Search PubMed⌕ Search

Biomedical subjects

S Lu

Publications and source records attributed to S Lu.

At least 289 records · Page 16Linked to original sources
PubMed1996

Limb salvage in primary malignant bone tumors by intraoperative microwave heat treatment.

OBJECTIVE: To use intraoperative microwave heat for the treatment of tumor-bearing bone in situ for limb-salvage in primary malignant bone tumor. PATIENTS AND METHODS: Twenty-five patients with malignant bone tumor received surgical protocol for limb-salvage by wide exposure and intraoperative microwave heat treatment of tumor bone in situ. The tumor was localized at distal femur in 16 patients, proximal tibia in 5, shaft of femur in 2, and illia in 2. RESULTS: The pathological diagnosis revealed osteosarcoma in 16 patients, parosteal osteosarcoma in 4, chondrosarcoma in 3, and leiomyosarcoma in 2. The stage of tumor was classified into IIB in 16 patients, IIA in 6, and IIIB in 3. The operative technique was wide exposure for tumor in soft tissues, protecting the surrounding normal tissue from heat injury by copper mesh, and heating tumor-bearing bone at 50 degrees C for 15 minutes. The patients were followed up from 4 to 180 months (mean, 63 months). The survival rate of 2, 5 and 10 years was 81.3%, 70.4%, and 53.8% respectively. The functional results were less than 50% in 4 patients, between 50% and 75% in 9, and more than 75% in 12, referred to the normal function of a normal limb. The complications consisted of infection in 4 patients, pathological fracture in 4, and separation of epiphysis in 1. Oncological results showed that local recurrences of tumor were in 4 patients, and 6 patients suffered from distant metastasis. CONCLUSION: The treatment is an alternative to replacement by prosthesis or allograft bridging techniques.

Adolescent↗
PubMed1996

Guided bone regeneration in long bone. An experimental study.

OBJECTIVE: In the concept of guided tissue regeneration (GTR), a space is created for selected cells to differentiate, proliferate and repair the defect at last by implanting a membrane around the defect area, which serves as a physiologic barrier. This experiment was designed to test GTR in long bone, namely, guided bone regeneration (GBR). METHODS: Ten New Zealand rabbits were used in this experiment. A piece of silicone membrane sutured as a tube was used to bridge a 10-mm defect on radius. 10-mm defects were also produced on the control sides. Radiography of forelimbs was taken weekly until 12 weeks. Gross sample examination, 3-point bending test and histology were involved in evaluating bone regeneration. RESULTS: By the 12th week, seven of 10 experimental sides were healed, 2 were healed with a connective cartilage zone, and I was not healed. None of the control was healed but the defect was occupied by soft tissue. CONCLUSIONS: The results of this preliminary study showed that GBR is present in long bone of rabbits. The following points relate to the mechanism of GBR; providing a space for bone regeneration; preventing surrounding tissue from the defect; increasing the density of osteogenic precursor cells and concentration of bone morphogenetic protein (BMPs); and maintaining a complete blood clot to bridge the fracture ends in the tube, which provides a structure for osteogenic cells ingrowth.

Animals↗
PubMed1996

[The clinical value of fetal congenital heart disease diagnosed by color Doppler echocardiography].

OBJECTIVE: To investigate the clinical value of color Doppler echocardiography for the diagnosis of fetal congenital heart disease (CHD). METHODS: 368 cases of high risk fetuses of CHD, aged from 20-40 gestational weeks, were examined by color Doppler echocardiography with Acuson 128 x P/10 color Doppler flow imaging system. The prenatal echocardiographic diagnosis were confirmed by fetal autopsy and echocardiographic examine after birth as well as follow-up. RESULTS: 11 cases of fetal CHD were detected by prenatal echocardiography, of those, 5 cases of CHD were confirmed by fetal autopsy after induction of labor and 5 cases of CHD were confirmed by color Doppler echocardiography after birth, 1 case of false-positive and 1 case of false-negative. CONCLUSIONS: The study suggests that four-chamber view is an important view for detecting fetal CHD by echocardiography, but multiple views are necessary for diagnosis of fetal complex CHD. Color Doppler echocardiography lists as the first choice for prenatal diagnosis of fetal CHD.

Adult↗
PubMed1996

[The effect of local hyperthermia on NK activity and lung metastasis in mice].

OBJECTIVE: To study the effects of local hyperthermia on primary and metastatic focus. METHOD: Animal tumor model was established in C57BL/6 mouse by injecting 5 x 10(5) Lewis lung carcinoma cells into the left foot pad. Ten days later, a tumor mass of 10 x 10 mm was seen, and local hyperthermia was performed at 37, 43, 45 and 47 degrees C for 30 minutes with water bath. 96 mice were randomly divided into four groups of 1, 2, 3, 4 weeks according to time of sacrifice. Every group had 6 mice. RESULTS: NK activity increased after 43-45 degrees C hyperthermia, and was higher than that of the control group (37 degrees C). The growth rate and lung metastasis decreased. CONCLUSION: Host immunity is thought to be enhanced by local hyperthermia and plays an important role in eradicating primary tumor and controlling distant metastasis.

Animals↗
PubMed1996

[Regenerating axons selectively reinnervate their target organs after the peripheral nerves were tubulated].

This study investigated target specificity during axonal regeneation of a mixed motor and sensory nerve after the canine tibial nerves were tubulated. 10mm gap of tibial nerve was connected by silicone tube. Three months later, the second operation was performed by spinal dorsal root ganglion (DRG) resection at the experimental side. Five months later, histalogical analysis results reveal that the regenerating motor nerve fibre of mixed nerve selectively grew into motor branches. The mean number of regenerated motor nerve fibers grew into its motor branches was 1199, and the number of that into its sensory branch was only 21. This result suggests that regenerating motor and sensory axons of mixed nerve can across 10-mm silicone chamber and be able to select their distal target organs exectly.

Animals↗
PubMed1996

Tandem repeating of the expression cartridge--a novel strategy to enhance the expression efficiency of cloned gene in Escherichia coli.

A novel strategy to enhance the expression efficiency of cloned target gene in Escherichia coli was developed. The whole expression cartridge, consisting of promoter, SD sequence, target gene and transcription terminator, was tandem repeatedly engineered into a expression plasmid. Consequently, the copy number of specific gene was increased substantially, leading to the improvement of expression efficiency. Using this approach, a recombinant plasmid, designed as pLYD, was constructed and transformated into the Escherichia coli strain DH5 alpha. Upon induction, the desired protein was synthesized in a considerable level and accumulated up to 63% of the total cell proteins. The present study revealed that tandem repeating of expression cartridge provided a convenient means to improve expression level efficiently.

DNA, Recombinant↗
PubMed1996

[The epidemiological study on human cytomegalovirus infection of pregnant women and the maternal-fetal transmission in three Chinese metropolis].

OBJECTIVES: To analyze the state of human cytomegalovirus (HCMV) infection of pregnant women and the maternal-fetal transmission in three chinese metropolis, and to study the methods of early prenatal diagnosis for intrauterine infection. METHODS: Enzyme linked immunosorbent assay (ELISA) technique was employed to screen HCMV specific antibodies in 5,015 pregnant women of different trimesters. From this cohort study, 301 cases of active infection were selected to detect HCMV DNA by polymerase chain reaction (PCR) technique in their appendages of fetus, blood and urine of neonates, as well as breast milk. RESULTS: The overall HCMV infection rate was 88.93% in the three metropolis and they were 96.74% and 91.42% in Shenyang and Shanghai respectively, which were significantly higher than that (79.53%) in Wuhan. The active infection rate was 5.42% generally while they were 11.23% and 10.89% in Wuhan and Shenyang respectively, which were significantly higher than that in Shanghai. In addition, the active infection rate of women with history of abnormal pregnancy was significantly higher than that was of the control group (14.59% vs 3.70%). By PCR technique, the detective rate of HCMV DNA were 16.00% in chroionic villi of early pregnancy and 35.33% in amniotic fluid of mid-trimester, which were not significantly different from these in umbilical blood, placentea at delivery and neonatal blood. CONCLUSIONS: In China, the HCMV infection rates during pregnancy varied in different regions. A majority of women at children bearing age had HCMV infection before pregnancies; the yertical transmission frequently occurs from the actively infected mother. ELISA combined with PCR techniques is a valuable method for early prenatal diagnosis of HCMV congenital infection.

Adult↗
PubMed1996

[Repairing bone defect with autogenous periosteal pieces in coagulum: experimental study and clinical application].

A 1.5 cm-long bony defect was established in rabbits one each on both sides. The defected area was filled with coagulum of peripheral blood or bone marrow blood, then autogenous pieces of the periosteum was put in the coagulum on one side, while the other side was served as the control without periosteal autograft. The osteogenetic capacity of the periosteum and the influence of different blood coagulum were evaluated by means of X-ray film, histology, the contents of calcium and phosphate in new osteocytes in the defected area, bone tissue morphometry, and computer-assisted image analysis. The autograft of the periosteum had osteogenetic effect. Autologous bone marrow blood had potential osteogenetic capacity, which however, was weaker than that of the periosteum. Peripheral blood coagulum did not have any osteogenetic effect. We have successfully used the periosteum-bone marrow blood complex (bone marrow blood as a carrier) in 12 patients.

Adult↗
PubMed1996

[Distribution and effectiveness of endogenic bone morphogenetic protein (BMP) in bone defect].

BMP is one of important factors in the pathophysiology of bone regeneration. Fifteen New Zealand rabbits were used in this experiment. We studied the distribution and effectiveness of endogenic BMP on a 10 mm bone defect of radius, by utilizing immunohistochemistry of BMP and quantitative computer imaging system. On the 3rd day, death of osteocytes and BMP positive blood clot were observed. The mesenchymal cells from periosteum and endoosteum, and osteoblast were also BMP positive. By quantitative study, we found there was a gradient distribution of BMP in bone defect, i.e, the value of BMP decreased gradually along the distance from the fracture ends. The maximal value of BMP was noted at the 1st week postoperation. In conclusion, two sources of endogenic BMP were found, one was from the absorption of necrotic tissue of fracture ends, the other was from the secretion of osteogenic mesenchymal cells during the process of bone regeneration. Nonunion of bone defect was caused in part by the gradient distribution of BMP. Accordingly, the concept of effective quantity of endogenic BMP was drawn rosen. It might be a new method in the treatment of bone defect by increasing the concentration of endogenic BMP and improving its distribution.

Animals↗
PubMed1996

[An experiment study of the guided bone regeneration].

During the process of wound healing, different cellular components have varied speeds of migrating. By implanting a membrane, a space was created for selected cells, that is so called guided tissue regeneration. Since bone had the potential of regeneration, the concept of guided tissue regeneration was used in the process of bone regeneration in the present study, namely, guided bone regeneration. Defects of 10 mm-long were produced on bilateral radii of 10 adult New Zealand rabbits by surgery. The defects on experimental sides were bridged with silicone tube. The opposite side served as the control. Radiography of forearms of rabbits was taken weekly. Samples were treated with 3-point bending test and histology respectively. On experimental sides, by 3-4 weeks, new bone from the fractured ends grew into bone defect, seven of ten healed within 6-8 weeks. The other 2 only had a gap less than 1 mm left. No one healed on the control sides. The maximum value of 3-point bending test on experimental sides was 11.7 times greater than that of the control sides. It was shown that bone regenerated in the tube, and no callus formed out the tube by both gross samples and histologic examinations. On histology, the gap less than 1 mm on X-ray films was fibrocartilage zone, which connected regenerated bone from both distal and proximal bone ends. The defects on the control were occupied by connective tissue. In conclusion, guided bone regeneration also presents in long bone, that may provide a new method in the treatment of bone defect and promote fracture healing.

Animals↗
PubMed1996

[Transseptal re-operation for recurrent pituitary adenoma].

To summarize the suitable approach for recurrent pituitary adenoma, fifteen patients with recurrent pituitary adenoma were re-operated via the transseptal sphenoid approach for the second time. During the operation, some degree of adhesion was noted in septal mucous membrane. The sphenoid cavity was filled with fibrous tissue which has correlated to the methods of reconstructing sellar floor during the previous operation. Follow-up study showed satisfactory results. It showed that transseptal sphenoid re-operation is still the best approach for treating recurrent pituitary adenoma in spite of some degree of operative difficulties.

Adenoma↗
PubMed1995

Use of DNAs expressing HIV-1 Env and noninfectious HIV-1 particles to raise antibody responses in mice.

Two DNA constructs encoding portions of the human immunodeficiency virus type-1 (HIV-1) genome have been used to raise antibody responses in BABL/c mice. One DNA (pNL4-3.env) expresses the natural form of the envelope glycoprotein (Env) of HIV-1-NL4-3 (NL4-3). The second (pNL4-3.dpol) produces noninfectious NL4-3 particles. These two DNAs (alone or in combination) raised only transient titers of anti-Env IgG. In the same group in which pNL4-3.dpol DNA raised only transient antibody responses to Env, this DNA raised persistent antibody responses to the p24 virion capsid protein (CA). Antibody responses to Env and CA also showed different abilities to be boosted. The final boosts of pNL4-3.dpol DNA increased titers of anti-CA antibody, but failed to boost the falling titers of anti-Env antibody. At peak titers of anti-Env activity, sera with relatively low ELISA titers of anti-Env IgG (end points of 1:6250) had good titers of neutralizing antibody (approximately 1:3800 for 50 TCID50 of NL4-3). At the end of the experiment (a time when anti-Env antibodies had fallen to near background levels), in vitro-restimulated splenocytes from both pNL4-3.env and pNL4-3.dpol DNA vaccine groups exhibited similar cytotoxic activity.

AIDS Vaccines↗
PubMed1995

Isolation and characterization of the human tissue transglutaminase gene promoter.

Tissue transglutaminase belongs to a family of calcium-dependent enzymes, the transglutaminases that catalyze the covalent cross-linking of specific proteins by the formation of epsilon (gamma-glutamyl)lysine isopeptide bonds. The goal of this study has been the isolation and characterization of the human tissue transglutaminase gene promoter. Genomic DNA clones, spanning the 5' region of the gene, were isolated and the structure of the 5'-end of the human tissue transglutaminase gene was determined. 1.74 kilobases of flanking DNA were sequenced and were found to contain a TATA box element (TATAA), a CAAT box element (GGACAAT), a series of potential transcription factor-binding sites (AP1, SP1, interleukin-6 response element), and a glucocorticoid response elements. Transient transfection experiments showed that this DNA fragment included a functional promoter, which is constitutively active in multiple cell types.

3T3 Cells↗
PubMed1995

Cloning and promoter mapping of mouse kappa opioid receptor gene.

We have isolated mouse kappa opioid receptor (KOR) genomic clones containing the complete 5'-untranslated region, a portion of the 3'-untranslated region, and its coding region. The mouse KOR gene spans at least 16 kb and contains at least 4 exons. Exon I encodes the major portion of 5'-untranslated sequence and transcription initiation is determined, by primer extension experiments, to reside at 3 major sites, located at 334, 340, and 716 nucleotides upstream from the translation initiation codon. No typical TATA or CAAT boxes can be identified within an approximately 1-kb upstream region. Exon II contains 271 nucleotides, including 14 nucleotides of 5'-untranslated sequence. Exon III contains 353 nucleotides and exon IV begins at amino acid position #204 and encodes the rest of the 3'-end sequence of the cloned cDNA. Based upon Northern blot analysis, KOR transcript is estimated to be approximately 6 kb in length.

Amino Acid Sequence↗