How Students' Motivation and Learning Experience Affect Their Service-Learning Outcomes: A Structural Equation Modeling Analysis

Guided by the expectancy-value theory of motivation in learning, we explored the causal relationship between students' learning experiences, motivation, and cognitive learning outcome in academic service-learning. Based on a sample of 2,056 college students from a university in Hong Kong, the findings affirm that learning experiences and motivation are key factors determining cognitive learning outcome, affording a better understanding of student learning behavior and the impact in service-learning. This research provides an insight into the impact of motivation and learning experiences on students' cognitive learning outcome while engaging in academic service-learning. This not only can discover the intermediate factors of the learning process but also provides insights to educators on how to enhance their teaching pedagogy.

Dysregulation of microRNA-204 mediates migration and invasion of endometrial cancer by regulating FOXC1

MicroRNAs (miRNAs) regulate mRNA stability and protein expression, and certain miRNAs have been demonstrated to act either as oncogenes or tumor suppressors. Differential miRNA expression signatures have been documented in many human cancers but the role of miRNAs in endometrioid endometrial cancer (EEC) remains poorly understood. This study identifies significantly dysregulated miRNAs of EEC cells, and characterizes their impact on the malignant phenotype. We studied the expression of 365 human miRNAs using Taqman low density arrays in EECs and normal endometriums. Candidate differentially expressed miRNAs were validated by quantitative real-time PCR. Expression of highly dysregulated miRNAs was examined in vitro through the effect of anti-/pre-miRNA transfection on the malignant phenotype. We identified 16 significantly dysregulated miRNAs in EEC and 7 of these are novel findings with respect to EEC. Antagonizing the function of miR-7, miR-194 and miR-449b, or overexpressing miR-204, repressed migration, invasion and extracellular matrix-adhesion in HEC1A endometrial cancer cells. FOXC1 was determined as a target gene of miR-204, and two binding sites in the 3'-untranslated region were validated by dual luciferase reporter assay. FOXC1 expression was inversely related to miR-204 expression in EEC. Functional analysis revealed the involvement of FOXC1 in migration and invasion of HEC1A cells. Our results present dysfunctional miRNAs in endometrial cancer and identify a crucial role for miR-204-FOXC1 interaction in endometrial cancer progression. This miRNA signature offers a potential biomarker for predicting EEC outcomes, and targeting of these cancer progression- and metastasis-related miRNAs offers a novel potential therapeutic strategy for the disease.

Patients with malignant or pre-malignant cervical lesion have increased risk of becoming hepatitis B carrier

Human Papillomavirus (HPV) and Hepatitis B virus (HBV) are known aetiology of cervical and hepatocellular carcinoma, respectively. Both diseases share a similar clinical course, that is, the vast majority of those infected by these two viruses can eradicate the viruses spontaneously. A small sub-group who fails to clear the virus becomes chronic carrier and can progress to carcinoma many years later. We postulated that patients with pre-malignant or malignant cervical lesion are at increased risk of becoming chronic HBV carrier if infected, which may be attributed to inherent immunological deficiency against viral infection. We tested HBV carrier status from 288 patients with cervical carcinoma, 242 patients with high grade cervical intra-epithelial neoplasia (CIN) and 311 women with neither of the above conditions as control subjects. The HBV carrier rate in the Cancer Group, CIN Group and Control Group was 21.4%, 24.1% and 10.6%. The carrier rate was significantly higher in both the Cancer Group (p<0.01) and the CIN Group (p<0.01), compared to the Control Group. Our study suggests that a common immunological mechanism is involved in eradication of HBV and HPV infections and inherent immuno-deficiency might lead to an association of HBV carrier status with cervical carcinoma. Further studies are needed to confirm our findings and delineate the mechanism involved.

Is aortic lymphadenectomy necessary in the management of endometrial carcinoma?

OBJECTIVE

To evaluate the role of aortic lymphadenectomy in the management of endometrial carcinoma.

METHODS

Clinical notes of 163 patients with endometrial carcinoma were reviewed. All patients had peritoneal cytology, total abdominal hysterectomy, bilateral salpingo-oophorectomy and pelvic lymphadenectomy with or without aortic lymphadenectomy.

RESULTS

Seventy-five (46.0%) patients had pelvic lymphadenectomy alone whereas 88 (54.0%) had both pelvic and aortic lymphadenectomy. Thirty-five (21.5%) patients had nodal metastases with positive pelvic and aortic nodes in 26 (16.0%) and 24 (27.3%) patients, respectively. Isolated aortic metastases were found in 17 cases (19.3%). Among 35 patients with nodal metastases, recurrence developed in 15 (42.9%) patients and all except one died within five to 50 months. The remaining patients had a median disease-free period of 55 months (13-93 months). The recurrence rate was higher (63.6%) among patients with upper aortic lymph node metastases, and all those who recurred died of disease within seven to 28 months.

CONCLUSIONS

Our data suggest that aortic lymphadenectomy provides both diagnostic and therapeutic value in the management of endometrial carcinoma with high metastatic risk. After surgical removal and adjuvant radiotherapy, patients with nodal metastases achieved a better survival chance.

Gene expression pattern associated with radiotherapy sensitivity in cervical cancer

The objective of the present preliminary study was to determine if a difference in the pattern of gene expression exists between tumors that were subsequently found to be sensitive to radiotherapy and tumors found to be resistant to radiotherapy.

PATIENTS AND METHODS

A total of 16 patients with invasive squamous cell carcinoma of the uterine cervix were included in this study. All patients were treated with standardized radiotherapy alone. Ten of the tumors were clinically radiosensitive and six were radioresistant. Total RNA, extracted from tumor specimens obtained prior to treatment, was hybridized onto an oligonucleotide microarray with probe sets complementary to over 20,000 transcripts. The genes were first subjected to a statistical filter to identify genes with statistically significant differential expression levels between those that were radiosensitive and those that were radioresistant. A back-propagation neural network was then constructed to model the differences so that patterns could be easily identified.

RESULTS

Although a number of genes were found to express differentially between radiosensitive and radioresistant tumors; the 10 most discriminating genes were used to construct the model. Using the expressions from these 10 genes, we found that neural networks constructed from random subsets of the whole data were capable of predicting radiotherapy responses in the remaining subset, which appears stable within the dataset.

DISCUSSION

This study shows that such an approach has the potential to differentiate tumor radiosensitivity, although confirmation of such a pattern using other larger independent datasets is necessary before firm conclusions can be drawn.

Identification of molecular markers and signaling pathway in endometrial cancer in Hong Kong Chinese women by genome-wide gene expression profiling

Endometrial cancer is the third most common gynecologic malignancy and the ninth most common malignancy for females overall in Hong Kong. Approximately 80% or more of these cancers are endometrioid endometrial adenocarcinomas. The aim of this study was to reveal genes contributing to the development of endometrioid endometrial cancer, which may impact diagnosis, prognosis and treatment of the disease. Whole-genome gene expression analysis was completed for a set of 55 microdissected sporadic endometrioid endometrial adenocarcinomas and 29 microdissected normal endometrium specimens using the Affymetrix Human U133 Plus 2.0 oligonucleotide microarray. Selected genes of interest were validated by quantitative real-time-polymerase chain reaction (qRT-PCR). Pathway analysis was performed to reveal gene interactions involved in endometrial tumorigenesis. Unsupervised hierarchical clustering displayed a distinct separation between the endometrioid adenocarcinomas and normal endometrium samples. Supervised analysis identified 117 highly differentially regulated genes (>or=4.0-fold change), which distinguished the endometrial cancer specimens from normal endometrium. Twelve novel genes including DKK4, ZIC1, KIF1A, SAA2, LOC16378, ALPP2, CCL20, CXCL5, BST2, OLFM1, KLRC1 and MBC45780 were deregulated in the endometrial cancer, and further validated in an independent set of 56 cancer and 29 normal samples using qRT-PCR. In addition, 10 genes were differentially regulated in late-stage cancer, as compared to early-stage disease, and may be involved in tumor progression. Pathway analysis of the expression data from this tumor revealed an interconnected network consisting of 21 aberrantly regulated genes involved in angiogenesis, cell proliferation and chromosomal instability. The results of this study highlight the molecular features of endometrioid endometrial cancer and provide insight into the events underlying the development and progression of endometrioid endometrial cancer.

Prospective self-controlled study on prevention of hysteroscopic dissemination in endometrial carcinoma

Patients diagnosed to have endometrial carcinoma without prior hysteroscopic examination were recruited from March 2000 to August 2003. Normal saline was used to distend the uterine cavity during the hysteroscopic examination to look for endocervical spread before the definitive surgical treatment. We performed laparotomy, clamped both fallopian tubes, and collected peritoneal washing before the hysteroscopic examination was performed. Peritoneal washing was collected once more after the hysteroscopic examination. Hysteroscopic assessment was performed in 103 patients. Of them, 10 patients were excluded from the study due to previous history of tubal sterilization or blockage. The final analysis was confined to 93 patients. Positive peritoneal cytology was found in 10 (10.8%) patients and this finding was significantly related to the tumor grading (P = 0.023), adnexal involvement (P = 0.003), cervical invasion (P = 0.01), and the presence of peritoneal seedlings (P = 0.001). In five of the 10 patients with positive peritoneal cytology before the hysteroscopic examination, malignant cells could also be recovered in the peritoneal washing collected after the hysteroscopic examination. For patients with negative peritoneal cytology before hysteroscopy, none exhibited positive peritoneal cytology after the procedure. Our data suggested that complete occlusion of both fallopian tubes can effectively prevent the dissemination of endometrial malignant cells into the peritoneal cavity during hysteroscopy.

Protein profiling of cervical cancer by protein-biochips: proteomic scoring to discriminate cervical cancer from normal cervix

Analysis of multiple proteins is thought to be essential for establishment of signature proteomic patterns that may distinguish cancer from non-cancer. Surface-enhanced laser desorption/ionization (SELDI) is an affinity-based mass spectrometric method in which proteins of interest are selectively absorbed to a chemically modified surface on a biochip. This technology may provide protein profiling of a variety of biological specimens. In this study, we explored whether the protein biochip SELDI approach could differentiate cervical cancer from non-cancer cohorts. We screened protein profiles generated by SELDI in 62 cervical epithelial cell samples microdissected from 35 invasive cervical cancer and 27 age-matched normal cervix tissue specimens, respectively. The cell lysates of pure populations of cervical cells were applied onto Ciphergen ProteinChip WCX2 Arrays. Proteins bound to the chips were analyzed on a ProteinChip Reader Model PBS II. Derived proteomic patterns were converted to a simple proteomic scoring for distinguishing cancer from non-cancer cohorts. SELDI protein profiles of cell lysates from 20 cervical cancer and 15 normal cervix tissue specimens were used to train and develop a classification scoring system that used a seven-protein mass pattern. The training samples could be correctly discriminated. When a test set of 27 samples was used for evaluation of this scoring system to distinguish cervical cancer from non-cancer, a sensitivity of 87%, a specificity of 100%, a positive predictive value of 100%, and a negative predictive value of 86% for the test population were obtained. All seven proteins appeared to be down regulated in cervical cancer. The results from this study indicate that the proteomics approach of SELDI mass spectrometry, in combination with a simple scoring system, may distinguish cervical cancer from its normal counterpart. If this approach is also workable in the analysis of cervical exfoliated cell lysate, it might potentially be used in the early diagnosis of invasive cervical cancer. In addition, the identification of these specific proteins in cervical cancer may also facilitate the discovery of new cervical tumor marker(s).

The value of pelvic and para-aortic lymphadenectomy in endometrial cancer to avoid unnecessary radiotherapy

The case histories of 95 patients with endometrial carcinoma treated between July 1998 and December 2002 were reviewed. These patients were staged according to FIGO classification and included peritoneal cytology, total abdominal hysterectomy/bilateral salpingo-oophorectomy (TAHBSO), and pelvic with or without para-aortic lymphadenectomy. The FIGO surgical stages were as follow: IA, 9 (9.5%); IB, 35 (36.8%); IC, 16 (16.8%); IIB, 10 (10.5%); IIIA, 5 (5.3%); IIIB, 1 (1.1%); IIIC, 19 (20.0%). In addition to TAHBSO, 47 (49.5%) patients had pelvic lymphadenectomy whereas 48 (50.5%) had both pelvic and para-aortic lymphadenectomy. Nineteen (20.0%) of 95 patients had nodal metastases. Positive pelvic and para-aortic lymph nodes were found in 15 (15.8%) of 95 and 12 (25.0%) of 48 patients, respectively. According to the result of the lymphadenectomy, 19 (20.0%) patients had their surgical stage upgraded to stage IIIC and 61 (64.2%) patients had a change in their management plan. Twelve (12.6%) patients required extended field irradiation due to para-aortic nodal metastases and 49 (51.6%) patients with negative nodes avoided postoperative external radiotherapy. By defining the lymphatic spread via surgical staging, postoperative radiotherapy can be recommended to patients with nodal metastases, while it can be withheld from those patients with negative nodes, irrespective of the presence of risk factors.

Intravenous leiomyomatosis with atypical histologic features: a case report

Intravenous leiomyomatosis (IVL) is a rare smooth muscle tumor. We report a case of IVL with atypical histologic features, which did not respond to gonadotropin-releasing hormone agonists and could be only partially resected due to adherence to the vessel wall. Atypical histology may signify more aggressive behavior. IVL should always be considered when a patient presents with both uterine leiomyoma and venous thrombosis, and a high index of suspicion is crucial for early diagnosis. An adequate surgical preparation including venous graft or prosthetic reconstruction is essential as difficulty in removal may arise if the intravascular tumor adheres to the vessel wall.