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D Y Chang

Publications and source records attributed to D Y Chang.

At least 19 recordsLinked to original sources
PubMed1998

Prognostic factors of primary adenocarcinoma of the uterine cervix.

OBJECTIVE: To determine which clinicopathological factors influence the prognosis of cervical adenocarcinoma. METHODS: Three hundred and two cases of primary adenocarcinoma of the uterine cervix, treated between 1977 and 1994, were studied retrospectively. Clinical data and pathological findings with respect to primary therapy were reviewed and evaluated. RESULTS: The 5-year survival rates for stages I, II, and III/IV were 75.9, 62.9, and 25.1%, respectively. International Federation of Gynecology and Obstetrics stage (P < 0. 0001), cell type (P = 0.0176), tumor grade (P = 0.023), lymph node status (P = 0.018), and bulky tumor (P = 0.007) were found to be independent factors using the stepwise Cox proportional hazards model. Old age (P = 0.0581), presence of hypertension (P = 0.46), diabetes mellitus (P = 0.18), obesity (P = 0.15), and oral contraceptive use (P = 0.42) were not found to adversely influence survival rates for cervical adenocarcinoma after adjusting for other covariates. Adenosquamous adenocarcinoma had a better prognosis than endocervical columnar cell adenocarcinoma in stages I and II (P = 0. 0235). Also, in cervical adenocarcinoma's early stages, multivariate modeling revealed that chances of survival were significantly better for patients treated by radical surgery than for patients treated by radiation therapy (P < 0.001). CONCLUSIONS: Survival rates for cervical adenocarcinoma were significantly influenced by stage, histologic subtype, tumor grade, the presence of a positive lymph node, and tumor size. Although a randomized prospective study is needed, our data imply that radical surgery may be considered a better primary modality of treatment than radiation therapy for the early stages of cervical adenocarcinoma. Further, the presence of hypertension, diabetes mellitus, or obesity may not adversely influence survival rates.

Adenocarcinoma↗
PubMed1997

A highly conserved nucleotide in the Alu domain of SRP RNA mediates translation arrest through high affinity binding to SRP9/14.

Binding of the signal recognition particle (SRP) to signal sequences during translation leads to an inhibition of polypeptide elongation known as translation arrest. The arrest activity is mediated by a discrete domain comprised of the Alu portion of SRP RNA and a 9 and 14 kDa polypeptide heterodimer (SRP9/14). Although very few nucleotides in SRP RNA are conserved throughout evolution, the remarkable conservation of G24, which resides in the region of SRP9/14 interaction, suggests that it is essential for translation arrest. To understand the functional significance of the G24 residue, we made single base substitutions in SRP RNA at this position and analyzed the ability of the mutants to bind SRP9/14 and to reconstitute functional SRPs. Mutation of G24 to C reduced binding to SRP9/14 by at least 50-fold, whereas mutation to A and U reduced binding approximately 2- and 5-fold respectively. The mutant RNAs could nevertheless assemble into SRPs at high subunit concentrations. SRPs reconstituted with mutant RNAs were not significantly defective in translation arrest assays, indicating that the conserved guanosine does not interact directly with the translational machinery. Taken together, these results demonstrate that G24 plays an important role in the translation arrest function of SRP by mediating high affinity binding of SRP9/14.

Base Sequence↗
PubMed1997

Prevalence of single and multiple infection with human papillomaviruses in various grades of cervical neoplasia.

Evaluation of human papillomavirus (HPV) diversity in various grades of cervical lesions is helpful for understanding the characteristics of HPV infection in the pathogenesis of cervical neoplasia. A total of 227 women with normal cervices (n = 72), low- and high-grade cervical squamous intraepithelial lesions (SILs) (n = 55 and 53, respectively) and cervical carcinomas (n = 47) were screened for human papillomavirus (HPV) types 6, 11, 16 and 18 infection by the polymerase chain reaction. The prevalence of multiple HPV infections in patients with normal cervices, low-grade SILs, high-grade SILs and cervical carcinomas was 22.2%, 61.8%, 41.5% and 21.3%, respectively, while the prevalence of a single-type infection was 36.1%, 21.8%, 30.2% and 61.7%, respectively. HPV 16/11 and 16/18 were the most common combinations observed in multiple infections. Multiple HPV infections were seen most frequently in patients with low-grade SILs, and the prevalence decreased with increasing severity of cervical neoplasia. In contrast, infection with a single HPV type was most commonly observed in patients with cervical carcinoma, and the prevalence decreased with decreasing severity of cervical neoplasia. HPV 16 was the predominant single-type infection in patients with cervical carcinoma and this prevalence decreased steadily with decreasing severity of cervical neoplasia. Conversely, HPV 11 was the predominant single-type infection in patients with normal cervices. This prevalence decreased with increasing severity of cervical neoplasia. Patients with low-grade SILs had a higher prevalence of HPVs, regardless of single or multiple infection status, and larger copy numbers of virus genome were seen more frequently in patients with more severe lesions.

Adolescent↗
PubMed1997

Adenomyosis in the broad ligament and tamoxifen: report of a case.

Adenomyosis confined to the broad ligament is extremely rare. Herein we present a case of adenomyosis in the broad ligament with unusual gross features. This 41-year-old woman had been on tamoxifen therapy for 3 years due to breast cancer. Ten months after discontinuing tamoxifen, she underwent exploratory laparotomy for a right adnexal mass suspected as ovarian malignancy. At laparotomy, the mass was located in the right broad ligament with a fibrous stalk connecting to the uterus. Total abdominal hysterectomy with bilateral salpingo-oophorectomy was performed. Histopathologic examination revealed adenomyosis with cyst formation and an unusual thick capsule. The possible effects of tamoxifen upon the uterus are discussed in this article, in view of reports of tamoxifen associated with endometrial carcinoma and endometriosis.

Adnexal Diseases↗
PubMed1997

The potential of serum levels of soluble tumour necrosis factor receptor I as a biochemical marker in cervical cancer.

OBJECTIVES: To investigate the significance of serum levels of soluble tumour necrosis factor receptor I (sTNF-RI) as a potential biochemical marker in women with cervical cancer. DESIGN: A prospective, case-controlled study. PARTICIPANTS: Seventy-one women with cervical cancer and 33 women with myoma were enrolled in this study. METHODS: Pre-operative serum levels of sTNF-RI were measured with a standard enzyme-linked immunosorbent assay utilising murine monoclonal antibody against sTNF-RI. MAIN OUTCOME MEASURES: All data in both groups were evaluated and correlated with the pre-operative serum levels of sTNF-RI. Data analysis was carried out using ANOVA with multiple comparison and linear regression. RESULTS: The mean serum level of sTNF-RI in the cervical cancer group was significantly lower than that in the myoma group (P < 0.001). The sTNF-RI levels decreased sequentially with disease progression from Stage Ia to IIb in women with cervical cancer. The mean serum level of sTNF-RI was also significantly lower in women with positive lymph node (P < 0.05) or recurrent cancer (P < 0.001). A negative correlation was observed between serum levels of sTNF-RI and tumour size (r = -0.622, P < 0.0001). CONCLUSIONS: Decreased pre-operative serum levels of sTNF-RI are observed in women with cervical cancer. The results do not support that the use of sTNF-RI as a biochemical marker for cervical cancer.

Adult↗
PubMed1997

The decline in human Alu retroposition was accompanied by an asymmetric decrease in SRP9/14 binding to dimeric Alu RNA and increased expression of small cytoplasmic Alu RNA.

Alu interspersed elements are inserted into the genome by a retroposition process that occurs via dimeric Alu RNA and causes genetic disorders in humans. Alu RNA is labile and can be diverted to a stable left monomer transcript known as small cytoplasmic Alu (scAlu) RNA by RNA 3' processing, although the relationship between Alu RNA stability, scAlu RNA production, and retroposition has been unknown. In vivo, Alu and scAlu transcripts interact with the Alu RNA-binding subunit of signal recognition particle (SRP) known as SRP9/14. We examined RNAs corresponding to Alu sequences that were differentially active during primate evolution, as well as an Alu RNA sequence that is currently active in humans. Mutations that accompanied Alu RNA evolution led to changes in a conserved structural motif also found in SRP RNAs that are associated with thermodynamic destabilization and decreased affinity of the Alu right monomer for SRP9/14. In contrast to the right monomer, the Alu left monomer maintained structural integrity and high affinity for SRP9/14, indicating that scAlu RNA has been under selection during human evolution. Loss of Alu right monomer affinity for SRP9/14 is associated with scAlu RNA production from Alu elements in vivo. Moreover, the loss in affinity coincided with decreased rates of Alu amplification during primate evolution. This indicates that stability of the Alu right monomer is a critical determinant of Alu retroposition. These results provide insight into Alu mobility and evolution and into how retroposons may interact with host proteins during genome evolution.

3T3 Cells↗
PubMed1996

Monomeric scAlu and nascent dimeric Alu RNAs induced by adenovirus are assembled into SRP9/14-containing RNPs in HeLa cells.

Nearly 1 000 000 copies of Alu interspersed elements comprise approximately 5% of human DNA. Alu elements cause gene disruptions by a process known as retrotransposition, in which dimeric Alu RNA is a presumed intermediate. Dimeric Alu transcripts are labile, giving rise to stable left monomeric scAlu RNAs whose levels are tightly regulated. Induction of Alu RNA by viral infection or cell stress leads to a dramatic increase in dimeric Alu transcripts, while scAlu RNA increases modestly. Each monomer of the dimeric Alu element shares sequence homology with the 7SL RNA component of the signal recognition particle (SRP). The SRP protein known as SRP9/14 is also found in a discrete complex with scAlu RNA, although whether dimeric Alu RNA is associated with SRP9/14 had been unknown. Here we show that antiserum to human SRP9 immunoprecipitates both scAlu RNA and dimeric Alu RNAs and that these RNPs accumulate after adenovirus infection, while levels of SRP9, SRP14, SRP54 and 7SL SRP RNA are unaffected. Dimeric Alu RNAs are also associated with the La protein, indicating that these are indeed nascent RNA polymerase III transcripts. This report documents that induced Alu transcripts are assembled into SRP9/14-containing RNPs in vivo while SRP levels are unchanged. Implications for Alu RNA metabolism and evolution are discussed.

Adenoviruses, Human↗
PubMed1996

Effect of liposomal composition on photoactivated liposome fusion.

Bennett and O'Brien [(1995) Biochemistry 34, 3102] showed that the ultraviolet light exposure of two-component large unilamellar liposomes (LUV) composed of a 3:1 molar mixture of dioleoylphosphatidylethanolamine (DOPE) and 1,2-bis[10-(2'-hexadienoyloxy)decanoyl]-sn-glycero-3-phosphatidyl- choline (bis-SorbPC) facilitated liposome fusion. The rate and extent of liposome fusion was dependent on the extent of photopolymerization, the temperature, and the pH. Examination of the temperature dependence of fusion of photolyzed and unphotolyzed liposomes demonstrated that an enhancement of the rate of fusion occurred in the temperature range associated with the initial appearance of precursors to the inverted cubic (QII) phase [Barry et al. (1992) Biochemistry 31, 10114]. Here, the effect of the molar lipid ratio of the DOPE/bis-SorbPC liposomes on the temperature for the onset of fusion, i.e. the critical fusion temperature, was characterized by changing the relative amounts of unreactive polymorphic lipid and reactive lamellar lipid. In each case, photopolymerization of bis-SorbPC lowered the critical fusion temperature by ca. 15-20 degrees C. The photoreaction of the bis-SorbPC-containing LUV yields cross-linked poly-SorbPC, enhancing the lateral separation of the DOPE and the polylipid and causing isothermal induction of liposome fusion by lowering the temperature for the onset of fusion. Evidence is presented to support the hypothesis that the critical temperature for fusion of two LUV populations depends on the molar ratio of the monomeric lipids in heterodimers of the two LUV. This analysis indicates that the photopolymerization of appropriately designed LUV can decrease the critical fusion temperature from above to below 37 degrees C.

4-Chloro-7-nitrobenzofurazan↗
PubMed1996

Prediction of residual neoplasia based on histopathology and margin status of conization specimens.

OBJECTIVE: To evaluate the status of cone margins and the severity of cervical neoplasia as predictors of residual lesions in the remaining cervices. METHODS: We performed a 7-year retrospective study and reviewed 172 patients who had undergone cervical conization followed by subsequent hysterectomy. Pathological findings of the cone margins and residual lesions in the postcone hysterectomy specimens were recorded for analysis. RESULTS: The prevalence rates of positive cone margins were 0, 18.6, 23.8, and 25%, respectively, in patients with low-grade squamous intraepithelial lesion (SIL) (n = 6), high-grade SIL (n = 129), stage IA1 cervical cancer (CC-IA1) (n = 21), and CC-IA2 (n = 16). The prevalence rates of positive residual lesions in postcone hysterectomy specimens were 0, 23.3, 23.8, and 43.8%, respectively, in those with low-grade SIL, high-grade SIL, CC-IA1, and CC-IA2. Residual lesions were significantly more frequently found in patients with positive cone margins (84.8%) than in those with negative margins (10.1%) (X2 = 76.81, P < 0.0001). All six patients with low-grade SIL had free cone margins. Positive predictive values of margin status for the presence of residual lesions were 83.3, 80, and 100%, respectively, in patients with high-grade SIL, CC-IA1, and CC-IA2. Only two (6.1%) of 33 patients with positive cone margins had more advanced residual lesions. Negative predictive values of margin status for the absence of residual lesions were 100, 90.5, 93.8, and 75%, respectively, in patients with low-grade SIL, high-grade SIL, CC-IA1, and CC-IA2. None of the 139 patients with negative margins had invasive residual lesion. CONCLUSIONS: (1) The prevalence of positive cone margin and residual lesion increased with higher severity of cervical neoplasia. (2) Patients with positive cone margins had significantly higher chances of having residual lesion than those with negative margins. (3) Free cone margin does not ensure the absence of residual lesion in the remaining cervix. However, the possibility of residual invasive cancer in the remaining cervix is remote. (4) Positive cone margin does not invariably indicate the presence and persistence of more severe residual lesion. Subsequent hysterectomy may be reserved for the patient with invasive cone pathology, the patient with concomitant morbid uterine condition, or the patient who is not reliable for continuous follow-up.

Conization↗
PubMed1996

Risk factors for recurrence in patients with stage IB, IIA, and IIB cervical carcinoma after radical hysterectomy and postoperative pelvic irradiation.

OBJECTIVE: To identify risk factors for cancer recurrence in patients with stage IB, IIA, and IIB cervical carcinoma after abdominal radical hysterectomy with pelvic lymph node dissection and postoperative pelvic irradiation. METHODS: One hundred and eighty-seven patients with cervical carcinoma stage IB (n = 63), IIA (n = 43), and IIB (n = 81) disease who received abdominal radical hysterectomy with pelvic lymph node dissection and postoperative pelvic irradiation were followed-up for 2-10 years. The histologic type, grade, lymphovascular tumor emboli, tumor size, invasion sites, deep cervical stromal invasion, and pelvic lymph node metastases were assessed for correlation with cancer recurrence. RESULTS: Recurrence occurred in 45 cases (24%), of whom 40 had died of the disease at the 5-year follow-up period. Univariate proportional hazards analysis revealed that the significant risk factors were adenocarcinoma, bulky tumor size (4 cm or greater), lymphovascular tumor emboli, deep cervical stromal invasion, and lymph node metastases, especially iliac nodal metastases and bilateral nodal metastases. Multivariate proportional hazards analysis showed that bulky tumor size (hazard ratio 2.34), tumor emboli (hazard ratio 2.74) and iliac nodal metastases (hazard ratio 5.31) remained significant risk factors. In contrast, no deaths occurred in the other 142 cases who did not have recurrence. CONCLUSION: This retrospective study suggests that stage IB, IIA, and IIB cervical carcinoma cases with the above-mentioned pathologic factors are at higher risk of recurrence after abdominal radical hysterectomy with pelvic lymph node dissection and postoperative pelvic irradiation.

Combined Modality Therapy↗
PubMed1996

Scalene lymph node metastases with the negative pelvic nodes in invasive cervical carcinoma.

Cervical carcinoma spreads predominantly by lymphatic routes and lymph node metastases may occur even in early stages of disease. Metastases usually first appear in pelvic lymph nodes, then disseminate along the efferent lymphatic chain to the extrapelvic lymph nodes. Cases of positive lymph node metastases with negative pelvic nodes in invasive cervical carcinoma are extremely rare. We report a 50-year-old woman with bulky stage IIA cervical carcinoma who had scalene lymph node metastases in the absence of pelvic lymph node metastases after radical hysterectomy and postoperative pelvic irradiation. This rare "skipping" nodal metastasis was probably via posterior trunk lymphatic drainage of the bulky cervical carcinoma which mainly invaded the posterior vaginal cuff. Neoadjuvant or adjuvant chemotherapy is recommended to prolong survival of patients in such cases.

Carcinoma, Squamous Cell↗
PubMed1996

Triplet pregnancy complicated by intrauterine fetal death of conjoined twins from an umbilical cord accident of an acardius. A case report.

BACKGROUND: Acardius is a rare occurrence in monozygotic multiple pregnancies. Triplet pregnancy composed of an acardiac fetus and a pair of conjoined twins is even more rare. The outcome of the acardius is invariably fatal, and the mortality rate of the other fetuses ranges between 50% and 70%. Perinatal mortality results mainly from complications of twin-twin transfusion syndrome. CASE: Intrauterine fetal death, caused by an umbilical cord accident, with twisting of the acardius's cord around the fused cords of conjoined twins is reported in this present work. CONCLUSION: An acardius should be thoroughly sought when monochorionic multiple pregnancies are found by ultrasound during prenatal care. The complications of pregnancy caused by an acardiac fetus can be avoided by using proper management.

Adult↗
PubMed1996

Mature cystic teratoma of the ovary: a clinicopathologic study of 283 cases.

BACKGROUND: Although in the English literature, much has been published about ovarian teratoma, no large series has been reported in Taiwan. Therefore a retrospective study of 283 consecutive cases of mature cystic teratomas of the ovary, operated at National Taiwan University Hospital between 1988 and 1993, was undertaken. METHODS: This series was based on a retrospective chart study at the Department of Obstetrics and Gynecology of the National Taiwan University Hospital from 1988 to 1993. All cases included in this study were proven by pathology review. The clinical data, pathology and complications are summarized. RESULTS: The incidence of mature cystic teratoma was 32.6% of primary ovarian neoplasm. As for the age distribution, the youngest patient was 12 years old and the oldest, 76. The largest number of cases was found in patients between the ages of 20 and 30 years; the mean age was 35.4 years. Pain, the most common complaint, was noted in 48.1% of the cases in whom it varied from a dull ache to the sharp, stabbing pain of torsion. Of greater interest was an unexpectedly high incidence (16.6%) of asymptomatic cysts found on routine physical examination. The right ovary was involved in 51.2%, the left ovary in 40.6% and bilateral ovaries were involved in 8.2%. The incidence of torsion was 9.2%, and was the highest in all complications. Ten concurrent pregnancies were noted, an incidence of 3.5%. The incidence of malignant transformation was 0.7%, with a pathology of squamous cell carcinoma. CONCLUSIONS: Mature cystic teratom is the most common germ cell tumor and accounts for about 33% of all ovarian neoplasm They occur primarily during the reproductive years, but may occur in the postmenopausal period or in childhood. A cystic teratoma can undergo malignant transformation; it occurs most frequently in postmenopausal women, and the prognosis is poor. However, it is a rare complicaiton, with an incidence less than 1%.

Adolescent↗
PubMed1996

The suitable treatment for adenocarcinoma in situ of uterine cervix: a report of four cases.

Adenocarcinoma in situ (AIS) of the uterine cervix is a rare disease. Some authors suggested that conization is a suitable treatment for AIS as for squamous cell carcinoma in situ. However, others did not agree. Four cases of AIS, from 1984 to 1994, have been diagnosed in the Hospital of National Taiwan University. If the diagnosis of the conization specimen showed AIS, abdominal total hysterectomy was performed days thereafter. The remaining uterine cervix was checked by histopathology to determine whether it was free of cancer lesions. AIS lesions remained in the uterine cervix, as shown by conization in two cases. AIS is not like lesion as squamous cell carcinoma in situ lesion which is easy to be removed by conization. It is suggested that conization is not an adequate treatment for AIS, rather, a total hysterectomy should be performed.

Adenocarcinoma↗
PubMed1995

Human signal recognition particle (SRP) Alu-associated protein also binds Alu interspersed repeat sequence RNAs. Characterization of human SRP9.

Nearly 1 million interspersed Alu elements reside in the human genome. Alu retrotransposition is presumably mediated by full-length Alu transcripts synthesized by RNA polymerase III, while some polymerase III-synthesized Alu transcripts undergo 3'-processing and accumulate as small cytoplasmic (sc) RNAs of unknown function. Interspersed Alu sequences also reside in the untranslated regions of some mRNAs. The Alu sequence is related to a portion of the 7SL RNA component of signal recognition particle (SRP). This region of 7SL RNA together with 9- and 14-kDa polypeptides (SRP9/14) regulates translational elongation of ribosomes engaged by SRP. Here we characterize human (h) SRP9 and show that it, together with hSRP14 (SRP9/14), forms the activity previously identified as Alu RNA-binding protein (RBP). The primate-specific C-terminal tail of hSRP14 does not appreciably affect binding to scAlu RNA. Kd values for three Alu-homologous scRNAs were determined using Alu RBP (SRP9/14) purified from HeLa cells. The Alu region of 7SL, scAlu, and scB1 RNAs exhibited Kd values of 203 pM, 318 pM, and 1.8 nM, respectively. Finally, Alu RBP can bind with high affinity to synthetic mRNAs that contain interspersed Alus in their untranslated regions.

Amino Acid Sequence↗
PubMed1995

Leiomyosarcoma of the broad ligament: a case report and literature review.

Solitary tumors of the broad ligament are rare. The most frequent solid tumor of the broad ligament is leiomyoma. Leiomyosarcoma of the broad ligament (LBL) is an extremely rare malignant tumor. Nine cases of leiomyosarcoma of the broad ligament had been reported previously. A 59-year-old woman with LBL is reported. Treatment consisted of resection and total abdominal hysterectomy with bilateral salpingo-oophorectomy. No evidence of metastasis is noted after 12 months follow-up. We conclude that the management of LBL is excision of the leiomyosarcoma as completely as possible and postoperative adjuvant chemotherapy.

Broad Ligament↗