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Biomedical subjects

Li Zhu

Publications and source records attributed to Li Zhu.

At least 109 records · Page 6Linked to original sources
PubMed2004

Sentinel lymph node biopsy or detection of micrometastasis in bone marrow: which might be an alternative to axillary lymph node dissection in breast cancer patients?

Axillary lymph node status has limited prognostic significance in breast cancer patients and much improvement can be made. Sentinel lymph node biopsy is emerging as an alternative to axillary lymph node dissection for staging, but its prognostic relevance is still uncertain. Detection of micrometastases in sentinel nodes and bone marrow may provide more information, but the clinical significance still needs to be confirmed by ongoing large trials. In this review, we focus on the possibility of sentinel lymph node biopsy or detection of bone marrow micrometastasis replacing traditional axillary lymph node dissection.

Axilla↗
PubMed2004

Boundary events: contact-dependent and contact-facilitated signaling between platelets.

The theme of this review is that formation of a stable hemostatic plug requires adhesive interactions and signaling events that continue beyond the initial phases of platelet aggregation. These interactions and events are facilitated and, in some cases made possible, by the persistent close contacts between platelets that can only occur after the onset of aggregation. The molecules that are involved include integrins, cell adhesion molecules, receptor tyrosine kinases, and ligands that are either attached to or shed from the surface of activated platelets. The picture that emerges is one in which events after aggregation are nearly as complex as those that precede aggregation and the initiation of platelet plug formation.

Animals↗
PubMed2004

Rural-urban comparisons of nursing home residents with multiple sclerosis.

CONTEXT: Multiple sclerosis (MS) is the most common neurologic disease that disables younger adults, affecting as many as 350,000 Americans. PURPOSE: The objectives of this study are to develop profiles of nursing home residents with MS from rural areas and compare them to residents with MS who lived in urban areas, suburban areas, and large towns. METHODS: We analyzed all admission assessments for residents with MS (13,357 assessments) in the Minimum Data Set between June 23, 1998, and December 31, 2000, that also had the resident's ZIP code of primary residence before admission. FINDINGS: Urban and rural comparisons of residents with MS demonstrate a range of significant demographic differences. Significantly greater proportions of MS residents from rural areas exhibited a sense of initiative or involvement in activities of the nursing facility compared with residents with MS from urban and suburban areas. The differences in the utilization of physical and occupational therapies were striking, with MS residents from rural areas averaging significantly fewer minutes of these therapies. We also found that MS residents from rural areas averaged fewer minutes of psychological therapy in the nursing facility and also were less likely to have seen a licensed mental health specialist than MS residents from urban areas. CONCLUSIONS: Nursing home residents with MS from rural areas receive fewer therapies and less mental health care than residents with MS from other areas.

Female↗
PubMed2004

Urban/rural differences in decision making and the use of advance directives among nursing home residents at admission.

CONTEXT: Advance directives promote patient autonomy and encourage greater awareness of final care options while reducing physician and family uncertainty regarding patient preferences. PURPOSE: To investigate differences in decision making authority and the use of advance directives among nursing home residents admitted from urban and rural areas. METHODS: A total of 551,208 admission assessments in the Minimum Data Set were analyzed for all residents admitted to a nursing facility in 2001. Using the Rural Urban Commuting Areas (RUCA) methodology and ZIP code of primary residence before admission, these residents were classified into 4 urban/rural areas. FINDINGS: Residents from rural areas were significantly more likely to have executed a durable power of attorney for health care or for financial decisions than residents admitted from the other areas, with the largest differences observed between residents admitted from urban and rural areas. Almost 6 residents in 10 from urban areas had no advance directives in place at admission compared with only 4 residents in 10 admitted from rural areas. CONCLUSIONS: Health providers and social workers in both rural and urban areas should advise patients about the value of advance directives.

Advance Directives↗
PubMed2004

Study of trace elements in blood of thyroid disorder subjects before and after 131I therapy.

Both trace elements and thyroid hormones play essential roles in the human body. However, the previous results about the interaction between these two factors are often controversially given. In order to make clear the influence of thyroid hormones on the homeostasis of trace elements, we studied the variation of Fe, Cu, and Zn in erythrocyte and serum from patients with hyperthyroidism before and after 131I therapy by the X-ray fluorescence method. The different thyroid statuses of the patients before and after the therapy were assayed by determining the levels of thyroid hormones. The results showed that the homeostasis of metal ions in both serum and erythrocyte could be more or less influenced by the altered thyroid hormones. The serum Cu and Zn exhibited the significantly positive correlation with triiodothyronine (T3) and thyroxine (T4). Although the serum Cu and Zn differed significantly before and after the therapy, no difference was observed in the concentrations of Cu and Zn in erythrocyte, except that the erythrocyte Zn in the patients with hypothyroidism exhibited an obvious increase. Furthermore, the erythrocyte Zn showed a markedly negative correlation with T3.

Copper↗
PubMed2004

[Mandibular contour sculpture by osteotomy].

OBJECTIVE: To investigate the method for mandible osteotomy in order to make the mandible of various square face appear harmony. METHODS: According to different types of the mandible, mandible angle osteotomy was performed in combination with mandible edge, mandible half ring osteotomy or chin augmentation. RESULTS: A total of 312 cases have been treated since 1996. In this series, mandible angle and mandible edge osteotomy was performed in 200 cases; only mandible edge osteotomy in 23; mandible half ring osteotomy in 15, chin sharpening in 9, chin augmentation with autogenous bone implantation, in 32. Postoperative follow-up of 150 cases for 1-12 months showed that the satisfactory rate was 97%. CONCLUSION: Integrated mandible osteotomy can make the square face look natural and nice-looking.

Humans↗
PubMed2004

[Effects of the site and method of liposuction on differentiation of human preadipocytes].

OBJECTIVE: To illustrate the effects of the site and method of liposuction on differentiation of human preadipocytes. METHODS: Forty-two fatty samples were obtained with liposuction, which were then divided into four groups according to operation sites (abdomen, hip or extremity) and the methods (conventional negative-pressure or syringe method). Each sample was treated with collagenase I to release preadipocytes for in vitro culture. Affected by the differentiation-induced agents for 9 days or 28 days, the cultured adipocytes were stained with Nile red and observed under a fluorescent microscope. The differentiation rates were examined with flow cytometric analysis and the quantity of intracytoplasmic lipids was determined with oil red O staining. The results were analyzed with independent samples t-test (Mann-Whitney) using SPSS 10.0. RESULTS: There was no statistical difference in differentiation at the 9th day or 28th day among the preadipocytes obtained from the abdomen, hip or extremity with the negative-pressure method. The preadipocytes from the abdomen differentiated more at the 28th day than the 9th day (P < 0.05), which was not observed in the hip or the extremity. The preadipocytes obtained from the abdomen with the negative-pressure method differentiated more than those with the syringe method (P < 0.05). CONCLUSION: No essential difference was found in preadipocyte differentiation among the liposuction sites, while the abdomen might have some superiority. The negative-pressure method of liposuction is the first option in future research of tissue engineering. The flow cytometric analysis is a convenient way to study preadipocyte differentiation.

Abdomen↗
PubMed2004

[The gene expression of Th1/Th2 cytokines and its role in hypopharyngeal carcinoma].

OBJECTIVE: To observe the mRNA expression of Th1/Th2 cytokines in hypopharyngeal neoplasms and to explore the pathogenesis of it. METHOD: The gene expression of Th1/Th2 cytokines in patients with hypopharyngeal neoplasms was detected by RT-PCR. RESULT: The cytokines expression of Th2 was significantly stronger than Th1 in tissue of hypopharyngeal carcinoma. CONCLUSION: The dominant expression of Th2 cytokines in hypopharyngeal neoplasms may inhibit the human immunity and enhance the growth and metastasis of hypopharyngeal carcinoma.

Aged↗
PubMed2004

CDNA cloning of a short isoform of human liver NADP (H) -dependent retinol dehydrogenase/reductase and analysis of its characteristics.

In this report we found a new short PCR product when we amplified a 635 bp of NRDR fragment by RT-PCR. With 3'-Race and 5'-Race,we obtained two full-length cDNA sequences from human liver tissue,one 1 261 bp NRDR cDNA,another 1 003 bp NRDR isoform (NRDRiso,GenBank accession number:AY071856). The NRDR gene comprises eight exons and seven introns. The NRDRiso cDNA is produced by alternative splicing of NRDR cDNA, with the removal of 4, 5, 6 exons composed of consecutive 258 bp. The open reading frames of the NRDRiso cDNA predict a single polypeptide of 174 amino acids with the calculated minimum molecular mass of 18.6 kDa.

Alcohol Oxidoreductases↗
PubMed2004

[An experimental study on the repair mechanism after pulmonary embolism].

OBJECTIVE: To study the role of basic fibroblast growth factor (bFGF) and small vascular density in the repair mechanism after pulmonary embolism (PE). METHODS: After peripheral pulmonary arteries had been embolized, 8 dogs were killed 1, 7, 14, and 28 days after embolization. One piece of tissue was taken from the region embolized and unembolized respectively, then HE staining and immunohistochemical staining were performed. The pathological change of the lung, changes of small vascular density and expression of bFGF were observed, and were compared between regions embolized and unembolized at different time points. RESULTS: (1) The course of pathological change during the pulmonary embolism period. (2) The bFGF was increased from 1st day to 14th day after PE (1st day: chi(2) = 44.335, 7th day: chi(2) = 71.911, 14th day: chi(2) = 84.460; P < 0.01), and decreased to normal on 28th day (chi(2) = 2.961, P > 0.05). (3) Small vascular density in embolized region (4.56 +/- 0.50) showed no statistical difference from that of unembolized region (4.11 +/- 0.76) on 1st day (P > 0.05), while it (7th day: 10.17 +/- 1.08, 14th day: 10.54 +/- 0.93, 28th day: 11.47 +/- 1.11) was significantly higher than that of unembolized region (7th day: 6.17 +/- 0.90, 14th day: 7.55 +/- 1.19, 28th day: 7.03 +/- 1.24) after embolized 7, 14, 28 days (P < 0.05). CONCLUSIONS: After PE, with increased expression of bFGF in embolized region, the formation of collateral arteries between pulmonary artery system and bronchial artery system is promoted, and absorption of the transuded blood cells and fluid is accelerated. This mechanism may be important in prevent pulmonary infarction.

Animals↗
PubMed2004

[Sequencing and bioinformatic analysis of NRDRiso cDNA].

This study describes the cDNA sequencing and the bioinformatic analysis of a novel NADP(H)-dependent retinol dehydrogenase/reductases isoform (NRDRiso). Based upon the concensus sequences of human and mouse NRDR coding region, we have identified a short 377 bp RT-PCR product from human liver tissue. The cDNA sequence of a NRDR isoform was then isolated using RACE approach and its sequence was analysed. The full-length cDNA is 1,003bp in length and was submitted to GenBank as NADP-dependent retinol dehydrogenase/reductase short isoform (NRDRiso). The open reading frames of NRDRiso cDNA is 525 bp.

Alcohol Oxidoreductases↗
PubMed2003

EBV-induced molecule 1 ligand chemokine (ELC/CCL19) promotes IFN-gamma-dependent antitumor responses in a lung cancer model.

The antitumor efficacy of EBV-induced molecule 1 ligand CC chemokine (ELC/CCL19) was evaluated in a murine lung cancer model. The ability of ELC/CCL19 to chemoattract both dendritic cells and T lymphocytes formed the rationale for this study. Compared with diluent-treated tumor-bearing mice, intratumoral injection of recombinant ELC/CCL19 led to significant systemic reduction in tumor volumes (p < 0.01). ELC/CCL19-treated mice exhibited an increased influx of CD4 and CD8 T cell subsets as well as dendritic cells at the tumor sites. These cell infiltrates were accompanied by increases in IFN-gamma, MIG/CXCL9, IP-10/CXCL10, GM-CSF, and IL-12 but a concomitant decrease in the immunosuppressive molecules PGE(2) and TGFbeta. Transfer of T lymphocytes from ELC/CCL19 treated tumor-bearing mice conferred the antitumor therapeutic efficacy of ELC/CCL19 to naive mice. ELC/CCL19 treated tumor-bearing mice showed enhanced frequency of tumor specific T lymphocytes secreting IFN-gamma. In vivo depletion of IFN-gamma, MIG/CXCL9, or IP-10/CXCL10 significantly reduced the antitumor efficacy of ELC/CCL19. These findings provide a strong rationale for further evaluation of ELC/CCL19 in tumor immunity and its use in cancer immunotherapy.

Adoptive Transfer↗
PubMed2003

Celecoxib modulates the capacity for prostaglandin E2 and interleukin-10 production in alveolar macrophages from active smokers.

PURPOSE: Preclinical data suggest that the cyclooxygenase (COX)-2/prostaglandin (PG) E2 signaling pathway plays an essential role in conferring the malignant phenotype in non-small cell lung cancer. We hypothesized that treatment with oral celecoxib, a selective COX-2 inhibitor, would favorably alter biomarkers of lung cancer risk. This study evaluated the feasibility of COX-2 inhibition as a form of chemoprevention for lung cancer. EXPERIMENTAL DESIGN: Heavy active smokers were enrolled into a pilot study and treated with celecoxib. Bronchoscopy with bronchoalveolar lavage was performed both before and after 1 month of celecoxib treatment to recover alveolar macrophages (AMs) and lining fluid for study. After harvest, AMs were immediately stimulated in vitro with the calcium ionophore A23187. AMs obtained from smokers before treatment and from nonsmoking control subjects were also cultured overnight with SC58236, a selective COX-2 inhibitor, with or without lipopolysaccharide stimulation. RESULTS: Treatment with celecoxib significantly reduced calcium ionophore-stimulated PGE2 production from AMs recovered from smokers. AMs recovered from smokers, but not nonsmokers, were primed to produce high levels of PGE2 and interleukin (IL-10) when stimulated with lipopolysaccharide, and SC58236 significantly abrogated the production of these factors. Moreover, both plasma and bronchoalveolar lavage fluid obtained from treated subjects significantly reduced the production of PGE2 that resulted when a lung cancer cell line, A549, was stimulated with IL-1beta or A23187. CONCLUSIONS: Our findings suggest that oral celecoxib is capable of inhibiting the overproduction of PGE2, as well as modulating the production of IL-10 in the lung microenvironment in individuals at risk for lung cancer.

Aged↗
PubMed2003

Small angle X-ray scattering study of the yeast prion Ure2p.

The GdmCl-induced equilibrium unfolding and dissociation of the dimeric yeast prion protein Ure2, and its prion domain deletion mutants Delta 15-42Ure2 and 90Ure2, was studied by small angle X-ray scattering (SAXS) using synchrotron radiation and by chemical cross-linking with dithiobis(succinimidyl propionate) (DTSP). The native state is globular and predominantly dimeric prior to the onset of unfolding. R(g) values of 32 and 45A were obtained for the native and 5M GdmCl denatured states of Delta 15-42Ure2, respectively; the corresponding values for 90Ure2 were 2-3A lower. SAXS suggests residual structure in the 4M GdmCl denatured state and chemical cross-linking detects persistence of dimeric structure under these conditions. Hexamers consisting of globular subunits could be detected by SAXS at high protein concentration under partially denaturing conditions. The increased tendency of partially folded states to form small oligomers points to a mechanism for prion formation.

Binding Sites↗
PubMed2003

Amyloid nucleation and hierarchical assembly of Ure2p fibrils. Role of asparagine/glutamine repeat and nonrepeat regions of the prion domains.

The yeast prion protein Ure2 forms amyloid-like filaments in vivo and in vitro. This ability depends on the N-terminal prion domain, which contains Asn/Gln repeats, a motif thought to cause human disease by forming stable protein aggregates. The Asn/Gln region of the Ure2p prion domain extends to residue 89, but residues 15-42 represent an island of "normal" random sequence, which is highly conserved in related species and is relatively hydrophobic. We compare the time course of structural changes monitored by thioflavin T (ThT) binding fluorescence and atomic force microscopy for Ure2 and a series of prion domain mutants under a range of conditions. Atomic force microscopy height images at successive time points during a single growth experiment showed the sequential appearance of at least four fibril types that could be readily differentiated by height (5, 8, 12, or 9 nm), morphology (twisted or smooth), and/or time of appearance (early or late in the plateau phase of ThT binding). The Ure2 dimer (h = 2.6 +/- 0.5 nm) and granular particles corresponding to higher order oligomers (h = 4-12 nm) could also be detected. The mutants 15Ure2 and Delta 15-42Ure2 showed the same time-dependent variation in fibril types but with an increased lag time detected by ThT binding compared with wild-type Ure2. In addition, Delta 15-42Ure2 showed reduced binding to ThT. The results imply a role of the conserved region in both amyloid nucleation and formation of the binding surface recognized by ThT. Further, Ure2 amyloid formation is a multistep process via a series of fibrillar intermediates.

Amino Acid Motifs↗