PubMed Health⌕ Search

Biomedical subjects

T M Ko

Publications and source records attributed to T M Ko.

At least 37 records · Page 2Linked to original sources
PubMed1997

Complete androgen insensitivity syndrome. Molecular characterization in two Chinese women.

OBJECTIVE: To study the molecular basis of complete androgen insensitivity syndrome (AIS). STUDY DESIGN: The coding region of the human androgen receptor (hAR) gene in two women with AIS was amplified with polymerase chain reaction using 12 pairs of oligonucleotide primers and then sequenced with a dye terminator method. RESULTS: Both patients had mutation in exon E of the androgen-binding domain. In one patient, codon 732 GAC (aspartic acid) was changed to ACC (asparagine), and her CAG polyglutamine tract had 27 repeats. In the other patient, codon 765 GCC (alanine) was changed to ACC (threonine), and her CAG polyglutamine tract in exon A had 19 repeats. CONCLUSION: Except for CAG polyglutamine polymorphism, these two missense mutations were the only differences detected in the coding region of the hAR gene. Both mutations involved the CpG sequence, which has been regarded as a mutation hotspot. To the best of our knowledge, these two mutations have not been observed before in Chinese women. Elucidation of the molecular defects of AIS patients would be very helpful for genetic counseling and prenatal diagnosis.

Adolescent↗
PubMed1996

Norplant subdermal contraceptive system: experience in Taiwan.

From November 1988 to December 1994, a total of 567 female volunteers were enrolled in Norplant implant studies at the National Taiwan University Hospital. After a median follow-up of 29 months, only 3 of the 529 available cases became pregnant (a cumulative rate of 1.2 pregnancies per 100 users over 5 years). Chromosome analysis of 2 of the 3 abortuses revealed 46,XX/46,XX,inv(3) and 46,XX. Menstrual problems were the most common adverse effects and were also the main reason for discontinuation (65%, 108/166). The continuation rate was 90%, 78%, 70%, 61%, and 42% at the end of 1, 2, 3, 4, and 5 years after insertion, respectively. In the 21 patients who wished to become pregnant, fertility recurred soon after removal of the Norplant implants. The data suggested that the Norplant implants system is a highly effective, safe, and long-acting method of reversible contraception. It would be worthwhile to introduce this contraceptive system to Taiwan's family planning program.

Abortion, Induced↗
PubMed1996

Leiomyosarcoma of the pulmonary vein.

OBJECTIVE: We report a case of leiomyosarcoma (LMS) of the pulmonary vein and comment on the natural history and determinants for survival for this rare condition. EXPERIMENTAL DESIGN: Our retrospective review is only the fourth such case reported in the world's literature. SETTING: A teaching hospital with an active surgical residency program. PATIENT OR PARTICIPANT: A 61-year-old female who presented with a central pulmonary mass. INTERVENTIONS: Complete resection without pneumonectomy of cardiopulmonary bypass. Pathology showed low grade LMS. MEASURES: Determinants for survival include complete surgical resection and a low mitotic activity of the tumor. RESULTS: The patient remains no evidence of disease three years following initial treatment. CONCLUSIONS: One reported case of LMS of the pulmonary vein had favorable determinants for survival; complete surgical resection and low mitotic activity of the tumor. These factors may have contributed to the successful outcome. The natural history of LMS of the pulmonary vein appears similar to the more widely studied LMS of the inferior vena cava.

Female↗
PubMed1995

Ultrasonographic scanning of placental thickness and the prenatal diagnosis of homozygous alpha-thalassaemia 1 in the second trimester.

In order to evaluate the association between placental thickness (PT) and fetal homozygous alpha-thalassaemia 1 before the appearance of classic ultrasound findings of haemoglobin (Hb) Bart's hydrops fetalis, a total of 473 pregnancies were collected. The control group included 422 normal pregnancies with a gestational age from 14 to 23 weeks and the study group included 51 affected fetuses in the same gestational period. Fetal biparietal diameter (BPD) and PT were measured by high-resolution ultrasound. PT was evaluated against BPD. In the control group, the PT generally increased in parallel with the advancement of gestational age. All PT measurements in the study group were above the mean PT of their respective gestational week in the control group. Forty-six (90 per cent) of the pregnancies in the study group had PT larger than the mean plus two standard deviations of the control group. This study suggests that ultrasound measurement of PT may be a useful aid in the prenatal diagnosis of Hb Bart's hydrops fetalis before its classic findings become apparent in the late second trimester or third trimester.

Female↗
PubMed1995

Prenatal diagnosis of 46,XX/47,XXY mosaicism: a case report.

A case of 46,XX/47,XXY mosaicism was diagnosed at 22 gestational weeks by amniocentesis and fetal blood sampling. After genetic counselling, the couple elected to have the pregnancy terminated. Culture of the fetal skin and both gonads confirmed the prenatal diagnosis. In external appearance, the abortus had no remarkable findings except hypospadia. Histology of both gonads showed testicular tissue without evidence of ovarian components.

Abortion, Induced↗
PubMed1995

Prenatal diagnosis by transabdominal chorionic villus sampling in the second and third trimesters.

From October 1989 through December 1993, 124 pregnant women (114 in the second trimester and 10 in the third trimester) underwent transabdominal chorionic villus sampling (CVS) for prenatal molecular or cytogenetic diagnosis. The mean gestational age was 18.2 weeks. Indications for CVS comprised single gene disease (72%), fetal anomalies detected by ultrasound (17%), advanced maternal age (6%), and previous siblings with chromosomal aberration (5%). Among the 89 fetuses at risk for single gene disease, 20 were diagnosed as affected by DNA analysis. Among the 35 fetuses at risk for chromosomal anomaly, 4 had trisomy, 3 had a 45,XO karyotype and 2 had a structural chromosomal abnormality. The miscarriage rate was 1.8% (2/114) and the spontaneous preterm birth rate was 2.4% (3/124). No maternal or other fetal complications occurred. This study suggested that second- and third trimester CVS is a safe and useful method for prenatal diagnosis.

Abnormalities, Multiple↗
PubMed1995

In vitro fertilization pregnancy achieved with epididymal caput sperm of a patient with obstructive azoospermia.

A successful epididymal sperm aspiration, in vitro fertilization and embryo transfer in a woman whose husband had previously undergone extensive attempts at recanalization of the spermatic ducts is reported. A twin pregnancy was achieved using sperm obtained from the husband's epididymal caput. This case demonstrates that pregnancy can be achieved by this reproductive technique in cases of obstructive azoospermia, even after extensive surgery.

Adult↗
PubMed1994

Prenatal diagnosis of X-linked hydrocephalus in a Chinese family with four successive affected pregnancies.

We report on a woman with four successive pregnancies affected with X-linked hydrocephalus (XLH). The first child had prenatal craniocentesis and died in utero. The second child had a postnatal shunting operation, but suffers from severe growth and mental retardation at 5 years of age. In the third pregnancy, prenatal ultrasound detected hydrocephalus at the 16th and 20th weeks of gestation and the pregnancy was terminated. In the fourth pregnancy, ultrasound scanning at the 17th and 20th weeks of gestation revealed no remarkable findings, but hydrocephalus was detected at the 24th week. Autopsy confirmed the prenatal diagnosis. DNA polymorphism analysis of the Bc1I site of exons 17-18 of factor VIII gene of the woman and her last two fetuses seemed to be compatible with a linkage between the XLH locus and factor VIII gene. Although XLH has a variable presentation of ventriculomegaly, ultrasound scanning is still a useful tool for prenatal diagnosis at present. Earlier and more accurate prenatal diagnosis will be feasible with molecular analysis of the XLH locus or its flanking regions.

Adult↗
PubMed1994

Recurrent Down's syndrome due to maternal ovarian trisomy 21 mosaicism.

A family with three children who had Down's syndrome and one healthy child is reported. Cytogenetic studies of the peripheral blood revealed trisomy 21 in the affected children, and normal karyotypes in both the parents and the healthy child. However, a biopsy of the mother's right ovary showed a mosaic trisomy 21 cell line (8/20 cells). By DNA polymorphism analysis, segregation of trisomy oogonia appeared to be the cause of recurrent trisomy 21.

Adult↗
PubMed1994

Amniocentesis in mothers who are hepatitis B virus carriers does not expose the infant to an increased risk of hepatitis B virus infection.

Sixty-seven pairs of mothers with hepatitis B virus (HBV) surface antigen (HBsAg) and their infants were divided into two study groups to determine the effect of amniocentesis on intrauterine HBV infection. In the first study group (35 pairs), the infant's HBsAg status in cord blood was studied and the results were compared with those obtained in the cord blood from 65 infants born to HBsAg-positive women who did not have an amniocentesis. In the second study group (32 pairs), the HBV status of the infants was studied at the age of three months to five years and compared with the HBV status of 3,454 infants in the National HBV Prevention Program. In the first study group, one sample (2.9%) was weakly positive for HBsAg; while in the first control group, two (3.1%) were positive. In the second study group, three (10%) infants were positive for HBsAg. The failure rates of immunoprophylaxis in the second study and control groups were similar (9.4% vs 11% for HBsAg carrier mothers; 30% vs 14% for HBe antigen-positive carrier mothers). This suggested that genetic amniocentesis did not increase the risk of intrauterine HBV infection.

Adult↗
PubMed1994

Increased level of second trimester maternal serum chorionic gonadotropin in pregnancy with a fetus affected by homozygous alpha-thalassemia 1.

With enzyme immunoassay, maternal serum chorionic gonadotropin (MShCG) level was determined in 58 pregnancies affected with fetal homozygous alpha-thalassemia 1. In 40 pregnancies with a gestational age of 10 to 14 weeks, 8 (20%) had an MShCG level above 2.5 multiples of the median (MoM); while in the other 18 pregnancies with a gestational age of 15 to 23 weeks, 14 (78%) had a level above 2.5 MoMs and none had a level below the median. Homozygous alpha-thalassemia 1 of the fetus was associated with an elevated MShCG. Therefore in second-trimester screening for Down's syndrome by measurement of MShCG, homozygous alpha-thalassemia 1 should also be considered if elevated MShCG levels are found.

Adult↗
PubMed1994

Infrequent mutation in tumor suppressor gene p53 in gestational trophoblastic neoplasia.

In order to determine the p53 status of gestational trophoblastic neoplasia, 24 cases of molar pregnancies and two choriocarcinoma cell lines (JAR and JEG-3) were evaluated for the presence of mutations. The evaluation involved the whole coding sequence (i.e. exons 2-11) of the p53 gene with polymerase chain reaction (PCR) amplification of genomic DNA, followed by single strand conformation polymorphism (SSCP) and sequencing. Only one case of hydatidiform mole was found to have a missense point mutation (codon 295, CCT-->CTT, i.e. proline to leucine) of the p53 gene. The results suggest that p53 mutation is rarely involved in the pathogenesis of gestational trophoblastic neoplasia.

Base Sequence↗
PubMed1994

Cytogenetic study of spontaneous abortions with the Giemsa banding method.

Among 102 spontaneous abortuses karyotyped, 29 were from parents with a history of unexplained recurrent spontaneous abortion (group A), and 73 were from parents without a history of recurrent spontaneous abortion (group B). The mean maternal ages of these two groups were not significantly different. The chromosomal aberration rate in group A was 48.3% and in group B was 53.4%. The difference was not significant. The most common chromosomal anomaly was autosomal trisomies in both groups, while monosomy X was more common in group B. The subsequent spontaneous abortion rate was also not significantly different between the two groups.

Abortion, Habitual↗
PubMed1994

Prevalence and molecular studies of thalassemia in five aboriginal groups in Taiwan.

A total of 1,342 blood samples from five aboriginal groups in Taiwan, comprising 522 of the Ami, 246 of the Bunum, 227 of the Atayal, 214 of the Paiwan and 133 of the Yami group, were collected. A complete blood count was performed in each case. In subjects with a mean corpuscular volume < 85 fl or hemoglobin (Hb) < 12 gm% (female) or 13 gm% (male), quantitation of Hb A2 and DNA analysis of alpha- and beta-globin genes were performed. Alpha-thalassemia was diagnosed by Southern hybridization of subject's DNA to alpha-, and zeta-globin gene fragments, and to Lo probe if needed. DNA from beta-thalassemia carriers was studied by polymerase chain reaction and direct sequencing. In the Ami, 42 (8.2%) were alpha-thalassemia 1 carriers, 42 (8.2%) were alpha-thalassemia 2 carriers, one had Hb H disease, and four (0.8%) were beta-thalassemia carriers. In the Bunun, one (0.2%) was an alpha-thalassemia 1 carrier, and two (0.4%) were alpha-thalassemia 2 carriers. In the Atayal, one (0.2%) was an alpha-thalassemia 1 carrier. In the Paiwan, seven (3.3%) were alpha-thalassemia 1 carriers, and one (0.5%) was an alpha-thalassemia 2 carrier. In the Yami, none were either alpha- or beta-thalassemia carriers. Diverse genetic origin, intragroup breeding and malarial selection may play a role in the significant differences of thalassemia prevalences both between the Chinese and the aborigines, and among different groups of aborigines.

Female↗
PubMed1993

Prenatal diagnosis of Hb H disease due to compound heterozygosity for South-east Asian deletion and Hb constant spring by polymerase chain reaction.

A pregnant woman has two children affected by moderately severe Hb H disease due to compound heterozygosity of South-east Asian deletion and Constant Spring mutation. In her third pregnancy, transabdominal chorionic villus sampling was performed at the tenth gestational week to obtain fetal DNA. The polymerase chain reaction was used for detection of both the South-east Asian deletion and the Constant Spring mutation. Hb H disease was diagnosed in the fetus. After genetic counselling, the couple elected to have the pregnancy terminated.

Abortion, Therapeutic↗
PubMed1993

Alpha-thalassemia in the four major aboriginal groups in Taiwan.

A total of 1309 unrelated blood samples from four major Taiwan aboriginal groups, including 522 of the Ami, 246 of the Bunun, 227 of the Atayal, and 214 of the Paiwan groups, were collected. Subjects with a mean corpuscular volume below 85 fl and Hb A2 values below 3.5% were further studied with Southern hybridization to determine the status of alpha-globin genes. In the Ami, 43 (4.1%) chromosomes had alpha-thalassemia 1 and 43 (4.1%) had alpha-thalassemia 2. Of the 43 alpha-thalassemia 1 chromosomes, 33 were of the Thailand, one of the Philippine, and nine of the Southeast Asian deletion. Of the 43 alpha-thalassemia 2 chromosomes, 42 were of the type I rightward deletion and one was of leftward deletion. In the Bunun group, one chromosome (0.2%) was of the Thailand deletion and two (0.4%) were of type I rightward deletion. In the Atayal group, only one chromosome (0.2%) was of the Philippine deletion. In the Paiwan group, four chromosomes (0.9%) were of the Southeast Asian deletion and three (0.7%) were of the Thailand deletion. Among the four groups, the Ami had the highest prevalence of alpha-thalassemia, which was also higher than that of the Chinese living in Taiwan.

Blotting, Southern↗
PubMed1993

Surface characterization and platelet adhesion studies of plasma-sulphonated polyethylene.

Canine platelet adhesion on sulphur dioxide and allyl phenyl sulphone plasma-treated low density polyethylene (LDPE) was studied. Both 5 W plasma excitation energy-treated surfaces showed the highest S:C atomic ratio by ESCA analysis. Surface hydrophilicity increased drastically after plasma treatment. However, surface hydrophilicity decreased with time. This might be due to the diffusion of the hydrophilic functional groups into the bulk of the material and/or the migration of low molecular weight hydrocarbon species into the surface region. The allyl phenyl sulphone plasma-treated LDPE was less platelet-activating in terms of platelet adhesion and spreading and was independent of the different plasma excitation energy levels used. Sulphur dioxide plasma-treated LDPE showed a higher level platelet activation than the untreated LDPE. Among the sulphur dioxide plasma-treated LDPE samples, the sample prepared using the 5 W excitation energy was less platelet-activating than the samples treated by higher plasma excitation energies.

Allyl Compounds↗