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Biomedical subjects

S Lu

Publications and source records attributed to S Lu.

At least 109 records · Page 6Linked to original sources
PubMed2000

[Further clinical study of acupuncture anesthesia for supratentorial craniocerebral operations].

OBJECTIVE: To improve the successful rate of acupuncture anesthesia for supratentorial craniocerebral operations. METHODS: On the basis of previous study of acupuncture anesthesia for craniocerebral operations, 72 cases of front fossa and temporo-parieto-occipital region lesions were operated on by acupuncture anesthesia with new modified acupoints and adjuvants from 1993 to 1998. RESULTS: One hundred percent of successful rate was achieved in all 72 cases by the new methods. CONCLUSION: Acupuncture anesthesia has distinct advantage and should be widely used as one of the effective anesthesia for supratentorial craniocerebral operations.

Acupuncture Analgesia↗
PubMed2000

[Dynamic changes in dermal cell cycles, contents of hydroproline and ratios of collagen type I/III in the burned wound].

OBJECTIVE: To study the dynamic changes in the dermal cell cycles contents of hydroproline and ratios of collagen type I/III in the burned wound. METHODS: The dermal cell cycles, contents of hydroproline, ratios of collagen type I/III and pathologic changes were dynamically observed in 48 deep partial burn rats (TBSA 10%), attempting to investigate the process of deep partial burn wound healing. RESULTS: The percentage of S-phase reached the highest point on PBD 10. On PBD21, it was still significantly higher than that of normal group. OHP increased gradually after burn, and peaked on PBD14. On PBD21, the level of OHP was still significantly higher than that of normal group. The ratios of collagen type I/III decreased gradually and significantly lower than those of the normal group after burn. The strips of WBC infiltrating into wound were observed on PBD3, 7 and 10. On PBD 14, a large number of regenerative epidermal cells crept over wound surface. CONCLUSIONS: The inflammation is obvious from PBD3 to PBD10. The proliferation of dermal cell and the synthesis, deposition of new collagen are predominant from PBD10 to PBD14, and the repair of dermis is not complete on PBD21. The proliferation and migration of epidermal cells are major activities from PBD14 to PBD21.

Animals↗
PubMed2000

[The attractive effects of nerve regeneration chamber fluid and degenerated nerve segments on the growth and the migration of the cocultured dorsal root ganglion neuron].

OBJECTIVES: We intended in this study to investigate the neurotropic effects of regeneration chamber fluid (RCF) and the degenerated nerve segments from distal of the regeneration chamber on the dorsal root ganglion (DRG). METHODS: The capillary model was first tested for its reliability to form concentration gradient with a dye being contained in the capillaries. The tissue culture in RCF test was divided into two groups each with 8 DRGs implanted in 8 dishes. RCF was contained in capillaries inserted down to the bottom of the dishes with their lower ends at a distance of about 1 mm to the DRGs in the experimental group, and DMEM media was contained in the control group. Segments of degenerated sciatic nerve from distal of the regeneration chamber were implanted with DRGs at a distance of about 0.5 - 1 mm in the coculturing experiment. DRGs were observed for the direction of the growth of the cells and the fibres. RESULTS: While the capillary containing the dye was put down to the bottom of the culture dish coated with a piece of nylon pad, the red color slowly disseminated with heavier staining in the center and lighter staining in the peripheral portion. We believe this pattern of shade could simulate the concentration gradient of tropic factors in this model. There were significantly more nerve fibres growing from the DRGs towards the capillaries in 6 of the 8 dishes in the experimental group after 72 hours of culture. The tissue and nerve fibers grew evenly in the control group. 76.5% of all the nerve fibres were growing in the direction facing the degenerated nerve segments after 12 hours of coculturing, and only 33.3% of the nerve fibres growing in that direction in the control group. Cells from the DRGs migrated towards the degenerated nerve segments, yet they tended to avoid the normal nerve segments. The migration index of the cells was 0.98 in average in the coculturing experiment with the degenerated nerve segments, but only 0.43 in average with the normal nerve coculturing. CONCLUSION: The capillary model was effective in studying the chemotactic growth of nerve tissue. RCF and the degenerated nerve segments had definite neurotropic effects on DRGs tissue.

Animals↗
PubMed2000

[Surgery for patients with primary liver cancer: report of 1,038 patients].

OBJECTIVE: To investigate methods for enhancing safety of and improving the survival in patients with primary liver cancer (PLC). METHODS: One thousand and thirty eight patients with PLC were treated in our hospital from January 1990 to December 1998. The early period group (from January 1990 to December 1996) consisted of 731 patients [312 patients (42.7%) receiving liver resection]; the late period group (from January 1997 to December 1998) included 307 patients [217 patients (70.7%) receiving liver resection]. RESULTS: The mortality within one month after hepatectomy was 2.24% in the early group and 0.74% in the late group. The 1-, 3- and 5-year survival rates were 73.1%, 54.2%, and 34.0% respectively in patients undergoing hepatectomy in the early group and 91.1%, 63.8% and 40.2% in the late group. CONCLUSIONS: Regular follow-up of high risk patients is helpful to discover small PLC. High proportion of small PLC, progress of perioperative management, and improvement of operative techniques including hepatopetal blood occlusion of half liver or in vitro-bypass through bio-pump during hepatectomy might be important approaches to enhance the safety of surgical treatment and improve the prognosis of patients with PLC.

Adolescent↗
PubMed2000

[Treatment of spondylolisthesis with pedicle screw instrumentation and anterior or posterior lumbar interbody fusion].

OBJECTIVE: To investigate the treatment of spondylolisthesis with pedicle screw instrumentation and anterior or posterior lumbar interbody fusion. METHODS: 26 patients, 14 males and 12 females, underwent spinal instrumentation with RF or SOCON instrumentation and anterior or posterior interbody fusion with TFC. Among them, 6 patients underwent RF instrumentation and posterior interbody fusion with TFC, 15 SOCON instrumentation and posterior interbody fusion with TFC, and 5 RF instrumentation and anterior interbody fusion with composite cortical ring. RESULTS: All the patients were followed up for an average of 22 months (range 6 - 18 months) after operation. The reduction of spondylolisthesis was 88%, and the fusion rate 89%. There was no recurrence of spondylolisthesis. CONCLUSIONS: High quality SOCON instrumentation may be reliable for the treatment of spondylolisthesis. Implantation of TFC into the interbody space can stabilize the fused segments, prevent the collapse of the interbody space, avoid bone resorption, remain or increase the heights of the interbody space, facilitate the union of the fused segments, and allow early mobilization.

Adult↗
PubMed2000

[The treatment of premature arrest of growth plate with a novel engineered growth plate: experimental studies].

OBJECTIVES: To observe the role of the engineered growth plate (EGP) in the treatment of premature arrest of growth plate and to establish a novel treatment method for the premature arrest of the growth plate. METHODS: The engineered growth plates were cultured for the first time by using polylactic acid (PLA) as cell scaffold seeded with growth plate chondrocytes and they were implanted into the medial proximal defects of growth plates of New Zealand rabbit tibia. The degree of deformity of the tibia was evaluated by X-ray and the expression of collagen II mRNA of regenerating growth plate was detected by in situ hybridization technique. RESULTS: Little deformity appeared in the EGP group 8 weeks after operation. Some deformity was seen in the EGP group 16 weeks after operation, whereas it's degree was much less than that of the control group (P = 0.0001). The degree of the angular deformity of the EGP precultured with bFGF and TGF-beta group was less than that of the EGP group (P < 0.05). The cells in the regenerating growth plate arranged in column and were stained blue by in situ hybridization technique. CONCLUSION: The EGP can prevent the formation of bony bridge and restore the growth of the damaged growth plate.

Animals↗
PubMed2000

[An epidemiologic study of irritable bowel syndrome in Beijing - a stratified randomized study by clustering sampling].

OBJECTIVE: To explore the prevalence of irritable bowel syndrome (IBS) and its risk factors in Beijing. METHODS: Phase I: a screening program for IBS was carried out in Beijing area according to symptoms using both Manning (modified including constipation) and Rome criteria. Random clustered sampling involving 2 486 subjects of the inhabitants was carried out under stratification of city, suburban and rural areas. Sample size of each studied area was in proportion to the population of the area. The range of age was 18 - 70. All subjects studied were requested to fill in a questionnaire assisted by trained doctors or medical students during the visit to their families. Phase II: a small number of patients who fulfilled the Manning criteria were further selected to undergo detail clinical examination in the hospital including laboratory examination, abdominal ultrasonography, colonoscopy or/and barium enema to exclude organic disease of the colon. Prevalence of IBS of the population was then adjusted by the rate of correct diagnosis during phase II study. Minnesota Multi - Personality Indices was used in some cases. Potential risk factors were explored by comparing frequencies among IBS group and non - IBS group using chi(2) and logistic analysis of multifactors. RESULTS: The adjusted point prevalence of IBS in Beijing according to Manning criteria was 7.26%, in contrast to Rome criteria - 0.82%. Higher prevalence rate of IBS in the city (10.50%) than in rural areas (6.14%) (P < 0.001) was noticed. Male to female ratio was 1:1.15 with majority of IBS fell in age 18 - 40 (51.6%), and among intellectuals. Our study indicated that history of dysentery (OR = 3.00), exposure to coldness (OR = 1.55), ingestion of cold food and raw materials (OR = 1.24) might serve as the most important risk factors (P < 0.001). Patients with IBS seemed to have a higher tendency of abnormal personalities. CONCLUSION: IBS is a common disorder in Beijing which deserves greater care.

Adolescent↗
PubMed2000

[An experimental study on cerulenin induced apoptosis of human colonic cancer cells].

OBJECTIVE: To investigate whether cerulenin could induce apoptosis and suppress the proliferation of human colonic cancer cells. METHODS: Cell morphology, microculture tetrazolium assay (MTT), agarose gel electrophoresis and flow cytometry assays were performed to identify the inhibitory effect on cell proliferation and the induction of apoptosis in human colonic cancer cells (LoVo). RESULTS: Cerulenin was able to induce LoVo cells death via apoptosis. Cerulenin also inhibited the proliferation of LoVo cells in vitro and was dose-dependent. Nuclear DNA of apoptotic cells displayed ladder bands characteristic of internucleosomal DNA fragmentation and apoptotic peak. The inhibitory effect of cerulenin on proliferation of LoVo cells was associated with cell cycle arrest from S to G(2)-M phase transition and with induction of apoptosis. In contrast, cerulenin could not affect the proliferation of human fibroblasts in vitro. CONCLUSION: The fatty acid synthase inhibitor, cerulenin, enables to induce cell apoptosis and to suppress the growth of human colonic cancer cells by inhibition of the synthesized fatty acids endogenously in the cancer cells.

Apoptosis↗
PubMed2000

[Zymographic analysis of matrix metalloproteinases in mouse carcinoma cell lines with different lymphatic metastasis potential].

OBJECTIVE: To investigate the correlation between lymphatic metastasis and matrix metalloproteinases (MMPs) activity. METHODS: Zymographic analysis was used to detect the difference of MMPs product and activities between high lymphatic metastatic cell line (HCa-F) and low lymphatic metastatic cell line (HCa-P), that were cultured in the medium including homogenate of lymph node or liver or spleen tissue. RESULTS: HCa-F and HCa-P cells produced small quantities of MMP-9 in 1640 medium. After adding lymph node homogenate to the culture medium, F cells produced a large quantity of MMP-9 as well as active MMP-9 and MMP-2. P cells also produced MMP-9, active MMP-9 and MMP-2, but were much lower than that of F cells. Neither F cells nor P cells produced MMPs in the media with homogenate of liver or spleen added. CONCLUSION: The metastatic potential of F cells is stronger than that of P cells may be due to F cell's ability to secrete MMPs is stronger than P cell's, therefore the production of MMPs of hepatocarcinoma cells is closely correlated to their metastatic potential.

Animals↗
PubMed2000

[Cerulenin inhibits growth of human colonic carcinoma in nude mice].

OBJECTIVE: To determine the effects of fatty acid synthase inhibitor, cerulenin, on tumor growth of human colonic carcinoma (LoVo) in nude mice. METHODS: The transplantable colonic carcinoma cell line LoVo model was established in BALB/CA-nu/nu mice by subcutaneous implantation. Cerulenin was administrated by i.p. injection (80 mg/kg, 160 mg/kg each time) for 10 times. 17 days later the mice were killed and tumor size evaluated. RESULTS: The size of tumors in cerulenin-treated group were significantly smaller than in control group and were similar to that of the 5-Fu treated group. Transmission electronic microscopy (TEM) revealed that death of LoVo cells treated by cerulenin was associated with apoptosis characterized by cell shrinkage, condensation and chromosome fragmentation. bcl-2 oncoprotein expression rate was significantly lower in cerulenin-treated group in comparing with the control group. The expression rate of bax was the opposite to that of bcl-2. CONCLUSIONS: Cerulenin effectively suppresses the growth of human colonic carcinoma cells in vivo. The mechanism of cell death may be correlated with apoptosis, and bcl-2 and bax gene may play an important role in regulating cerulenin-induced apoptosis.

Animals↗
PubMed2000

[Detection of minimal residual disease in childhood hematological malignancies and its clinical significance].

OBJECTIVE: Exploring the detection of minimal residual malignant cells in bone marrow from children with hematological malignancies to predict the prognosis. METHODS: Seventy-five patients with acute lymphoblastic leukemia (ALL), stage IV non-Hodgkin's lymphoma or stage IV neuroblastoma were studied. Complete remission was maintained for over 3 months before the detection. Minimal residual disease was detected by polymerase chain reaction (PCR) for IgH and TcRgamma rearrangements in lymphoid tumors by reverse transcriptase-polymerase chain reaction (RT-PCR) for neuroblastoma patients. RESULTS: Thirty five patients were positive for minimal residual disease, and 21 of them (60%) relapsed 3 - 40 months later, while only 7 (17%) negative patients relapsed (chi(2) = 12.59, P < 0.01). CONCLUSION: Minimal residual disease detection in bone marrow by PCR might predict prognosis in some childhood hematological malignancies.

Adolescent↗
PubMed2000

[Cell cycle analysis and pathological changes of malignant tumors treated with electrochemical therapy].

To investigate the mechanism and to observe the effectiveness of electrochemical therapy(ECT), 33 patients of late stage cancers which treated by ECT were included in this study. Flow cytometry (FCM) and pathology were used to observe the changes of tumor cells before and after ECT. Tumor cells of G1, G2/M, S phases and aneuploid cells were found to be killed almostly and the ratio of apoptosis was elevated greatly after ECT. Also, pathological evidence proved the death of tumor cells and some characters of apoptosis. So, ECT can non-selectively kill tumor cells and induce the apoptosis of them, and FCM was a way to evaluate the effectiveness of ECT.

Adult↗
PubMed2000

[Expression of IL-2 receptors on the surfaces of L1210 cells and bioactivity assay for IL-2-toxin fusion proteins].

OBJECTIVE: To confirm that L1210 cells surfaces express IL-2 receptors (IL-2R) and to establish experimental models for studying the cytotoxic effect of IL-2-toxin fusion protein in vivo and in vitro. METHODS: IL-2R on mouse leukemia L1210 cells was analyzed with immunofluorescence stain and FACS. The cytotoxic effects in vitro of these fusion proteins IL-2-PEZNM and IL-2-K-PEZNM were assayed by MTT method; mice ascitic L1210 leukemia was induced by i.p. L1210 cells and the therapeutic effect of IL-2-K-PEZNM was observed. RESULTS: 86.3% of L1210 cells expressed IL-2R on their surfaces and the relative fluorescence intensity was 51.55. Two fusion proteins IL-2-PEZNM and IL-2-K-PEZNM showed dose-related cytotoxicities to L1210 cells in vitro with the IC50 of 0.51 and 0.67 microgram/ml respectively. IL-2-K-PEZNM (5 micrograms/d) showed significantly inhibitory effect on L1210 cells and prolonged the survival time of mice by 78.6%. CONCLUSIONS: L1210 cells as a model system to measure the cytotoxic activity of IL-2-toxin fusion proteins both in vitro and in vivo is simpler, stabler, and safer model than those with other cells such as Hut102 and activated T lymphocytes.

Animals↗
PubMed2000

[High level expression of foreign gene via multiple joined operons and a new concept on the restricted constant of total amount of plasmid DNA per cell of Escherichia coli].

OBJECTIVE: To examine the feasibility of linking operons in tandem to enhance expression of heterologous genes in Escherichia coli and to clarify the potential control mechanism of the total plasmid DNA amount in each host cell. METHODS: Two series of expression plasmids, CW11 and CW12, containing 1 to 4 and 1 to 3 heterologous gene operon(s), respectively, were constructed. The molecular size of the CW11 series varied from 5.47 kb to 12.26 kb in 2.25 kb increments. The CW12 series varied from 5.40 kb to 9.72 kb in 2.16 kb increments. Protein expression was analyzed via SDS-PAGE and laser scanning. Plasmid copy number was determined by incorporation with 3H-TdR([3H]-thymidine). RESULTS: No influence of the tandem-joined operons on host growth and plasmid stability was observed. Upon induction, the desired protein accumulated in the CW11 series were 46.0%, 54.8%, 56.1%, and 60.1% of total cell protein. In the CW12 series, the yields were 33.5%, 44.0%, and 47.1% of total cell protein. With increasing size, however, plasmid copy number decreased. Further calculation showed that the total amount of plasmid DNA per cell is restricted to some extent. There seems exists a mechanism to control the maximum level of total plasmid DNA amount in each host cell. CONCLUSIONS: Increasing the target gene dosage by tandem linking of operons enhanced the expression level of a desired protein. Although the size (kb) and the copy number of each plasmid are negatively interrelated, it seems that as for certain plasmids, their total DNA amount per cell is a restricted constant for a specific E. coli strain under identical incubation condition.

Cloning, Molecular↗
PubMed2000

[Vibrational spectroscopic investigation of a series of heterometallic cubane-like M'-Mo (W) cluster compounds].

By combining the results of IR spectroscopic experiments with the molecular structures, the main stretching vibrations of a series of the heterometallic tetranuclear cluster compounds with [M3YS3M'] cluster core (M = Mo, W; Y = O, S; M' = Cu, Sn, Pb, Sb, Bi) have been assigned. The characteristic features and the bonding situations of the five configuration types are discussed. It is shown from the IR and Raman spectra that when M' is a transition metal such as Cu, the nu M's frequency of the [M3YS3M'] core has a value comparable to that of corresponding M'-S covalent bond thus indicating a close combination of M' with [M3YS3]. Whereas when M' is a main group metal, the nu M'-s vibration is always observed in a lower region than of the M'-S covalent bond because of a loose combination of M' with[M3YS3]. However, remarkable enhancement of M-M band strength due to the addition of M' is demonstrated by Raman spectra. Some comments for the M-M vibration of various structures of these compounds are also described.

English Abstract↗
PubMed2000

[Vibrational and electronic spectra of a discrete and a tetramer containing [Mo3S7] core].

In this paper, the IR, Raman and UV-Vis spectra of a discrete cluster [Mo3S7(dtp)3I]1 and its tetramer [[Mo3S7(dtp)3]4I].[(HgI3)4].K]2(dtp = S2P(OC2H5)2-) were reported. The spectral characteristics of the compounds were discussed. According to the results of the studies on the structure and spectra, it was the weak intermolecular interaction and electrons transfer after tetramerization that led to the variation in the electronic structure of the compounds.

English Abstract↗
PubMed2000

[IR study on a series of tungsten clusters].

In this paper, the IR study on a series of tungsten clusters which contain a [W2S4]2+ or [W2MM'S4]4+ (M,M'=Cu,Ag) core is reported. According to the results of X-ray structural analysis and the IR spectra of the clusters, some characteristic IR absorptions of the clusters were assigned. The study of IR spectra of these clusters shows that the variation of structure can reflect on the IR spectra significantly.

Spectrophotometry, Infrared↗