Biomedical subjects

Feng Wang

Publications and source records attributed to Feng Wang.

At least 181 records · Page 10Linked to original sources

PubMed2004

[Experimental study of the thrombolytic effects in a canine model of pulmonary thromboembolism induced by autologous radioactive blood clots].

OBJECTIVE: To compare the thrombolytic effects of the two dosing regimes with urokinase (UK) in a canine model of pulmonary thromboembolism induced by radioactive blood clots. METHODS: Seventeen dogs were randomly assigned into three groups: the control group, the UK(2h) group (UK infused over 2 hours) and the UK(12h) group (UK given over 12 hours). The thrombolytic differences was investigated among the three groups. Thrombolysis was assessed by continuously counting over both lung fields with single photon emission computed tomography (SPECT) and calculated by regions of interest (ROI) technology and by counting radioactivity in the lung in vitro. The extent of thrombolysis was calculated as the difference between the radioactivity originally incorporated in the clot (decay-corrected) and the radioactivity in the lung in vitro. RESULTS: In three groups, the lysis rates measured by ROI technology were (6.2 +/- 4.0)%, (39.5 +/- 13.9)%, and (16.9 +/- 8.9)% respectively, and (6.0 +/- 2.7)%, (42.8 +/- 12.4)%, and (17.7 +/- 9.3)% by the method in vivo. The thrombolytic ratio of the UK(2h) group was significantly higher than that of the other two groups (P < 0.01), and there was no marked difference between the control group and the UK(12h) group. There was a thrombolytic peak in the UK(2h) group at the first four hours after infusion of agent. CONCLUSIONS: For the fresh thrombi, the UK(2h) regime is superior to the UK(12h) due to its higher thrombolytic ratio and prompt thrombolytic property. The model and methods are highly reliable.

Animals↗

PubMed2004

[Role of heat shock protein 70 expression in DNA damage induced by benzo(a)pyrene].

OBJECTIVE: To explore heat shock protein 70 (HSP70) expression of A549 cells and its role in DNA damage caused by benzo(a)pyrene (BaP). METHODS: Human adenocarcinoma A549 cells were cultured in vitro, exposed by different concentrations of BaP (0, 1.25, 2.50, 5.00, 10.00 micro mol/L) for 6 hours, or 10 micro mol/L of BaP for different time (0, 4, 8, 12, 16, 24 and 48 h). Then HSP70 expression and DNA damage were detected using Western-blot and single cell gel electrophoresis (SCGE) assay respectively, and the relationship between HSP70 expression and DNA damage was further analyzed. RESULTS: The integral optical densities of HSP70 in A549 cells treated with 1.25, 2.50, 5.00 and 10.00 micro mol/L BaP for 6 h (49.63 +/- 1.30, 45.72 +/- 1.03, 40.53 +/- 0.95, 37.50 +/- 1.20 respectively) were lower than that of the control cells (59.43 +/- 1.17) (P < 0.05). When A549 cells were exposed to 10 micro mol/L BaP for 4, 8, 12, 16 h, the integral optical densities of HSP70 were 33.33 +/- 0.80, 29.23 +/- 0.91, 12.51 +/- 0.96, 9.50 +/- 1.25 respectively, and there was an increasing tendency of the expression of HSP70 for 24 - 48 h (20.06 +/- 1.38, 24.51 +/- 1.39), however, all were different from that in control group (56.59 +/- 0.85) (P < 0.05). DNA damage scores in 10(6) A549 cells treated with 2.50, 5.00 and 10.00 micro mol/L BaP for 6 h (23,718 +/- 2,938, 30,128 +/- 2,937, 44,231 +/- 3,846) were significantly higher than that of the control cell (9,615 +/- 1,923) (P < 0.05). When A549 cells were exposed to 10 micro mol/L BaP for 4, 8, 12, 16, 24, 48 h, DNA damage scores (16,667 +/- 4,003, 38,461 +/- 1,924, 5,615 +/- 3,847, 76,282 +/- 2,937, 7,513 +/- 1,110 and 58,975 +/- 9,487) were also higher than that of control group (P < 0.05). There was a negative correlation between DNA damage and the expression of HSP70 when A549 cells were exposed to different concentrations of BaP. CONCLUSION: HSP70 might enhance intracellular defenses against DNA damage induced by BaP.

Benzo(a)pyrene↗

PubMed2004

Construction of eukaryotic expression plasmids of hepatitis B surface antigen and helper T lymphocyte epitope.

BACKGROUND: DNA immunization provides a promising approach to elicit protective humoral and cellular immune responses against HBV. This study was to construct an eukaryotic expression plasmid containing helper T lymphocyte epitope, which will enhance the immunogenicity of a novel hepatitis B virus (HBV) fusion protein DNA vaccine. METHODS: The target gene containing pan-DR helper T cell epitopes (PADRE) and HBsAg was amplified by polymerase chain reaction (PCR). The PCR products were linked with PMD-18T vector. Plasmid DNA was purified from transformed E.coli competent cell JM109 and digested with Hind III and EcoR I. Then, the target gene was cloned in pcDNA3.1(+) digested by Hind III and EcoR I. Finally, the identity of DNA was verified by digestion and DNA sequencing. RESULTS: The recombinant expression vectors of pcDNA3.1(+)-PADRE/HBs were identified by restriction enzyme digestion and DNA sequencing. The insert DNA fragment was consistent with the expected sequence. CONCLUSIONS: The constructed eukaryotic expression plasmid of pcDNA3.1(+)-PADRE/HBs is convenient for further study of eukaryotic transfection and response for cellular and humoral immunity against HBV.

Epitopes, T-Lymphocyte↗

PubMed2004

[A new orthotopic retinoblastoma model expressing green fluorescent protein].

OBJECTIVE: In order to observe the growth and metastasis of the tumor directly, a new orthotopic retinoblastoma model was established with human RB cells expressing green fluorescent protein (GFP). METHODS: pEGFP-N(1), the eukaryotic expressive plasmid of GFP, was transferred into human RB cell line HXO-RB(44) by liposome Dosper. Then, the cell clones expressing GFP steadily were selected by means of neomycin, fluorescence microscope, and flow cytometer. Two microliters of RB cells (density at 4.5 x 10(8) - 5.5 x 10(8) cells per ml) were injected into the subretinal space of 30 nude mice (60 eyes) under binocular operating microscope. The growth of transplanted RB was observed in vivo using fluorescence stereomicroscope. The nude mice were killed at different times post-operatively to investigate the metastasis process of the tumor to the optic nerve, brain, and other organs including lung, liver and kidney. RESULTS: The spread process of the tumor in the subretinal space was successfully observed under stereomicroscope. Transplanted RB developed into extra-ocular stage phase at 34 - 37 days after the operation. And metastasis to the cranium along the optic nerve was observed, with green RB cells distributing along the optic nerve sheath and long posterior ciliary artery. The histopathological characteristics of the transplanted tumor were similar to the human RB. Immunohistochemical staining showed positive expression of GFP in the tumor cells. CONCLUSION: The established orthotopic RB model expressing GFP via injection of human RB cells into the subretinal space of nude mice provides a new approach to exploring the growth and metastasis processes of RB in natural situations.

Animals↗

PubMed2004

[Application of fresh amniotic membrane transplantation in treatment of stenosis of conjunctival sac].

OBJECTIVE: To evaluate the clinical efficiency of fresh amniotic membrane transplantation in treatment of stenosis of conjunctival sac. METHODS: Thirty cases (30 eyes) of stenosis of conjunctival sac were treated with fresh amniotic membrane transplantation. Amniotic membrane was obtained under sterile conditions after elective cesarean delivery. The woman's serum was negative for HBsAg, syphilis, and human immunodeficiency virus. The placenta was first washed free of blood clots with sterile saline. Under sterile conditions, the inner amniotic membrane was separated from the chorion by blunt dissection, and was cleaned of blood with the sterile saline again. The membrane was then flattened onto a surgidrape adhesive paper with the epithelium surface up. The paper with the adherent amniotic membrane was then cut into 5 cm x 8 cm pieces, and then rinsed in solution containing 4 x 10(6) U/L of gentamycin and stored at 4 degrees C. It could be stored for 12 hours after preparation. The adhesiotomy was performed firstly. The separation between the conjunctiva and scar tissue should be complete and wide enough to reach to the orbital margin. The adhesiectomy was taken secondly. The scar tissues were removed completely. The fresh amniotic membrane was flattened onto the conjunctival defect with epithelium side up. The fresh amniotic membrane was 10 mm more than the conjunctival defect by trimming off the excess portion. This fashioned membrane was then secured to surrounding conjunctival edge with continuous 7-0 nylon sutures. The necessary mattress suture of inferior conjunctival fornix via skin next to the inferior orbital margin was performed simultaneously. The retrobular implantation of the an artificial globe made of hydroxyapatite was performed on some patients with sunken eye. Correction of traumatic ptosis was performed on a few patients. RESULTS: The operation of reconstruction of partial conjunctival sac for 30 cases was successful. All amniotic membrane grafts were alive. The cosmetic result was complete favorable. The infection and contracture of the graft, immunologic rejection and amniotic lysis were not observed in all cases during the follow-up period of 13-18 months. CONCLUSION: Fresh amniotic membrane transplantation can be used in reconstruction of the partial conjunctival sac effectively and can be popularized in the local hospital in China because the amniotic membrane can be obtained easily.

Adult↗

PubMed2004

[Subretinal transplantation of genetically modified human retinal pigment epithelium cells delay photoreceptor degeneration and functional deterioration in rats].

OBJECTIVE: To investigate whether subretinal transplantation of genetically modified human retinal pigment epithelium cells can rescue photoreceptor degeneration in RCS rats. METHODS: A spontaneously derived adult human retinal pigment epithelium (RPE) cell line (CRL-2302) was infected by gfp retrovirus, then transfected by liposome mediated CNTF expression plasmid transfer. Around 1 x 10(5) genetic modified cells were injected to subretinal space of the right eye at 4 - 5 weeks old, the left eye was left without injection or injected with PBS as controls. RESULTS: The GFP expression cells under the retina were observed from 1 to 6 weeks after transplantation. Histologic and ultrastructural assessment demonstrated substantial sparing of photoreceptors and correction of RPE phagocytosis defect. Electrophysiological assessment revealed an increased sensitivity of treated eyes to white light. CONCLUSION: The results demonstrate that potential of genetically modified RPE cells for ultimate application in therapeutic transplantation strategies for human retinal degenerative diseases.

Animals↗

PubMed2004

[Study on the relationship between the polymorphism of P22phox C242T, vitamin E and coronary heart disease].

OBJECTIVE: To study the C242T mutation frequency of the cytochrome b4 (P22phox) in Chinese and to further ascertain the relationship between the polymorphism of P22Phphox C242T, vitamin E and coronary heart disease (CHD). METHODS: 151 patients with CHD and 254 controls were genotyped for the P22phox C242T polymorphism by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis, the concentrations of the vitamin E in plasma were measured by reversed-phase high performance liquid chromatography (RP-HPLC). RESULTS: The study shows that the allele frequency of C and T is 92.72% and 7.28% in the whole people and the polymorphism of P22phox C242T is associated with CHD in Chinese. Vitamin E is protective against CHD and there is effect on the progress of CHD in the interaction of the polymorphism of P22phox C242T and vitamin E. By stepwise Logistic regression analysis the results suggest that male, smoking, non-drinking, hypertension, diabetes, stroke of parents and low concentration of vitamin E in plasma are the possible risk factors in CHD. CONCLUSION: The polymorphism of P22phox C242T is associated with CHD in Chinese. Vitamin E is protective against CHD and there is effect on the progress of CHD in the interaction of the polymorphism of P22phox C242T and vitamin E.

Aged↗

PubMed2004

[Effect of 1-MCP on senescence and quality in cold-stored edible podded pea].

The effects of 1-MCP (1-methylcyclo-propene) at 0.5, 1 and 2 muL/L on senescence and quality attributes in edible podded pea (Pisum sativum L.var.Saccharatum) during cold storage at 1 degrees C were investigated. The results indicated that treatments with 1 and 2 microL/L 1-MCP significantly inhibited respiratory rate, ethylene production and superoxide production, maintained higher levels of SOD, AsA-POD activities and chlorophyll and AsA contents, reduced the increases in MDA and fiber contents and decay index, thereby delayed the senescence process and quality deterioration. Treatment with 0.5 microL/L 1-MCP showed no significant effects on senescence and quality changes in harvested edible podded pea.

Cold Temperature↗

PubMed2004

[Study on the cleavage activity of U1 small nuclear RNA chimeric ribozyme against HCV RNA in vitro].

OBJECTIVE: To study the cleavage activity on the HCV RNA of a chimeric recombinant of HCV specific ribozyme and U1 small nuclear RNA, which compartmentalizes within the nucleolus. METHODS: The third stem-loop sequence of human U1 snRNA (position 95-116) within pBSIISK+ U1 was substituted by hammerhead ribozyme against HCV RNA by PCR and cloning methods, and the constructed plasmid was named pBSIISK+ (U1-Rz). Then the whole gene fragment of the chimeric ribozyme was cloned into a pGEM-T vector under the control of T7 promoter, and the constructed plasmid was named pGEM- (U1-Rz). The pGEM- (U1-Rz) and pGEM-Rz (containing the same ribozyme sequence as that in U1-Rz) transcripts as enzyme were transcribed in vitro. Also the (32)P-labeled pCMV/T7-NCRC luc (containing the gene sequence of the whole 5'-NCR and part core of HCV RNA) transcripts as target-RNAs were transcribed in vitro. The enzymes were incubated with the target RNAs under different conditions and autoradiographed after denaturing gel-electrophoresis. RESULTS: The sequencing result showed that the construction of U1 snRNA chimeric ribozyme was correct. Compared with the ribozyme alone, both of them were active at 37 degree C and with Mg2+ (10 mmol/L) and TrisCl (10 mmol/L, pH7.9), and there was no remarkable difference between them. The cleavage activity of the chimeric ribozyme increased with the prolongation of reaction time and increment of enzyme concentration. CONCLUSION: Both ribozyme and U1 snRNA chimeric ribozyme exhibited specifically catalytic activity against HCV RNA in vitro. There was no remarkable difference between their cleavage efficiencies.

Chimera↗

PubMed2004

[Arrested proliferation and molecular mechanism of MAPKs' activations in manganese-treated PC12 cell line].

OBJECTIVE: We employed a model in vitro that used PC12 cell line to test the concentration and time dependent relationship of Mn-treatment as well as the characteristics of MAPKs pathway under the same conditions, to explore the Neurotoxicity mechanisms of manganese. METHODS: PC12 cells in logarithm period incubated in culture media of 200, 400, 600, 800 micromol/L manganese (MnCl2) for 1 day, 2 days, 3 days, 4 days respectively. The neurotoxic concentration of manganese (MnCl2) on PC12 cells was screened by MTT and Plate clone forming tests. Cell growth curve was made in Typan-blue dying experiment. Western-blot was used to test p-Erk1/2 and p-p38. RESULTS: MTT and plate clone tests showed that 200, 400, 600, 800 micromol/L MnCl2 could suppress the proliferation of PC12 cells in dose and time-dependent trend during 1 d, 2 d, 3 d, 4 d respectively. The cell inhibited ratio on the fourth day in 600 micromol/L MnCl2 culture medium approached 50% or more. Western-blot tests showed that p-Erk2 of PC12 cells incubated in 600 micromol/L MnCl2 culture medium was decreasing gradually on the 1st, 2nd, 3rd and 4th day and on the 2nd day less than control group by 75% (n = 3, P < 0.05). With cells treated by 200, 400, 600 micromol/L MnCl2 for 4 days, p-Erk2 lost by degrees. On the 4th day, p-Erk2 of 400 micromol/L MnCl2-treated group was less 78% than that of control group (n = 3, P < 0.05). P-p38 of PC12 cells incubated in 600 micromol/L MnCl2 culture medium was increasing gradually on the 1st, 2nd, 3rd and 4th day and on the 3rd day 6.6 times higher than that of control group (n = 3, P < 0.05). P-p38 of PC12 cells enhanced by degrees in 200, 400, 600 micromol/L MnCl2 treated for 4 days and in 400 micromol/L MnCl2 treated group on the 4th day was 4.7 times higher than that of control group (n = 3, P < 0.05). CONCLUSION: The decreased p-Erk2 and the increased p-p38 maybe co-worked to induce proliferation arrest and apoptosis in PC12 cells.

Animals↗

PubMed2004

[Relationship of plasma nitric oxide concentration and the activity of nitric oxide synthase with coronary heart disease].

OBJECTIVE: To study the levels of nitric oxide synthase (NOS) and nitric oxide (NO) in patients with coronary heart disease (CHD), and the factors affecting them. METHODS: Concentrations of NO and the activities of NOS in plasma in 136 patients and 206 controls using the corresponding Kits were measured. The data were analyzed using covariance and multiple linear regression analysis with SAS 8.1. RESULTS: The levels of NO [(217.05 +/- 153.31) micromol/L] and NOS [(14.09 +/- 7.14) U/ml] in patients were significantly higher than that in the healthy controls [(140.69 +/- 90.96) micromol/L, (7.75 +/- 3.79) U/ml, respectively, P < 0.01]. Smoking and drinking were the independent risk factors for NOS, while sex was the independent risk factor for NO (P < 0.01). CONCLUSIONS: The levels of plasma NO and NOS are closely related with coronary heart disease.

Adult↗

PubMed2004

[Characteristics of municipal sewage chem-bioflocculation treatment process by using PCR-DGGE technology].

It is reported that without cultivation, DNA could be directly extracted from environmental samples with molecular biological methods, such as polymerase chain reaction (PCR) and denaturting gradient gel electrophoresis (DGGE). To analyze the community diversity of activated sludge and bio-film in the municipal sewage, work was done to directly extrude crude DNA from activated sludge and bio-film samples, separate and amplify 16S rDNA by PCR and sequence it with DGGE. The results show the significant microbe community difference between cultivated and uncultivated activated sludge. Further research on the community diversity of two different sewage treatment processes was done and initial discussion on the microbial distribution in the same reactor and microbial structure in different experimental conditions was carried out. The sequences of several 16S rDNA DGGE fragments were determined and some possible bacteria were confirmed in comparision in GeneBank (NCBI). The results show that the PCR-DGGE technology combined with sequences determination is a feasible and efficient method for microorganism analysis in environmental sample.

Biodegradation, Environmental↗

PubMed2003

Role of the epidermal growth factor receptor in signaling strain-dependent activation of the brain natriuretic peptide gene.

The epidermal growth factor receptor (EGFR) and ectoshedding of heparin-binding epidermal growth factor (HBEGF), an EGFR ligand, have been linked to the development of cardiac myocyte hypertrophy. However, the precise role that the liganded EGFR plays in the transcriptional activation of the gene program that accompanies hypertrophy remains undefined. Utilizing the human (h) BNP gene as a model of hypertrophy-dependent gene activation, we show that activation of the EGFR plays an important role in mediating mechanical strain-dependent stimulation of the hBNP promoter. Strain promotes endothelin (ET) generation through NAD(P)H oxidase-dependent production of reactive oxygen species. ET in turn induces metalloproteinase-mediated cleavage of pro-HBEGF and ectoshedding of HBEGF, which activates the EGFR and stimulates hBNP promoter activity. HBEGF also stimulates other phenotypic markers of hypertrophy including protein synthesis and sarcomeric assembly. The antioxidant N-acetylcysteine or the NAD(P)H oxidase inhibitor, apocynin, inhibited strain-dependent activation of the ET-1 promoter, HBEGF shedding, and hBNP promoter activation. The metalloproteinase inhibitor, GM-6001, prevented the induction of HBEGF ectoshedding and the hBNP promoter response to strain, suggesting a critical role for the metalloproteinase-dependent cleavage event in signaling the strain response. These findings suggest that metalloproteinase activity as an essential step in this pathway may prove to be a relevant therapeutic target in the management of cardiac hypertrophy.

Animals↗

PubMed2003

Extended life span is associated with insulin resistance in a transgenic mouse model of insulinoma secreting human islet amyloid polypeptide.

Pancreatic amyloid is found in patients with insulinomas and type 2 diabetes. To study mechanisms of islet amyloidogenesis, we produced transgenic mice expressing the unique component of human islet amyloid, human islet amyloid polypeptide (hIAPP). These mice develop islet amyloid after 12 mo of high-fat feeding. To determine whether we could accelerate the rate of islet amyloid formation, we crossbred our hIAPP transgenic animals with RIP-Tag mice that develop islet tumors and die at 12 wk of age from hypoglycemia. At 12 wk of age, this new line of hIAPPxRIP-Tag mice was heavier (29.7 +/- 1.0 vs. 25.0 +/- 1.3 g, P < 0.05) and had increased plasma glucose levels (4.6 +/- 0.4 vs. 2.9 +/- 0.6 mmol/l, P < 0.05) compared with littermate RIP-Tag mice. However, the hIAPPxRIP-Tag mice did not display islet amyloid or amyloid fibrils despite high circulating hIAPP levels (24.6 +/- 7.0 pmol/l). Interestingly, hIAPPxRIP-Tag mice had a longer life span than RIP-Tag mice (121 +/- 8 vs. 102 +/- 5 days, P < 0.05). This increase in life span in hIAPPxRIP-Tag was positively correlated with body weight (r = 0.48, P < 0.05) and was associated with decreased insulin sensitivity compared with RIP-Tag mice. hIAPPxRIP-Tag mice did not develop amyloid during their 4-mo life span, suggesting that increased hIAPP secretion is insufficient for islet amyloid formation within such a short time. However, hIAPPxRIP-Tag mice did have an increase in life span that was associated with insulin resistance, suggesting that hIAPP has extrapancreatic effects, possibly on peripheral glucose metabolism.

Aging↗

PubMed2003

Modulation of Ca2+ channel currents by a novel antidementia drug N-(4-Acetyl-1-piperazinyl)-p-fluorobenzamide monohydrate (FK960) in rat hippocampal neurons.

N-(4-Acetyl-1-piperazinyl)-p-fluorobenzamide monohydrate (FK960), a novel antidementia drug, has been demonstrated to ameliorate memory deficits in various experimental models of dementia. This drug selectively increases somatostatin release from hippocampal slices and augments long-term potentiation (LTP) in the CA3 area of the hippocampus. In the present study, the effects of FK960 on voltage-activated Ca2+ channels were investigated in acutely isolated rat hippocampal neurons, using whole-cell patch-clamp technique to clarify the cellular mode of action of FK960. Application of somatostatin significantly reduced Ca2+ currents via G protein-coupled signaling pathways. This inhibitory effect was significantly abolished by FK960 when applied in combination. In contrast, FK960 showed only modest inhibition on the reduction in Ca2+ currents produced by baclofen, an agonist of GABAB receptor. Intracellular application of the protein kinase inhibitor H-7 did not alter somatostatin-induced inhibition and had no significant effect on blockade by FK960. In addition, application of FK960 alone produced modest but apparent increases in Ca2+ currents without significant changes in the activation kinetics of the channels. The dose-response relationship on calcium current enhancement was bell-shaped with a maximum effect at 0.1 microM FK960, the same concentration as that for increasing on somatostatin release and CA3-LTP. These results show that FK960 reverses G protein-dependent inhibition of Ca2+ currents by somatostatin in hippocampal neurons. Enhancement of Ca2+ currents by FK960 may be due to its modulatory actions on Ca2+ channels, rather than removal of G protein-inhibited tonic currents. Together, these mechanisms may be involved in the selective effects of FK960 on somatostatin release, excitatory transmission, and synaptic plasticity in the hippocampus.

Animals↗

PubMed2003

Targeted gene disruption of glycerol-3-phosphate dehydrogenase in Colletotrichum gloeosporioides reveals evidence that glycerol is a significant transferred nutrient from host plant to fungal pathogen.

Unidirectional transfer of nutrients from plant host to pathogen represents a most revealing aspect of the parasitic lifestyle of plant pathogens. Whereas much effort has been focused on sugars and amino acids, the identification of other significant metabolites is equally important for comprehensive characterization of metabolic interactions between plants and biotrophic fungal pathogens. Employing a strategy of targeted gene disruption, we generated a mutant strain (gpdhDelta) defective in glycerol-3-phosphate dehydrogenase in a hemibiotrophic plant pathogen, Colletotrichum gloeosporioides f.sp. malvae. The gpdhDelta strain had severe defects in carbon utilization as it could use neither glucose nor amino acids for sustained growth. Although the mutant mycelia were able to grow on potato dextrose agar medium, they displayed arrhythmicity in growth and failure to conidiate. The metabolic defect of gpdhDelta could be entirely ameliorated by glycerol in chemically defined minimal medium. Furthermore, glycerol was the one and only metabolite that could restore rhythmic growth and conidiation of gpdhDelta. Despite the profound defects in carbon source utilization, in planta the gpdhDelta strain exhibited normal pathogenicity, proceeded normally in its life cycle, and produced abundant conidia. Analysis of plant tissues at the peripheral zone of fungal infection sites revealed a time-dependent reduction in glycerol content. This study provides strong evidence for a role of glycerol as a significant transferred metabolite from plant to fungal pathogen.

Althaea↗

PubMed2003

Profiles of methotrexate in blood and CSF following intranasal and intravenous administration to rats.

The aim of this paper was to investigate the levels of methotrexate (MTX) in blood and the cerebrospinal fluid (CSF) in rats to find out whether there is any direct drug transport from nasal cavity to CSF following intranasal administration. Methotrexate was administered to male Sprague-Dawley rats either intranasally or intravenously. Drug concentrations were determined from CSF and plasma samples collected from the cisterna magna and caudal vein, respectively. To collect CSF sample continuously, blank artificial CSF was infused into the lateral ventricle. The plasma levels achieved following intranasal administration were significantly lower than those after intravenous administration (P<0.01) were, while CSF concentrations achieved after intranasal administration were significantly higher than those after intravenous administration (P<0.01). The ratio of the AUC(CSF) value between the intranasal route and the intravenous injection was 13.76, whereas the absolute bioavailability was only 6.3%, the drug targeting index (DTI) of nasal route was 21.7. In conclusion, these results showed that the antineoplastic MTX must be directly transported from the nasal cavity into the CSF in rats.

Administration, Intranasal↗

PubMed2003

Measurement of the frequency-dependent conductivity in sapphire.

Electron transport of photoexcited single-crystal sapphire (alpha-Al2O3) is characterized by terahertz time-domain spectroscopy. The complex conductivity displays a Drude-type frequency dependence, which yields carrier scattering rates and densities. Carrier scattering is dominated by interactions with acoustical and optical phonons at low and high temperatures, respectively, and follows Matthiessen's law over the measured temperature range of 40-350 K. The results, including low-temperature mobilities >10000 cm(2)/V s, are compatible with a large-polaron description of the conduction electrons.

Journal Article↗