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F Chen

Publications and source records attributed to F Chen.

At least 397 records · Page 22Linked to original sources
PubMed1997

Involvement of NF-kappaB in silica-induced cyclooxygenase II gene expression in rat alveolar macrophages.

The role of nuclear factor (NF)-kappaB transcription factor in silica-induced cyclooxygenase (COX) II gene expression was examined in the rat alveolar macrophage cell line NR8383. Our results indicate that NF-kappaB can be activated in this cell line by silica exposure. Suppression of NF-kappaB activation in these cells leads to an attenuation of COX II mRNA accumulation induced by silica. Using an electrophoretic mobility shift assay and a reporter gene assay, we provide evidence that at least two kappaB sites in the 5'-flanking region of the rat COX II gene are involved for silica-induced transcriptional control of the COX II gene. The first motif, -404 GGGGATTCCC -395, is absolutely conserved in sequence and is localized in a similar position among the COX II genes found in humans, rats, and mice. The second motif, -91 GGGGAAAGCC -82, was conserved only in the mouse and rat COX II genes in sequence and in location. Aspirin, a COX inhibitor, was shown to suppress silica-induced NF-kappaB activation. However, prostaglandin E2, one of the important downstream reaction products catalyzed by the COX enzyme, was also shown to attenuate silica-induced NF-kappaB activation by retarding the degradation of silica-induced inhibitor NF-kappaB. These results suggest that an interdependent regulation may exist between NF-kappaB activation and COX or its products.

Animals↗
PubMed1997

Purification and characterization of the NADP-malic enzyme from Bradyrhizobium japonicum A1017.

An NADP-malic enzyme [EC 1.1.1.40] was purified to homogeneity from Bradyrhizobium japonicum A1017, and the molecular and physiological characteristics were surveyed. The molecular mass of one subunit of the purified enzyme was evaluated to be 77,600 Da by SDS-PAGE, and the native enzyme was a tetramer in pH 7.0 and dimer in pH 8.0 conditions, showing complex oligomeric characteristics corresponding to pH value.

Amino Acid Sequence↗
PubMed1997

Noninvasive detection of atherosclerotic lesions by 99mTc-based immunoscintigraphic targeting of proliferating smooth muscle cells.

BACKGROUND: Mouse/human chimeric antibody Z2D3 identifies an antigen produced exclusively by proliferating smooth muscle cells of human atheroma, and also cross reacts with experimentally induced atherosclerotic lesions in rabbits. Fab' fragments of Z2D3 antibody were labeled with (99m)Tc using glucaric acid as a weak transchelator. The potential role of (99m)Tc-labeled Z2D3 scintigraphy was explored for noninvasive imaging of experimental atherosclerotic lesions. METHODS AND RESULTS: (99m)Tc-Z2D3 Fab' was utilized for noninvasive imaging in four rabbits with experimentally induced atherosclerotic lesions and in one control rabbit. In addition, (99m)Tc-labeled nonspecific 103D2 Fab' was used for comparison in four other rabbits with atherosclerotic lesions. The atherosclerotic lesions were induced by balloon de-endothelialization of the infradiaphragmatic abdominal aorta and 12 weeks of hyperlipidemic diet. An aliquot of 15 mCi (550 mBq) of (99m)Tc pertechnetate was incubated with 6.25 mg of glucaric acid for 30 min followed by incubation of (99m)Tc glucarate with 375 microg of Z2D3 Fab' or 103D2 Fab' for an additional 30 min. Instant thin-layer chromatography demonstrated almost complete radiolabeling. (99m)Tc-Z2D3 was administered IV and gamma imaging was performed at the time of injection, 3, 6, 9, and 12 h, followed by ex vivo imaging of the excised aorta, and biodistribution was performed. Unequivocal visualization of atherosclerotic lesions was possible in all four animals at 9 to 12 h with Z2D3 Fab'. Quantitative uptake, as represented by mean lesion-to-liver count density ratio, was 0.6+/-0.05. Imaging with nonspecific 103D2 Fab' did not show any localization in the abdominal aorta (lesion-to-liver ratio, 0.45+/-0.02, p=0.02). Ex vivo lesion-to-normal aortic segment ratio was 4.3+/-0.9 for Z2D3 and 1.04+/-0.08 for nonspecific 103D2 Fab' (p=0.01). Biodistribution studies demonstrated 0.03+/-0.003% injected Z2D3 dose per gram in the atherosclerotic lesions as compared with 0.01+/-0.003% in the nondenuded thoracic aorta of atherosclerotic rabbits (p=0.008). However, only 0.008+/-0.002% of the mean injected dose per gram was obtained in the atherosclerotic lesions (p=0.001) as compared with 0.005+/-0.003% in the normal aortic segments with 103D2. No Z2D3 uptake in normal rabbits was observed on either the in vivo or ex vivo images. CONCLUSIONS: The present study demonstrates that (99m)Tc-based immunoimaging of the vascular lesions may be feasible by the use of smaller antibody fragments. Earlier visualization is possible at the expense of a lower absolute antibody uptake in the lesions as compared to the use of intact antibody or larger fragments with longer circulating time.

Animals↗
PubMed1997

[Gene frequency of HPA among Hunan population of Han nationality].

We used allele specific primer PCR (ASP-PCR) method to detect the genotype of five major HPA systems among Hunan population of Han nationality. The results showed: The gene frequency of PLA1 was 81.00% and 85.87% for Kob, 71.00% for Baka, 91.00% for Pena, 90.67% for Brb which provided the basis for further clinical application of HPA.

Adult↗
PubMed1997

[Analysis of the EGG waveform of vocal polyps].

To study the effect of vocal polyps on vocal vibration, the authors analysed the EGG waveform of 201 cases of vocal polyps of various location and shape. The results showed that the EGG waveform in opening phase appeared a notch for vocal polyps with pedicle, and appeared steep for vocal polyps with a wide base. Among the polyps whose waveform appearing a notch in closing phase, most of their base located below vocal cord. Whether the polyps were located in the anterior, middle or posterior of the vocal cord and whether the polyps were unilateral or bilateral there are no effect on the EGG waveform. EGG was the potential technique for studying vocal function.

Adolescent↗
PubMed1997

[Choice of time and mode of operation in severe acute pancreatitis].

We report the treatment of 75 patients of severe acute pancreatitis. Operations were performed on patients with pancreatic infection and organ failure according to the principle of "individualization". Operation was also indicated for the patients aged 60 who had had no improvement after a short period of non-operative treatment because of the susceptibility to develop MOF, Non-operative treatment was administered to other patients. This therapeutic mode can increase the cure rate while complications can be decreased. Early operation is necessary for patients with single organ failure in case sequential MOF might happen. The main components of operation were elimination of necrostic lesion, lysis of the pancreas, multiple drainage, and adequate postoperative peritoneal lavage. This operation can not only eliminate necrostic tissue, but also prevent progressive pancreatic necrosis. It introduces free drainage, and can bring satisfactory therapeutic result and reduce the possibility of reoperation.

Adult↗
PubMed1997

[Combined resection of the pancreas and portal vein replaced by blood vessel prosthesis for pancreatic head carcinoma: report of two cases].

The resectability and prognosis of carcinoma of the pancreatic head are still poor. The higher resectability rate was achieved by combined resection of the pancreas and portal vein. Two patients in whom the portal vein, surrounded but not penetrated by pancreatic carcinoma, was resected and replaced by an expanded Teflon (Gore-Tex) tube (diameter 8 mm). One patient, who survived 32 months without recurrence of disease, had a ultrasonography and CT proved patent graft 6 and 32 months after operation. A second survivor had a patent graft at 20 month. Excision of involved portal vein during pancreatoduodenectomy for carcinoma of the head of the pancreas is a feasible and valid procedure in the absence of metastases. Vein grafting is the best means for portal vein reconstruction. Gore-Tex appears to be suitable prosthesis when the portal vein must be sacrificed.

Adult↗
PubMed1997

[Fully length MDR1 cDNA transfer conferring resistance to adriamycine on sensitive cells GLC].

Human lung cancer leads the mortality of cancers and the chemotherapy is often uneffective because of drug resistance. In order to study the role of mdr-1 gene in resistant lung cancer, the fully length mdr-1 cDNA was transferred into a sensitive lung cancer cell line GLC. The mdr-1 cDNA was constructed in a retroviral vector, pDORneo. The transfection of recombinant plasmid was carried out by lipofectin. Supernatant containing infective viruses derived from a G418 resistant clone of package cell PA317 was used to infect GLC cell which is sensitive to chemotherapeutic agents. After G418 and adriamycine selections, three P-glycoprotein positive clones were isolated and the integration of mdr-1 cDNA was demonstrated by PCR of genomic DNA. The relative resistance of 3 clones to adriamycine as and elevated by 5.4, 6.0 respectively 7.8 times compared with the untransfected cell and the transcription of mdr-1 gene in these transfected cells as obviously enhanced by in situ hybridization. This results suggest that the mdr-1 gene plays a role in increasing drug resistance of human lung cancer.

Adenocarcinoma↗
PubMed1997

[Surgical management of patients with infected vascular prostheses].

We evaluated the therapeutic efficacy of surgical management of patients with infected vascular prostheses. Eight cases of infected vascular prosthetic grafts from 250 prosthetic bypasses were reviewed. The rate of graft infection was 3.2%. Clinical manifestations were localized wound infection with prosthetic graft exposure, anastomotic hemorrhage and gangrene in lower extremity. Treatment included graft removal and debridement; graft removal and primary amputation; graft removal and revascularization; debridement and local graft irrigation. Two cases died from anastomotic hemorrhage and the others recovered. The predisposing factors of vascular prosthetic infection are diabetes mellitus, secondary hemotoma and reoperation in the same position. Conservative treatment efforts without revascularization justifies a more aggressive approach to suspected graft infection.

Adult↗
PubMed1997

[Long-term effect of voice rehabilitation in 125 patients following total laryngectomy].

One hundred and twenty-five patients received voice rehabilitation operations following total laryngectomy over the period from August 1977 to December 1994. Among them, 119 were male and 6 were female, the eldest was 70 years old and the youngest 30 years old, and the average age was 55.3 years. Clinical staging was as follows: stage II, 2 cases; stage III, 45 cases; stage IV, 66 cases; and recurrence, 12 cases. The voice rehabilitation operations included pharynx-trachea anastomosis 18 cases and trachea-esophagus fistulization 107 cases. One hundred and fourteen patients were followed-up for 13 months to 18 years. The 3, 5, and 10 year survival rates were 78.2%, 61.4%, and 40.5% respectively. The effective rates of voice rehabilitation according to hearing voice distance were 84.6%, 81.1%, and 67.5% 3 weeks, 1 year, and 5 years respectively after operation. The causes of failure were closure of fistula 15 cases; food aspiration 8 cases and unknown 3 cases. The clinical value, advantages and disadvantages of voice rehabilitation, and the time to evaluate the effect of voice rehabilitation were discussed.

Adult↗
PubMed1997

[New digital carotid compressor].

Since 1979, many cases of paraganliomas in the neck have been successfully treated in Tianjin Cancer Hospital. All patients who would be subjected to this operation should undergo preoperative compressing exercises of the carotid artery to promote better circulation of collateral cerebral crossflow. Therefore, a reliable and compact instrument is necessary for the compressing exercises of the carotid artery and the long-term ambulatory monitoring of the compressing effect. This paper introduces our developed instrument, Adjustable and Digital Carotid compressor, which is based on the principle of volume-oscillometric method. During the gradual change in cuff pressure, the amplitude of consecutive arterial volume pulsation associated with pulse pressure shows change characteristically due to the nonlinearity of arterial pressure-volume (P-V) relation. Arterial pressure can be determined by detecting this change in the amplitude, while the arterial volume change can be noninvasively obtained as a function of this transmural pressure, provided that the state of blood flow are determined during this pressure measurement. Considering the simplicity and practicability of this instrument, we have designed a new portable one which consists of pulse pressure transducer, signal amplifier, peak voltage locking circuit and liquid crystal displayer. The validity and accuracy of this instrument and a few examples of its clinical application are presented.

Blood Pressure↗
PubMed1997

Mutation effect of high altitude balloon flight on rice and green pepper seeds.

Dry seeds of rice and green pepper were carried in the basket of a high altitude balloon to 30-40 km for 8 h. The treated seeds were planted on the ground and characters of these seeds and their progenies, such as development, fruiting, disease resistance were observed. The results showed that the SP2 generation of the treated rice showed strong mutation. A Japonica male fertility restorer rice line was found out. It could be hybridized with sterile line of Indica rice, and their progeny had strong hybrid vigor, high setting percentage and good plumpness of grain. Disease resistance, high-yield, big-fruit and high vitamin C content strains were selected from the progenies of treated green pepper seeds. The above results indicated that the special conditions in high altitude could produce a variety of mutations and most of them are hereditable. Therefore, high altitude balloon flight can be used as a new method of mutation breeding.

Agriculture↗
PubMed1997

[Simultaneous determination of carotenoids and chlorophylls in algae by high performance liquid chromatography].

An isocratic reversed-phase HPLC method for the simultaneous determination of carotenoids and chlorophylls in algae is presented. Both carotenoids and chlorophylls were separated by using a C18 column and a mobile phase consisting of dichloromethane/acetonitrile/methanol/water (22.5:9.5:67.5:0.5). The flow rate was 1.0mL/min. These pigments were detected by a UV-VIS absorbance detector set at 450nm. The average recoveries of these pigments by standard addition method were 99.1% for lutein, 98.5% for alpha-carotene, 99.4% for beta-carotene, 100.6% for chlorophyll a and 99.9% for chlorophyll b. The relative standard deviations of these pigments were 2.4% for lutein, 5.6% for alpha-carotene, 6.0% for beta-carotene, 4.1% for chlorophyll a and 4.0% for chlorophyll b. The calibration curves for these pigments gave good linearity over a wide range of 0-50mg/L (r = 0.9992-0.9999). The retention times were 3.0 min for lutein, 4.7 min for chlorophyll b, 6.3 min for chlorophyll a, 14.1 min for alpha-carotene, and 14.7 min for beta-carotene. Using this method, carotenoids and chlorophylls were determined in Spirulina platensis, Chlorella vulgaris and Haematococcus lacustris. Chlorella vulgaris and Haematococcus lacustris samples were ground in a B. Braun homogenizer. Spirulina platensis sample was smashed by supersonic wave. Acetone was used as extractant.

Carotenoids↗
PubMed1997

Genetic analysis of the components of winterhardiness in barley (Hordeum vulgar L.).

Winterhardiness in cereals is the consequence of a number of complex and interacting components: cold tolerance, vernalization requirement and photoperiod sensitivity. An understanding of the genetic basis of these component traits should allow for more effective selection. Genome map-based analyses hold considerable promise for dissecting complex phenotypes. A 74-point linkage map was developed from one hundred double haploid lines derived from a winter x spring barley cross and used as the basis for quantitative trait locus (QTL) analyses to determine the chromosome location of genes controlling components of winterhardiness. Despite the greater genome coverage provided by the current map, a previously-reported interval on chromosome 7 remains the only region where significant QTL effects for winter survival were detected in this population. QTLs for heading date under 24 h light map to the same region. A QTL for heading date under this photoperiod regime also maps to chromosome 2. A distinct set of QTLs mapping to chromosomes 1, 2, 3 and 5 determined heading date under 8 h light. Patterns of differential QTL expression underscore the complexity of Winterhardiness.

Acclimatization↗
PubMed1997

[Relationship between subjective cognition and observed life-style in nursing students].

Complex interactions between long-standing lifestyles and genetic factors are strongly involved in the pathologenesis of adult diseases or chronic degenerative diseases. We usually use a questionnaire to obtain life-style information from subjects in a health survey. However, the response to questionnaires is a subjective recognition, therefore, it does not always precisely correspond to the actual situation. The purpose of this research is to compare the response to the questionnaire about life-styles with facts that can be objectively observed. Furthermore, each aspect of life-styles was examined on a mutual influence grade. The subjects were ninety-eight nursing college students aged from 18 to 23 years old, in good health. Subjective symptoms and daily life practices were investigated by a 15-item questionnaire, as the first step. Therefore, we asked them to record their behavior on a time chart, everyday for ten days. Seven days of serial records were obtained from sixty-four subjects (65.3% of 98 persons). 1) The response "yes" to the questionnaire "Do you sleep well?" and "Do you fall asleep, easily?" was influenced by the hours of sleep, rather than what time the subjects "go-to-bed" or "get-up". The response to "Do you wake up often during the night?" expressed an actual situation, well. 2) For subjective cognition regarding excretion, the answer for "constipation" was associated with the number of defecation per week, though the answer for "diarrhea" was not. 3) The answer to "Do you eat breakfast?" reflected the actual situation. However, the answer for "Do you eat between meals?" did not express the actual situation, that is, even the subjects who answered "occasionally" or "I don't eat between meals" had eaten between meals 6.1 times per week, on average. 4) There were mutual influences among sleeping, eating breakfast and excretion.

Adult↗
PubMed1997

Expression of proliferating cell nuclear antigen in Wilms' tumor.

OBJECTIVE: To investigate the expression of proliferating cell nuclear antigen (PCNA) and its clinical significance in Wilms' tumor. METHODS: PCNA immunoreactivity on paraffin-embedded tissues was assessed retrospectively in 35 cases using labelled streptaridin biotin (LSAB) procedure, and its association with clinical and other biological features was studied. RESULTS: Twelve tumors (34.29%) expressed PCNA. Expression rate increased with the advance of stage (P < 0.05). The S-phase fraction and proliferation index (PI) in children with PCNA positive expression were higher than those in children with negative PCNA expression (P < 0.05). The survival rate (16.67%) in patients with positive PCNA expression was significantly lower than that (73.91%) in no-expression ones (P < 0.01). CONCLUSION: PCNA is a sensitive indicator for cell proliferation and is clinically useful in identifying a poor prognostic group of patients with Wilms' tumor.

Child↗