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Biomedical subjects

S Lu

Publications and source records attributed to S Lu.

At least 73 records · Page 4Linked to original sources
PubMed2001

Immunotoxin depletion of T cells and its effect on hematopoietic progenitor cells in human cord blood.

OBJECTIVE: To study the selective toxicity of immunotoxin (IT) on T cells in cord blood and simultaneously determine its effect on hematopoietic progenitor cells. METHODS: The percentage of CD5 and CD8 T cell subsets in cord blood (CB) and bone marrow (BM) as well as peripheral blood (PB) was measured by immunoenzymatic labeling of monoclonal antibodies using immune complexes of alkaline phosphatase and monoclonal anti-alkaline phosphatase (APAAP complexes). One-way mixed lymphocyte cultures (MLC) were performed to compare the proliferative response of CB with that of PB. The proliferative capability of cord blood T cells and T lymphocyte transformation capacity were evaluated in the presence of anti-CD8 or anti-CD5 immunotoxin by one-way MLC and colorimetric MTT (tetrazolium) assay, respectively. The effect of IT on the growth of hematopoietic progenitor cell of colony forming unit-granulocyte and macrophage (CFU-GM), burst forming unit-erythroid(BFU-E), multipotential hemotapoietic progenitors (CFU-Mix) from CB were estimated by colony-forming assays. RESULTS: A certain proportion of CD5 and CD8 T cells existed in CB. The alloproliferative capacity of CB was similar to that of PB. CD5: Ricin at a dosage of 1 x 10(-10)-1 x 10(-8) mmol/L and CD8: Ricin concentration in the range of 1 x 10(-9)-1 x 10(-8) mmol/L effectively decreased both the proliferative capability of T cells in MLC during CB and T cell transformation. Over the dosage of 1 x 10(-10)-1 x 10(-9) mmol/L, both kinds of IT didn't obviously affect the growth of hematopoietic progenitor cells. CONCLUSION: CD5: Ricin and CD8: Ricin may effectively deplete T cells and may not significantly inhibit the function of hemaptopoietic cells at a specific dosage.

CD5 Antigens↗
PubMed2001

[Bax gene expression in endometrial carcinoma].

OBJECTIVE: To study the relationship between bax gene expression and endometrial carcinoma. METHODS: Bax mRNA expression was evaluated by RT-PCR in a series of 8 normal proliferative endometrium (NPE), 6 simple and complex hyperplasia (SCH), 6 atypical hyperplasia (AH) and 42 endometrial carcinoma (EC). RESULTS: All of the 8 NPE showed moderate bax mRNA expression. In 1 of 6 SCH, 2 of 6 AH and 27 of the 42 EC (64.3%), there was overexpression of bax mRNA. In endometrial carcinoma, with the progression of clinical stage, increase in histologic grade and in depth of invasion to muscle layer, and lymph node metastasis, the positive rate of bax overexpression was correspondingly increased. CONCLUSION: The results suggest that bax expression affects the balance between the endometrial cell proliferation and apoptosis. Bax might play an important role in carcinogenesis and tumor progression of endometrial carcinoma. As a high risk factor it can be used to evaluate the biological behavior of endometrial carcinoma.

Disease Progression↗
PubMed2001

[The investigation with contrast sensitivity after implantation with UV and UVCY types of intraocular lens].

OBJECTIVE: To research the difference in vision after UV and UVCY two types of intraocular lens implantation (The light 380-790 nm may transmit through the UV lens, and the UVCY lens may partly filter the light < 640 nm including part of the light < 460 nm.). METHODS: MCT 8000 contrast tester was used in the postoperative two months. RESULTS: The contrast sensitivity of the patients with UVCY lenses was superior to that with UV lenses obviously (P < 0.05) under the condition of glare and 3 c/d, 6 c/d space frequency. CONCLUSION: The UVCY lens is more advantageous to improve visual function.

Aged↗
PubMed2001

[Expression of matrix metalloproteinase-2 in rat pulmonary fibrosis].

OBJECTIVE: To study the role of matrix metalloproteinase-2 (MMP(2)) in rat pulmonary fibrosis. METHODS: (1) Dynamic changes of MMP(2) expression were observed in bleomycin-induced rat pulmonary fibrosis by use of immunohistochemical technique. (2) RT-PCR was carried out to show the dynamic changes of MMP(2) mRNA expression of isolated pulmonary fibroblasts (PFbs) during rat pulmonary fibrosis. (3) Northern blot analysis and immunocyto chemistry techniques were performed to detect the expression of MMP(2) mRNA and their relevant protein in cultured rat PFbs after treatment with transforming growth factor 1 (TGF beta(1)). RESULTS: (1) On day 1-7th after receiving bleomycin, the infiltrated pulmonary macrophages and septa mesenchymal cells showed positive reaction with anti-MMP(2) and an increase in number. After 14 days and on 28 th of bleomycin treatment, the number of positive staining macrophages and mesenchymal cells were decreased respectively. (2) The gene expression of MMP(2) mRNA of PFbs were enhanced after bleomycin treatment from the Day 1 and decreased by Day 28. (3) The expression of MMP(2) mRNA and their relevant protein were enhanced in rat PFbs after TGF beta(1) treatment. CONCLUSIONS: Over expression of MMP(2) in pulmonary tissue may be an important factor in the initiation of pulmonary fibrogenesis.

Animals↗
PubMed2001

[GATA-2 gene expression in leukemia patients and its significance].

OBJECTIVE: To investigate GATA-2 gene expression in leukemia patients and its clinical significance. METHODS: GATA-2 gene transcripts were detected by reverse transcriptase polymerase chain reaction (RT-PCR), and bcr/abl or PML/RAR alpha transcripts were detected in patients with chronic myeloid leukemia (CML) and acute promyelocytic leukemia (APL), respectively. RESULTS: The GATA-2 transcripts were revealed in 93% of acute myeloid leukemia (AML), in 70% of acute lymphoblastic leukemia (ALL), and 83% of CML patients, but not in normal bone marrow and peripheral blood cells. GATA-2 expression in remission patients was similar to newly diagnosed or relapsed patients. In post-transplantation patients, GATA-2 expression was significantly decreased. In these cases GATA-2 transcripts could be detected with bcr/abl fusion gene disappeared in 2 of 12 CML, whereas neither GATA-2 nor PML/RARalpha transcripts could be detected in APL. CONCLUSION: GATA-2 transcripts was highly expressed in leukemia patients and had no change in remission but significantly decreased in post-transplantation patients. Detection of GATA-2 expression would give information about the residual leukemia stem cells.

Bone Marrow Cells↗
PubMed2001

[A clinical evaluation on reconstruction in extended partial laryngectomy for transglottic cancer].

OBJECTIVE: Transglottic cancer has been a definite indication for total laryngectomy in decades, compromising function of the larynx. The purpose of this study is to present a new radical surgery of extended partial laryngectomy and reconstruction to restore the essential function of larynx. METHODS: Forty-one cases of transglottic cancer were treated by extended vertical laryngectomy (26/41), extended frontolateral laryngectomy (5/41) and subtotal laryngectomy (10/41); the defects of larynx were reconstructed by rotary door myocutaneous flap in twenty-seven cases, by sternohyoideus flap in seven cases, by osteomuscular flap in five cases and by sternocleidomastoid flap in two cases. RESULTS: The 3 and 5 year survival rates were 85.7% (30/35) and 74.1% (20/27) respectively, those for stage III were 84.6% (22/26) and 76.2% (16/21), for stage IV were 3/4 and 1/2 respectively. All cases resumed acceptable voice, 92.7% (38/41) and enjoyed satisfactory phonation. The over-all decannulation rate was 87.8% (36/41), those with rotary door myocutaneous flap was 96.3% (26/27), with sternohyoideus flap was 5/7, with osteomuscular flap was 4/5 and with sternocleidomastoid flap was 1/2. All patients had normal swallow function. CONCLUSION: Extended partial laryngectomy is a kind of radical operation in selected cases of transglottic cancer. The method of reconstruction with rotary door myocutaneous flap can improve curative effect and the essential functions of the larynx.

Adult↗
PubMed2001

[Expression of T-lymphocytes and cytokines in the decidua of mifepristone with misoprostol for terminating early pregnancy].

OBJECTIVE: To investigate the expression of T-lymphocyte subsets (CD3+, CD4+, CD8+), natural killer cells (NK cells, CD56+, CD16+), tumor necrosis factor-alpha (TNF-alpha) and transforming growth factor-beta (TGF-beta) in mifepristone and misoprostod treated ducidua for terminating human early pregnancy. METHODS: Thirty eight women who volunteered to terminate their pregnancy were divided into 3 groups: mifepristone group (group I, n = 13), mifepristone with misoprostol group (group II, n = 12) and control group (group Il, n = 13), The expression of T-lymphocyte subsets, NK cells, TNF-alpha and TGF-beta were assessed by flow cytometry. RESULTS: The expression of CD4+ were (30.91 +/- 2.57)% and (31.58 +/- 3.28)% in group I and II respectively. Which were significantly higher than that in group III (25.64 +/- 2.36)% (P < 0.05, P < 0.01). CD56+ were (22.40 +/- 2.77)% and (26.88 +/- 3.79)% in group I and II, which were significantly higher than that in group III (18.58 +/- 4.04)% (P < 0.05, P < 0.01), CD16+ were (8.98 +/- 2.18)% and (10.84 +/- 2.51)% in group I and II, which were significantly higher than that in group III (6.34 +/- 2.01)% (P < 0.01, P < 0.001). The expression of TNF-alpha in group I and II were higher than that of group III, TGF-beta in group I and II were lower than that of group III, but there was no significant difference (P > 0.05). The expression of CD3+, CD8+, CD4+/ CD8+ ratio were not significant difference among the three groups (P > 0.05). CONCLUSIONS: Mifepristone with misoprostol for terminating early pnegnancy might be affect the expression of lymphocyte and cytokines and induce the disorder of decidual micro-environment which might be the reason of medical abortion.

Abortifacient Agents↗
PubMed2000

Isolation and characterization of a new chemokine receptor gene, the putative chicken CXCR1.

This study delineates the isolation and characterization of a novel chemokine receptor gene, the putative chicken CXC receptor 1 (cCXCR1). Using a human CXCR1 probe, we isolated several positive clones from a chicken genomic library. One of the clones contained a fragment of approximately 5000bp that hybridized strongly with the hCXCR1 probe. This fragment was sequenced and subjected to a variety of computer analyses. The open reading frame for this gene predicts a seven transmembrane domain protein with all the characteristics of a chemokine receptor and with 67% sequence homology to hCXCR1, 65% to hCXCR2 and also with considerable sequence homology to other human chemokine receptors such as hCXCR4 (50%), hCCR2 (49%) and hCCR1 (49%). However, the homology to a previously isolated potential G-protein-coupled receptor for chickens (AvCRL1) is only 47%. Using 5' RACE, two transcription initiation sites were identified suggesting the potential for the expression of two protein isoforms (I and II) in vivo. The promoter for the putative cCXCR1 contains a variety of consensus transcription factor binding elements that can potentially be involved in the expression of this chicken receptor upon stimulation by stress-inducing agents. RT-PCR analysis was used to determine the pattern of expression of the larger isoform (I) of this receptor in a variety of tissues. This form of the receptor is expressed primarily in the organs of the gastrointestinal tract, tissues that are frequently exposed to stress-inducing agents, but not in the central nervous system, tissues that are protected from insult by the blood barrier. Using the same RT-PCR approach we show that stress-inducing agents, such as 'first-hand' and 'second-hand' cigarette smoke components, tumor promoters and thrombin, differentially stimulate the expression of the isoform I in primary fibroblasts. Thrombin is an enzyme that plays many important roles in thrombosis, angiogenesis and wound healing and exposure to both cigarette smokes and/or to tumor promoters can lead to tumorigenesis. Therefore, upregulation of chemokines and their receptors by stress-inducing agents can confer highly regulated modulation of cellular responses to traumatic and pathological situations.

Amino Acid Sequence↗
PubMed2000

Protein kinase C-regulated dynamitin-macrophage-enriched myristoylated alanine-rice C kinase substrate interaction is involved in macrophage cell spreading.

Macrophage spreading requires the microtubule cytoskeleton and protein kinase C (PKC). The mechanism of involvement of the microtubules and PKC in this event is not fully understood. Dynamitin is a subunit of dynactin, which is important for linking the microtubule-dependent motor protein dynein to vesicle membranes. We report that dynamitin is a Ca(2+)/calmodulin-binding protein and that dynamitin binds directly to macrophage-enriched myristoylated alanine-rice C kinase substrate (MacMARCKS), a membrane-associated PKC substrate involved in macrophage spreading and integrin activation. Dynamitin was found to copurify with MacMARCKS both during MacMARCKS purification with conventional chromatography and during the immunoabsorption of MacMARCKS using anti-MacMARCKS antibody. Vice versa, MacMARCKS was also found to cosediment with the 20 S dynactin complex. We determined that the effector domain of MacMARCKS is required to interact with the N-terminal domain of dynamitin. MacMARCKS and dynamitin also partially colocalized at peripheral regions of macrophages and in the cell-cell border of 293 epithelial cells. Treatment with phorbol esters abolished this colocalization. Disrupting the interaction with a short peptide derived from the MacMARCKS-binding domain of dynamitin caused macrophages to spread and flatten. These data suggest that the dynamitin-MacMARCKS interaction is involved in cell spreading. Furthermore, the regulation of this interaction by PKC and Ca(2+)/calmodulin provides a possible regulatory mechanism for cell adhesion and spreading.

Adenosine Triphosphatases↗
PubMed2000

High-risk behaviors during incarceration in African-American men treated for HIV at three Los Angeles public medical centers.

OBJECTIVES: This paper describes research that examined the association between high-risk sexual and drug-using behaviors during incarceration and HIV infection for African-American men receiving HIV care at three public medical centers in Los Angeles County (LAC), California. METHODS: A case-control study was conducted in which 305 HIV-infected African-American men and 305 neighborhood controls, ages 20 to 49, were frequency-matched by age. RESULTS: After controlling for anal sex while not incarcerated, we found no association between anal sex during incarceration and HIV (odds ratio [OR], 1.1; 95% confidence interval [CI], 0.6-2.2). Among men with a history of incarceration (n = 332), the percentage reporting anal sex with men outside of incarceration (45%) was greater than those reporting anal sex while incarcerated (16%). Injection drug use (IDU) during incarceration was also not associated with HIV when controlling for IDU outside of incarceration (OR, 1.6; 95% CI, 0.5- 4.9). Increased time in jail or prison was associated with less HIV infection (p =.001). CONCLUSIONS: Although high-risk behaviors are more common in the community than in the incarcerated setting for this study group, incarcerated populations represent a high-risk group for whom access to prevention messages is limited. Periods of incarceration represent a unique opportunity to convey prevention messages that focus on high-risk behaviors outside the incarcerated setting.

Adult↗
PubMed2000

Bis(1-acetonylpyridinium) pyridinium hexaiodobismuth(III).

The crystal structure of the title complex, (C(8)H(10)N)(2)(C(5)H(6)N)[BiI(6)], contains discrete [BiI(6)](3-) anions, and (HNC(5)H(5))(+) and (CH(3)COCH(2)NC(5)H(5))(+) cations separated by normal van der Waals contacts. The [BiI(6)](3-) anion has the Bi atom on an inversion centre. The (HNC(5)H(5))(+) cation also lies about an inversion centre and is disordered. The (CH(3)COCH(2)NC(5)H(5))(+) cation lies in a general position.

Journal Article↗
PubMed2000

Photopolymerized, multilaminated matrix devices with optimized nonuniform initial concentration profiles to control drug release.

This paper describes a novel approach to obtain desired release profiles from diffusion-controlled matrix devices by employing nonuniform initial concentration profiles theoretically and experimentally. Theoretically, a model was developed to examine the effect of nonuniform initial concentration profiles on matrix release behavior, and an optimization technique was investigated to determine suitable nonuniform initial concentration profiles which provide desired release patterns. Experimentally, release rates of an organic dye from photopolymerized matrix devices were measured to test the application of these mathematical techniques and the efficacy of photolaminated matrices in approximating the optimized release behavior. All system parameters were measured by independent experiments, and the experimental release data agree very well with the computed results.

Acrylates↗
PubMed2000

Dynamic susceptibility contrast MR imaging: correlation of signal intensity changes with cerebral blood volume measurements.

Cerebral blood volume (CBV) maps derived from dynamic susceptibility contrast (DSC) magnetic resonance (MR) imaging provide valuable information regarding intracranial micro-hemodynamics and have been helpful in characterizing primary brain tumors and guiding stereotactic biopsy. Another parameter, the maximum signal drop (MSD) during the first pass of intravascular contrast bolus due to T2* effect, can also be measured directly without extensive post-processing and data manipulation. The purpose of our study is to determine whether MSD maps provide information similar to CBV maps in patients presenting with intracranial mass lesions. Twenty-nine patients with various intracranial mass lesions were studied with DSC MR imaging prior to stereotactic biopsy or volumetric resection. Maps of both CBV and MSD are calculated on a pixel-by-pixel basis and displayed as color overlays over the raw images. Relative CBV (rCBV) and MSD (rMSD) values were measured in regions of interest (ROIs) within areas of abnormality and compared. In addition, computer-generated noise was added to the data to estimate the sensitivity of each measurement to noise. The rMSD values were strongly correlated with rCBV values (r = 0.87, P = 0.0001). CBV values were much more sensitive to added noise than MSD values (P < 0.01). MSD maps derived from DSC MR imaging provide information similar to CBV maps in patients with intracranial mass lesions. MSD maps are a simple and reliable indicator of vascularity that can easily be incorporated into routine MR imaging.

Brain Neoplasms↗
PubMed2000

Changes in function of cardiac receptors mediating the effects of the autonomic nervous system in the muscular dystrophy (MDX) mouse.

Adrenergic and muscarinic receptor mediated effects on the force of contraction and heart rate were studied in the isolated left atria and right atria from dystrophin-deficient mdx mice and age matched C57BL/10ScSn (C57) mice, respectively. The pD(2) and pA(2) values of (-)-isoprenaline and CGP 20712A, respectively, were not different in left atria and right atria from mdx and C57 mice. (-)-Phenylephrine produced a small positive inotropic effect on mdx left atria that could be antagonized by prazosin, whereas in C57 left atria no positive inotropic response was seen. In contrast, the positive chronotropic effect of (-)-phenylephrine was reduced in right atria from mdx compared to C57 right atria (P<0.05). The potency and efficacy to carbachol in the presence of (-)-isoprenaline were higher in right atria from mdx compared to C57 mice (P<0.05), although in left atria only a greater efficacy was evident in mdx mice. In left atria, basal force of contraction and maximum Ca(2+)-induced increases in force of contraction were lower from mdx compared to C57 mice (P<0. 001 and P<0.05, respectively). In conclusion, marked changes were demonstrated in the function of alpha1-adrenoceptors and muscarinic receptors, but not in beta1-adrenoceptors in left and right atria from mdx mice.

Animals↗
PubMed2000

Age- and sex-associated changes in cardiac beta(1)-adrenoceptors from the muscular dystrophy (mdx) mouse.

Variations in beta(1)-adrenoceptor function due to age or sex were examined in the mouse model of Duchenne muscular dystrophy. Positive chronotropic and inotropic responses to (-)-isoprenaline and antagonist effects of CGP20712A were determined in isolated right and left atria from young (12 week) and old (12 month) male and old (12 month) female mdx mice and their age- and sex-matched C57BL/10ScSn (C57) mice. There was no difference in efficacy to (-)-isoprenaline when expressed as an increase in the rate of contraction or force of contraction as a percentage of Ca(2+)-induced increase respectively in right or left atria from age- and sex-matched mdx and C57. Old mdx males showed a decreased sensitivity to (-)-isoprenaline (P<0.05) and a reduced affinity to CGP 20712A (P<0.05) in both right and left atria compared with old C57 males. These same changes were also observed in left atria between old and young mdx males. A reduced efficacy to (-)-isoprenaline was also evident when young and old mdx males were compared. In contrast, in old females, mdx showed an increased affinity to CGP20712A in left and right atria (P<0.05), and an enhanced sensitivity to (-)-isoprenaline in right atria. Finally, in left atria, the maximum Ca(2+)-induced increase in force of contraction was lower in all mdx compared to their age- and sex-matched C57 (P<0.05). In conclusion, age- and sex-associated changes in beta(1)-adrenoceptor function and responses to calcium were demonstrated in cardiac muscle from mdx mice, with a marked deterioration in beta(1)-adrenoceptor function occurring with aging in male mdx being particularly evident.

Aging↗
PubMed2000

Alterations of basement membrane in di-isopropanolnitrosamine-induced carcinogenesis of the rat thyroid gland: an immunohistochemical study.

Alterations of basement membrane (BM) in di-isopropanolnitrosamine (DIPN)-induced carcinogenesis of the rat thyroid gland were examined by means of immunohistochemical localization of collagen type IV (CN-IV), laminin (LN), and fibronectin (FN) in prenodular and nodular thyroid lesions, correlating with the morphogenesis and proliferative activity of these lesions. Adult male rats of the Wistar strain were injected s.c. in the back with DIPN, and the thyroid glands were removed at the 15th and 30th week of treatment. Each of 133 thyroid lesions was histochemically analyzed. The follicular epithelial BM as revealed by CN-IV and LN was discontinued or completely lost during the progression of thyroid lesions from pre-nodular to nodular lesions and finally overt carcinomas. At the same time, the BM of vascular endothelial cells demonstrated a loss of dense capillary networks of follicles, a sinusoidal dilatation and, predominantly in carcinomas, development of interstitial-type blood vessels. However, FN, which was hardly stained in the normal thyroid tissue, was remarkably deposited in the interstitium of invasive carcinomas. These observations strongly suggested that alterations of BM structure play a key role in the morphogenesis of rat thyroid tumors, and that the expression of FN is an important step in the invasive growth of thyroid tumors.

Animals↗