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Biomedical subjects

S N Chow

Publications and source records attributed to S N Chow.

At least 55 records · Page 3Linked to original sources
PubMed1994

Evaluation of immunosuppressive acidic protein in human ovarian cancer.

This study was conducted to determine the levels of serum immunosuppressive acidic protein (IAP) in Chinese female controls and patients with ovarian tumors; and to examine the usefulness of serum IAP as an additional diagnostic test for ovarian cancer. Serum IAP was determined by a single radial immunodiffusion method. Blood samples were collected prior to surgery from patients with ovarian tumors and from female controls. A histologic diagnosis was made, and staging was performed on the basis of the FIGO staging system for ovarian cancer. The studied subjects included 33 healthy controls, 33 patients with benign ovarian tumors and 32 patients with ovarian cancer (stage I-III, and recurrent). The data were analyzed by Student's t test, Fisher's exact test and the one-way ANOVA test. The mean (+/- SD) level of serum IAP in controls was 330 +/- 61 micrograms/ml. The calculated normal upper limit (mean plus 2 SD) was 452 micrograms/ml. The mean value (867 +/- 392 micrograms/ml) in ovarian cancer was significantly higher than the controls (p < 0.001) or the benign ovarian tumors (333 +/- 95 micrograms/ml) (p < 0.001). Five (15.6%) of 32 patients with ovarian cancer had false-negative results. Three (9.1%) of 33 patients with benign ovarian tumors showed false-positive IAP levels. The pathologic diagnosis of these three patients revealed that two had endometrioma and one had mucinous cystadenoma with hemorrhagic necrosis. Three of four patients with epithelial ovarian cancer of borderline malignancy had IAP levels only slightly higher than the cut-off point of 452 micrograms/ml.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1994

Loop electrosurgical excision procedure for conization of the uterine cervix.

The application of loop electrosurgical excision procedure (LEEP), a new method of conization of the uterine cervix used to diagnose cervical intraepithelial neoplasia (CIN) or cervical cancer is presented herein. A loop electrode consists of a thin wire that allows deep excision of the transformation zone (TZ). The cone-shaped tissue removed can be examined histologically. Over a period of one year, a total of 41 cases underwent LEEP. Without anesthesia, the patients did not have any noticeable pain during the procedure. There were no complications, such as fever, wound infection, massive bleeding or cervical stenosis. In low-grade CIN, follow-up colposcopy and cytology did not show persistence or recurrence. In two cases of high-grade CIN, subsequent hysterectomy revealed residual lesions on hysterectomized specimens. LEEP is a simple and quick procedure of diagnostic conization that can be done at the first visit without major complication. If the histopathology after LEEP is moderate- to high-grade CIN or invasive cancer, the conization cannot be regarded as a sufficient therapeutic procedure, and such a patient needs further treatment.

Biopsy↗
PubMed1994

A study on the usefulness of local anaesthesia for the laser vaporization of conizations in the uterine cervix.

The purpose of our study is to evaluate the need to use anaesthesia during laser ablation treatment of cervical intraepithelial neoplasia (CIN) in populations of Asian women. Forty patients who were to undergo the ablation of CIN grade 1 or 2 were randomly divided into two groups. One group of patients was treated without any anaesthesia and the other group was treated using a paracervical block with lidocaine. The patients' experience of pain during the procedure was measured. These evaluations included an objective assessment made by the surgeons during the procedure using an objective pain scoring system, and a subjective estimation made by the patients themselves after the procedure using a visual analogue scale. Patients' feelings concerning the acceptability of either procedure were also elicited. Our results show that the case distribution of objective pain scores between the two groups of patients is not statistically different (p > 0.05). The mean visual analogue score of the patients who were not given anaesthesia (24.1%, SD 9.4) does not differ statistically from that of the patients who were administered a paracervical block (25.0%, SD 10.0, p > 0.05). Further, the acceptability rates of both groups are high (85% with paracervical block, 90% without anaesthesia), and the overall rates of the two groups are not statistically different (p > 0.05). These results imply that there may be differences in pain perception between Eastern and Western women. We conclude that in populations of Asian women, it is unnecessary to use anaesthesia during cervical laser ablation.

Adult↗
PubMed1993

Point mutation of the ras oncogene in human ovarian cancer.

The ras oncogene exists in a variety of human cancers, including carcinomas of bladder, breast, colon, kidney, liver, lung, ovary, pancreas, and stomach. The ras genes acquire transforming activity either by enhanced expression or by a single point mutation. A single base-pair mutation at specific sites within ras genes endows them with the capacity to transform certain cell lines in vitro. In this study, we showed the patterns of point mutations in codons 12, 13, and 61 of ras genes in human ovarian cancer. The experimental procedures were isolation of genomic DNA from normal ovary and ovarian cancer tissue specimens, amplification of a genomic DNA segment (about 100 bp) using different 5' and 3' extension primers in the polymerase chain reaction (PCR), labeling and purification of synthetic mutation-specific oligonucleotide probes, slot-blot hybridization, and autoradiography. The three reaction steps for the PCR cycle were: 96 degrees C for 1 min in step 1, 56 degrees C for 1 min in step 2, and 74 degrees C for 1 min in step 3. The PCR reaction was repeated totally for 30 cycles. In 28 tissue specimens of human ovarian cancer examined, one specimen was found with a c-Ha-ras point mutation at codon 12, two had a c-Ki-ras mutation at codon 12, and one had a c-Ki-ras mutation at codon 13.

Autoradiography↗
PubMed1993

Vulvar neoplasia associated with other primary malignancies.

It is recognized that a significant number of patients with vulvar neoplasia have had previous, concurrent, or subsequent genital tract neoplasia. This has resulted in speculation that there may be a common etiology and, in particular, of the possibility of an infection element. Among 59 cases of vulvar cancer diagnosed at the National Taiwan University Hospital from 1976 to 1991, there were seven cases (12%) associated with other primary malignancies. Carcinoma of the cervix was the most frequent other primary cancer (6/7, 86%). The possible role of human papilloma virus infection in genital neoplasia is discussed.

Adult↗
PubMed1993

Maternal and fetal outcome of pregnant women with idiopathic thrombocytopenic purpura: retrospective analysis of 25 pregnancies.

The optimal management of pregnant women with idiopathic thrombocytopenic purpura (ITP) is controversial. We reviewed our experience with 25 pregnancies in 19 women with ITP over a 14-year period. The incidences of bleeding during pregnancy and postpartum hemorrhage were 12.0% and 24.0%, respectively, in our series. No maternal mortality was noted. Thirteen infants were born by vaginal delivery and 12 by cesarean section. Moderate to severe neonatal thrombocytopenia (platelet count < 100 x 10(9)/L) was diagnosed in six newborns. One of them had intracranial hemorrhage complicated by a bilateral sensorineural hearing loss. ITP mothers with a prenatal platelet count < 30 x 10(9)/L and a platelet count < 100 x 10(9)/L at delivery had a higher risk of giving birth to infants with moderate to severe neonatal thrombocytopenia. Cesarean section may improve the outcome of these fetuses.

Adult↗
PubMed1993

Human chorionic gonadotropin pattern in maternal circulation. Amniotic fluid and fetal circulation in late pregnancy.

This study had two purposes. One was to investigate the placental gradients and the relationship of human chorionic gonadotropin (hCG) concentrations in maternal serum (MS), amniotic fluid (AF) and fetal serum (FS). The other was to study the fetal sex effect. This study included 93 patients with normal singleton term pregnancies. AF samples contaminated with blood were excluded. Fetuses did not have any abnormalities. We measured hCG by double antibody beta hCG radioimmunoassay. We found that there were conspicuous hCG slopes in MS, AF and FS levels. The hCG level in MS was 12.9 +/- 1.3 IU/mL (mean +/- SE, n = 93). It was much higher than levels in AF or FS. AF (0.461 +/- 0.053 IU/mL, n = 25) also had higher hCG level than FS (0.038 +/- 0.0056 IU/mL, n = 93). The hCG concentrations in AF and FS were highly correlated with those in corresponding MS (P < .001 and P < .05, respectively). The concentrations in AF were also positively correlated with those in corresponding FS (P < .05). The mean of MS/AF ratios for hCG was 413.6 +/- 23.4 (+/- SE); of MS/FS, it was 37.8 +/- 9.2; of AF/FS, it was 15.3 +/- 2.6. At late pregnancy, higher hCG levels of MS, AF or FS may result in female fetuses than in male fetuses. The results revealed that there were hCG concentration gradients on both placental and fetal membranes. It also implied that hCG levels in AF may decline as gestation ages advance. For biochemical studies in FS, using pure cord venous blood may have more consistent results than using mixed blood.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Cryptococcal infection of the vagina.

BACKGROUND: Cryptococcal infection is opportunistic and occurs most commonly in immunocompromised patients. Meningitis is the most frequent manifestation and causes marked morbidity and mortality. Other sites are less common. We report a case of vaginal cryptococcal infection. CASE: A 72-year-old patient who had undergone resection of the colon for cancer 9 years earlier was noted to have a suspicious lesion on the right vaginal wall after an abnormal Papanicolaou test. Biopsy of the lesion showed findings compatible with cryptococcal infection. Serial examinations revealed no evidence of systemic infection or immunocompromised condition. Empirical treatment was tried with fluconazole. Follow-up colposcopy showed almost complete disappearance of the vaginal lesion, and histologic section and culture of the tissue failed to reveal cryptococcus. CONCLUSION: Cryptococcal infection is rare, especially in a patient with no evidence of an immunocompromised condition. The preliminary result of fluconazole treatment was satisfactory. However, further follow-up and evaluation are needed to confirm the effectiveness of fluconazole in our patient.

Aged↗
PubMed1991

Combined analysis of serum lactic dehydrogenase levels and isozyme patterns in ovarian neoplasms.

A total of 65 cases of ovarian tumor admitted for surgical intervention were prospectively enrolled in this study, including 40 cases with benign ovarian tumors and 25 cases of ovarian cancer. The 25 malignancies were comprised of 22 cases of common epithelial origin and three cases with Krukenberg tumors. Serum total LDH level and its isozyme activity were measured preoperatively in each patient. The mean value (+/-SD of serum LDH in the malignant group was 876.3 (+/- 450.4) IU/1, which was significantly higher than 364.8 (+/- 87.9) IU/1 in the benign group. Twenty-two cases of ovarian malignancy (88%) and 6 cases of the benign group (15%) had elevated serum LDH levels above 450 IU/1. Analysis of the LDH isozyme pattern demonstrated that there was a significant shift to LDH-4 and LDH-5 fractions in ovarian malignancy when compared to the benign group (with the mean value of 9.5%, 14.6% vs. 6.5% and 4.6%, respectively). The elevated LDH level could yield 88% and 85% in sensitivity and specificity for detecting ovarian malignancy, while the abnormal isozyme pattern could yield 84% and 77.5%, respectively. From combined analysis of total LDH levels and isozyme patterns, the true positive detection rate and true negative detection rate could both reach 100%. In conclusion, the present findings imply that total serum LDH level and isozyme activity measurement may provide significant aids in evaluation and detection of human ovarian cancers among patients with ovarian tumors.

Female↗
PubMed1990

Amplification and expression of c-Ki-ras oncogene in human ovarian cancer.

The amplification and expression of the cellular oncogene c-Ki-ras have been detected in twelve tissue specimens of human ovarian adenocarcinoma, one ascites of ovarian cancer and ovarian cancer cell line NIH: OVCAR-3. Four out of the twelve cancer tissue specimens, one specimen of cancer ascites cells and the NIH: OVCAR-3 cancer cell line showed elevated amplification of c-Ki-ras, as compared to the human fibroblast cell line FS4 and normal ovarian tissues. The amplification of the c-Ki-ras gene showed some correlation with clinical stages of ovarian cancer. The levels of c-Ki-ras specific RNA transcripts and ras gene product p21 were also elevated in these four cancer tissue specimens. Surprisingly, a discrepancy between amplification and expression of c-Ki-ras was noted in five of the other eight cancer tissue specimens, in which enhanced expression of c-Ki-ras was present without the accompanying elevated amplification of c-Ki-ras. The results do provide some clues to understanding the possible mechanisms of tumorigenesis in human ovarian cancer.

Adenocarcinoma↗
PubMed1990

Rapid and simple immunoassays for measurement of human chorionic gonadotropin using monoclonal antibodies.

Two monoclonal antibodies, designated Gab-35 and Gab-144, were used in competitive radioimmunoassay (RIA) and solid-phase sandwich enzyme immunoassay. By SDS-polyacrylamide gel electrophoresis and protein blot enzyme immunobinding assay, Gab-35 and Gab-144 were shown to react specifically to the alpha-subunit and beta-subunit of human chorionic gonadotropin (hCG), respectively. The immunoglobulin class and subclass of these two monoclonal antibodies were found to be IgG1 by the Ouchterlony double gel immunodiffusion test. The beta-subunit specific monoclonal antibody of Gab-144 was used in competitive RIA for determination of serum hCG in the range of 5-500 mIU/ml. The assay results correlated well with the monoclonal antibody-based RIA system and commercial RIA kits using polyclonal antisera. Moreover, the present competitive RIA system showed a shorter incubation time (1 hour 20 minutes) and a shorter total assay time (1 hour 40 minutes), as compared to those of the commercial RIA kit. A solid-phase sandwich enzyme immunoassay was developed using a combination of the Gab-35 antibody-coated microtiter plate and the beta-subunit specific antibody of Gab-144 conjugated with horseradish peroxidase (HRP). The assay range was 20-200 mIU/ml, and the incubation time was only 30 minutes. In addition, the solid-phase sandwich enzyme immunoassay developed in the present study could also be used as a qualitative hCG assay with a cutoff point of 50 mIU/ml as an early pregnancy test at or just a few days before the missed period.

Animals↗
PubMed1989

Applications of monoclonal antibodies to human follicle-stimulating hormone in enzyme immunoassays.

Monoclonal antibodies against human follicle-stimulating hormone (hFSH) were generated by using an improved hybridoma technique with a semisolid medium in methylcellulose for initial cloning. The generated monoclonal antibodies were characterized with respect to their subunit and epitope specificity as well as cross-reactivity to other glycoprotein hormones. Monoclonal antibodies of high affinity and high specificity to hFSH were finally selected for applications in sandwich enzyme immunoassay. The monoclonal antibody specific to the alpha-subunit of FSH was coated on microtiter wells and served as the first antibody. The other high-affinity monoclonal antibody specific to beta-subunit of FSH was labeled with horseradish peroxidase and served as the second antibody. This immunoassay can be performed within 70 min at room temperature and has a minimum sensitivity of 2 mIU/ml for serum sample.

Animals↗
PubMed1988

Generation and epitope analysis of thyroid stimulating hormone-specific monoclonal antibodies for enzyme immunoassays.

By using an improved hybridoma technique with a semisolid medium of methylcellulose for initial cloning, numerous high affinity monoclonal antibodies against human thyroid stimulating hormone (TSH) were generated. These antibodies were characterized with respect to their subunit and epitope specificity. Epitope analysis of antibodies specific to the beta-subunit of TSH was performed by a sandwich pairing procedure. Based on the results of this analysis, it was concluded that there are four distinct TSH-specific epitopes on the beta-subunit of TSH; these are designated a, b, c, and ab. The five antibodies binding to epitopes a, b, and c are not mutually exclusive. However, the antibody binding to epitope ab prevents further binding of other antibodies to epitope a or b, but not to epitope c. This epitope analysis enabled us to combine three high affinity monoclonal antibodies, each of which reacts with epitopes a, b, and c, respectively, in a typical sandwich enzyme immunoassay. One was immobilized on polystyrene beads and the other two were conjugated with horseradish peroxidase and served as the second antibodies. This enzyme immunoassay can be performed within 90 min and with a minimum sensitivity of 0.2-0.3 microIU/ml.

Antibodies, Monoclonal↗
PubMed1987

Sex difference of antifertility effect by passively immunized monoclonal sperm antibodies.

Sperm-specific monoclonal antibodies (MS 204, MS 207, HS 11, and HS 63) that had been shown to inhibit fertilization of mouse oocytes in vitro were used to passively immunize male and female mice. In vitro and in vivo fertilization experiments were performed to compare the efficacy of resulting antifertility effects owing to the presence of circulating sperm antibodies. When the sperm from the antibody-treated mice were recovered for insemination, a partial inhibition of fertilization of mouse oocytes in vitro was observed. However, under the same antibody dose that effectively inhibits the in vivo fertilization of treated female mice the fertilization rate of the treated male was not significantly reduced, when they were mated with normal superovulated females followed by in vitro embryo culture. Similarly, on day 9 after mating with the antibody-treated males, the number of fetuses in mated females was not significantly different from that of the control. In contrast, when the antibody-treated females were mated with the proven fertile males, the number of fetuses was significantly reduced in response to the antibody treatment. When I-125-labeled monoclonal sperm antibodies were used to passively immunize male mice, the percentage of antibodies recovered from epididymis (relative to that of blood) was not much different from that of other organs, except for lower percentages detected in brain and testis. In treated females, oviduct and uterus revealed the presence of relatively high percentages of antibodies.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1987

Purification and characterization of metal-binding proteins and the corresponding mRNA from human placentas.

Two metal-binding proteins, designated as PI and PII, were isolated and purified from normal term human placentas by gel filtration and ion-exchange chromatography. The molecular weights were determined to be 10,000 and 12,000 daltons, and isoelectric points (pI) were 4.8 and 5.9, respectively. The amino acid composition of these proteins was quite different from that of metallothionein. Total amount of acidic amino acid residues was in large excess over that of basic amino acid residues. Cadmium and zinc were the major metals bound to these proteins. The metal contents of cadmium and zinc in placental tissue were 39.34 and 22.23 ng/g placenta, respectively, as measured by flame atomic absorption spectrophotometry. The in vitro translated metal-binding proteins encoded by the corresponding mRNA were characterized by the purified rabbit antiserum against PI and PII. The demonstrated presence of these metal-binding proteins in human placenta suggests its possible role of detoxification activity and protective effect to the fetuses in utero.

Cadmium↗