[Progress of experimental pharmacologic study on the effect of Astragaus on the cardiac vascular system].
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Animals↗
Biomedical subjects
K Chen
Publications and source records attributed to K Chen.
[An epidemiological study on the incidence rates of colorectal cancer through different drinking water sources].
OBJECTIVE: In order to identify the association of incidence rates of colorectal cancer and different drinking water sources. METHODS: With the retrospective cohort method, 8 villages or townships in Haining city were randomly selected as the study area where a total 408 cases were collected during 1977 to 1996. The incidence rates according to the drinking water sources were calculated by sex and sites of the cancer. The RR estimates were given to each sex and site by comparing to that in well water source. RESULTS: The incidence rates of colorectal cancer by sequence of the sources were shown as follows drinking water: (male: pool water 126.04/10(5); female: 81.76/10(5)), river water (male: 45.06/10(5); female: 63.43/10(5)), tap water (male: 7.99/10(5); female: 5.17/10(5)) and well water (male: 3.19/10(5); female: 3.06/10(5)). All of them were statistically significance through chi(2) trend tests. Poisson test was used to have found the differences of incidences of colorectal cancer between different drinking water sources (P < 0.01). RR estimates showed that the risk of colorectal cancer with pool or river water sources were 7 times higher than that with well water. CONCLUSION: Study of this kind might uncover the differences which accounted for the associations between the drinking water sources and colorectal cancer.
China↗
[Randomized controlled trial of sequence mass screening program for colorectal cancer].
OBJECTIVE: In order to assess the effectiveness of mass screening program for colorectal cancer, a sequence mass screening program based on RPHA-FOBT and individual quantitative risk assessment model (attributive degree value, AD) was used and evaluated on its effectiveness in a randomized controlled trial. METHODS: The residents of Jiashan county aged 30 years and over were randomized to either screening or control groups in 1989. Participants in screening group were asked to fill in a questionnaire and to submit one paper slide with stool. Participants who tested positive underwent diagnostic evaluations including flexible sigmoidoscopy and colonoscopy. RESULTS: According to the cancer registry of Jiashan, after initial mass screening in 1989, the 8-year cumulative incidence per 1,000 of colorectal cancer in screening and control groups appeared to be 3.95 (95% CI 3.81 - 4.10) and 4.01 (95% CI 3.86 - 4.16) respectively. There was no significant statistical difference between two groups (P > 0.05). Nevertheless, the 8-year cumulative mortality for colorectal cancer in screening group (2.08 per 1,000; 95% CI 1.96 - 2.18) was reduced 14.7% comparing with the control group (2.44 per 1,000; 95% CI 2.33 - 2.55). In particular, the cumulative mortality of rectal cancer was significantly (31.7%) lower than that in control group. Log-rank test showed that survival rate of rectal cancer in screening group was higher than that in controls (log-rank = 9.01, P = 0.0027). CONCLUSIONS: The sequential mass-screening program which based on RPHA-FOBT and ADV might reduce the mortality for colorectal cancer in the Chinese population.
Adult↗
[Investigation on E. coli O157 in Fujian, China].
OBJECTIVES: To understand the distribution of Escherichia coli O157 (E. coli O157) in human beings, livestock and fowls in Fujian Province, and biological features of the isolated strains. METHODS: Fecal specimens from diarrheal patients, livestock and fowls and meat specimens in Putian and Fuzhou were collected for detection of E. coli O157 during 1997 - 1998. RESULTS: A total of 2,725 specimens were detected, and 76 strains of E. coli O157 were isolated from pigs, pigeons, cattle, chickens, ducks, et al., as well as from the diarrheal patients. These strains could be classified into three types according to their serological tests, including 33 strains of O157: H7, 21 strains of O157: NM, and 22 strains of O157: H?. Detecting rate of E. coli O157 from pigs was the highest. The isolated strains could cause diarrhea in human and obvious pathological changes in the intestines of mice, but could not produce cytotoxin Vero, or heat-stable or heat-liable enterotoxin LT or ST. CONCLUSIONS: There were three types of E. coli O157 in Fujian. But, pathogenic factors of O157: H7 and O157: NM were different from those reported abroad. It suggested that there possibly existed some new pathogenic factors.
Animals↗
[Drinking water types, microcystins and colorectal cancer].
OBJECTIVE: To assess the relationship between microcystins (a blue-green algal toxin) in drinking water and colorectal cancer. METHODS: Eight townships were randomly selected as study sites in Haining city of Zhejiang province, China. Four hundred and eight colon and rectum carcinoma cases diagnosed from 1977 to 1996 were identified from cancer registry in the study sites. A retrospective survey on types of drinking water of all 408 cases was conducted. Population data and drinking water sources data were provided by local household registration and local health institution, respectively. Water samples from different sources (well, tap-water, river and pond) were collected and microcystins concentrations were measured by an indirect competitive ELISA method. RESULTS: The incidence rates of colorectal cancer were significantly higher among people drinking river or pond water than those who drank well water or tap-water in both males and females. And comparing with other sources to well water, the relative risks (RR) were much higher for people using river water (7.94) and pond water (7.70). The positive detection rates (> 50 pg/ml) of microcystin in well, tap-water, river and pond water were 0.00%, 0.00%, 36.23% and 17.14% respectively. The highest concentrations of microcystins were 1 083.43 pg/ml (river) and 1 937.94 pg/ml (pond) in the positive samples. Microcystins concentrations in river and pond were significantly higher than the concentrations in well and tap water (P < 0.01). The Spearman rank correlation analysis showed that in the study sites, the microcystins concentrations of river and pond water were positively correlated with the incidence of colorectal cancer (r = 0.881, P < 0.01). CONCLUSION: Drinking surface water (river or pond) is one of the risk factors for colorectal cancer. Microcystins may be associated with incidence of colorectal cancer. It is suggested that further study should be carried out to clarify the relationship between colorectal cancer and microcystin in drinking water.
Bacterial Toxins↗
[Clinical study on treatment of nasopharyngeal carcinoma by radio- and chemotherapy with supplementary moxibustion on Shenque point].
OBJECTIVE: To evaluate the effect of supplementary moxibustion in treating III, IV a stage nasopharyngeal carcinoma (NPC) with radio- and chemotherapy. METHODS: Fifty-six cases of NPC were randomly divided into two groups, 28 in each group. They were treated with radiotherapy in routine or chemotherapy adopting AD protocol. Salt-separated moxibustion on Shenque (Ren 8) point was given to the treated group from beginning of radio- and chemotherapy for 30 times as one therapeutic course. RESULTS: The remission rate in the two groups after radio- and chemotherapy was not different significantly. The toxic and side-effect occurrence was less in the treated group than that in the control group (P < 0.05). The 5-year local control rates of NPC and cervical lymphnode were 85.7% and 85.0% in the treated group, which were higher than those in the control group (78.6% and 78.9%). The 5-year survival rate in the two groups were 50.0% and 35.7% respectively. After radio- and chemotherapy, the blood content of malonyldialdehyde (MDA), middle molecular substance and sulfhydryl reduced the SOD activity ascended in the treated group, the difference was significant as compared with those in the control group (P < 0.05, P < 0.01). CONCLUSION: The supplementary moxibustion on Shenque point could obviously reduce the toxic side-effect of advanced NPC patients treated with radio- and chemotherapy.
Acupuncture Points↗
[Effect of xiongshao capsule on proliferation and apoptosis of vascular smooth muscle cells in rabbits observed by serum pharmacological method].
OBJECTIVE: To observe the effect of Xiongshao Capsule (XSC) on proliferation and apoptosis of aortic smooth muscle cells (SMC) of rabbits by serum pharmacological method. METHODS: SMC were isolated from thoracic aorta of the normal rabbits and passaged. The SMC proliferation model was established by endothelin (ET). The medicated serum was prepared after given the normal rabbits suspension of XSC through gastrogavage for 10 days. The proliferation and apoptosis of SMC were observed by methyl thiazolyl tetrazolium (MTT) colorimetry, flow cytometry and agarose gel electrophoresis. RESULTS: ET obviously promoted proliferation of SMC, and the serum medicated with XSC could lower the proportion of SMC in S + G2 phase and markedly inhibited the proliferation of SMC caused by ET in dose dependent manner. It also had certain effect on inducing apoptosis of SMC. CONCLUSION: XSC could markedly inhibit the proliferation of SMC caused by ET and induce apoptosis of SMC, which might be the mechanism of preventing coronary restenosis after interventional treatment.
Animals↗
[Effects of chuanxiong-chishao dispensing ratio on the pharmacokinetics of paeoniflorin in the canine].
OBJECTIVE: To explore the effects of dispensing ratio of Chinese herbs on the pharmacokinetic characteristics of effective components. METHODS: Paeoniflorin (PF) in serum was determined by RP-HPLC with UV-detector. The concentration-time data were fitted using 3P87 Pharmacokinetic Program, and the pharmacokinetic parameters were compared by t-test. RESULTS: The concentration-time curves of PF in both groups of Chuanxiong: Chishao 1:2 and 2:1 Xiongshao Pharmaceutics administrated intragastrically fitted open one compartment model. Parameters of Chuanxiong: Chishao 1:2 and 2:1 groups: Ka = 0.0082 +/- 0.0010 and 0.0088 +/- 0.0011(min-1), Ke = 0.0060 +/- 0.0015 and 0.0071 +/- 0.0008(min-1), t1/2Ka = 86.10 +/- 12.38 and 79.11 +/- 18.69(min), t1/2Ke = 119.95 +/- 27.23 and 98.14 +/- 10.82(min), tpeak = 169.16 +/- 21.18 and 149.39 +/- 29.51(min), Cmax = 3845.89 +/- 716.70 and 1635.81 +/- 230.95 (micrograms.L-1) respectively. The pharmacokinetic parameters of the two groups had no statistically significant differences (p > 0.05). CONCLUSION: Different formulae of Chinese herbs do not always result in changes of pharmacokinetic characteristics of some one component.
Animals↗
[Treatment of skeletal Class II malocclusion by orthodontic and surgical means].
OBJECTIVE: Skeletal class II malocclusion is often occurred in Oriental and Black. It is difficult to gain the ideal treatment objective either using the orthognathic surgery or orthodontic treatment alone. However, the combined orthodontic and surgical treatment can reach it, so we investigate the methods and characteristics of combined orthodontic and surgical treatment in skeletal class II malocclusion. METHODS: We analyzed the recent 22 cases with skeletal class II malocclusion in Hospital of Stomatology, West China University of Medical Sciences with 7 male and 15 female from 20 to 30 years old. In the study, we discussed the time of extraction, the peculiarity of orthodontic treatment and the selection of surgery type. RESULTS: After the combined orthodontic and surgical treatment, all the patients regained satisfactory face appearance and function. The selection of surgery type is decided by the skeletal characteristics of malocclusion (the malformation degree and the position). The upper first premolars were extracted before the orthodontic treatment for the purpose of better curing of surface of the skeletal wound. And the pre and post-surgical orthodontic treatment were very important and necessary to regain the ideal face appearance and function. CONCLUSION: The combined orthodontic and surgical treatment is an efficient way to cure skeletal class II malocclusion. Suitable orthognathic surgery and rational orthodontic treatment are important to treat adult skeletal class II malocclusion.
Adult↗
[The predication equation of the permanent canine and premolar crown].
OBJECTIVE: It is important to predict mesiodistal crown diameter of the permanent canines and premolars in the mixed dentition, which helps to determine malocclusion and its further development. But there is still no article about this equation of Chinese used to predict mesiodistal crown diameter of cuspids and premolars. This research is to measure mesiodistal crown diameters, to study relationship between lower incisors and canines and premolars, and to provide the most accurate and easy basis in orthodontic diagnosis and treatment for Chinese people. METHODS: 140 Chinese students (60 male, 80 female) who were from eighteen to twenty-five years old without orthodontic history Chengdu were randomly collected in. All teeth must be free of visible malform, aberration, and fully erupted. Impressions were taken, and measurements were made, parallel to the occlusal plane at the greatest mesiodistal width of each tooth on dental cast with electronic caliper (0.01 mm). Each tooth was measured twice and the average of the two readings was taken as the dimension for that individual tooth. Mesiodistal crown diameters were statistically analyzed with t-test and linear regression, using the SAS (Statistic Analyses System) computer package. RESULTS: It was found that mesiodistal crown diameters had significantly statistical difference in gender. Hence the mesiodistal crown diameters were assessed and investigated separately for the male and the female. It was also found that the total mesiodistal crown diameter of lower incisors was closely correlated with the total mesiodistal crown diameter of canines and premolars. The correlation coefficients between the independent variable and dependent variables were 0.599 for upper canines and premolars and 0.654 for lower canines and premolars in the males and 0.586 and 0.635, respectively, in the females. The P were found to be less than 0.001 for both arches. The correlation coefficients had significantly statistical difference. CONCLUSION: The equations predicting overall mesiodistal crown diameters of upper and lower unerupted canines and premolars for male and female Chinese people were established respectively: Maxillary (y = 10.87 + 0.51 x (male)), y = 11.88 + 0.46 x (female), Mandibular (y = 10.36 + 0.50 x (male), y = 10.03 + 0.49 x (female)), y (total mesiodistal crown diameter of canines and premolars), and x (total mesiodistal crown diameter of lower incisors).
Adolescent↗
[Determination of chiral purity of synthetic amino acids by high performance liquid chromatography].
A series of synthetic beta-heterocyclic and beta-naphthyl alanine and aromatic substituted phenylalanine were separated by reversed-phase HPLC as diastereomeric derivatives obtained after derivatization with (1-fluoro-2,4-dinitrophenyl)-5-L-valinamide (FDNP-Val-NH2). The separation was performed with gradient elution. The mobile phase A was acetonitrile containing 0.1% trifluoroacetic acid and mobile phase B was 0.1% trifluoroacetic acid. According to the hydrophobicity of the side chain of the amino acids, 6 different linear gradient programs were selected and all gradients completed in 20 minutes. Good resolution was obtained for neutral amino acids. All L-L diastereomer of neutral amino acids (the first letter refers to the configuration of amino acid) were eluted faster than the D-L diastereomer with retention times less than 16 minutes. In the same gradient eluting system, the hydrophobic parameter (pi value) and the position of the substituent in benzene ring of phenylalanine also influence the retention time of diastereomers. Usually the retention time of the phenylalanine with a large pi value was longer than that with a small one. Among the three phenylalanines containing the same substituent, compounds with the substituent in 2-postion gave the shortest retention time. In the case of basic amino acids, the D-L diastereomers eluted prior to the L-L diastereomers and showed rather poor resolution. The chiral purity (ee) of the optical active amino acids (synthetic DL-amino acids after resolution by different enzymes) were calculated with the equation as follows: ee = [[A(L- or D-) - A(D- or L-)]/[A(L-) + A(D-)]] x 100% (L- or D-), A: peak area; L-, D-: amino acid diastereomer.
Amino Acids↗
[Design and optimization of a centrifugal pump for CPCR].
Requirements for an optimal centrifugal pump, the vital component in the equipment for cardiopulmonary cerebral resuscitation(CPCR), have been presented. The performance of the Sarns centrifugal pump (Sarns, Inc./3M, Ann arbor, MI, U.S.A) was tested. The preliminarily optimized model for CPCR was designed according to the requirements of CPCR and to the comparison and analysis of several clinically available centrifugal pumps. The preliminary tests using the centrifugal pump made in our laboratory(Type CPCR-I) have confirmed the design and the optimization.
Cardiopulmonary Bypass↗
[Inhibition of extracts of ampelopsis sinica roots on DHBVsAg in sera of ducklings].
The ducklings, which are infected with Duck HBV to produce DHBVsAg in sera in advance, are treated with extracts from Ampelopsis sinica roots and some of them are treated with interferon alpha (INF) as positive control group. According the titer of DHBVsAg in Ducklings sera and the results of observing the tissues of the duckling's livers, it is demonstrated that the extracts of Ampelopsis sinica roots possess a certain action inhibiting DHBV and the action is enduring.
Ampelopsis↗
[The identification of Bungarus multicinctus multicinctus and its confused species by SDS-PAGE].
The comparative study of the proteins of Bungarus multicinctus multicinctus and Natrix annularis was carried out by SDS-PAGE. The results showed that there were significant differences between their SDS-PAGE figures. On the basis of the study the molecular weights of their characteristic proteins were determined. The results could be regarded as a reference for identification of Bungarus multicinctus multicinctus and its confused species.
Animals↗
[Erythroid differentiation denucleation factor: a family of erythroid regulators for mammalian erythroid terminal differentiation/tumor suppression and the cloning of their related genes].
The role of regulation of erythroid differentiation denucleation factor(EDDF) on mammalian erythroid differentiation and myeloma cell malignancy as well as cloning of their stage related genes were serially studied. Through a series of cybrid and hybridization experiments between mammalian erythroid cells and erythroleukemia or non-erythroid myeloma cells, we have demonstrated a novel family of erythroid regulators(EDDFs) in the mammalian differentiating erythroblasts which with an active peak occurred concomitantly with marked decreases in DNA, RNA and the nuclear anchoring vimentin-IF, but increased in hemoglobin synthesis in cytoplasm prior to the denucleation process during terminal differentiation. The results of cell fusion experiments verified that the supplement of regulators(EDDFs) was critical to the recovery of the originally lost features of terminal differentiation and the reversion of malignant phenotype of tumor cells. Here we showed that the erythroid regulator family EDDFs were essential regulators for the sequential expression of stage related genes of erythroid terminal differentiation, and for the redifferentiation of tumor cells to express the originally inactive globe genes, repressed the oncogenes, and vimentin-IF system, thus initiated nuclear condensation and denucleation. The EDDF gene family consisted of MEDDF, HEDDF-1, HEDRF-1, HEDRF-2 and HCNBP-1 were cloned. All were novel cDNA sequences that have been searched and registered in GenBank. They expressed varying in a stage specific manner, and acted on corresponding genes of terminal differentiation.
Activins↗
Alteration of the reduction potential of the [4Fe-4S](2+/+) cluster of Azotobacter vinelandii ferredoxin I.
The [4Fe-4S](2+/+) cluster of Azotobacter vinelandii ferredoxin I (FdI) has an unusually low reduction potential (E(0')) relative to other structurally similar ferredoxins. Previous attempts to raise that E(0') by modification of surface charged residues were unsuccessful. In this study mutants were designed to alter the E(0') by substitution of polar residues for nonpolar residues near the cluster and by modification of backbone amides. Three FdI variants, P21G, I40N, and I40Q, were purified and characterized, and electrochemical E(0') measurements show that all had altered E(0') relative to native FdI. For P21G FdI and I40Q FdI, the E(0') increased by +42 and +53 mV, respectively validating the importance of dipole orientation in control of E(0'). Protein Dipole Langevin Dipole calculations based on models for those variants accurately predicted the direction of the change in E(0') while overestimating the magnitude. For I40N FdI, initial calculations based on the model predicted a +168 mV change in E(0') while a -33 mV change was observed. The x-ray structure of that variant, which was determined to 2.8 A, revealed a number of changes in backbone and side chain dipole orientation and in solvent accessibility, that were not predicted by the model and that were likely to influence E(0'). Subsequent Protein Dipole Langevin Dipole calculations (using the actual I40N x-ray structures) did quite accurately predict the observed change in E(0').
Azotobacter vinelandii↗
Synthesis and acetylcholinesterase inhibitory activity of huperzine A-E2020 combined compound.
The synthesis of huperzine-E2020 combined compound (3) has been accomplished and the activities of 3 and the intermediates 12 and 13 to inhibit the activity of acetylcholinesterase have been measured. Conformation analyses and molecular docking studies of E2020 and the eight isomers of 12 were carried out. The results indicated that binding energies of all isomers of 12 with AChE was much lower than E2020 except for isomer RRZ, which might be the reason that the activity of 12 was lower than that of E2020. Interaction pattern of RRZ in AChE was also studied. Both binding energy and interaction pattern shows that the biological activity of RRZ might be higher than that of E2020.
Alkaloids↗
Annexin VII and annexin XI are tyrosine phosphorylated in peroxovanadate-treated dogs and in platelet-derived growth factor-treated rat vascular smooth muscle cells.
The intraperitoneal administration of peroxovanadate results in the rapid accumulation of many tyrosine-phosphorylated proteins in the liver and kidney of treated animals. The availability of large pools of tyrosine-phosphorylated proteins derived from normal tissues facilitates the purification and identification of previously unknown targets for cellular tyrosine kinases. Using this procedure, we have thus far identified four proteins in the liver and kidney of peroxovanadate-treated dogs. Two of these, annexin VII and annexin XI, were novel and had not been previously reported to be substrates of tyrosine kinases while the remaining two, ezrin and clathrin, have been reported to be tyrosine phosphorylated in some cell culture systems. In the present study, isolated proteins were identified both by sequence analysis and immunological methods. Annexin VII and annexin XI are present in cultured rat vascular smooth muscle cells and both were tyrosine phosphorylated in response to a physiological ligand, platelet-derived growth factor-BB (PDGF-BB). Furthermore, the extent of tyrosine phosphorylation in response to PDGF-BB was augmented by the co-addition of peroxovanadate to cell cultures. In vitro phosphorylation assays showed that PDGF receptor, calcium-dependent tyrosine kinase (CADTK/Pyk-2), Src kinase, and epidermal growth factor receptor all were able to phosphorylate purified annexin VII and XI on tyrosine residues. These findings confirm the usefulness of phosphatase inhibition by peroxovanadate as a tool for identifying previously unknown physiological targets for cellular protein tyrosine kinases.
Amino Acid Sequence↗