Toxicity of PCBs (Aroclor-1221, 1254) to embryos and larvae of Xenopus laevis.
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Animals↗
Biomedical subjects
L Cong
Publications and source records attributed to L Cong.
[Effect of free fatty acids on glucose transporter 4 and insulin signaling proteins in rat skeletal muscle cells].
OBJECTIVE: To investigate the effect of free fatty acids on glucose transpoter4 (GLUT4) and insulin signaling proteins Grb2 and ERK2 in rat skeletal cells. METHODS: After the skeletal muscle cells of Sprague-Dawley rats were incubated with palmitate (0.25 mmol/L) or oleate (0.125 mmol/L) for 12, 24 and 36 hours, Western blotting was used to assess the levels of GLUT4 and insulin signaling proteins Grb2 and ERK2. The level of GLUT4 RNA was determined by dot blotting. RESULTS: The protein and RNA contents of GLUT4 were significantly decreased (P < 0.05) and the protein levels of Grb2 and ERK2 were decreased also compared with control in rat skeletal muscle cells after incubated with free fatty acids for 12, 24 and 36 hours (P < 0.05). CONCLUSION: Free fatty acids inhibit glucose metabolism and insulin activity in rat skeletal muscle cells by downregulating the expression of GLUT4 gene and protein and downregulating the protein expression of Grb2 and ERK2.
Adaptor Proteins, Signal Transducing↗
[Pathogens of transmitted disease in the pathogenesis of acute pelvic inflammatory disease].
OBJECTIVE: To study the pathogenesis of pathogens of sexually transmitted disease (STD) in acute pelvic inflammatory disease (PID). METHODS: Neisseria gonorrhoeae, chlamydia trchomatis, ureaplasma urealyticum were cutured respectively in 130 patients with acute PID. RESULTS: The pathogens of STD had been found in 55 patients. The detective rate of Neisseria gonorrhoeae was 6.9% (9/130), about half of them were mixed infection; the detective rate of chlamydia trachomatis was 4.6% (6/130), all of them were mixed infection; the positive percentage of ureaplasma urealyticum was 37.7% (49/130), one third of them were mixed infection. CONCLUSION: The pathogens of STD might cause acute PID or only play a synergetic role in it.
Acute Disease↗
[Effect of exercise on leptin in streptozotocin-induced diabetic rats].
The effect of exercise on leptin in streptozotocin(STZ)-induced diabetic rats was investigated. Four group of SD rats (10 in each group) including exercise STZ diabetic group, non-exercise STZ diabetic group, exercise normal group and non-exercise normal group were used in the study. Exercise groups were treated with treadmill. The results showed that: (1) blood glucose of STZ diabetic rats was higher, serum insulin, C-peptide and leptin level were lower than that of normal rats; (2) blood glucose was decreased, and blood insulin and C-peptide were increased in exercised STZ diabetic group. The levels of leptin in plasma, brain and adipose tissue were increased in exercise groups. It is concluded that appropriate exercise training may have impacts on insulin and leptin production to correct the abnormal glucose metabolism and energy metabolism in diabetic rats.
Animals↗
[Characteristics of producing-fumonisin and dimorphic fungus of fusarium moniliforme].
OBJECTIVE: To study the carcinogenesis of fusarium moniliforme and its fumonisins in animals. METHODS: The producing-fumonisin and dimorphic fungus pathogenicity of F. moniliforme from Zhejiang, China were identified and characterized. RESULTS: The F. moniliforme isolated from foodstuffs was shown to produces fumonisin B(1) > 400 microg/g in medium by IC-ELISA. Ten foodstuffs samples showed (2% - 100%) detection rate of F. moniliforme and contained fumonisin B(1) between (3.7 - 143.1) microg/g. The strains of F. moniliforme formed yeast-like colony in Sabouraud's agar plates contained 9% NaCl at 37degrees C incubator and budding multiplication mostly. In blood agar plates the strains of F. moniliforme showed grass green haemolytic reactions. CONCLUSION: It is important to carry out (or to perform) oulepidemiologicol survey of F. moniliforme as a primary pathogenic fungus, as well as the mycotoxins of F. moniliforme in vitro.
Carcinogens, Environmental↗
[Effect of zinc on the growth of cerebral cortex neurons of human fetus].
With the primary cultured cerebral cortex neurons of human fetus, studies were made to investigate the effect of zinc on the growth of neurons by using immunohistochemical stain and image analysis. The main results were as follows: (1) The growth of neurons of zinc group was the most prosperous at the 10-14 day of primary culture. The number of survival neurons was increased at the 1-28 day of culture (P < 0.01). (2) In the presence of zinc, the number and the length of neurites as well as the soma areas were all increased remarkably(P < 0.01). It was concluded that zinc could promote the growth of neurons.
Cell Count↗
Okadaic acid activates atypical protein kinase C (zeta/lambda) in rat and 3T3/L1 adipocytes. An apparent requirement for activation of Glut4 translocation and glucose transport.
Okadaic acid, an inhibitor of protein phosphatases 1 and 2A, is known to provoke insulin-like effects on GLUT4 translocation and glucose transport, but the underlying mechanism is obscure. Presently, we found in both rat adipocytes and 3T3/L1 adipocytes that okadaic acid provoked partial insulin-like increases in glucose transport, which were inhibited by phosphatidylinositol (PI) 3-kinase inhibitors, wortmannin and LY294002, and inhibitors of atypical protein kinase C (PKC) isoforms, zeta and lambda. Moreover, in both cell types, okadaic acid provoked increases in the activity of immunoprecipitable PKC-zeta/lambda by a PI 3-kinase-dependent mechanism. In keeping with apparent PI 3-kinase dependence of stimulatory effects of okadaic acid on glucose transport and PKC-zeta/lambda activity, okadaic acid provoked insulin-like increases in membrane PI 3-kinase activity in rat adipocytes; the mechanism for PI 3-kinase activation was uncertain, however, because it was not apparent in phosphotyrosine immunoprecipitates. Of further note, okadaic acid provoked partial insulin-like increases in the translocation of hemagglutinin antigen-tagged GLUT4 to the plasma membrane in transiently transfected rat adipocytes, and these stimulatory effects on hemagglutinin antigen-tagged GLUT4 translocation were inhibited by co-expression of kinase-inactive forms of PKC-zeta and PKC-lambda but not by a double mutant (T308A, S473A), activation-resistant form of protein kinase B. Our findings suggest that, as with insulin, PI 3-kinase-dependent atypical PKCs, zeta and lambda, are required for okadaic acid-induced increases in GLUT4 translocation and glucose transport in rat adipocytes and 3T3/L1 adipocytes.
3T3 Cells↗
Dependence of insulin-stimulated glucose transporter 4 translocation on 3-phosphoinositide-dependent protein kinase-1 and its target threonine-410 in the activation loop of protein kinase C-zeta.
Previous studies have suggested that 1) atypical protein kinase C (PKC) isoforms are required for insulin stimulation of glucose transport, and 2) 3-phosphoinositide-dependent protein kinase-1 (PDK-1) is required for activation of atypical PKCs. Presently, we evaluated the role of PDK-1, both in the activation of PKC-zeta, and the translocation of epitope-tagged glucose transporter 4 (GLUT4) to the plasma membrane, during insulin action in transiently transfected rat adipocytes. Overexpression of wild-type PDK-1 provoked increases in the activity of cotransfected hemagglutinin (HA)-tagged PKC-zeta and concomitantly enhanced HA-tagged GLUT4 translocation. Expression of both kinase-inactive PDK-1 and an activation-resistant form of PKC-zeta that is mutated at Thr-410, the immediate target of PDK-1 in the activation loop of PKC-zeta, inhibited insulin-induced increases in both HA-PKC-zeta activity and HA-GLUT4 translocation to the same extent as kinase-inactive PKC-zeta. Moreover, the inhibitory effects of kinase-inactive PDK-1 were fully reversed by cotransfection of wild-type PDK-1 and partly reversed by wild-type PKC-zeta, but not by wild-type PKB. In contrast to the T410A PKC-zeta mutant, an analogous double mutant of PKB (T308A/S473A) that is resistant to PDK-1 activation had only a small effect on insulin-stimulated HA-GLUT4 translocation and did not inhibit HA-GLUT4 translocation induced by overexpression of wild-type PDK-1. Our findings suggest that both PDK-1 and its downstream target, Thr-410 in the activation loop of PKC-zeta, are required for insulin-stimulated glucose transport.
3-Phosphoinositide-Dependent Protein Kinases↗
The comparative trial of TCu 380A IUD and progesterone-releasing vaginal ring used by lactating women.
The objective of this paper was to compare the efficacy, acceptability, safety, and bleeding pattern of TCu 380A intrauterine device (IUD) and progesterone-releasing vaginal ring used by breastfeeding women. The study population included 97 breastfeeding women using IUD and 100 women using vaginal ring. Of the IUD users, no insertion failure, perforation, or accidental pregnancy occurred in 12 months. There was one IUD expulsion. There were no discontinuations of IUD due to medical reasons other than expulsion. The total discontinuation rate was 2.3%. In the ring group, no accidental pregnancy occurred. The major reasons for discontinuation were ring use-related problems and vaginal problems. The total discontinuation rate was 65.4% within 1 year. The frequency of any one complaint among the ring users was higher than that among the IUD users. There were no differences in the proportion of women having no sexual activity and in the weight of their babies between the two groups. Compared with the IUD users, the median number of bleeding/spotting (B/S) episodes and B/S days of the vaginal ring users were fewer; consequently, the mean length of B/S-free interval was longer in all four reference periods; the mean length of B/S episode and segment were the same; the occurrence of amenorrhea was more frequent; in contrast, the proportions of normal bleeding patterns were fewer. The frequencies of prolonged bleeding, frequent bleeding, and infrequent bleeding patterns did not differ between the two groups. The percentage of irregular bleeding was fewer only in the first two reference periods. It is concluded that the TCu 380A IUD and progesterone-releasing vaginal ring used by breastfeeding women are safe and effective. The higher discontinuation rate of the ring users was mainly because of use-related problems. Breastfeeding women with TCu 380A IUD had better tolerance and acceptability. The TCu 380A IUD does not, but the progesterone-releasing vaginal ring does, suppress the recovery of ovarian function. However, once return of menstruation occurred, there were no differences in bleeding patterns between the two contraceptive methods.
Administration, Intravaginal↗
[Radioimmunoassay of substance P in human hypertrophic scar].
OBJECTIVE: To measure the content of substance P in human hypertrophic scar. METHOD: The method of radioimmunoassay was used to determine the content of substance P in human hypertrophic scar, non-hypertrophic scar and normal skin. RESULT: The content of substance P in hypertrophic scar was significantly higher than that in non-hypertrophic scar and normal skin (P < 0.01). CONCLUSION: Substance P may play an important role in the process of hypertrophic scar development.
Adolescent↗
En bloc transplation of kidney and whole pancreas with a segment of duodenum in rats.
For meeting the clinic needs in simultaneous pancreas and kidney transplantation (SPK), we successfully establish a syngeneic SPK transplatation model in Lewis rats. The results indicate that this model is feasible with a 82.6% successful rate of operation and a 69.6% survival rate in the first postoperative week. In long-term survived rats, the blood supplies are well established, function of the grafts (pancreas and kidney) maintains normal. This model is suitable for theoretical research in SPK transplantation for its reasonable physiology with pancreatic juice drained into intestine and reduced postoperative complications in urinary tract and carbohydrate metabolism.
Animals↗
A gene cluster involved in nogalamycin biosynthesis from Streptomyces nogalater: sequence analysis and complementation of early-block mutations in the anthracycline pathway.
We have analyzed an anthracycline biosynthesis gene cluster from Streptomyces nogalater. Based on sequence analysis, a contiguous region of 11 kb is deduced to include genes for the early steps in anthracycline biosynthesis, a regulatory gene (snoA) promoting the expression of the biosynthetic genes, and at least one gene whose product might have a role in modification of the glycoside moiety. The three ORFs encoding a minimal polyketide synthase (PKS) are separated from the regulatory gene (snoA) by a comparatively AT-rich region (GC content 60%). Subfragments of the DNA region were transferred to Streptomyces galilaeus mutants blocked in aclacinomycin biosynthesis, and to a regulatory mutant of S. nogalater. The S. galilaeus mutants carrying the S. nogalater minimal PKS genes produced auramycinone glycosides, demonstrating replacement of the starter unit for polyketide biosynthesis. The product of snoA seems to be needed for expression of at least the genes for the minimal PKS.
Amino Acid Sequence↗
[Relationship between aflatoxin and sclerotia production in aspergillus flavus].
Eighty strains of Aspergillus flavus (AF) isolated from grain produced in Zhejiang Province were studied experimentally on their abilities of sclerotia production, and 51.3% of the strains could produce sclerotia in Czapek solution agar containing 3% sodium nitrate at 30 C incubation for 12 days, with an average diameter of 827 +/- 131 microns, and no toxigenic S strain producing abundant small sclerotia was found. Most of the toxigenic strains producing sclerotia were L strain. There were no significant difference in the rates and amount of sclerotia production between toxigenic and a toxigenic strains. There was difference in diameter of sclerotia produced between them, with a smaller one in the toxigenic strains.
Aflatoxins↗
Phase separation of photogenerated carriers and photoinduced superconductivity in high-Tc materials.
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Journal Article↗
Comparison among three screening methods for aflatoxigenic isolates.
Seventy-six isolates of Aspergillus flavus, which were isolated from one hundred food stuffs in Zhejiang Province, were detected with RMC, AMCS and APA methods for aflatoxigenicity. The rates of toxigenic isolates detected by the three methods were 11.8%, 18.4% and 9.2% respectively. There were twenty toxigenic isolates detected by the three methods (26.3%) AMCS method was better than other methods. False negatives appeared in all methods. False positive appeared in both AMCS method and APA method. It was suggested that AMCS method may be a safe, simple and reliable method for screening toxigenic isolated if some aspects were improved.
Aflatoxins↗
Immunosuppressive effects of Tripterygium wilfordii hook F in a rat liver transplant model.
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Animals↗