential of 510-540 mV (vs. SCE). It has been shown that each of the three vitamins has more than one peak in NH3-NH4Cl (pH 9.0) which were mainly caused by the decomposition products in weak base medium and by heat except those from impurities. The electrochemical detector has better performance for the three vitamins from CZE and MECC. They can be separated either by CZE or by MECC. The separation by CZE is better than that by MECC with sodium dodecyl sulfate (SDS). SDS and buffer acidity can influence the retention time, peak sequence and height. The separation efficiency of CZE in 0.01 mol/L NH3-NH4Cl was 468 800 theoretical plates for VC.
Simultaneous pyrolysis and methylation gas chromatography (SPM-GC) is a fast analytical method which was developed in recent years. However, the strong alkalinity of tetramethylammonium hydroxide (TMAH) may result in the isomerization and degradation of polyunsaturated fatty acids in oils and fats during analysis. This paper describes the application of SPM-GC to polyunsaturated fatty acids in soybean oil and the isomerization and degradation may be prevented by choosing the optimum proportion of TMAH to methanol which is 1:50 (pH 8.8). With this chosen optimum proportion there were no detectable isomerized and degraded peaks in the chromatograms. Pyrograms were obtained by interfacing a Curie-point pyrolyser to a Shimadzu GC-14A gas chromatograph equipped with a flame ionisation detector. A capillary column (FFAP) was used. All of the pyrolysis products were identified by mass spectrometry which was carried out with a Varian 3400 gas chromatograph interfaced to a Finnigan SSQ 710 mass spectrometer using electron impact ionisation (70 eV). This method is simpler and more convenient than both the methods "neutralization of acid" and "simultaneous injection of the sample and a short chain fatty acid methylester" reported in the previous papers.
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