Biomedical subjects

Y Lu

Publications and source records attributed to Y Lu.

At least 451 records · Page 25Linked to original sources

PubMed1999

Diagnostic agreement of quantitative sonography of the calcaneus with dual X-ray absorptiometry of the spine and femur.

OBJECTIVE: The aim of our study was to evaluate the diagnostic agreement between quantitative sonography of the calcaneus and dual X-ray absorptiometry (DXA) of the spine and femur for revealing osteoporosis. SUBJECTS AND METHODS: In 1252 patients (795 women, 54.9+/-15 years old; 457 men, 50.5+/-15 years old [mean+/-SD]), bone mineral density measurements of the lumbar spine (posteroanterior, L1-L4) and the proximal femur (neck, trochanter, intertrochanteric region, total proximal femur, and Ward's triangle) and quantitative sonographic measurements of the stiffness of the calcaneus were performed. The presence of osteoporosis is defined, according to the World Health Organization criteria, as a T-score lower than -2.5. The percentage of patients below the threshold (prevalence of osteoporosis) was calculated for each imaging technique. The diagnostic agreement in identifying individuals as osteoporotic was assessed using kappa scores. RESULTS: Forty-nine percent of the women and 42% of the men were classified as osteoporotic by quantitative sonography, 32% of women and 30% of men by DXA of the spine, and 23-54% of women and 16-54% of men by the different regions of interest revealed on femoral DXA. Kappa analysis showed the diagnostic agreement among these measures to be generally poor (kappa = .28-.41 [women] and .25-.45 [men]). CONCLUSION: The considerable diagnostic disagreement between quantitative sonography and DXA could cause confusion in the daily practice of radiology and make establishing the correct diagnosis a difficult task. The choice of imaging technique influences which patients are diagnosed as osteoporotic.

Absorptiometry, Photon↗

PubMed1999

Biodiversity and bioseparation of HIV-1 envelope glycoproteins.

Since 1984, studies from almost every branch of modern biology have filled in many gaps in our knowledge of human immunodeficiency virus type 1 (HIV-1). This review focuses on studies of biodiversity and bioseparation of HIV-1 envelope glycoproteins from the vaccine development point of view. It presents an updated picture of different systems for producing either native or recombinant HIV-1 envelope glycoproteins for the preparation of vaccine candidates. The prevention of HIV-1-associated disease is highly relevant to the abrogation of the neoplastic processes associated with this pathogen.

AIDS Vaccines↗

PubMed1999

Gabapentin attenuates nociceptive behaviors in an acute arthritis model in rats.

In this study, we investigated the effectiveness of gabapentin (Neurontin), administered spinally with a microdialysis fiber, in reducing nociceptive behavioral responses induced by a knee joint inflammation model. This model is produced by injection of the knee joint with kaolin and carrageenan in rats. The resultant knee joint inflammation produces a secondary hyperalgesia to radiant heat applied to the hindpaw. Both pretreatment and post-treatment protocols were examined. Spinal administration of gabapentin (10 mg/ml) infused 1.5 h before induction of knee joint inflammation, although having no effect on the baseline, prevented the development of heat hyperalgesia. Gabapentin also prevented the development of other pain-related behaviors scored subjectively. Gabapentin had no effect, however, on the joint circumference increase typical in this model. In animals with fully developed knee joint inflammation, gabapentin produced a reversal of heat hyperalgesia. The paw withdrawal latency responses and subjective pain scores were no longer significantly different from baseline, but joint circumference increases remained. These data suggest that gabapentin is an effective antinociceptive agent when administered either before or after induction of knee joint inflammation acting through a central neurogenic mechanism.

Acetates↗

PubMed1999

Desensitization of nicotinic agonist-induced [3H]gamma-aminobutyric acid release from mouse brain synaptosomes is produced by subactivating concentrations of agonists.

Several neurochemical and electrophysiological studies have shown that neuronal nicotinic receptors are desensitized by pretreatment with lower agonist concentrations than are required to activate the receptors, but the extent of desensitization and agonist concentration required to produce desensitization vary depending upon receptor subtype. Recently, we reported that nicotinic agonists will stimulate the release of [3H]gamma-aminobutyric acid (GABA) from synaptosomes prepared from mouse brain. The studies described herein evaluated desensitization of [3H]GABA release produced by pretreatment with 12 nicotinic agonists. Pretreatment produced near total desensitization that developed slowly (onset T(1/2) = 3.46 min) and was totally reversible (recovery T(1/2) = 4.95 min). Nine of the 12 compounds tested induced total or near total desensitization at concentrations that were less than those required to produce a reliably measured increase in [3H]GABA release. Nicotine produced total block with an IC(50) value of 26 nM. This value is two orders of magnitude lower than the EC(50) for nicotine-induced [3H]GABA release (1630 nM). The three compounds that showed an overlap of the desensitization and activation concentration-effect curves (cytisine, anabasine, nornicotine) are all partial agonists. Comparison of the desensitization properties of the [3H]GABA release with an ion ((86)Rb+) efflux that we have measured previously suggests that the receptor that mediates GABA release and (86)Rb(+) efflux is the same, most likely the alpha4beta2 subtype.

Animals↗

PubMed1999

Overexpression of edg-2/vzg-1 induces apoptosis and anoikis in ovarian cancer cells in a lysophosphatidic acid-independent manner.

Lysophosphatidic acid (LPA) is one of the major growth factors in ascites from ovarian cancer patients and appears to play an important role in proliferation, survival, and invasion of ovarian cancer cells. Recently, several groups have shown that Edg-2, which belongs to the G-protein coupled receptor family, is a functional LPA receptor. Northern blot analysis showed that most ovarian cancer cell lines express Edg-2. Edg-2 expression was especially high in the cisplatin-resistant and slowly proliferating 2780cp cell line and was almost absent from the cisplatin-sensitive and rapidly proliferating A2780 cell line. We thus assessed whether Edg-2 could contribute to changes in cell viability, cell proliferation, or cisplatin resistance. Stable overexpression of Edg-2 in A2780 cells induced an exogenous LPA-independent decrease in proliferation but did not alter cisplatin sensitivity. The LPA-independent decrease in growth rate induced by overexpression of Edg-2 could be explained, at least in part, by Edg-2-induced apoptosis rather than by effects on cell cycle progression. In agreement with the results in stably transfected A2780 cells, transient expression of Edg-2 in Jurkat T cells also induced apoptosis. When cells were separated from the extracellular matrix, they underwent a specialized form of apoptosis called anoikis, which is particularly important in survival of cells in the circulation during metastasis. A2780 cells engineered to overexpress Edg-2 were particularly sensitive to anoikis. These observations suggest that Edg-2 may be a negative regulator for ovarian epithelial cell growth and metastasis.

Animals↗

PubMed1999

Construction of La-tPA vector and expression in the mammary gland of transgenic mice.

Expression vectors of long acting human tissue plasminogen activator (La-tPa) in the mammary gland was constructed using the promoters of sheep beta-lactoglobulin gene (BLG, 5 kb) containing the first and the second introns obtained by PCR. Transgenic mice were established by microinjection. 540 fertilized eggs were injected and 6 transgenic mice were screened out from the offspring by PCR and Southern Blot analysis. The foreign gene integrating rate was 32%. The expression of La-tPA in mammary glands of transgenic mice was confirmed by milk assay and Northern blot analysis. Expression level of La-tPA reached 6 ug/ml in milk of transgenic mice.

Animals↗

PubMed1999

[Expression of endothelial nitric oxide synthase mRNA in human placenta].

OBJECTIVE: To determine the localization and type of nitric oxide synthase in human placenta. METHODS: By polymerase chain reaction and in situ hybridization. The eNOS mRNA expression was observed in 10 cases of human normal term placenta and cord. RESULTS: In human normal term placenta, positive staining of eNOS was evident in the syncytiotrophoblast and the endothelium of umbilical artery and vein, positive staining also presented in the endothelium of stem villous vessels, but it was absent in the endothelium of terminal villous capillary. CONCLUSION: eNOS is present in syncytiotrophoblast and endothelium of stem villi vessels, and it can synthesize nitric oxide which results in the increase of nitric oxide in pregnancy.

Adult↗

PubMed1999

[Clinical study on transvaginal hysterectomy for moderate enlarged uterus].

OBJECTIVE: To assess the feasibility and safety of performing transvaginal hysterectomy(TVH) on moderate enlarged uteri. METHODS: Twenty-five transvaginal hysterectomies were performed on enlarged myomatous uteri, with the size equivalent to 12-17 gestational week or 280-570 g. Bisection, enucleation, morcellation and combinations thereof were used to facilitate the operation by reducing the uterine volume. The operation time, blood loss, morbidity as well as complications were observed and analyzed. RESULTS: Twenty-two out of 25 vaginal hysterectomies were successfully completed with a success rate of 88%. Another 3 cases were converted to transabdominal hysterectomies, 2 of them were due to technical difficulties. One bladder injury and one severe intraoperative hemorrhage occurred. Two cases required blood transfusion. The mean operating time was (119 +/- 32) min. The mean blood loss was (231 +/- 107) ml with a range of 100-500 ml except the case with severe hemorrhage. The morbidity rate was as low as 4% and the average postoperative hospital stay was (5.5 +/- 1.1) days. The follow-up at 2-48 months after operation showed excellent recovery in all cases without any late postoperative complications. CONCLUSION: In the hands of experienced vaginal operation surgeons some of the enlarged uteri(> or = 12 weeks gestational size, i.e. > or = 280 g) with benign disease can be safely removed transvaginally through reduction of uterine volume if the uterus is mobile and obtaind more satisfactory recovery.

Adult↗

PubMed1999

[A quantitative histological investigation of salivary glands of human and experimental animals].

The pairs of three major salivary glands of eight kinds of full grown experimental animals were sectioned and examined by morphometric techniques. The televised image-analysis system was used to determine the acinar area and proportional volumes of component tissue. The results were compared with those of the same glands from human. There were no differences between the three acinar areas of human and monkey. The acinar area of human parotid was the smallest except that of rabbit. The acinar area of human submandibular gland was larger than that of rodents but smaller than that of other animals. There were no differences between the acinar area of sublingual glands of human and animal except those of rabbit and goat. The acinar area of mucous acini was larger than that of serous and seromucous acini. The mean proportional volume of acini of human parotid was less than that of other animals. The duct systems of rodents submandibular were far more than those of other animals. In sublingual glands, there were no differences in mean proportional volume of component tissue between human and animals except there were more acini and less fiber in rodents' subingual glands.

Animals↗

PubMed1999

Five types of glycophorin variants found in southern China.

PURPOSE: To summarize the results of gene analysis for five types of glycophorin (GP) variants found in a screening survey conducted in several regions of Southern China. DATA SOURCES: Papers cited in Chinese biochemical and biomedical literatures with a bibliographic review of articles relevant to hematology and biochemistry. STUDY SELECTION: All GP variant reports of our research group published during 1991-1997 were included. DATA EXTRACTION: Data concerning 5 types of GP variants found in Southern China were briefly abstracted. GP variant frequencies with their phenotypes among 3 districts and those among Han, Li, Buyi and Yao ethnic groups were calculated. RESULTS: Five phenotypes of GP variants [Sta, Mi III, Mi V (J.L.), Mi VI and a novel case] were identified from 180 unrelated healthy individuals (Hunan, Hainan) and 222 residents of a tertian malaria hyperendemic area (Guizhou), using immunoblotting techniques, Southen hybridization and PCR-direct sequencing. CONCLUSIONS: These five types of GP variants were first reported in China. There were some differences in the geographical distribution of GP variants among Hunan, Hainan and Guizhou districts. Mi III GP was commonly found in national minorities of Li and Buyi, while the frequency of Sta GP occurrence was considerably higher in Han ethnic group. The frequency of GP variants in a malaria hyperendemic area of Guizhou Province does not depend upon the severity of tertian malaria morbidity.

China↗

PubMed1999

A surveillance study on penicillin-resistant streptococcus pneumoniae in China.

OBJECTIVES: To find out whether there are also penicillin-resistant streptococcus pneumoniae and the resistant rate in China. METHODS: A surveillance study which is a part of the international surveillance on pneumococci resistance to penicillin and other antimicrobial agents was conducted in Beijing, China. More than 900 pediatric patients with respiratory tract infections aged from six months to three years selected from two pediatric units were enrolled in the study. Perthroat swabs were immediately streaked onto blood agar plates. Isolates were identified as pneumococci by their typical appearance, gram stain, confirmation tests. Antibiotic susceptibility was assessed by the disk diffusion method and minimal inhibition concentration (MIC) determination according to Protocol and National Committee for Clinical Laboratory Standards (NCCLS). RESULTS: Of the 51 streptococcus pneumoniae isolates, 5 strains had zones of inhibition indicative of penicillin resistance, of which two had penicillin MICs > or = 0.1 mg/L and were considered to be relatively or fully resistant to penicillin. The MICs of two penicillin resistant strains were 2 mg/L and 4 mg/L. Resistant rates to ceftriaxone and cefotaxime were 0% and 10% respectively. For the other ten antimicrobial agents, the resistant rates were as follows: ampicillin 12%, piperacillin 26%, furbenicillin 14%, cefuroxime 6%, erythromycin 54%, clarithromycin 52%, meleumycin 64%, roxithromycin 52%, chloramphenicol 35%, tetracycline 100%. CONCLUSIONS: The study suggested that penicillin resistant streptococcus pneumoniae strains existed in China and were also resistant to ampicillin, piperacillin, furbenicillin and cefuroxime. Moreover, the resistant rates of penicillin resistant streptococcus pneumoniae to macrolides and tetracycline were high.

Ampicillin Resistance↗

PubMed1999

[Study on combined detection of M. genitalium, M. pneumoniae and C. pneumonia by nested polymerase chain reaction in respiratory tract infections in pediatric patients].

OBJECTIVE: To study the respiratory tract infections by Mg, M. genitalium (Mpn), Cpn, and co-infections by these agents in pediatric patients. METHODS: Mg DNA, Mpn DNA and Cpn DNA were detected in respiratory tract specimens obtained by throat swab from 231 children by the nested polymerase chain reaction (PCR) technique. DNA sequencings were detected and analysed between every two positive specimens of Mg and Cpn and typical strains. RESULTS: Positive rates of Mg DNA, Mpn DNA and Cpn DNA by nested PCR in 231 children were 22.5%, 30.7% and 32.9%. The Positive rates of co-infection were 5.2% (Mg and Mpn), 2.6% (Mg and Cpn), 10.8% (Mpn and Cpn) and 8.7% (Mg and Mpn and Cpn). There was only one base mutation in 1 Mg DNA. Other DNA sequencings were same as those from model strains. The homogeneity was 99.8%. CONCLUSIONS: Mg could be one of the pathogens in respiratory tract infections in pediatric patients. There exists co-infection by Mg, Mpn and Cpn.

Child↗

PubMed1999

[A novel human DNA sequence with tumor metastasis suppressive activity].

OBJECTIVE: To isolate human tumor metastasis suppressive DNA sequence and to study the molecular mechanisms regulating tumor metastasis. METHODS: A mouse lung adenocarcinoma cell clone 12 derived from its parent cell line LM2, which had been transduced with normal human genomic DNA, was previously reported. Compared with LM2, the metastatic potential of clone 12 was very much decreased. Clone 12 was used in this study to amplify the human DNA fragments by Inter Alu PCR technique. The human DNA fragments obtained were then transfected into LM2 cells and their malignant phenotype was observed in vitro and in vivo, and compared with that of the untransfected LM2 cells. RESULTS: Three human DNA fragments of 700, 500 and 300 bp were isolated. DNA sequencing revealed that the 700 bp fragment does not show homology with hitherto reported genes and was accepted by the GenBank (pt 712 U67835). In vitro proliferation and colony formation in soft agar of the 700 bp fragment-transfected LM2 cells were significantly inhibited as compared to the untransfected LM2 cells. Upon subcutaneous inoculation to syngeneic T739 mice, the 700 bp-transfected LM2 cells grew more slowly and smaller tumors developed compared to the un-transfected ones. Moreover, lung metastasis was not found in 6 of 10 mice inoculated with the 700 bp-transfected LM2 cells, while it was found in 9 of 10 mice inoculated with the un-transfected LM2 cells. The difference was statistically significant (P < 0.001). The frequency of lymph node metastasis was also statistically different between the 2 groups of mice. CONCLUSION: The newly isolated 700 bp human DNA fragment may be a metastasis suppressor gene of malignant tumor.

Animals↗

PubMed1999

[Effects of shenmai injection on plasma neuropeptide Y, endothelin and atrial natriuretic polypeptide in heart failure patients].

OBJECTIVE: To investigate the effect of Shenmai injection (SMI) on neuroendocrine function in the patients with heart failure (HF). METHODS: Sixty patients with HF were randomly divided into the treated group administered with SMI combined with western medicine, and the control group administered with western medicine alone. The change of cardiac function was observed, and plasma neuropeptide Y (NPY), endothelin (ET) and atrial natriuretic polypeptide (ANP) were determined by immunoradiometric assay. RESULTS: The total effective rate and markedly effective rate were higher in the treated group than that of the control group, the level of NPY, ET and ANP of both groups were higher than healthy subjects. The plasma NPY, ET and ANP of both groups were significantly reduced after treatment, the effect of treated group was better than that of control group. CONCLUSION: SMI could improve the HF patient's cardiac function, reduce the level of plasma NPY, ET and ANP, their neuroendocrine activity was affected at the same time.

Aged↗

PubMed1999

[Clinical observation on radio- or chemotherapy plus Traditional Chinese medicine in treating brain metastatic tumor].

OBJECTIVE: To observe the clinical efficacy of radio- or chemotherapy plus traditional Chinese medicine (TCM) by Syndrome Differentiation in treating brain metastatic tumor. METHODS: Forty-one patients were randomized into four groups: Group A treated with chemotherapy plus TCM, Group B with radiotherapy plus TCM, Group C with chemotherapy alone and Group D with radiotherapy alone. The efficacies of the four groups were compared. RESULTS: The short-term response rate, living quality, 1-, 2-, 3- and 4-year survival rate, median survival period and immunity of the Group A and B were significantly higher than those of the Group C and D (P < 0.05). CONCLUSION: Radio- or chemotherapy plus TCM by Syndrome Differentiation has the effect of tumor growth inhibition, survival period extension and living quality enhancement in treating brain metastases.

Adult↗

PubMed1999

[Expression and clinical study of multidrug resistance gene and multidrug resistance associated protein gene in acute leukemia].

OBJECTIVE: To evaluate the relationship between the expression of multidrug resistance gene (mdr1) or multidrug resistance-associated protein gene (MRP) and the prognosis in patients with acute leukemia (AL). METHODS: The expression of mdr1 and MRP were measured in 55 patients with AL by reverse transcription polymerase chain reaction (RT-PCR). RESULTS: The mdr1 and MRP gene expression levels in the relapsed AL and the blastic phase of CML group (0.735 +/- 0.249, 1.157 +/- 0.447) were significantly higher than those in the untreated group (0.408 +/- 0.186, 0.465 +/- 0.253) (P < 0.01). The complete remission (CR) rate in high mdr1 and MRP expression group was significantly lower than that in low mdr1 and MRP expression group (P < 0.01) in a follow up of 40 AL patients. CONCLUSION: Increased expression of mdr1 and MRP gene might be an important factor for predicting drug resistance, relapse and unfavorable prognosis in AL patients.

Acute Disease↗

PubMed1999

[The effect of early escheractomy on expression of ICAM-1 and E-selectin mRNA of endothelial cells].

OBJECTIVES: To examine the effect of burned serum on change in endothelial cell ICAM-1 and E-selectin mRNA expression and whether these alterations can be corrected by the means of escharectomy during burn shock period. METHODS: One hundred and seventy-six Wistar rats with 30% III degree TBSA on back were studied. Endothelial cell ICAM-1 and E-selectin mRNA were tested with the method of RT-PCR. RESULTS: ICAM-1 and E-selectin expression showed an increase after stimulation by serum of 4 hours post burn, reaching peak levels 168 hours after injury. ICAM-1 and E-selectin expression levels could decrease to baseline within 168 hours in the rats which underwent escharectomy during shock stage, but kept higher than normal in rats without escharectomy or underwent 96 hours post burn. CONCLUSIONS: These findings suggest that eschar can induce endothelial cells to express adhesion molecule. Early escharectomy is important to prevent adhesion molecule expression and SIRS.

Animals↗

PubMed1999

[The relationship between anticardiolipin antibodies and fetal intrauterine growth retardation].

To investigate the relationship between anticardiolipin antibodies(ACA) and fetal intrauterine growth retardation(IUGR), serum ACA was determined in 60 pregnant women by enzyme linked immunosorbent assay(ELISA). Binding index(BI) of ACA-IgM or ACA-IgG in cases with IUGR(n = 30) was significantly higher than that in normal pregnant women(n = 30) (P < 0.05). There was no obvious relationship between the weight of neonate and BI of ACA-IgM(r = 0.1904), ACA-IgA(r = 0.1829) or ACA-IgG(r = 0.2013) in IUGR group. Increased ACA-IgM had a negative association with C3 (r = -0.4108, P < 0.05) and C4(r = -0.4092, P < 0.05), respectively. After routine therapy for IUGR during 27-35 weeks' gestation, the weights of neonates were 2436.87 +/- 437.29 gram in ACA-IgG positive group(n = 15) and 2905.33 +/- 195.95 gram in ACA-IgG negative group(n = 15). There was a statistical significance between these two groups(P < 0.01). It is concluded that ACA may play an important role in the pathogenesis of IUGR. The determination of ACA is also useful for early diagnosis and treatment of IUGR.

Adult↗