Biomedical subjects

Yueju Li

Publications and source records attributed to Yueju Li.

7 recordsLinked to original sources

PubMed2006

Type-2 dominant cytokine gene expression following hepatic surgery.

BACKGROUND/PURPOSE: Hemorrhage and ischemic liver injuries associated with hepatic resection are thought to play a role in postoperative complications, possibly through altered cytokine production. The current study was performed to investigate the effects of hepatectomy on cytokine gene expression. METHODS: We collected blood preoperatively, at completion of operation, and on postoperative days 1 and 5 from ten patients undergoing hepatic resection. The peripheral blood mononuclear cells were evaluated with real-time quantitative reverse transcription-polymerase chain reaction (RT-PCR) for gene expression of interleukin-10 (IL-10), proinflammatory cytokines (interferon-gamma [IFNgamma], IL-15, tumor necrosis factor alpha [TNFalpha], and chemokines regulated on activation, normal T expressed and secreted [RANTES], macrophage inflammatory protein 1 alpha [MIP-1alpha], [MIP-1beta]). Wilcoxon Rank and paired t-tests were used for statistical analysis. RESULTS: Immediately following hepatectomy there was a significant (31.4 +/- 60.5-fold; P < 0.05) increase in IL-10 gene expression that was sustained until the first postoperative day. In contrast, there was a significant downregulation (38 +/- 71 eight fold lower than preoperative; P < 0.05) of IFNgamma gene expression on day 1. By postoperative day 5, the changes in gene transcript levels of both IL-10 and IFNgamma had returned to the preoperative baselines. This contrasting change in IL-10 and IFNgamma gene expression in response to hepatic resection was statistically significant (P = 0.02). CONCLUSIONS: Hepatectomy elicits an imbalance towards the immunosuppressive type-2 cytokine profile in the early postoperative period. Measurement of cytokine gene transcripts following hepatic resection may have predictive value for clinical outcome, and deserves further study.

Chemokines↗

PubMed2005

Use of quantitative real-time PCR (qRT-PCR) to measure cytokine transcription and viral load in murine cytomegalovirus infection.

A quantitative real-time PCR (qRT-PCR) assay was developed to measure cytokine transcription profiles and viral load during sub-clinical and clinical infection with murine cytomegalovirus (MCMV). Primers/fluorogenic probes specific for mouse cytokines and for the immediate early gene 1 (IE1) of MCMV were used to quantitate cytokine responses and viral load in various organs of MCMV infected mice. Increased mRNA levels of TNF-alpha, INF-gamma and IL-10 were detected in the spleens, lungs and livers of clinically infected mice at 5 days post-infection. Transcription of these cytokines was 2-5-fold lower (p=0.07 for each cytokine) in the spleens and 10-100-fold lower in the lungs (p=0.03 for INFgamma, not significant for IL-10 and TNFalpha) and livers (p<0.05 for each cytokine) of sub-clinically infected mice. Clinical MCMV infection induced high levels of IL-6 in the lungs and spleens of infected animals, while no significant transcription of IL-6 was detected in any organ during sub-clinical infection (p<0.05). The timing of peak amounts of INF-gamma, IL-10 and IL-6 observed in the spleens of clinically infected mice correlated with high viral loads in these organs. Cytokine expression rose in the salivary glands later, at day 15, corresponding to the increase in salivary gland viral load. The qRT-PCR demonstrates that infection with MCMV induces an organ-specific cytokine response characterized by the production of TNF-alpha, INF-gamma, IL-6 and IL-10 which correlates with severity of the disease (sub-clinical versus clinical) and with viral load. In summary, qRT-PCR is a sensitive and accurate method to study MCMV infection and host responses to the virus.

Animals↗

PubMed2004

Survival and cell cycle kinetics of human prostate cancer cell lines after single- and multifraction exposures to ionizing radiation.

PURPOSE: Fractionated radiation therapy is frequently used to treat prostate cancer with an underlying assumption that each daily dose of ionizing radiation (IR) results in equal cell killing. We used three human prostate cancer cell lines to evaluate how survival after a single 2-Gy dose may predict responses after daily repeated 2-Gy exposures. METHODS AND MATERIALS: LNCaP, CWR22R, and PC3 cells were used in these studies. Survival after IR exposures was assessed using clonogenic assays and cell cycle responses were determined by flow cytometry. RESULTS: The experimentally determined multifraction survival differed significantly from that predicted from their single-dose SF2. LNCaP and CWR22R cells showed lower than predicted survivals; PC3 cells exhibited greater than predicted survival. Daily IR exposures resulted in changes in the cell cycle distributions beyond those caused by a single exposure to IR. CONCLUSIONS: Our results show that in these prostate cancer cells: (1) survival after a clinically relevant dose of IR does not predict survival after multifraction IR, (2) cell cycle responses after a single 2 Gy dose can differ from those that occur when cells receive daily 2 Gy doses, and (3) some cell cycle changes that result from fractionated IR may predict their ultimate survival responses from such treatment.

Cell Cycle↗

PubMed2004

Effects of a genistein-rich extract on PSA levels in men with a history of prostate cancer.

OBJECTIVES: To determine whether supplemental amounts of soy isoflavone (genistein-rich extract) would lower prostate-specific antigen (PSA) levels more than 50% in patients with prostate cancer (CaP). METHODS: A total of 62 men (mean age 73.6 years, range 61.4 to 89.3) with histologically proven CaP who had two consecutive elevated PSA readings were accrued during a 13-month period. An open-label pilot study was conducted for 6 months in which the patients took capsules containing the genistein-rich extract three times daily by mouth. The subjects were in one of five groups: after radical retropubic prostatectomy (n = 9), after radiotherapy (n = 17), after both radical retropubic prostatectomy and radiotherapy (n = 6), off-cycle during hormonal therapy (intermittent hormones; n = 14), or active surveillance (n = 16). The primary endpoint for the trial was a 50% reduction in the PSA level at 6 months compared with before treatment. RESULTS: Of the 62 men enrolled, 52 were available for evaluation at 6 months. Three patients discontinued because of adverse events (diarrhea) and seven because of personal choice. One of 52 patients had a more than 50% reduction in the PSA level (1.9% response, 95% confidence interval 0.1% to 10.3%). An additional 7 patients had PSA reductions that were less than 50%. All 8 patients with lower PSA levels at 6 months were in the active surveillance (watchful waiting) treatment subgroup. Repeated measure regression models allowing for correlation between initial levels and change also indicated a decline in PSA in this group compared with other groups: 0 of 52 had a complete response, 9 (17%) had a partial response, 8 (15%) had stable disease, and 35 (67%) had disease progression. In the 9 patients with a partial response, 6 had pathologic findings that were moderately differentiated, 2 had well-differentiated findings, and 1 had poorly differentiated findings. Therefore, the response in this group of patients did not appear to be driven by the Gleason score. The total testosterone level was lowered in one of the patients responding, but it was higher in five others. CONCLUSIONS: A genistein-rich extract as the sole treatment for CaP did not reduce PSA levels by 50% or more in 51 of 52 subjects. Thus, it does not appear to be an effective treatment for CaP when given alone. However, 8 of 13 evaluated patients in the active surveillance group had either no rise or a decline in PSA levels of less than 50%. More study is warranted for those choosing active surveillance.

Adenocarcinoma↗

PubMed2002

Does HER2/neu expression provide prognostic information in patients with advanced urothelial carcinoma?

BACKGROUND: Muscle-invasive urothelial carcinoma of the bladder is a highly lethal malignancy, particularly in the setting of locally advanced or metastatic disease. Prior reports of HER2/neu (c-erbB-2 or HER2) expression in bladder carcinoma have been mixed; therefore, its value in predicting metastasis or response to therapy has not been established in this tumor type. Thus, the authors evaluated a possible correlation between HER2 expression in patients with high-grade, muscle-invasive urothelial carcinoma of the bladder and outcome in patients who received paclitaxel-based chemotherapy. METHODS: Archival tumor tissues from patients with advanced urothelial carcinoma who were enrolled on two clinical trials of paclitaxel-based chemotherapy regimens were analyzed for HER2/neu expression by immunohistochemistry (IHC). The authors correlated HER2 expression by IHC with clinical outcomes, such as response rate, progression free survival, and overall survival, using univariate analysis. RESULTS: Thirty-nine tumor specimens were assessed for HER2 expression, most of which (70%) were collected from patients with metastatic disease. All were high-grade urothelial carcinomas (transitional cell carcinomas, Grade 3). Strong HER2 expression (2+/3+) was seen in 28 patients (71%). Patients with responding disease had an HER2 expression rate of 78%, similar to the rate seen in patients with stable disease (75%). In contrast, patients with progressive disease had an HER2 expression rate of 50%, although this difference did not reach statistical significance. However, univariate analysis showed that increased HER2 expression predicted an improvement in progression free and overall survival. When HER2 status was used as a dichotomous variable, tumors with positive HER2 expression did not have any association with response or with progression free survival; however, positive HER2 status was associated significantly with a decreased risk of death (P = 0.03). CONCLUSIONS: This study of HER2 expression in bladder carcinoma focused on patients who were treated prospectively in a standardized fashion, unlike prior studies that have evaluated banked, archival specimens. The authors confirmed the findings of others that high-grade, muscle-invasive urothelial carcinoma of the bladder has a significant rate of HER2 expression (71%). However, contrary to other reports, the current study found that HER2 expression in the context of paclitaxel-based chemotherapy decreased the risk of death significantly. Further research is warranted on the possible association of HER2 expression with chemosensitivitiy in urothelial carcinoma as well as the efficacy of HER2-targeted therapies (such as trastuzumab) for patients with high-grade, muscle-invasive urothelial carcinoma of the bladder.

Adult↗

PubMed2002

Statistical methods for analysis of time course gene expression data.

Since many biological systems or regulatory networks are dynamic systems, gene expression levels measured over different time points during a given biological process can often provide more insights about the underlying system. These gene expression data measured over time are often called the time-course gene expression data. One unique feature of such data is the time dependency of the gene expression levels for a given gene at different times or between two different genes. Statistical analysis needs to account for such dependency in order to make valid inferences. This paper presents several statistical methods for analyzing such time-course gene expression data, including the time-lagged correlation coefficient for analyzing the relationship between genes, a mixed-effects model with splines for clustering genes and for estimating missing gene expression data, and a new method for aligning gene expression profiles obtained under two experimental conditions and for identifying gene clusters that show significant changes between two experimental conditions. We used the yeast cell cycle gene expression data sets to illustrate these methods and obtained the biologically meaningful conclusions from these analyses.

Cell Cycle Proteins↗

PubMedDate not supplied

An evaluation of barriers to accrual in the era of legislation requiring insurance coverage of cancer clinical trial costs in California.

PURPOSE: Clinical trials are essential to improve cancer therapy, but only 3% of newly diagnosed adult cancer patients enroll annually. We previously conducted a prospective analysis of factors affecting trial accrual at the UC Davis Cancer Center between 1997 and 2000. It was found that the accrual rate was 14% and that patients with private insurance were significantly less likely than patients with government insurance to enroll, suggesting that fear of insurance denial was a barrier. In 2002, a new California law (SB37) required insurers to reimburse routine costs of care for cancer trials. METHODS: To assess the impact of SB37 on accrual, we repeated our study using the same sur vey instrument. Oncologists seeing new patients at the UC Davis Cancer Center from August to November 2002 completed questionnaires that inquired about patient characteristics and eligibility, protocol availability, and patient willingness to participate. RESULTS: Physicians considered clinical trials for 55% (118/216) of patients, but trials were available for only 53% (62/118). Eligibility criteria were met by 82% (51/62). Of these, 69% (35/51) agreed to participate (vs 51% previously). No patient declined to participate because of insurance limitations (vs 8% previously). Furthermore, insurance type was no longer a significant factor in determining whether patients would enroll. This suggests that although the overall rate of accrual is only slightly increased after passage of SB37, patients may be more willing to enroll. Efforts to increase participation must include enhancing physician and patient awareness of SB37.

Adolescent↗