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Biomedical subjects

W Fu

Publications and source records attributed to W Fu.

At least 109 records · Page 6Linked to original sources
PubMed1996

A study of time window for oxidative stress associated with myocardial ischemia and reperfusion.

OBJECTIVE: To investigate the time window for oxidative stress occurred in myocardial tissue and associated with reperfusion. METHODS: Thirty nine conscious rabbits were subjected to 0.5 hours (h) of myocardial ischemia and reperfusion for 0 h, 6 h, 24 h and 72 h, respectively, and nine rabbits served as controls. Activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-px) and myeloperoxidase (MPO), and contents of GSH and malondyaldehyde (MDA) were measured in myocardial tissues taken from ischemic non-necrotic area (INNA), ischemic necrotic area (INA) and non-ischemic area (NIA), respectively. RESULTS: The antioxidant status of INNA was weakened at 6th h, 24th h, and 48th h of reperfusion. Activities of Mn-SOD and Cu-Zu-SOD returned to normal value at 72nd h of reperfusion, but GSH-px activity and GSH content remained in lower value. MDA content had a marked increase at 6th h, 24th h, 48th/h and 72nd h of reperfusion. MPO activity had a progressive increase after reperfusion, with its peak value at 48th h, and PMN accumulation occurred mostly in necrotic zone and its outer board zone. A mild oxidative stress also occurred in non-ischemic tissue, but without obvious neutrophils infiltration. CONCLUSIONS: The time window for oxidative stress associated with myocardial ischemia and reperfusion lasts for at least 72 h, and PMN infiltration is one of the most important factors of delayed myocardial reperfusion injury.

Animals↗
PubMed1996

[Displaying of infrared thermogram of temperature character on meridians].

In this work we have observed the skin temperature of central line of the back and chest-abdomen on the human body truck by the infrared thermography. Here care the results: (a) Of all the volunteers, 57.1% central lines of the back and 7.7% central lines of the chest-abdomen of the volunteers are the longitudinal high thermal lines in normal state. (b) After moxibustion at Mingmen (GV 4) point, the temperature of 70.4% central lines of the back is going up. After moxibustion at Zhongwan (CV 12) point, the temperature of 56.0% central lines of the chest-abdomen is going up. The high thermal lines are longer and their continuity is hotter after moxibustion. (C) The lines on the back which are about 20 approximately 50 centimetres are longer than those on the chest-abdomen which are about 10-30 centimetres. The results suggest that the high thermal lines are the objective display of the temperature character on the Governor and Conception vessel. The formation of high thermal line may have some relationship with the compact connective tissue or microcirculation.

Acupuncture Points↗
PubMed1996

[A study on changes and its mechanisms of intestinal mucosal permeability after severe burn].

The changes in the intestinal mucosal permeability were observed by quantitatively assessing plasma to luminal clearance of 99mTc-labeled DTPA, and the influence of platelet activating factor (PAF) on it was investigated. The results showed that intestinal permeability was significantly elevated after severe burn and was positively correlated with increase in PAF in the intestinal tissue (r = 0.94, P < 0.01). PAF antagonist therapy could significantly attenuate postburn intestinal mucosal permeability. It is concluded that PAF is one of the important factors causing increased intestinal permeability after severe burn.

Animals↗
PubMed1996

[Selection of surgical approaches in the treatment of aortoiliac arterial occlusive disease].

31 patients with aortoiliac occlusive disease with or without infrainguinal occlusion was treated with thromboendarterectomies, aortoiliac or aortofemoral arterial bypasses, extra-anatomic bypasses and sequential arterial bypasses in the past 5 years. The results were satisfactory. The surgical mortality was 3.2%, the primary 5-year patent rate was 84.2%, and the secondary 5-year patent rate was 96.5%. We emphasize the value of ABI to indicate arterial reconstruction.

Aged↗
PubMed1996

[In situ saphenous vein arterial bypass for lower limb ischemia].

28 patients with 30 ischemic lower limbs were treated by in situ saphenous vein femorodistal arterial bypass using self-made valvulotome at Zhongshan Hospital from 1989 to 1994. All patients had claudication in the lower extremities and were diagnosed angiographically. The preoperative ABI was from 0 to 0.57 (mean 0.41). All the vein grafts were patent postoperation and the dorsalis pedis or posterior tibial arteries were palpable in 18 legs immediately postoperation and the dorsalis pedis or comitant arterial reconstruction. Graft occlusion within 3 days after original operations occurred in three cases and secondary surgical corrections were successful. Postoperative mean ABI increased from 0.41 to 0.84. The limb salvage rate was 100% and the cumulative patency rate, by the lifetable analysis in 1, 2, 3, 4 and 5 years, were 92%, 88%, 86%, 78% and 71% respectively. The results suggest that the in situ saphenous vein arterial bypass is the superior method for distal arterial reconstruction and concomitant procedures to ensure sufficient inflow as well as outflow are essential to the patency of the graft.

Aged↗
PubMed1995

Synthesis and 1H NMR characterization of the six isomeric mono-O-sulfates of 8-methoxycarbonyloct-1-yl O-beta-D-galactopyranosyl-(1-->4)-2-acetamido-2-deoxy-beta-D-glucopyran oside.

All six isomeric mono-O-sulfates of beta-D-Galp-(1-->4)-beta-D-GlcpNAc-O-(CH2)8COOMe (LacNAc-MC) have been chemically synthesized and characterized by high resolution 1H NMR spectroscopy. Sulfation causes characteristic substitution-site-specific downfield shifts of 1H NMR signals. The 4C1 chair conformation of both pyranose residues of LacNAc are unaffected by mono-O-sulfation, and, with the exception of the 3-O-sulfate derivative, glycosidic torsion angles are also unaffected.

Amino Sugars↗
PubMed1995

The effect of mannitol and anisodamin on the prevention of free radical injury to post-ischaemia flaps: an experimental study.

Rat abdominal skin flaps were subjected to total venous occlusion for 8 h. Five minutes before release of the vascular occlusion, mannitol, mannitol plus anisodamin, anisodamin or placebo (0.9% normal saline) was administered intravenously. Drug treated flaps showed a statistically significant increase in the proportion of area surviving (P < 0.001). The combination of mannitol and anisodamin was not more effective than either agent alone in increasing the proportion of area surviving. The results of biochemical analyses indicated that neither mannitol nor anisodamin affected xanthine oxidase activity (p > 0.05) but that both agents significantly reduced the increase of malondialdehyde (MDA) concentration caused by ischaemia-reperfusion (p < 0.01). Treatment with mannitol or anisodamin also prevented the increase of lactate and water content and the decrease in glucose content in the island skin flap tissue which occurred on reperfusion. The data indicate that mannitol and/or anisodamin have the potential to salvage anticipated flap necrosis. It is possible that the mechanism of action is inhibition of damage caused by toxic oxygen species and improvement in capillary reperfusion.

Animals↗
PubMed1995

Physical activity and survival from breast cancer.

The association between recreational physical activity and survival from breast cancer was investigated in a population-based cohort of breast cancer patients in Adelaide, South Australia. These patients, aged 20-74 years at diagnosis, had been recruited between 1982 and 1984 into a case-control study of diet, hormones and breast cancer. Of the 451 patients with breast cancer originally enrolled, 412 were followed for a median interval of 5.5 years. The study participants reported their weekly levels of light, moderate and vigorous recreational physical activity, which were then converted into estimates of kilocalories per week of energy expenditure. Despite some fluctuation in the hazard ratios by level of physical activity, there was little evidence for an association between total recreational physical activity and risk of death from breast cancer overall, or within menopausal strata. Similarly, there was little evidence for associations between individual types of recreational physical activity and risk of death from breast cancer.

Adult↗
PubMed1995

Multiple regions of Harvey sarcoma virus RNA can dimerize in vitro.

Retroviruses contain a dimeric RNA consisting of two identical molecules of plus-strand genomic RNA. The structure of the linkage between the two monomers is not known, but they are believed to be joined near their 5' ends. Darlix and coworkers have reported that transcripts of retroviral RNA sequences can dimerize spontaneously in vitro (see, for example, E. Bieth, C. Gabus, and J. L. Darlix, Nucleic Acids Res. 18:119-127, 1990). As one approach to identification of sequences which might participate in the linkage, we have mapped sequences derived from the 5' 378 bases of Harvey sarcoma virus (HaSV) RNA which can dimerize in vitro. We found that at least three distinct regions, consisting of nucleotides 37 to 229, 205 to 272, and 271 to 378, can form these dimers. Two of these regions contain nucleotides 205 to 226; computer analysis suggests that this region can form a stem-loop with an inverted repeat in the loop. We propose that this hypothetical structure is involved in dimer formation by these two transcripts. We also compared the thermal stabilities of each of these dimers with that of HaSV viral RNA. Dimers of nucleotides 37 to 229 and 205 to 272 both exhibited melting temperatures near that of viral RNA, while dimers of nucleotides 271 to 378 are quite unstable. We also found that dimers of nucleotides 37 to 378 formed at 37 degrees C are less thermostable than dimers of the same RNA formed at 55 degrees C. It seems possible that bases from all of these regions participate in the dimer linkage present in viral RNA.

Base Sequence↗
PubMed1995

[Streptococcus pneumoniae-induced pulmonary consolidation prevented with tumor necrosis factor alpha monoclonal antibody in mouse].

Streptococcus pneumoniae stimulate mouse peritoneal macrophages to release tumor necrosis factor alpha (TNF alpha) in vitro. When penicillin was added to lysate bacterium, TNF alpha release was accelerated. 150 Kunming mice were infected with streptococcus pnumoniae through inspiration. Dynamic changes of TNF alpha concentration in serum and bronchoalveolar lavage fluid were detected; pulmonary pathological changes were also observed. It was found that TNF alpha monoclonal antibody significantly attenuates TNF alpha activity in serum and bronchoalveolar lavage fluid, white blood cell chemotaxis, emigation, and infiltration were inhibited. We conclude that streptococcus pneumoniae infection stimulates TNF alpha release, and TNF alpha is probably the major mediator that causes tissue damage during streptococcus pneumoniae infection. As penicillin accelerates TNFa release, single therapy of penicillin may worse tissue damage.

Animals↗
PubMed1995

[Establishment of hybridoma lines and protective study of monoclonal antibodies against lipid A of endotoxins].

For developing monoclonal antibodies (MAb) that bound to lipid A of the LPS molecule, we established several hybridomas cell lines by fusion of SP2/0 and spleen cells from BALB/c mice immunized by J5 mutant strain of E. coli 0111:B4. Each MAb exhibited a high titer by ELISA assay. Six of MAb were of immunoglobulin G isotype and another one immunoglobulin M. All of these MAb demonstrated different capacity to cross-react with several gram-negative bacteria and their endotoxins. Among them, 9G6 MAb improved the survival rate of mice significantly when administered 2 hours before the challenge by pseudomonas A and E. coli. These findings suggest that MAb will probably be useful in the treatment of sepsis caused by a wide variety of gram-negative bacteria.

Animals↗
PubMed1995

[The roles of platelet activating factor in intestinal mucosal barrier injury after burn].

In order to investigate the roles of platelet activating factor (PAF) in postburn intestinal barrier injury, the changes in intestinal mucosal potential difference (PD), intestinal PAF, Phospholipase A2 (PLA2), myeloperoxidase (MPO) and malondialdehyde (MDA) were measured in a model of rats with 30% TBSA III degrees burns. The results showed that the intestinal PAF level was significantly elevated after severe burn and was negatively correlated with the decrease of intestinal mucosal PD (r = -0.94, P < 0.01). PAF antagonist WEB 2170 treatment could significantly inhibite the increase of PAF in intestinal tissue, enhance intestinal mucosal PD, attenuate the levels of PLA2, MPO and MDA in intestinal tissue, and alleviate the pathological changes in ileal mucosa, compared with the burn group. The results suggest that PAF is an important factor causing postburn intestinal mucosal barrier injury, and activation of leukocyte and PLA2 as well as the release of superoxide are important intermediate mechanisms for PAF leading to intestinal mucosal injury.

Animals↗
PubMed1995

Treatment of 23 patients with advanced gastric cancer by intravenously transfer of autologous tumor-infiltrating lymphocytes combined with rIL-2.

Tumor-infiltrating lymphocytes (TIL) isolated from metastatic lymph nodes in patients with nonoperable advanced gastric cancer were induced to become LAK-like cytotoxic activity of TIL after in vitro culture with rIL-2. Twenty-three patients with advanced gastric cancer were treated by intravenously transfer of autologous TIL combined with rIL-2. The tumor focus disappeared (complete remission, CR) in 3 patients (13.0%) and significantly decreased (partial remission, PR) in 5 patients (21.7%). Fifteen patients did not respond to the treatment. The amount of soluable IL-2 receptor in serum was significantly decreased after treatment, the cytotoxicity of NK cells and OT test were significantly increased. No significant difference in CD4/CD8 was found between before and after treatment. No serious side effect was observed in the treatment.

Adenocarcinoma↗
PubMed1995

Pentoxifylline ameliorates pulmonary damage caused by Streptococcus pneumoniae infection in mouse.

Streptococcus pneumoniae stimulated mouse peritoneal macrophage to release tumor necrosis factor-alpha (TNF alpha) in vitro. When penicillin was added into the medium with bacteria, TNF alpha release was accelerated. Pentoxifylline (PTX), a phosphodiesterase inhibitor, significantly attenuated TNF alpha release caused either by Streptococcus pneumoniae or by its lysates. In this experiment, 150 Kunming mice were infected with Streptococcus pneumoniae through inspiration. Dynamic changes of TNF alpha concentration in serum and bronchoalveolar lavage fluid were determined, and pulmonary pathological changes were also observed. It was found that PTX significantly attenuated TNF alpha activity in serum and bronchoalveolar lavage fluid, and inhibited white blood cell chemotaxis, emigration and infiltration. In conclusion, Streptococcus pneumoniae infection stimulates the release of TNF alpha which is probably the major mediater that causes tissue damage during Streptococcus pneumoniae infection. The mechanism is probably that Streptococcus pneumoniae and its lysates activate TNF alpha gene transcription. As penicillin accelerates TNF alpha release, treatment with penicillin alone may aggravate the tissue damage. Combined treatment with PTX may be more reasonable.

Animals↗
PubMed1994

nifU gene product from Azotobacter vinelandii is a homodimer that contains two identical [2Fe-2S] clusters.

The nifU gene product is required for the full activation of the metalloenzyme nitrogenase, the catalytic component of biological nitrogen fixation. In the present work, a hybrid plasmid that contains the Azotobacter vinelandii nifU gene was constructed and used to hyperexpress the NIFU protein in Escherichia coli. Recombinant NIFU was purified to homogeneity and was found to be a homodimer of 33-kDa subunits with approximately two Fe atoms per subunit. The combination of UV/visible absorption, variable-temperature magnetic circular dichroism, EPR, and resonance Raman spectroscopies shows the presence of a [2Fe-2S]2+,+ center (Em = -254 mV) with complete cysteinyl coordination in each subunit. The electronic, magnetic, and vibrational properties of the [2Fe-2S]2+,+ center do not conform to those established for any of the spectroscopically distinct types of 2Fe ferredoxins. These distinctive properties appear to be a consequence of a novel arrangement of coordinating cysteinyl residues in NIFU, and the residues likely to be involved in cluster coordination are discussed in light of primary sequence comparisons to other putative [2Fe-2S] proteins. The observed physicochemical properties of NIFU and its constituent [2Fe-2S] cluster also provide insight into the role of this protein in nitrogenase metallocluster biosynthesis.

Azotobacter vinelandii↗
PubMed1994

A preliminary epidemiological study of the patient population visiting an urban ED in the Republic of China.

The objective of this study was to evaluate the characteristics of the patient population of an urban emergency department (ED) in The People's Republic of China. A prospective observational study was conducted at a university-affiliated hospital adult ED medical unit and included all patients visiting the medical unit of the ED during a 2-week period. A data collection log was designed and placed in the ED. Data were recorded by the attending ED physician for all patients presenting during the study period. There were 569 patients recorded in the 2-week period. The major presenting complaints were fever (20.9%), abdominal pain (20.1%), and chest pain (11.4%). The most common diagnosis were upper respiratory tract infection (11.6%), angina pectoris (6.3%), and acute gastritis (4.9%). Eight percent of the patients were admitted, 29.0% were held in an observation unit, and 0.6% died. The average length of stay in the ED observation unit was 5.6 days. These data offer emergency physicians a preliminary understanding of the clinic presentations and diagnoses of patients seen in a university-affiliated urban hospital ED in China. The number and length of time patients were held in observation unit point out the shortage of in-hospital beds. This study is useful for describing and understanding characteristics of the patient encounter and for improving the delivery of emergency care in China.

Adolescent↗
PubMed1994

Characterization of human immunodeficiency virus type 1 dimeric RNA from wild-type and protease-defective virions.

We have characterized the dimeric genomic RNA in particles of both wild-type and protease (PR)-deficient human immunodeficiency virus type 1 (HIV-1). We found that the dimeric RNA isolated from PR- mutant virions has a lower mobility in nondenaturing gel electrophoresis than that from wild-type virions. It also dissociates into monomers at a lower temperature than the wild-type dimer. Thus, the dimer in PR- particles is in a conformation different from that in wild-type particles. These results are quite similar to recent findings on Moloney murine leukemia virus and suggest that a postassembly, PR-dependent maturation event is a common feature in genomic RNAs of retroviruses. We also measured the thermal stability of the wild-type and PR- dimeric RNAs under different ionic conditions. Both forms of the dimer were stabilized by increasing Na+ concentrations. However, the melting temperatures of the two forms were not significantly affected by the identity of the monovalent cation present in the incubation buffer. This observation is in contrast with recent reports on dimers formed in vitro from short segments of HIV-1 sequence: the latter dimers are specifically stabilized by K+ ions. K+ stabilization of dimers formed in vitro has been taken as evidence for the presence of guanine quartet structures. The results suggest that guanine quartets are not involved in the structure linking full-length, authentic genomic RNA of HIV-1 into a dimeric structure.

Biopolymers↗