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Biomedical subjects

M Y Chang

Publications and source records attributed to M Y Chang.

At least 55 records · Page 3Linked to original sources
PubMed1996

Case manager follow-up to failed appointments and subsequent service utilization.

Case manager responses to failed appointments were monitored for 83 seriously mentally ill persons in a rural community mental health center. Case manager actions taken were grouped into four categories of follow-up from most intensive to least intensive: home visit, phone call, letter, and no follow-up. On the whole, case managers most frequently did not follow-up missed appointments (56.7%), followed up by letters (21.3%), and telephone calls (18.7%), and home visits (3.3%). Analyses revealed that home visits were most intensive and all clients who were visited following failed appointments did not fail the subsequent appointment. Clients who received telephone calls or letters were about equally likely to fail the subsequent appointment, but were much more likely to attend the subsequent appointment than were clients who received no follow-up to the failed appointment. Interestingly, clients who failed appointments and received no follow-up were much more likely to need emergency services rather than a regular appointment as their next contact with the clinic.

Appointments and Schedules↗
PubMed1996

Comparison of hysterosalpingography and hysteroscopy in female infertility.

STUDY OBJECTIVE: To determine the diagnostic value of hysterosalpingography (HSG) and diagnostic hysteroscopy in infertility evaluations. DESIGN: Comparative 2-year study. SETTING: Outpatient infertility clinic of a tertiary medical center. PATIENTS: Two hundred sixteen women being investigated for infertility. INTERVENTIONS: An HSG was followed by a diagnostic hysteroscopy. MEASUREMENTS AND MAIN RESULTS: The HSGs were interpreted as normal in 79 (36.9%) women and as showing some abnormalities of the uterine cavity in 135 (63.1%). In the former group, 51 patients had a normal uterine cavity, but 28 had abnormal findings on hysteroscopy, a false negative rate of 35.4%. Of 135 women with an abnormal HSG, hysteroscopy found a normal uterine cavity in 21, a false positive rate of 15.6%. The sensitivity of HSG was 80.3% in revealing intrauterine abnormality and its specificity was 70.1%. Although some abnormalities were identified by both methods in 114 women, findings of both procedures were similar in only 88 (77.2%). In 75 (35.0%), the findings of HSG differed from those of hysteroscopy. In only 139 (65%) patients were the findings (normal and abnormal) similar for both methods. CONCLUSIONS: We advocate hysteroscopy in the investigation of female infertility for its accuracy, safety, simplicity, and convenience.

Adolescent↗
PubMed1996

Mechanisms by which HLA-class II molecules protect human B lymphoid tumour cells against NK- and LAK-mediated cytolysis.

We have previously shown that mutant B lymphoblastoid cell lines, totally deficient in expression of human leucocyte antigen (HLA)-class II molecules, but with normal HLA-class I expression, develop enhanced susceptibility to natural killer (NK) and lymphokine-activated killer (LAK) cell lysis. The current investigations were aimed at examining the role of HLA-DR and native peptides occupying the antigen-presenting grooves of HLA-class II molecules in protecting mutants of the same B-lymphoid lines against LAK-mediated lysis. No augmentation in LAK lysis was observed despite using two mutant B-cell lines (9.22.3 and 3.1.0) that lacked HLA-DR. Both these lines expressed HLA-DP and HLA-DQ. However, when using other B-cell lines with point mutations in certain regions of the HLA-DR alpha-chain (78, 80 and 96) significantly increased their susceptibility to LAK lysis despite normal expression of HLA-DR and the other class I and II molecules. Of particular interest was the finding that absence of native peptides in antigen-presenting grooves of all the HLA-class II molecules did not render the mutant B cell (9.5.3) susceptible to LAK lysis. These observations support the concept that there are different NK or LAK clones. Certain LAK clones recognize 'self' major histocompatibility complex (MHC) antigens (but not the native peptides in their antigen-presenting grooves). Presence of 'self' MHC antigens inhibits such clones. Conversely, other NK or LAK clones recognize 'non-self' in the context of MHC antigens. Hence, point mutations at certain specific sites on the MHC molecules or foreign peptides in the antigen-presenting grooves enhances the susceptibility of these cells to LAK clones recognizing 'non-self'.

Antigen Presentation↗
PubMed1996

Preimplantation diagnosis of alpha-thalassemia by blastomere aspiration and polymerase chain reaction: preliminary experience.

The ability to diagnose and detect the presence of debilitating and life-threatening diseases would be an invaluable asset to those involved in in vitro fertilization programs. To investigate the possibility of diagnosing severe alpha-thalassemia before implantation, DNA sequences targeting the abnormal deletion breakpoint and the normal region of the alpha-globin gene were amplified by polymerase chain reaction from blastomeres aspirated from human preimplantation embryos. Before performing this experiment, a mouse model blastomere aspiration technique was examined to confirm embryo survival and normal development capability. The mouse embryos showed undisturbed development in the five- to seven-, as well as the eight-cell stages when one, or two (eight-cell stage only) blastomeres were aspirated. The four-cell embryos had a lower survival rate but had a blastocyst formation rate comparable to the more advanced stages and the control embryos. In the human embryo experiment, no homozygous Southeast Asian alpha-thalassemia was detected in the aspirated blastomeres, although two heterozygotic alpha-thalassemia embryos were discovered. The sensitivities of targeting sequence detection in the mouse and human blastomeres were between 50% and 76% in the respective groups. This study supports the feasibility of preimplantation diagnosis of severe alpha-thalassemia when both father and mother are carriers of this inheritable disease.

Animals↗
PubMed1996

The effects of Vero cell co-culture on human zygotes resulting from in vitro fertilization and oocytes following subzonal insemination.

A variety of co-culture systems have been devised to enhance the human embryo development in vitro. Vero cells were selected because they can be highly controlled and are easy to handle. To evaluate the embryotrophic effects of Vero cell monolayers, when they were co-cultured with human in vitro fertilized zygotes or subzonal inseminated oocytes. Total 1695 two-pronuclear embryos resulting from in vitro fertilization were cultured with Vero cells or medium alone for 24 hours. Similarly, sixty-six two-pronuclear embryos resulted from subzonal insertion of sperm (SUZI) with co-culture starting immediately following SUZI were compared with fifty-two two-pronuclear embryos resulted from SUZI, without co-culture. The numbers of blastomere and morphology of embryos were compared between the co-culture group and control group using student's t-test. Cell numbers in each embryo were greater in the IVF/co-culture group than in the control group (4.01 +/- 1.32 vs. 3.86 +/- 1.45, p < 0.05). The rates of poor quality embryo with major fragmentation were lower in the co-culture group than in the control group(11.5% vs. 19.9%, p < 0.001, for IVF embryos; 9% vs. 27%, p < 0.005, for SUZI oocytes). Co-culture SUZI oocytes on Vero cells prior to fertilization did not positively influence embryo cleavage, but improved embryo quality. We conclude that Vero cells can enhance human embryo development; however, the period for one-day or two-day co-culture is too short to provide a maximal support. Short term co-culture did not increase implantation rates. Immediate co-culture following SUZI might somewhat rescue the microinseminated oocytes. However, a longer duration of co-culture is necessary to exert the maximal effects on embryo development and implantation.

Adult↗
PubMed1996

Improved sperm recovery rate with Percoll gradient method in intrauterine insemination.

The purpose of this study was to compare the different sperm manipulation methods on the recovery rate of motile sperm that was collected to use in the intrauterine insemination. Three hundred and thirty-five IUI (intrauterine insemination) cycle from a total of 963 treatment cycles was performed for non-peritoneal factor infertility couples. The sperm separation methods were swim-up, swim-down and Percoll gradient (since Mar. 1992). We compared the different sperm preparation methods in normal and abnormal semen analysis group. Our results show that in the abnormal semen samples (oligospermic approximately, asthenospermic approximately), the Percoll gradient method is superior to the swim-up and swim-down methods on the recovery of a higher number of total, motile and active motile spermatozoa (p < 0.05), even though the sperm quality before preparation was rather poorer than the samples prepared by the other two methods. The pregnancy rate in both groups are not statistically significant. We conclude that the Percoll gradient is an improved method for semen manipulation as it allows greater recovery of sperm with higher motility in intrauterine insemination.

Adult↗
PubMed1995

Inhibition of hypercholesterolemia-induced atherosclerosis in the nonhuman primate by probucol. II. Cellular composition and proliferation.

In nonhuman primates (Macaca nemestrina) treated with the antioxidant probucol during diet-induced hypercholesterolemia, intimal lesion area in the thoracic aorta was decreased, with increased resistance of plasma LDL to oxidation. The cellular and molecular changes associated with the decrease in lesion size in the probucol-treated hypercholesterolemic animals are quantitatively evaluated in this study. Lesions from the probucol-treated animals appear less mature and have altered lipid distribution. Abundant lipid-laden smooth muscle cells are found in the intima and media of the probucol-treated animals, with fewer medial lipid-laden macrophages, compared with lesions at similar sites in the control hypercholesterolemic animals. In both the control and probucol-treated animals, macrophages are the predominant cells in most lesions, but the ratio of macrophages to smooth muscle cells is decreased in the lower thoracic and upper abdominal aortic sites in the probucol-treated animals. Lesions at all aortic sites in the probucol-treated animals have a 35% to 80% reduction in the percentage of cells in cell cycle traverse, as indicated by immunostaining for proliferating cell nuclear antigen (% PCNA-positive). In both groups, macrophages and smooth muscle cells are PCNA-positive, but the majority (> 60%) are macrophages. No difference in % PCNA-positive cells is seen in the iliac arteries, where the most advanced lesions were present at the time probucol administration was initiated. Limited Northern analysis of growth-regulatory molecules possibly involved in the cellular changes associated with lesions shows a 30% to 50% decrease in mRNA levels of platelet-derived growth factor (PDGF) B-chain, PDGF beta-receptor, colony-stimulating factor type 1, and monocyte chemotactic protein 1. Thus, a potential role for an antioxidant such as probucol in the treatment of atherosclerosis may be to alter the early inflammatory fibroproliferative processes of the disease. Whether these effects are directly related to the antioxidant properties or some other activity of probucol is not yet known.

Animals↗
PubMed1995

Parameters of semen analysis affecting the pregnancy rate of artificial insemination with husband's spermatozoa.

The efficacy of intrauterine insemination with husband's semen (AIH) is well established for some types of infertility. Results that had been reported previously were Dwing difficult to assess owing to the low number of patients or treatment cycles as well as an inadequate definition of the indications in most cases. In this study, we report our experience with intrauterine insemination (IUI) using post-treated sperm suspension from husband's semen in the treatment of infertility. A total of 328 treatment cycles were completed from January to December in 1991. The indications for AIH/IUI were male infertility (130 cycles), unexplained infertility (87 cycles), sex selection (72 cycles) and anovulatory disorder (39 cycles). Sixty-eight pregnancies were achieved. The clinical usefulness of AIH/IUI with or without concomitant hMG regimens were established according to diagnostic subgroups. In our results, the cycle fecundity of pregnancy was higher in patients with ovulatory disturbance. The importance of sperm motility confirmed by our results that have compared by the serial sperm parameters. The motile sperm count may appear to be a highly consistent parameter that serves as a sensitive indicator of sperm function and correlation of successful pregnancy in our results. In conclusion, this study indicates that AIH with controlled ovarian hyperstimulation can result in higher viable pregnancy rate, and it is also a non-invasive and relatively easy procedure. We believe that this is a transient useful method for the treatment of non-organic infertility, prior to any attempt of aggressive assisted reproductive procedures.

Female↗
PubMed1995

Major complications during laparoscopy-assisted vaginal hysterectomy--report of four cases and review of the literature.

This paper presents four recent cases of complications resulting from of a total 130 cases of laparoscopy-assisted vaginal hysterectomies performed at Chang Gung Memorial Hospital from March 1991 till January 1993. These included two cases of bladder injury, one case of vessel laceration and one case of colon injury. In addition, the literature about complications occurring at laparoscopy are reviewed and classified. This paper will: 1. present precautionary measures for avoiding intraoperative complications; 2. describe management of complications.

Adult↗
PubMed1995

Transvaginal ultrasound-guided aspiration and surgical starch sclerosis therapy in recurrent pelvic inclusion cysts--report of two cases.

Pelvic inclusion cyst is one of the complications of major abdominal surgery. Treatment of the symptomatic mass is either surgical or needle aspiration. However, recurrence of the condition is still not uncommon. Repeated surgery or aspiration could result in serious morbidity. We report two cases of recurrent pelvic inclusion cyst which were successfully treated with transvaginal aspiration and sclerosing therapy with starch powder from surgical gloves and normal saline solution. The aspirations were guided by transvaginal ultrasound and on local paracervical anesthesia. Starch and normal saline solution were injected through the aspiration needle for irrigation three times. One patient with a large cyst needed two treatment courses, the other only one. Both patients had no discomfort both intra- and postoperatively. A Follow-up ultrasonography proved no recurrence to date.

Adult↗
PubMed1994

Matrix solid-phase dispersion extraction and gas chromatographic screening of polychlorinated biphenyls in fish.

A matrix solid-phase extraction (MSPD) and gas chromatographic-electron-capture detection method for determining polychlorinated biphenyls (PCBs) in fish (grass carp) is described. The method uses an octadecylsilyl-derivatized silica and acidic silica gel-based MSPD co-column for direct in-line clean-up. The performance of the method compares favourably with that of the traditional approach but the sample size, analysis time and overall cost are lower. The method may serve as a screening protocol for the isolation and determination of PCBs in fish.

Animals↗
PubMed1994

Solitary plasmacytoma of bone.

From 1978 to 1992, 19 patients were diagnosed with solitary plasmacytoma of bone (SPB) accounting for 5.5% of plasma cell neoplasms in Chang Gung Memorial Hospital. Fourteen were male and five were female, with ages ranging from 21 to 71 years (median, 53 years). M-protein was detected at diagnosis in five patients, and during follow-up in three. The most common sites of SPB were the vertebral bodies, with seven involving the thoracic, four involving the lumbar and two involving the cervical spine. The remaining sites included the skull in four, and femur and pelvis in one each. Fifteen of the patients received local radiotherapy, local control was achieved in all; nine patients were alive with no evidence of disease for seven to 77 months, two patients remained in apparent remission at 14 and 92 months, two patients progressed to multiple myeloma at 12 and 84 months, one patient developed extramedullary plasmacytoma at three months, and one patient died of intercurrent disease at four months. The four patients who were not treated with radiation therapy ultimately developed local recurrence or dissemination within four years. In our series, local recurrence or dissemination was always associated with the appearance of, or an increase in, the M-component; thus, measurement of M-protein is helpful in assessing tumor control or progression. Based on our experience and a review of the literature, it is recommended that irradiation of the primary sites is the treatment of choice. Chemotherapy is indicated in those patients with disease progression, recurrence, or dissemination.

Adult↗
PubMed1994

Alveolar soft part sarcoma of the vagina. A case report.

We present a case of alveolar soft part sarcoma of the vagina in an 18-year-old woman. The presenting symptoms were menometrorrhagia and a painless vaginal mass. The tumor was in the vaginal stroma with intact mucosa. Periodic acid-Schiff stain showed positive diastase-resistant crystals in some of the tumor cells. Electron microscopy demonstrated characteristic intracytoplasmic crystals. Formaldehyde-induced fluorescence stain showed no catecholamines, and Grimelius stain showed no argyrophilic granules. Black pigment was found within some tumor cells; it proved to be melanin pigment by Masson-Fontana stain. The tumor mass recurred four months after local excision. Following the second surgical removal, the patient received adjuvant radiotherapy to the whole pelvis, including the vagina. At this writing she was currently alive, without evidence of recurrence, five years after the primary diagnosis.

Adolescent↗
PubMed1993

Low-density lipoprotein modification and arterial wall accumulation in a rabbit model of atherosclerosis.

Chemically or enzymatically modified low-density lipoproteins (LDL), with and without changes in surface charge, were studied in vivo in the healing, balloon catheter-deendothelialized rabbit aorta to determine the effect of LDL modification on its accumulation in arterial lesions. In this model, in which healing (reendothelialization) proceeds radially outward from individual aortic branch arteries, it was previously shown by autoradiography that two kinetically distinct compartments accumulated 125I-labeled LDL. In aortic regions which were still deendothelialized, accumulation was diffuse and labile. In contrast, at the edges of the islands of regenerating endothelium, LDL accumulation was intensely focal, as it is in human atherosclerotic lesions, and persisted for at least 40 h after injection in spite of falling levels of radiolabeled LDL in plasma [Chang, M. Y., et al. (1992) Arterioscler. Thromb. 12, 1088-1098]. In the present study, modified LDLs with gradations in charge change were prepared to clarify the role of changes in surface charge on focal aortic LDL accumulation. Oxidized LDL (weakly anionized), desialated LDL (weakly cationized), and reductively methylated LDL (no change in net charge) all accumulated focally. Focal accumulation of native LDL also occurred in ballooned rabbits fed probucol to inhibit LDL oxidation. Strongly anionized succinylated and diazobenzenearsonylated LDL and strongly cationized dimethylpropanediamine LDL did not accumulate focally. The results support the concept that focal sequestration of LDL in arterial lesions is mediated by specific, oxidation-independent patterns of charge and polarity on LDL which are disrupted by major changes in LDL surface charge.

Aniline Compounds↗
PubMed1993

The management of ovarian cysts by sono-guided transvaginal cyst aspiration.

Nineteen transvaginal, sono-guided ovarian cyst punctures were performed in 18 patients. These patients, who were high surgical risks, were diagnosed to possess benign ovarian tumors as revealed with sonography. Aspiration curettage of the inner surface of the cyst present during aspiration was also performed to facilitate cytologic diagnosis. The recurrence rate was 11.1%. Sono-guided transvaginal cyst aspiration has been demonstrated here to be the treatment of choice for dealing with an ovarian cyst in patients at high surgical risk.

Adult↗
PubMed1993

No detrimental effects in delaying initiation of gonadotropin administration after pituitary desensitization with gonadotropin-releasing hormone agonist.

OBJECTIVE: To determine if delaying initiation of exogenous gonadotropin administration after pituitary desensitization with gonadotropin-releasing hormone agonist (GnRH-a) is a realistic option to avoid scheduling clinical and laboratory work on weekends/holidays. DESIGN, PATIENTS: A review of 57 in vitro fertilization (IVF) cycles in which, after pituitary desensitization with GnRH-a, initiation of gonadotropin administration were delayed in an attempt to avoid off-hour work. Thirty-eight IVF cohort cycles served as control. SETTING: Tertiary medical center. RESULTS: There were no statistically significant differences in ovarian response, dose of gonadotropin required, oocytes and embryos obtained, pregnancy rates, and abortion rates between groups. Eighty-three percent of the delayed cycles had clinical and laboratory work that fell within weekdays. CONCLUSION: Delaying initiation of exogenous gonadotropin administration after pituitary desensitization had no detrimental effects on IVF outcomes. It may be used to avoid scheduling work on weekends/holidays.

Adult↗
PubMed1993

Treatment of infertility using controlled ovarian hyperstimulation with intrauterine insemination: the experience of 343 cases.

Fecundity rates were measured for 343 patients in 467 cycles of ovulation induction with intrauterine insemination (IUI) from January 1990 to April 1992. Total pregnancy rate per cycle (PR) was 15.6% with a spontaneous abortion (SA) rate of 19.2%, an ectopic pregnancy (EP) rate of 4.1%, a multiple pregnancy (MP) rate of 19.2%, and an ongoing or live-birth (LB) rate of 12.0%. Using gonadotropins as a unique or as an additional stimulatory reagent improved the pregnancy rate of anovulatory patients by more than three-fold over use of clomiphene citrate (CC) alone (33.3% vs 10.7%). In other diagnostic entities, the PRs were higher, but the difference was not statistically significant between these two stimulation protocols (13.9% vs 8.4%; t = 1.70, p > 0.05). Pretreatment sperm motility and the post-treatment total motile sperm count were significantly correlated with the PRs. The same phenomena occurred when the number of follicles > or = 12 mm and the serum estradiol concentrations were taken into account. The highest PR was detected when the endometrial thickness fell between 8 and 13 mm. The spontaneous abortion rate was higher in CC only cycles and when the serum E2 was below 1000 pg/mL on the day human chorionic gonadotropin was administered. A multiple pregnancy could be predicted when a cycle of more than 10 follicles > or = 12 mm was detected (44.4%). The complications of controlled ovarian hyperstimulation with IUI were low and mild in our study, comprising six cases of moderate to severe ovarian hyperstimulation syndrome and three cases of acute pelvic inflammatory disease.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗