Biomedical subjects

M Y Chang

Publications and source records attributed to M Y Chang.

At least 73 records · Page 4Linked to original sources

PubMed1993

Gonadotropin stimulation after pituitary desensitization with leuprolide acetate, comparison of FSH/hMG and hMG alone cycles--a study of 166 cases.

The tenet that a combination of human follicle-stimulating hormone (hFSH)/human menopausal gonadotropin (hMG) after pituitary desensitization with GnRH analogue improves follicular recruitment was assessed by treating infertile women in an in vitro fertilization (IVF) program. The participants of this study were one hundred sixty-six infertile patients on IVF program who received FSH/hMG, or hMG alone superovulation protocol after pituitary desensitization. Fertilization rate, cancellation rate, mean number of follicles, and endometrial thickness did not differ between the two groups. But in the FSH/hMG group, total oocyte per retrieval, embryo score, implantation rate, and viable pregnancy rates were slightly higher although the increase was not significant. Furthermore, the rate of preovulatory oocytes per retrieval, Estradiol (E2) level, embryos frozen, and embryos transferred were significantly higher in this group. This suggested that increasing the exogenous FSH/LH ratio in ovulation induction may result in a higher recovery of fertilizable oocytes and a subsequent potential for improvement in IVF outcome.

Adult↗

PubMed1993

Infarcted intramural uterine leiomyomata during buserelin acetate treatment.

Using continuous administration of gonadotropin releasing hormone analogues (GnRH-analogue) to induce a hypoestrogenic state and amenorrhea, leading to uterine fibroid volume reduction, has been reported to be successful and acceptable. Only a few adverse effects related to the therapy have been reported. We report a case of acute onset of abdominal pain, increased sedimentation rate and low grade fever during treatment with intranasal administration of Buserelin acetate. An emergent myomectomy was performed to remove an infarcted intramural myoma. We propose that acute ischemia of a large leiomyoma, especially during the postpartum period, is a noticeable complication during medical treatment with buserelin acetate for uterine leiomyoma.

Adult↗

PubMed1992

Isolation and characterization of four CSF-1-dependent placental macrophage cell lines.

By selection and cloning in the presence of colony-stimulating factor 1 (CSF-1), we have obtained from separate explants of individual 12- or 13-day mouse placentas four clonal cell lines dependent on CSF-1 for survival and growth in culture. All four cell lines show characteristics consistent with their derivation from placental macrophages. We describe the effects of CSF-1 on growth, morphology, and CSF-1 receptor phosphorylation. One cell line, JPL2A, which shows relatively complete growth arrest in the absence of CSF-1, was characterized in detail with respect to the effects of CSF-1 on DNA synthesis and protein turnover and its response to the duration of CSF-1 stimulation. In contrast to previous studies, our results suggest that extended stimulation leads to continuous recruitment of cells competent to reenter the cell cycle. These findings are discussed in terms of growth factor effects on the cell cycle and the usefulness of these cell lines for further study of growth factor signal transduction in macrophages.

Animals↗

PubMed1992

Time course of 125I-labeled LDL accumulation in the healing, balloon-deendothelialized rabbit aorta.

We previously showed by qualitative en face autoradiography that after 24 hours of circulation, 125I-labeled low density lipoprotein (LDL) injected in tracer amounts accumulated focally at the edges of regenerating endothelial islands in the balloon catheter-deendothelialized aorta of the normocholesterolemic rabbit. In the present study with the same animal model, we have used quantitative autoradiography to examine 125I-LDL accumulation in the healing aorta as a function of LDL circulation time from 2.5 to 40 hours. The results demonstrated that 125I-LDL accumulation in the healing aorta occurred in two kinetically and biochemically distinct compartments, one of which was in equilibrium with plasma and one of which sequestered LDL. LDL accumulation in the still-deendothelialized aorta (DEA) was diffuse and only moderately intense on autoradiography. It peaked 4 hours after injection; over the following 36 hours the disappearance of 125I-LDL from DEA paralleled the disappearance of 125I-LDL from plasma. In contrast, accumulation of 125I-LDL at the edges of regenerating endothelial islands was focal and intense. LDL accumulation in this compartment also peaked 4 hours after injection but remained elevated even at 40 hours, despite falling plasma levels of LDL. At 24 hours, edge LDL accumulation per unit area was more than five times greater than DEA accumulation. The data indicate that LDL accumulation in specific compartments of the functionally modified arterial wall occurs independently of either acute or chronic hypercholesterolemia. The contrast between labile LDL accumulation in DEA and persistent accumulation at the edges of healing aortic islands indicates that LDL accumulation in the two areas must involve different processes within the arterial wall itself.

Animals↗

PubMed1992

Simultaneous bilateral tubal pregnancies after in vitro fertilization and embryo transfer: report of a case.

Ectopic pregnancies continue to be a major complication of in vitro fertilization and embryo transfer (IVF-ET). A case of bilateral simultaneous tubal pregnancy after IVF-ET is described. The patient underwent ovum pick-up (OPU) through a laparotomy with concomitant pelvic surgery. Embryo transfer (ET) was performed two days after OPU; this resulted in bilateral tubal pregnancies, diagnosed and treated one month apart. There are several possible causal mechanisms for the increased rate of ectopic pregnancies following IVF-ET. It is important to recognize that care in the transfer technique, with respect to the catheter position and limiting the volume of transfer medium to 20 microL, and an awareness of previous occlusion of the tubal ostia, or of a salpingectomy before IVF-ET, can help to minimize this complication rate. Two important points are the possibility of a simultaneous bilateral tubal pregnancy after IVF-ET, and the necessity of carefully examining both adnexa at the time of surgery for an ectopic pregnancy. Early and accurate diagnosis of a simultaneous bilateral ectopic pregnancy can prevent the necessity of a second operation and reduce maternal morbidity and mortality.

Adult↗

PubMed1992

[Mouse embryos co-cultured with various generations of human ampullary cells].

The pregnancy rates for the gamete intra-fallopian transfer (GIFT) and tubal embryo transfer (TET) methods have been shown to be high. The oviductal environment appears to be suitable for fertilization and subsequent cleavage. Many authors have reported that when co-cultured with human ampullary cells, the embryos can develop in vitro as well as in vivo. Thus, significantly more embryos reach the early blastocyst stage, and more successful implantation may be obtained. However, the characteristics of the ampullary cells may change after a series of sub-cultures. In this study, we compared the first and the seventh sub-culture ampullary cell co-cultured systems with a control group. There were significantly more embryos cleaved to blastocysts in these two co-cultured systems than in the control group, but no significant difference between these two co-cultured systems. Detoxification of the medium by co-cultured cells may play an important role in improving embryo quality.

Animals↗

PubMed1992

Simplified instrumentation for laparoscopic ovarian cystectomy.

A modified technique that requires fewer specialized instruments for laparoscopic cystectomy is demonstrated. Twelve consecutive cases of laparoscopic management of the ovarian tumors are reported. Patients were not included if there was any suspicion of malignancy. Laparoscopic management of the ovarian tumors included ovarian cyst (N = 8) and endometrioma (N = 4). No intraoperative or postoperative complications occurred. The average hospital stay was 2.6 days. The whole tumor was removed through an infraumbilical incision. Laparoscopic cystectomy is a cost effective and safe procedure.

Adult↗

PubMed1992

Ovum donation program at Chang Gung Memorial Hospital, Taipei.

The ovum donation program at Chang Gung Memorial Hospital currently confronts the difficulty of limited oocyte resources. The oocytes might be donated from the surplus oocytes of IVF patients. However, after the successful introduction of embryo cryopreservation, patients preferred to have their surplus embryos cryop-reserved and thus, few surplus oocyts were available for donation from IVF program. In addition, official policies discourage use of oocytes donated by consanguineous relatives of either one of the recipient couple or for financial rewards. Among the first three oocytes recipients, with ovarian failure, one chemical pregnancy resulted. Oral premarin and transvaginal and intramuscular progesterone were administered as hormone replacement. The fourth recipient, who had had bilateral oophorectomy, received transdermal estradiol patch (Estraderm) and transvaginal progesterone (Utrogestan) as hormone replacement. The Estraderm/Utrogestan protocol became standard in later cases since the first ongoing pregnancy was achieved in patient 4. We feel this protocol satisfies the required ample levels of hormone replacement for ovum donation.

Adult↗

PubMed1991

Alteration of the T-cell receptor repertoire in A.CA mice expressing an Ead transgene.

In an effort to generate an A.CA mouse expressing Ed, the Ead gene has been introduced into A.CA mice which lack the major histocompatibility complex (MHC) class II E molecule. Flow cytometric analysis shows cell surface expression of the E alpha chain on lymphocytes and macrophages in the transgenic mice. Analysis of T-cell receptor (Tcr) genes deleted in some E-expressing mouse strains demonstrates that T cells expressing Tcrb-V5 are partially deleted in these transgenic mice while those expressing Tcrb-V8 and Tcrb-11 are not. In addition, the expressed E alpha d chain can promote Mycoplasma arthriditis mitogen (MAM)-induced T-cell proliferation. The expression of the E alpha chain, presumably as an A beta fE alpha d heterodimer, can alter the peripheral T-cell repertoire and T-cell reactivity to a microbial superantigen.

Animals↗

PubMed1991

A clinical pregnancy after a simple method of zona cutting, cryopreservation, and zygote intrafallopian transfer.

A 30-year-old nulliparous woman, who was infertile for greater than 3 years, conceived after the procedures of a simple method of zona cutting, cryopreservation, and ZIFT. This case illustrates: (1) acid medium, chymotrypsin, or sucrose are not needed for the procedure of zona cutting; (2) the zygotes resulting from zona cutting survive through freezing and thawing; and (3) oocyte retrieval can be done concomitant with conservative surgery for endometriosis.

Adult↗

PubMed1991

Comparison of histocompatibility between couples with idiopathic recurrent spontaneous abortion and normal multipara.

Since the immunological interaction between a mother and her intrauterine embryo is thought to be very important and since the human leukocyte antigens (HLA) are considered to be the most important correlative immunoresponsive antigens presently known, the present study was designed to investigate the HLA phenotype frequencies and antigen sharing percentages in couples suffering from recurrent abortion, as compared with normal fertile couples. The results showed that there were no HLA associations among these groups. The sharing study analyzed the similarities between single antigen groups (A, B, C, and DR) and multiple antigen complexes (AB and ABDR). The incidences for sharing more than one single antigen were 63.9%, 44.4%, 61.1% and 30.6% in the study group and 57.1%, 22.9%, 71.4% and 40.0% in the control group. Sharing of more than two antigens in the multiple antigen combinations were 36.2%, 47.2% for the study group and 22.9%, 42.9% for the control group. The statistical analyses reveals no significant differences. We conclude that although immunological reaction during the periimplantation period may be important and may play a role in later pregnancy stages, no single HLA antigen presentation or sharing of a certain number of antigens is related to the prognosis of pregnancy outcome.

Abortion, Habitual↗

PubMed1991

The survival and development rates in mouse embryo cryopreservation.

A research of mouse embryo cryopreservation was carried out in our department in order to establish the clinical service of human embryo cryopreservation. Mouse embryos were stored in glass vials using 1.5M propanediol (PROH) or 1.5M dimethyl sulfoxide (DMSO) as cryoprotectants and we used a modified four-step equilibration method to minimize osmolarity shock. We divided the 1490 embryos into two phases and compared phase 1 to phase 2. After achieving more sophisticated handling techniques and more accurate timing of each procedure, the survival rate (25% vs 59.8%) and stage advancing rate (5.2% vs 33.5%) were all improved in phase 2. The proportion of frozen embryos developing to hatched blastocysts was significantly increased from 14.5% to 56.7% in the 4-cell embryo groups compared to the 2-cell embryo groups. Two kinds of cryoprotectants were used in the 4-cell embryos and the results showed no difference in the post thaw survival rate but a better blastocystic development in the propanediol group (64.0% vs 41.5%). The results obtained from this study have encouraged us to initiate a major clinical trial of the technique in our IVF programs. Two pregnancies have been established upon the transfer of cryopreserved embryo and two normal healthy infants have already delivered at our hospital.

Animals↗

PubMed1990

Genetic recombination in the alpha 2 domain of the E alpha chain yields an Ed molecule with altered T cell activation.

We have used a novel T cell selection strategy to isolate a mutant of an H-2d/f murine macrophage line defective in its ability to present antigen to some Ed-restricted helper T cells. This mutant has an amino acid substitution in the alpha 2 domain of the Ed molecule. The mutation changes the sequence at codon 177 from ACC to CAC, which results in a threonine to histidine substitution and appears to be the first in vitro mutation to have arisen by genetic recombination. Even though the mutation is distal to the proposed antigen-binding groove, it affects antigen presentation, presumably by altering the scaffolding for the antigen-binding groove. This type of mutant might not be readily isolated using other selection techniques.

Amino Acid Sequence↗

PubMed1990

Focal accumulation of an apolipoprotein B-based synthetic oligopeptide in the healing rabbit arterial wall.

The functions of surface-accessible domains of apolipoprotein (apo) B, the protein moiety of low density lipoprotein (LDL), are unknown, aside from the LDL receptor-binding domain, which lies toward the carboxyl-terminal end of apoB. Since LDL accumulation in arterial lesions does not depend on recognition of LDLs by a cell-surface receptor, we synthesized an oligopeptide with the sequence of the trypsin-accessible domain of apoB that lies closest to the amino-terminal end of the protein and compared its biological activity to that of another synthetic oligopeptide with the sequence of the heparin- and apoB/apoE receptor-binding domains of apoE. (Tyrosine was added at the amino-terminal end of each peptide to facilitate radiolabeling.) The 18-amino acid apoB-based peptide included residues 1000-1016 of apoB, for which no function has been previously described. In radioautographs, the 125I-labeled peptide accumulated focally at the healing edges of regenerating endothelial islands in the balloon-catheter deendothelialized rabbit aorta. In contrast, the 21-residue apoE-based peptide, which included residues 129-148 of apoE, accumulated diffusely and uniformly throughout the deendothelialized areas of the aorta. The data show that focal binding of the apoB-based peptide can delineate arterial lesions and suggest that this arterial wall-binding domain of apoB mediates accumulation of LDLs in arterial lesions.

Amino Acid Sequence↗

PubMed1989

Immediate versus delayed progesterone supplementation in gamete intrafallopian transfer (GIFT).

Exogenous progesterone (P) was supplemented to gamete intrafallopian transfer (GIFT) patients to determine the optimal timing to start P supplementation and the role of isthmic block in GIFT. Patients were alternatively divided into two groups. In the immediate group, exogenous P was supplied from the day of surgery. In the delayed group, P was supplied 4 days after the surgery, the day the fertilized ovum is supposed to arrive in the uterine cavity. Except for higher serum P levels on luteal day 3 in the immediate group, no significant differences were found in serum P levels during the early luteal phase, the pregnancy rate, and the abortion rate between the two groups. It is possible that in stimulated cycles, higher serum P levels during the early luteal phase render the endometrium receptive for embryo implantation, albeit unlock the isthmic block. It may not be crucial to start exogenous P supplementation either before or after a fertilized egg(s) arrives in the uterine cavity. The role of isthmic block in GIFT needs further evaluation.

Fallopian Tubes↗

PubMed1989

Selective continuation in quadruplets pregnancy following treatment of GIFT plus IVF and ET.

In this report, we present the selective reduction of quadruplets to triplets by transabdominal ultrasound guided cardiac puncture and injection of 1% xylocaine and air. This treatment resulted in the successful continuation of pregnancy until premature labor developed at the 33th week. Alive births of a normal male and a normal female infant, and a dead female infant were delivered.

Abortion, Induced↗

PubMed1989

Transvaginal ultrasound-directed oocyte retrieval for in vitro fertilization.

Oocyte retrieval for in vitro fertilization and embryo transfer (IVF/ET) through the cul-de-sac under the guidance of a vaginal sector scanner was performed on 12 patients and compared with the previous laparoscopical oocytes retrieval for in vitro fertilization. Using a transvaginal sector scanner with puncture guide line, the needle was introduced through the posterior fornix of the vagina into the ovary. Vaginal sonography obviously has more benefits than the conventional laparoscopic method as the patients can be rid of the risk of repeated laparoscopy, can have less anesthetic and it is not necessary to have CO2 pneumoperitoneum, etc. When this method is compared with the transvesical approach, the transvaginal method does not require a full bladder, and has a shorter distance between the transducer and the follicles so it can provide better patient acceptability and better sonographic images which can increase the accumulated success rate. The recovery rate of oocytes was 8.83 per cycle which equals a mean recovery rate of 84%. The clinical pregnancy rate was 25% per retrieval cycle and 33.3% per embryo transfer. The results were not worse than those by laparoscopy and the transvesical method. This procedure is less time-consuming and has less blood loss than the other methods. We believe that, after a period of progression, IVF/ET can be performed in an outpatient setting with decreased risks and expenses of laparoscopy and general anesthesia.

Adult↗

PubMed1989

Factors affecting pregnancy rates of in vitro fertilization and gamete intrafallopian transfer.

Factors affecting pregnancy rates in gamete intrafallopian transfer (GIFT) and in vitro fertilization (IVF) were evaluated. Higher pregnancy rates were found when more mature oocytes were recovered (6.2 +/- 2.5 vs 3.8 +/- 3.0) and more oocytes (4.6 +/- 1.0 vs 3.3 +/- 1.2) or zygotes (4.7 +/- 1.4 vs 3.0 +/- 1.7) were transferred. Ultrasound-guided follicular aspiration was successful for in vitro fertilization and had a pregnancy rate (14.3%) comparable to the laparoscopic approach (13.3%). Laparotomy for correction of pelvic pathology concomitant with oocyte retrieval should be used cautiously despite the high preliminary pregnancy rate (42.9%). Failed fertilization of the surplus oocytes left after gamete intrafallopian transfer did not mean a poor chance of pregnancy (27.6%). The combined treatment of gamete intrafallopian transfer and in vitro fertilization may have a higher chance of pregnancy (43.5% vs 21.4% in GIFT and 13.3% in IVF), and more multiple pregnancies (40.0% vs 22.2% in GIFT and 16.7% in IVF). Cycles with spontaneous LH (luteinizing hormone) surges, detected by daily morning urine samplings, need not be aborted and the timing of ovum recovery should be individually evaluated.

Female↗