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Biomedical subjects

J Liu

Publications and source records attributed to J Liu.

At least 487 records · Page 27Linked to original sources
PubMed2001

Prospects for circular dichroism detection of nonracemic extraterrestrial organic molecules.

The use of circular dichroism is examined as a probe for the detection of nonracemic analytes on spacecraft explorations such as a planned mission to Titan. Advances in both instrument design and chemistry will be required to make such a method practicable. The focus of this paper is on chemical agents able to amplify the circular dichroism signal, which would simplify instrument problems and increase sensitivity. A classic phenomenon known as the Pfeiffer effect provides a conceptual strategy to achieve the necessary aims for chirality detection. Recent examples of Pfeiffer-related phenomena are discussed.

Circular Dichroism↗
PubMed2001

[Gene diagnosis of factor VIII gene inversion by LD-PCR for 60 patients with severe hemophilia A].

OBJECTIVE: To identify factor VIII(F VIII) gene inversion among 60 patients with severe hemophilia A (HA) in Tianjin region. METHODS: DNA was extracted from peripheral blood of HA patients; F VIII gene inversion was identified by long distance-polymerase chain reaction(LD-PCR) and 0.6% agarose gel electrophoresis. Those with only 11 kb band were diagnosed as the cases of F VIII gene inversion. Those with only 12 kb band were identified as wild type(non-inversion), and those with both 11 kb and 12 kb bands were recognized as inversion carriers. RESULTS: There were 21 patients with F VIII gene inversion, accounting for 35% of the 60 patients with severe HA. CONCLUSION: LD-PCR can be used to detect the F VIII gene inversion directly; it is an effective method for the gene diagnosis of severe hemophilia A.

Chromosome Inversion↗
PubMed2001

Molecular control of acid phosphatase secretion into the rhizosphere of proteoid roots from phosphorus-stressed white lupin.

White lupin (Lupinus albus) grown under P deficiency displays a suite of highly coordinated adaptive responses. Included among these is secretion of copious amounts of acid phosphatase (APase). Although numerous reports document that plants secrete APases in response to P deficiency, little is known of the biochemical and molecular events involved in this process. Here we characterize the secreted APase protein, cDNA, and gene from white lupin. The secreted APase enzyme is a glycoprotein with broad substrate specificity. It is synthesized as a preprotein with a deduced M(r) of 52,000 containing a 31-amino acid presequence. Analysis of the presequence predicts that the protein is targeted to outside the cell. The processed protein has a predicted M(r) of 49,000 but migrates as a protein with M(r) of 70,000 on sodium dodecyl sulfate gels. This is likely due to glycosylation. Enhanced expression is fairly specific to proteoid roots of P-stressed plants and involves enhanced synthesis of both enzyme protein and mRNA. Secreted APase appears to be encoded by a single gene containing seven exons interrupted by six introns. The 5'-upstream putative promoter of the white lupin-secreted APase contains a 50-base pair region having 72% identity to an Arabidopsis APase promoter that is responsive to P deficiency. The white lupin-secreted APase promoter and targeting sequence may be useful tools for genetically engineering important proteins from plant roots.

Acid Phosphatase↗
PubMed2001

[Treatment of severe hepatitis with artificial liver support system and liver transplantation].

OBJECTIVE: To observe and investigate the efficacy of the hybrid artificial liver support system plus liver transplantation in the treatments of patients with severe viral hepatitis. METHODS: Eight severe viral hepatitis patients with metaphase and advanced stage liver failure received the artificial liver support using a self-command extracorporeal hybrid artificial liver support system and orthotopic liver transplantation after the artificial support for 3-14 days. RESULTS: The liver failure of the 8 patients was controlled by the hybrid artificial liver support effectively. All patients were successfully bridged to orthotopic liver transplantation. Four out of the eight patients survived after transplantation. Four patients died of pulmonary infection or hepatorenal syndrome. CONCLUSIONS: Artificial liver support system combined with liver transplantation can be regarded as an efficient measure for the treatment of metaphase and advanced stage patients of severe viral hepatitis.

Adult↗
PubMed2001

[Intratumoral injection of macroaggragated albumin and colloidal 32P for the treatment of hepatocellular carcinoma].

OBJECTIVE: To study the tumor deposition and systemic distribution of colloidal (32)P in single colloidal (32)P injection and macroaggragated albumin (MAA) injection followed by colloidal (32)P and to evaluate their clinical effects and side effects for the treatment of hepatocellular carcinoma. METHODS: H(22) hepatocellular cancer cells were inoculated subcutaneously in the right fore leg of Balb/c mice. When the tumors reached to 1.0 cm in diameter about 10 days postinjection, the mice were divided into two groups randomly. In the first group, the tumors were only injected with 1.85 MBq of colloidal (32)P; while in the second group, with 1 +/- 10(5) particles of MAA followed by 1.85 MBq of colloidal (32)P. The radioactivity in the tumor, blood, heart, liver, kidney, spleen, and bone of each animal was determined at 30min, 24 h, 48 h, 8 d, and 16 d postinjection. Histopathology of tumors was observed at 16 d and 1 month postinjection. The ultrasound-guided intratumoral injection of MAA and colloidal (32)P was performed on 30 patients with hepatocellular cancer. The evaluation of efficacy and side effects was made on the basis of clinical manifestations, histopathological changes, variations in tumor size, serum AFP, the functions of heart, liver, kidney, blood routine, and immune functions before and after the treatment. RESULTS: Intratumoral injection of colloidal (32)P resulted in necrosis and fibrosis of the tumor cells. Pretreatment with MAA before administration of colloidal (32)P effectively decreased the diffusion of colloidal (32)P from the tumor to blood, and led to retention of colloidal (32)P in the tumor for a longer time. After treatment, a significant shrinkage of the tumor size was seen in all cases with the average shrinkage rate of 53.25%. Serum AFP values decreased remarkably. Clinical symptoms alleviated. The survival rate of 1, 2, and 3 years was 90%, 76.67%, 43.33%. No side effect was found. CONCLUSIONS: Intratumoral injection of MAA and colloidal (32)P is a simple, safe, and effective alternative for the treatment of hepatocellular cancer.

Adult↗
PubMed2001

[Seroepidemiologic study on hemorrhagic fever with renal syndrome virus in the migration areas of the Three-Gorges Reservoir Chongqing, Region, Yangtze River].

OBJECTIVE: To ascertain both the immune level and latent infection status among the migrants from the Three-Gorge Reservoir, Chongqing Region. METHODS: Epidemiological survey and seroepidemiologic study were performed on the spots. Sera HFRSV-IgG antibody of migrations was detected with the indirect immunofluorescent assay technique(IIFAT). RESULTS: Three in 5 migration areas were seral HFRSV-antibody-positive, i.e. Baitao Town of Fuling Section, Wansheng Village of Fengjie County and Dachang Town of Wushan County, which not only will be evacuated, but also be taken for relocation. However the antibody titer was not high, with positive rates of HFRSV-IgG Ab 0.9%, 3.3% and 3.5% respectively. The other two areas attributed to relocation, HFRSV-IgG-antibody were negative. CONCLUSIONS: This article confirmed that covert infection rate of HFRS in 5 migration areas was not high. The immune level remained low. Hence, it is very necessary to enhance the immunity of the immigrants.

China↗
PubMed2001

Prevalence of CMV in arterial walls and leukocytes in patients with atherosclerosis.

OBJECTIVE: To investigate the association of cylomegalovirus with atherosclerosis. METHODS: The presence of cylomegalovirus (CMV) nucleic acids was demonstrated in carotid and coronary arteries of patients with and without atherosclerosis by polymerase chain reaction (PCR). CMV was detected by PCR in the blood of patients with and without atherosclerosis. RESULTS: 83.3%-86.7% of the samples obtained from atherosclerotic patient arterial walls were shown to contain viral nucleic acids (CMV), CMV could be found among 6.7% of patients' arterial wall without atherosclerosis, significant difference can be found between them (P < 0.01). In blood CMV could be found in 42.4% of patients with atherosclerosis, in the control group, only 3% of samples had CMV, P < 0.01. CONCLUSION: CMV plays an important role in the pathologic process of the atherosclerosis and the atherosclerotic cerebral infarction.

Aged↗
PubMed2001

Relationship between lactone ring forms of HCPT and their antitumor activities.

AIM: To study the relationship between the lactone forms of 10-hydroxycamptothecin (HCPT) and their antitumor activities. METHODS: Antitumor activity of the two forms of HCPT was studied in vitro using seven cultured human and mouse tumor cell lines. Mice bearing sarcoma 180 and solid hepatoma were treated with HCPT (0.5, 1, and 2 mg/kg, ip) and tumor growth inhibition was assayed. HPLC method was employed to investigate the conversion of two forms of HCPT in different pH conditions and cultured tumor cells. RESULTS: It was found that both forms of HCPT (O-HCPT and C-HCPT) showed similar activities in vitro against a number of tumor cell lines at the same concentration; but C-HCPT was more effective (about two times) than O-HCPT in vivo. The difference between in vitro and in vivo results could be explained by the conversion of O-HCPT into C-HCPT in a certain condition, which was shown by the HPLC analysis of HCPT at different pH values and in cultured tumor cells. CONCLUSION: Both forms of HCPT were effective against tumor growth, but C-HCPT was more effective than O-HCPT, the latter could be converted into the former under certain conditions.

Animals↗
PubMed2001

[Effect of elevated atmospheric CO2 concentration on Rhopalsiphum padi population under different soil water levels].

With the aim of forecasting the wheat-aphid relationships under different precipitation in the future atmospheric CO2 environment, the effects of different atmospheric CO2 concentration on Rhopalsiphum padi population under different soil water levels in Open-Top chambers were studied. The results showed that Rhopalsiphum padi population grew constantly with the continuous rising of atmospheric CO2 and it grew more quickly when CO2 concentration increased from 350 microliters.L-1 to 550 microliters.L-1. In each CO2 concentration treatment, R. padi population were distinct under different soil water level, and they were the highest under 60% of field water capacity treatment. When CO2 concentration increased from 350 microliters.L-1 to 550 microliters.L-1, the increase of R. padi population under 60% of field water capacity treatment was higher than that under 40% and 80% treatment. When CO2 concentration increased from 550 microliters.L-1 to 700 microliters.L-1, the increases of R. padi population under 60% and 40% soil water treatments were the same and both higher than that under 80% treatment. These results suggested that R. padi population would grow more quickly from the beginning to the middle of the 21st century and bring more damages to the wheat in arid and semiarid area.

Animals↗
PubMed2001

[Study on factor IX gene mutation in 74 hemophilia B patients].

OBJECTIVE: To investigate the distribution of the FIX gene mutations in hemophilia B(HB) and compare the mutation patterns between the Chinese HB and Caucasian HB. METHOD: Genomic DNA was extracted from the blood samples of HB patients. Nine DNA segments of the FIX gene were amplified. Gene mutations of the amplified DNA segments were detected by direct sequencing. RESULT: Fifty eight independent mutations were detected and identified in 69 HB patients. Among them twenty nine mutations were novel and not reported before. A similar pattern of germline mutation was found in both Chinese HB and Caucasian HB patients. CONCLUSION: No difference was observed in mutation patterns between Chinese and Caucasian HB.

Americas↗
PubMed2001

[Chemical defense of plant to mammalian herbivore].

The research progress in the chemical defense of plant to mammalian herbivore was reviewed in this paper. The plant secondary compounds mainly are phenolics, terpenoids and nitrogen-containing compounds. The defense efficiency of plant to mammalian herbivores is different with the types and content of secondary compounds in plant. Secondary compounds inhibited the foraging of mammalian herbivores by affecting the intake, digestion, metabolites and reproduction of animal. It is the main trends to study the mode of coevolution of plant and animals mediated by plant secondary compounds.

Animals↗
PubMed2001

[Establishment and application of experimental animal model for hypertrophic scar].

OBJECTIVE: To establish a real animal model for hypertrophic scar. METHODS: 388 wounds on the ears of 47 rabbits were created including rounds 6 mm in diamiter on ventrol or dorsal side and 1.5 cm x 4.5 cm rectangular wounds. Histological and histochemical analyses, in situ hybridization and cell apoptosis were tested. RESULTS: 70 percent of the wounds can from excess dermal scarring which is similar to human hypertrophic scar. The hight of excess dermal scarring is as 3-4 times high as original ventol skin. The excess scarring can last 150 days at the most. while 80 percent appears on rectangular wounds and it lasts more than 262 days. Large amount of fibroblasts, nodular and spiral structures exist in excessive dermal scarring. Local injection of TGF-beta 1 and IFN-r can promote and inhibit the formation of excessive dermal scarring respectively. SDS-PAGE shows that type III collagen content increased in excessive dermal scarring. In situ hybridization shows long-lasting expression of type I and III precollagen mRNA in excessive dermal scarrint. TGF-beta 1 mRNA also cope with that of precollagen. Fibroblast apoptosis in excessive dermal scarring of this model indicate that fibroblast apoptosis plays an important role in the process of occurrance, development of abnormal scar. CONCLUSION: After wounding, rabbit ears can produce excessive dermal scarring which is similar to human hypertrophic scar. This can be used as an experimental model for the study of cicatrix.

Animals↗
PubMed2001

Intracranial aneurysms: experience in treating 500 patients.

OBJECTIVE: To summarize the experience in surgical treatment of patients with intracranial aneurysms. METHODS: The measures used in the treatment of 500 patients with intracranial aneurysms were retrospectively reviewed with regard to timing of surgery, induced-hypotensive anesthesia, brain protection combined with temporal occlusion of the feeding artery, dynamically monitoring of transcranial Doppler ultrasound, antivasospasm treatment, techniques of direct surgery, and endovascular embolization. RESULTS: In 465 patients undergoing surgery, intraoperative rupture was observed in 27(6.2%), postoperative death in 13 (2.7%), hemipalsy in 8(2.2%), and vegetative state in 2 (5.0%). The operative mortality was 3.8% in 210 patients before 1990, while 1.9% in 255 patients after 1990. CONCLUSION: The outcome of patients with intracranial aneurysms can be markedly improved by comprehensive measures.

Adult↗
PubMed2001

[The significance of nucleotide repeat sequences in FVIII gene for detecting hemophilia A carriers].

OBJECTIVE: To detect the carriers in hemophilia A(HA) families by haplotype analysis of the microsatellite polymorphisms at intron 13 [13(CA)n] and 22[22(GT)n(AG)n] in the factor VIII (FVIII) gene. METHOD: Multi-PCR amplification of 13(CA)n and 22(GT)n(AG)n combined with silver staining were used. RESULTS: In 35 HA families, 11 had HA history. There were 21 female members in the 11 HA families and all of them were subjected to molecular study. Fourteen of the 21 females were confirmed to be carriers and approximately 72.7%(8 of 11) of these families were informative. CONCLUSIONS: Besides the reliable detection of HA carriers, multi-PCR combined with silver staining in HA analysis has the advantages of time saving, simplicity for performing and no radiation contamination.

Alleles↗
PubMed2001

[A study of the effects of basic fibroblast growth factor on fibrovascular ingrowth into hydroxyapatite orbital implants].

OBJECTIVE: To investigate the effects of different doses of basic fibroblast growth factor (bFGF) on the fibrovascular ingrowth into hydroxyapatite orbital implants. METHODS: Thirty-six New Zealand albino rabbits were divided into 4 groups, and hydroxyapatite orbital spheres were implanted into their orbits. The implants were pretreated with 0.5, 1.5 and 5.0 g/L bFGF solution respectively in 3 groups, the untreated implants were used in the control group. At the postoperative 2, 4 and 6 weeks the implants were harvested. Observers classified the extent of the fibrovascular ingrowth in a blind manner under light microscopy. RESULTS: Histologic studies demonstrated that postoperatively, the rate of vascularization of the implants pretreated with 1.5 and 5.0 g/L bFGF solution was significantly increased at week 2 in comparison with that of the control group. No difference was noted between the group with the implants pretreated with 0.5 g/L bFGF solution and the control group. CONCLUSION: The bFGF 1.5 and 5.0 g/L in concentration may promote the fibrovascular ingrowth into hydroxyapatite orbital implants at week 2 after the implantation.

Animals↗