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Biomedical subjects

T H Cheung

Publications and source records attributed to T H Cheung.

48 records · Page 3Linked to original sources
PubMed1995

Prevalence and significance of HER-2/neu amplification in epithelial ovarian cancer.

Amplification of the HER-2/neu oncogene was assessed in 80 cases of epithelial ovarian tumors using differential polymerase chain reaction. HER-2/neu gene was amplified in 22 of 46 invasive cancers (48%) and in 5 of 34 borderline cancers (15%), but none of the 20 specimens of normal ovaries showed amplification. THis difference is statistically significant (p = 0.00004). The incidence of HER-2/neu amplification in late stage (III-IV, 77%) was significantly higher than that in early stage (I-II, 21%) in invasive epithelial carcinoma (p = 0.0004). There was no correlation between HER-2/neu amplification and cell type or grade of tumor. In cases of ovarian tumors of borderline malignant potential, the amplification of HER-2/neu was not correlated with clinicopathologic features. Follow-up with a mean of 22 months (6-50 months) was available for 39 cases of invasive ovarian cancers and all 34 borderline ovarian cancers. The incidence of HER-2/neu amplification in the invasive cancer and borderline cancer patients who were alive with disease was 50 and 50%, and is not statistically different from that in the patients who were alive with no evidence of disease (p = 0.662 and 0.345, respectively). The incidence of amplification in the invasive cancers of patients who died of the disease (86%) was higher than that in the patients who were still alive (44%), but the difference is not statistically significant (p = 0.175). This study supports the association of HER-2/neu amplification with progression of invasive ovarian cancer. It also suggests that HER-2/neu amplification may be an adjunctive prognostic factor of invasive epithelial ovarian cancer, shown to be associated with an unfavorable clinical course. In addition, HER-2/neu amplification occurs relatively infrequently in early invasive and borderline ovarian cancers, making it unlikely that such amplification is a general early event in ovarian carcinogenesis.

Base Sequence↗
PubMed1994

Ki67 and AgNORs staining in squamous cell carcinoma of the cervix: a comparison.

Ki67 immunostaining was performed on 48 cases of squamous cell carcinoma of the cervix and AgNOR silver staining on 29 cases. There was no correlation between the clinical stage of the tumor and the two methods of staining but both methods correlated with histological grade. There was no correlation between the two methods of staining in 17 case where they were done on adjacent blocks of tumor tissue. High Ki67 score but not high AgNOR count was significantly associated with early recurrence.

Carcinoma, Squamous Cell↗
PubMed1991

Puerperal haematomas.

Forty-seven out of 31,628 patients delivered in our hospital over the past 5 years developed puerperal genital tract haematomas. Four cases, representing different types of haematoma which required different managements, were presented to illustrate this problem. A literature review was also made.

Adult↗
PubMed1990

Macrosomic babies.

A review of 3,241 delivery records was made to study the obstetrics and the neonatal outcomes of 129 macrosomic (greater than or equal to 4,000g) babies. They were found to have a nearly 6-fold increase in the neonatal morbidity rate compared with normosomic babies. The emergency Caesarean section rate for nulliparas and parous women with macrosomic babies was 41.3% and 8.4% respectively. Among macrosomic babies, shoulder dystocia was not associated with maternal stature, induction of labour, use of oxytocin or abnormal labour patterns, but was associated with instrumental delivery. Macrosomic babies with shoulder dystocia after instrumental delivery had a higher neonatal morbidity rate than those delivered spontaneously.

Birth Injuries↗
PubMed1988

Influence of exercise on the immune function of rats of various ages.

The purpose of this study was to determine whether exercise could prevent the age-related decline in mitogenesis, which has been well documented in rats, mice, and humans. At 1, 6, 12, and 18 mo of age, male Fischer F344 rats were subjected daily to swimming exercise for 6 mo. At the end of the 6-mo training period, spleen lymphocytes were isolated from the exercised rats and from age-matched sedentary controls. The induction of lymphocyte proliferation was measured with the mitogens concanavalin A (ConA) and lipopolysaccharide (LPS). In addition, the ability of the lymphocytes to produce interleukin 2 (IL 2) in response to ConA induction was measured. ConA- and LPS-induced proliferation decreased 41-63% between 7 and 25 mo of age in both exercised and sedentary control rats. ConA-induced IL 2 production decreased 42 and 62% between 7 and 25 mo of age for exercised and sedentary control rats, respectively. Although the age-related decline in mitogen-induced proliferation and IL 2 production was smaller in exercised rats, this was due to a lower level of mitogenesis and IL 2 production in lymphocytes from young exercised rats. Exercise resulted in a significant decrease (23-32%) in mitogen-induced lymphocyte proliferation and IL-2 production in 7-mo-old exercised rats compared with 7-mo-old sedentary rats. However, in the 18- and 24-mo-old rats, mitogen-induced lymphocyte proliferation and IL 2 production was not significantly different between exercised and sedentary control rats.

Aging↗
PubMedDate not supplied

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.

Diagnosis, Differential↗
PubMedDate not supplied

Gene expression pattern associated with radiotherapy sensitivity in cervical cancer.

UNLABELLED: 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.

Adult↗
PubMedDate not supplied

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.

Adult↗
PubMedDate not supplied

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.

Adult↗