Changes in form of rare earth elements after acid rain leaching through soil column.
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Acid Rain↗
Biomedical subjects
L Dai
Publications and source records attributed to L Dai.
Amelioration of antigen-induced arthritis in rats by transfer of extracellular superoxide dismutase and catalase genes.
Reactive oxygen species (ROS) have been implicated in the pathogenesis of rheumatoid arthritis (RA), while antioxidant enzymes, such as extracellular superoxide dismutase (EC-SOD) and catalase, block radical-induced events. The present study tested if the ex vivo transfer of EC-SOD and catalase genes alone or in combination in the knee joint of rats with monoarticular antigen-induced arthritis (AIA) was anti-inflammatory, and examined the potential mechanisms involved. Synoviocytes isolated from female Wistar rats were immortalized with a retroviral vector SUV19.5. These cells were permanently transfected with an EC-SOD expression plasmid (pEC-SODZeo) or a catalase expression plasmid (pCatalaseZeo) to create cells overexpressing EC-SOD or catalase, as measured by RT-PCR and Western blots. The cells were engrafted in knee joints of animals at the time of the induction of AIA. Three gene transfer groups, an EC-SOD group, a catalase group and a combined therapy group (EC-SOD and catalase) were included in these experiments. Animals in the control group were engrafted with synoviocytes transfected with the plasmid pZeoSV2 without an insert. Clinical and histological assessments were performed, as well as tissue measurements of SOD, catalase and gelatinase activities. Ex vivo gene transfer of EC-SOD and catalase into rat knee joints produced about a six- to seven-fold increase in EC-SOD activity and a two- to three-fold increase in catalase activity compared with the control animals. Rats treated with cells overexpressing EC-SOD, catalase or a combination of EC-SOD and catalase showed significant suppression of knee joint swelling, decreased infiltration of inflammatory cells within the synovial membrane and reduced gelatinase activity in knee joints, compared with animals receiving cells transfected with the plasmid alone. No statistically significant difference was found between the groups treated with cells overexpressing EC-SOD, catalase or a combination of both. Gene therapy involving the local intra-articular overexpression of two antioxidant enzymes, EC-SOD and catalase, was anti-inflammatory in AIA. One mechanism appears to be the suppression of gelatinase activities by both EC-SOD and catalase.
Animals↗
Effects of lanthanum and cerium on the vegetable growth of wheat (Triticum aestivum L.) seedlings.
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Cerium↗
Quantitative analysis of DNA binding by the Escherichia coli arginine repressor.
Allosteric activation of the hexameric arginine repressor (ArgR) for specific operator DNA binding appears to involve alteration in its quaternary structure. Current models for activation include subunit assembly and/or domain rearrangements in response to binding of the coeffector l-arginine. To investigate the molecular basis for ArgR operator interactions, we have carried out a series of quantitative analyses of ArgR subunit assembly and of the affinity, stoichiometry, cooperativity, and l-arginine- and DNA sequence-dependence of ArgR-DNA binding. The results indicate that subunit assembly plays no role in activation, although communication among subunits of the ArgR hexamer is required for specific DNA binding. The data suggest that DNA is also an allosteric effector of ArgR.
Allosteric Regulation↗
IsCT, a novel cytotoxic linear peptide from scorpion Opisthacanthus madagascariensis.
A novel cytotoxic linear peptide, IsCT, was characterized from scorpion Opisthacanthus madagascariensis. It is a linear peptide with a molecular weight of 1501.9 Da composed of 13 amino acid residues without cysteines. MS/MS analysis showed that its C-terminal is amidated. The identity of IsCT is re-confirmed by comparing the chemical synthesized peptide with the natural one. IsCT demonstrated antimicrobial activity against both gram-positive and gram-negative bacteria and hemolytic activity to sheep red blood cells. Also, it can release histamine from rat peritoneal mast cells. The CD absorption suggested that IsCT had an alpha-helix configuration in aqueous TFE. IsCT is one of the shortest natural cytotoxic peptides described, and it will be a suitable model for studying peptide-lipid interactions.
Amino Acid Sequence↗
Increased sensitivity of mitochondrial respiration to inhibition by nitric oxide in cardiac hypertrophy.
Cardiac hypertrophy is a significant risk factor for the development of congestive heart failure (CHF). Mitochondrial defects are reported in CHF, but no consistent mitochondrial alterations have yet been identified in hypertrophy. In this study selective metabolic inhibitors were used to determine thresholds for respiratory inhibition and to reveal novel mitochondrial defects in hypertrophy. Cardiac hypertrophy was produced in rats by aortic banding. Mitochondria were isolated from left ventricular tissue and the effects of inhibiting respiratory complexes I and IV on mitochondrial oxygen consumption were measured. At 8 weeks post-surgery, 65+/-2% complex IV inhibition was required to inhibit respiration half maximally in control mitochondria. In contrast, only 52+/-6% complex IV inhibition was required to inhibit respiration half maximally in mitochondria from hypertrophied hearts (P=0.046). This effect persisted at 22 weeks post-surgery and was accompanied by a significant upregulation of inducible nitric oxide synthase (iNOS, 3.0+/-0.7-fold, P=0.006). We conclude that respiration is more sensitive to complex IV inhibition in hypertrophy. Nitric oxide is a well documented inhibitor of complex IV, and thus the combination of increased NO(.)from iNOS and an increased sensitivity to inhibition of one of its targets could result in a bioenergetic defect in hypertrophy that may be a harbinger of CHF.
Animals↗
Modeling and analysis of the structure of the thermostable catechol 2,3-dioxygenase from Bacillus Stearothermophilus.
The three-dimensional structure of thermostable catechol 2,3-dioxygenase(TC230) from Bacillus Stearothermophilus has been modeled basing on the known x-ray structure of catechol 2,3-dioxygenase(metapyrocatechase) from Pseudomonas putida mt-2, using computer graphics energy minimization techniques. The rationality of the resulting model was validated by Ramachandran plot and Profile-3D. The structure-functionally important residues, such as M++ binding residues and the substrate binding residues, were identified from the model. These residues are candidates for further site-directed mutagenesis experiments. The reason that the thermostability of TC230 is greater than metapyrocatechase(MPC) has been found, which may be due to the specific structure of the TC230 in the C-end mainly.
Amino Acid Sequence↗
Bioenergetics in cardiac hypertrophy: mitochondrial respiration as a pathological target of NO*.
A rat aortic banding model of cardiac hypertrophy was used to test the hypothesis that reversible inhibition of mitochondrial respiration by nitric oxide (NO*) elicits a bioenergetic defect in the hypertrophied heart. In support of this hypothesis, the respiration of myocytes isolated from hypertrophied hearts was more sensitive to exogenous NO* (IC(50) 200 +/- 10 nM vs. 290 +/- 30 nM in controls, P = 0.0064). Hypertrophied myocytes also exhibited significantly elevated inducible NO* synthase (iNOS). Consistent with this endogenous source for NO*, the respiration of hypertrophied myocytes was significantly inhibited at physiological O(2) tensions versus controls. Both the nonspecific NOS inhibitor nitro-L-arginine and the iNOS-specific inhibitor N-[3-(aminomethyl)- benzyl]acetamidine. 2HCl reversed this inhibition, with no effect on respiration of control myocytes. Consistent with an NO*-mediated mitochondrial dysfunction, the ability of intact perfused hearts to respond to a pacing workload was impaired in hypertrophy, and this effect was reversed by NOS inhibition. We conclude that endogenously generated NO* can modulate mitochondrial function in the hypertrophied heart and suggest that this bioenergetic defect may underlie certain pathological features of hypertrophy.
Amidines↗
Three-dimensional micropatterns of well-aligned carbon nanotubes produced by photolithography.
Three-dimensional micropatterns of well-aligned carbon nanotubes were prepared on photolithographically prepatterned substrates by pyrolysis of iron(II) phthalocyanine (FePc) under an Ar/H2 atmosphere at 800-1100 degrees C. The photopatterning was achieved by photolithographic cross-linking of a chemically amplified photoresist layer spin-cast on a quartz plate or a silicon wafer, coupled with solution development. Owing to an appropriate surface characteristic, the patterned photoresist layer was found in this case to support aligned carbon nanotube growth by pyrolysis of FePc, as were the photoresist-free substrate surfaces. The difference in chemical nature between the surface areas covered and uncovered by the photoresist film, however, caused a region-specific growth of the nanotubes with different tubular lengths and packing densities, leading to the formation of three-dimensional aligned nanotube patterns suitable for various device applications.
Crystallization↗
Can ultrasound predict the severity of acute pancreatitis early by observing acute fluid collection?
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Acute Disease↗
[A preliminary study on ecological response of dominant tree species in Korean pine broadleaf forest at Changbai Mountain to soil water stress and their biomass allocation].
Pot culture experiments were conducted to examine the ecological response and biomass allocation of Pinus koraienes, Fraxinus mandshurica, Juglans mandshurica, Tilia amurensis, and Quercus mongolica. The five dominant species in the Korean pine-broadleaf forest at Changbai mountain. Their seedlings were grown under three different soil moistures, e.g., 85%-100% (CK), 65%-85% (MW) and 45%-65% (LW) of field water-holding capacity. The results showed that drought significantly decreased the individual leaf area, number of fine root, root length, and individual biomass of seedlings. The root proportions of T. amurensis and F. mandshurica increased with increasing soil water content, but the leaf proportion of J. mandshurica and Q. mongolica in MW treatment was higher than that of CK and LW. There was no significant difference in stem proportions of 5 tree species among different water stress treatments. The response of the biomass of 5 tree species to water stress was significant, the total biomass of T. amurensis, F. mandshurica, J. mandshurica and P. koraienes in MW and LW decreased by 32.8%, 43.6%, 26.2% and 23.8%, respectively, while that in Q. mongolica increased by 4.8%, indicating that Q. mogolica was the most drought-tolerent species among 5 tested species.
Biomass↗
[Decomposition processes of Tilia amurensis leaves in the Changbai Mountain forest ecosystem].
A 4-year field experiment was carried out in the Changbai Mountain to study the decomposition process of Tilia amurensis leaf and its affecting environmental factors. The results reveal that the decomposition process of Tilia amurensis leaves could be expressed by an exponent equitation. With the increase of elevation and the change of vegetation types, the decomposition rate in 1-5 standard experimental fields was -0.391, -0.339, -0.257, -0.198 and -0.125, respectively, indicating that the decomposition rate was decreased with ascending elevation. The maximum decomposition took place when the environment was in the shadow of 60%-80%. The leaves were acceleratively decomposed when the tested moisture was increased. Moisture affected the decomposition process more strongly than light.
Biodegradation, Environmental↗
Detailed deletion mapping on chromosome region 9p21 in human periampullary neoplasms.
OBJECTIVE: To further define the extent of chromosome 9p21 deletion in periampullary neoplasms. METHODS: The loss of heterozygosity at 5 microsatellite polymorphic markers on chromosome 9p21 was detected by polymerase chain reaction (PCR), polyacrylamide gel electrophoresis (PAGE) and silver staining in 35 specimens of periampullary neoplasms and their matching blood samples. RESULTS: Fifty percent (4/8) of pancreatic cancer cases showed the loss of heterozygosity at one or more microsatellite loci, with the more frequent sites of D9S974 (37.5%) and D9S942 (28.6%), and some showing consecutive allelic loss. Sixty-two point five percent (5/8) of ampullary carcinoma cases showed loss of heterozygosity at one or more of the loci, frequent site of loss being D9S942 (42.9%) and the next most frequent being IFNA (37.5%) and D9S171 (37.5%). Loss of one locus was observed in 14.2% (1/7) of insulinoma. CONCLUSION: The minimal common region of chromosome deletion in periampullary neoplasms is defined between the D9S974 and D9S942 loci within a 15 kb interval in 9p21, suggesting the involvement of a novel tumor suppressor gene in their carcinogenesis.
Adolescent↗
Imaging diagnosis of cervical spine and spinal cord injuries in children.
OBJECTIVE: To provide the experience in imaging diagnosis of cervical spine and spinal cord injuries in children. METHODS: Imaging data of cervical spine and spinal cord injuries in 62 children were retrospectively reviewed. The routine radiography including the lateral, anteroposterior and open-mouth odontoid views were performed in all the patients. Tomography was available for 25 patients, and flexion-extension lateral views for 28 patients, CT scanning for 21 patients, MRI for 26 patients. RESULTS: Of these patients, 46 patients were identified with in juries of upper cervical spine (9 with atlantal arch fracture, seven with axial fracture, 21 with odontoid fracture, 1 with atlantal arch fracture combining with odontoid fracture, and 1 with atlantal transverse ligament disruption); 7 patients sustained injuries of lower cervical spine (3 fractures of vertebral body, 2 dislocations and 6 fracture-dislocations); 2 patients had multiple noncontiguous cervical injuries; and 3 had cervical spinal cord injury without radiographic abnormalities (SCIWORA). CONCLUSIONS: Imaging assessment is of great importance in the diagnosis of cervical spine and spinal cord injuries in children. Whenever cervical spine and spinal cord injuries are suspected for children patients, and the three-views should be routinely indicated. MRI should be routinely performed in all children with cervical SCIWORA.
Adolescent↗
[Expression of cytokeratin 7 and 20 in ovarian metastatic carcinomas].
OBJECTIVE: To study the distinctive clinicopathologic and immunohistochemical difference between ovarian metastatic carcinomas and primary ovarian carcinomas. METHODS: The clinical and pathological features of 27 cases of ovarian metastatic carcinomas (gastric carcinomas 12 cases, colon carcinomas 11 cases, others 4 cases) obtained from our department were reviewed. Immunostainings for CK (AE1/AE3), CK7, CK20, CEA, vimentin, nm23 were performed with SP staining methods. RESULTS: On gross examination, metastasis from gastric adenocarcinoma were usually bilateral, while solid (11/12) and metastases from colonic adenocarcinoma were more often unilateral and cystic (7/11). Microscopically, metastases from gastric adenocarcinoma revealed signet ring cells or poorly differentiated adenocarcinomas (12/12), whereas metastases from colonic adenocarcinomas showed similar morphology of endometrioid adenocarcinoma (8/11). The majority of ovarian metastases of gastric carcinoma (7/12) and colon carcinoma (8/11) were CK20 positive. In particular, CK20 was invariably expressed in colon cancer metastases. Most of the ovarian metastatic carcinomas from the gastrointestinal tract failed to react with immunostaining of CK7. A combined use of CEA, vimentin and nm23 had made a correct classification for 11/12 cases of the gastric carcinoma, 10/11 cases of the colonic cancer. CONCLUSIONS: CK7 and CK20 have been proved to be useful antibodies in distinguishing between metastatic carcinomas and primary carcinomas of the ovary. Combined use of a panel of antibodies can give more significant results.
Adenocarcinoma↗
[The change in resistance of Pseudomonas aeruginosa to gentamicin during in vitro subculturing].
OBJECTIVE: To observe the change in resistance of Pseudomonas aeruginosa (PA) to gentamicin (GM) during in vitro subculturing. METHODS: Twenty -- six strains of PA with resistance to GM isolated from burn patients were subcultured in vitro for 30 generations. The strains were also divided into high level (20 strains) and medium level (6 strains) of resistant groups according to their MIC (minimum inhibition concentration) values. The MIC and MBC (minimal bactericidal concentration) levels were examined in every strains of the 1st, 10th, 20th, and 30th filial generations of PA strain. RESULTS: There was no significant general difference of MIC and MBC values among the filial generations in each group (P < 0.05) when multiple comparisons of MIC and MBC mean values were made among every filial generations in high and medium levels of GM resistant groups. CONCLUSION: There was no evident difference in GM resistance among all the filial generations of PA. The result indicated that, the PA with different levels of GM resistance clinically found might come from different PA strains.
Anti-Bacterial Agents↗
A case of Erdheim-Chester disease with bilateral orbital involvement.
PURPOSE: To describe a case of Erdheim-Chester disease with bilateral orbital involvement. METHODS: A 43-year-old female with bilateral proptosis was presented. Its clinical features, image findings, pathological character and therapeutic effect were evaluated. RESULTS: CT demonstrated bilateral, diffuse orbital mass. Histopathologic assessment revealed a diffuse xanthogranulomatous process with clusters of lipidladen histocytes. Numerous Touton giant cells were scattered throughout the lesion. Renal and heart failure happened during a 6-year follow-up period. Long bones roentgenogram demonstrated diffuse symmetrical sclerosis with extensive, lytic lesions. Systemic administration of corticosteroids, chemotherapy, immunoglobulin and traditional Chinese medicine showed good therapeutic result. CONCLUSIONS: An administration of systemic corticosteroids, chemotherapy, immunoglobin and traditional Chinese medicine can control Erdheim-Chester disease. Further exploration of its pathogenesis and collection of useful clinical data are required.
Adult↗
[Analysis on the sex ratios at birth for deliveries in hospitals in China from 1987 to 1992].
OBJECTIVE: To estimate the sex ratios at birth (SRB) for livebirths in hospitals in China. METHODS: Data were collected by the birth defects monitoring network. The livebirths with gestation of 28 weeks or over delivered in hospitals of 30 provinces, municipalities and autonomous regions all over the country from 1987 to 1992 were analyzed and used for calculating the SRB. RESULTS: The high male bias in SRB was observed in the data from most areas, and there was an upward trend of SRB, especially in rural areas. The SRB for livebirths in the hospitals of urban areas was normal from 1987 to 1989, and rose to 108.9 in 1992. The SRB for rural areas was high and was 109.9 in 1987, and rose to 111.8 in 1992. The SRB for livebirths given by the mothers under 20 years of age and coming from lower educational background was higher than that for others. The SRB for higher parities was even higher. CONCLUSION: The SRB in China is high; this is possibly related to sex-preference. Under-reporting of female neonates and "missing females" are not the main causes of the rising SRB.
China↗