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Biomedical subjects

H C Liu

Publications and source records attributed to H C Liu.

At least 181 records · Page 10Linked to original sources
PubMed1995

Clomiphene citrate and hMG: an alternative stimulation protocol for selected failed in vitro fertilization patients.

PURPOSE: This study was carried out to evaluate the potential role of the combination clomiphene citrate/human menopausal gonadotropin (CC/hMG) for patients who failed previous in vitro fertilization (IVF) attempts with gonadotropin-releasing hormone analogs (GnRH-a) and/or exogenous gonadotropins. METHODS: Patients were stimulated with CC/hMG (n = 93) after unsuccessfully undergoing 182 gonadotropin cycles with (n = 106) or without (n = 76) luteal-phase GnRH-a. Cancellation rate, length of stimulation, and peak estradiol levels did not differ significantly between the two regimens. RESULTS: Although fewer oocytes were retrieved when the CC/hMG combination was used, 16 patients were able to successfully achieve a pregnancy (26.2% delivery rate/transfer). When daily follicle stimulating hormone (FSH) levels were measured in two successive cycles in those women who conceived with the CC/hMG stimulation, baseline levels did not differ when compared with a previous GnRH-a/hMG cycle. Nevertheless, serum FSH levels rose rapidly and remained higher in the GnRH-a/hMG cycle, reaching significantly higher levels on day of human chorionic gonadotropin (hCG) administration. CONCLUSION: Selected patients who failed previous IVF attempts with gonadotropins with or without GnRH analogs may benefit from the addition of CC to their ovarian stimulation protocol.

Adult↗
PubMed1995

Performance on a smell screening test (the MODSIT): a study of 510 predominantly illiterate Chinese subjects.

The 12-item Modular Smell Identification Test (MODSIT) was administered to 239 male and 271 female Chinese subjects whose age ranged from 50 to 92 years (68.3 +/- 10.9) and whose education ranged from 0 to 20 years (2.5 +/- 4.3). Every participant was examined by a physician and was found to be free of dementia, stroke, and Parkinson's disease. Different from the standard procedures, only one-third of each odor pad was used for each subject, the four odor choices were presented orally for the majority of subjects, and they were not forced to make a selection when they could not detect or identify the odor. The average level of performance was 46% correct. The score was negatively associated with age, positively associated with education and with performance on a dementia screening test, and corroborated with subjects' report of smell deterioration in recent years. Nonsmokers and women performed better than smokers and men. The 12-item MODSIT had an internal consistency reliability of 0.73 and a 7-month retest stability of 0.57 with different examiners. The MODSIT is satisfactory for group studies, even when administered with suboptimal procedures such as those used in the present study.

Age Distribution↗
PubMed1995

Mechanical properties and histological evaluation of sintered beta-Ca2P2O7 with Na4P2O7.10H2O addition.

The ultimate goal of implantation of biomaterials in the skeleton is to reach full integration of the non-living implant with the living bone. The biomaterial can be used much as a bone graft, resorbing or dissolving as bone growth occurs, and the end result is a new remoulded bone. Calcium pyrophosphate, Ca2P2O7, is one of the intermediate products of bone mineralization. beta-Dicalcium pyrophosphate (beta-DCP) doped with certain amounts of Na4P2O7.10H2O was prepared as the developed material. Na4P2O7.10H2O was used as a liquid-phase additive to improve the sintering process and promote physiological bioresorbability. Compressive strength and four-point bending strength were measured by the Bionix test system 858. The mechanical strength of the sintered beta-DCP increased with the addition of Na4P2O7.10H2O up to 5 wt%, but thereafter decreased. The microstructure and crystal structure were analysed by the techniques of SEM, EPMA, TEM and XRD. The relationship between the mechanical strength of the sintered bioceramics and the Na4P2O7.10H2O dopant was examined in terms of the presence of NaCa(PO3)3, grain growth and abnormal grain coalescence while the dopant increased. Preliminary in vivo evaluation was studied by rabbit femur condyle implantation. There was no inflammation or any toxic sign during the experimental period. The histological section of intraosseous implantation revealed that the new bone deposited directly on the surface of the material in the fourth week after operation. The implant gradually decreased in volume and was replaced by the surrounding regenerated bone in the rabbit condyle in vivo environment. The results led us to conclude that the developed material has great potential as a biodegradable bone substitute.

Animals↗
PubMed1995

The effects of ultrasonic stimulation on DP-bioglass bone substitute.

In previous studies, DP-bioglass showed good biocompatibility and can form a chemical bond with natural bone. After implementation in the rabbit femur condyle for 32 weeks, DP-bioglass gradually biodegraded and osteocytes grew into the material. In this study, an attempt has been made to utilize low intensity pulsed ultrasound to speed up the bone regeneration rate and DP-bioglass absorption rate when the DP-bioglass is implanted into the rabbit femur condyle as a bone substitute. The fundamental parameters of the ultrasound used were 1.5 MHz frequency, 0.5 W cm-2 intensity, on-off ratio 1:1 and 2 ms for the on-off time interval. The stimulation, in all cases, was started 24 h after the operations by applying the transducer to the skin using DIR ultrasound jelly as a coupling medium. The evaluation of the progress of bone regeneration and the material's biodegradable rate were conducted by histological examination and by measurements of the areas of regenerated bone, pores and DP-bioglass made with a planimeter. It was found that low intensity pulsed ultrasound had a profound effect on the rate both of bone regeneration and DP-bioglass bioabsorption in this rabbit model and that its mechanism of the action may be via an electromechanical kinetic effect on the cell membrane interfaces.

Animals↗
PubMed1995

Endometriosis: a stage by stage analysis--the role of in vitro fertilization.

OBJECTIVE: To investigate the impact of endometriosis stage on IVF. PATIENTS: A retrospective study of 214 patients diagnosed with endometriosis who underwent 360 cycles of IVF at The New York Hospital-Cornell Medical Center. Meanwhile, 111 pure mechanical (tubal) infertility patients treated in 160 cycles at the same time were designated as the control group for comparison. MAIN OUTCOME MEASURES: Patient's hormone and semen profiles, hormonal response and outcome to stimulation, as well as the outcome of pregnancy, abortion, and delivery rate were analyzed. RESULTS: No differences in the pregnancy outcome between the endometriosis and control groups were noted when compared among the subgroups of pure endometriosis, endometriosis plus tubal factor, endometriosis plus others (primarily endometriosis plus male factor), and control. Comparing the outcomes in pure endometriosis cases by staging, we could not find any discrepancies in terms of pregnancy rates (PRs) according to the severity of the disease. The addition of GnRH analogur down-regulation to gonadotropin stimulation resulted in an increase in PR. A relatively high delivery rate (38.9% per cycle, 41.9% per retrieval, and 43.2% per transfer) was achieved when the pure endometriosis patients were treated with concomitant leuprolide acetate down-regulation and gonadotropin. CONCLUSION: We have observed that pregnancy outcome in patients with endometriosis was not different than the outcome for patients with mechanical (tubal) infertility. There were no differences in PRs by stage of endometriosis.

Adult↗
PubMed1995

Day 3 estradiol serum concentrations as prognosticators of ovarian stimulation response and pregnancy outcome in patients undergoing in vitro fertilization.

OBJECTIVE: To test the hypothesis that elevated E2 levels on day 3 of IVF cycles without GnRH agonist (GnRH-a) are associated with reduced oocyte numbers and pregnancy rates (PRs). DESIGN: Day 3 levels of E2 and FSH were obtained from patients undergoing controlled ovarian hyperstimulation without GnRH analogue for IVF. PATIENTS: Five hundred ninety-two consecutive IVF cycles. RESULTS: Patients were grouped according to their day 3 E2 levels (< 30, 31 to 45, 46 to 60, 61 to 75, and > 75 pg/mL [conversion factor to SI unit, 3.671]). The ongoing PR per retrieval for patients with E2 levels < 30 pg/mL was significantly higher than for patients with E2 levels 31 to 75 pg/mL. There were no pregnancies if the E2 level was > 75 pg/mL. The mean number of oocytes per retrieval was significantly lower in patients from the E2 groups with E2 > 60 pg/mL compared with patients in groups with E2 < 60 pg/mL. Day 3 FSH and E2 levels also were evaluated simultaneously. In patients with the lowest levels of FSH and E2, the PR was the highest. No pregnancies occurred if the FSH level was > 17 mIU/mL (conversion factor to SI unit, 1.00) and the E2 level was > 45 pg/mL on day 3. CONCLUSIONS: For patients undergoing IVF without GnRH analogue, oocyte numbers and PRs decrease with increasing levels of day 3 E2. Combining day 3 FSH and E2 improved the prognostic ability of either of these hormones used alone.

Adult↗
PubMed1995

Endometrial thickness appears to be a significant factor in embryo implantation in in-vitro fertilization.

To evaluate the role of endometrial thickness and pattern in in-vitro fertilization (IVF), these parameters were prospectively measured in 516 cycles of IVF with embryo transfer at our clinic. Pregnancy and embryo implantation rates were assessed for each mm of endometrial thickness and for each of three endometrial patterns. Embryo implantation, clinical and ongoing pregnancy rates were significantly higher in the patients with an endometrial thickness > 9 mm (24.4, 48.6 and 42.2% respectively) compared with those of < 9 mm (14.3, 16.0 and 11.7% respectively; P < 0.005). Endometrial thickness was negatively influenced by age and positively influenced by oestradiol concentration. The majority of patients (69.8%) exhibited a 'ring' endometrial pattern. Embryo implantation and clinical pregnancy (statistically significant), as well as ongoing pregnancy rates (not statistically significant), were lower in patients exhibiting the 'solid' pattern. Endometrial thickness is independent of pattern in its effect on pregnancy outcome. In conclusion, endometrial thickness > 9 mm as well as ring and intermediate endometrial patterns denoted a more favourable prognosis for pregnancy in IVF but thinner endometrium and those exhibiting a solid configuration had an acceptable pregnancy outcome.

Adult↗
PubMed1995

Prevalence and subtypes of dementia in Taiwan: a community survey of 5297 individuals.

OBJECTIVE: To study the prevalence rate of dementia in Taiwan, the relative frequencies of its subtypes, and its associations with age, education, gender, and residence location. PARTICIPANTS: A total of 2753 men and 2544 women from four urban and four rural communities participated. Their age ranged from 41 to 88 years; 28% of them were at least 65 years old. Their education ranged from 0 to 20 years; 27% of them had less than 1 year of formal schooling. DESIGN: Phase I was a screening survey by trained nurses who administered a Chinese version of the Mini-Mental State Examination, the MMSE-T1, to all participants. Phase II involved the assessment for dementia by neurologists on the 1521 individuals who had scored less than 24 on the 30-point MMSE-T1. MAIN RESULTS: Thirty-one cases of dementia were identified by the DSM-III-R criteria, including 18 cases of Alzheimer's disease, 10 cases of vascular dementia, and three cases of other dementias. The prevalence rate in individuals aged 65 and over was 2.0%. Aging and illiteracy were associated with higher rates of dementia; gender and residence location made no difference. CONCLUSIONS: The prevalence rate of dementia was low in this Chinese population. Consistent with common findings from other parts of the world, a high rate of dementia was associated with older age and illiteracy, and Alzheimer's disease was the most frequent cause.

Adult↗
PubMed1995

The Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE) as a screening tool for dementia for a predominantly illiterate Chinese population.

The Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE) provides ratings of an individual's changes in everyday cognitive functions during the previous 10 years. Original studies conducted in Australia showed that its score was not influenced by the subjects' educational backgrounds and that it performed at least as well as the Mini-Mental State Examination (MMSE) as a screening instrument for dementia. The subjects of the present study were Chinese and included 399 community residents and 61 dementia patients. Their ages ranged from 50 to 92 years; their education levels ranged from 0 to 19 years, and 63% of them had never attended school. We administered the IQCODE to informants and the Cognitive Abilities Screening Instrument (CASI), from which a CASI-estimated score of the MMSE (MMSE-CE) can be obtained, to the subjects. The diagnosis of dementia was made independently by physicians according to the DSM-III-R criteria based on semistructured interview and testing, neurologic examination, and standardized assessments of cerebral vascular disease, Parkinson's disease, and depression. The Chinese IQCODE showed no association with the subjects' education level or gender, low association with their age, and moderately high association with their MMSE-CE score. The area under the receiver operating characteristic curve of the IQCODE was significantly larger than that of the MMSE-CE for the whole group and for the subgroup with 1 to 19 years of education but not for the subgroup with 0 years of education. Nine of the 26 items of the IQCODE could be deleted without appreciable reduction in sensitivity and specificity. The IQCODE (1) can be shortened to 17 items, (2) had good cross-cultural applicability, and (3) was better than the MMSE-CE as a screening tool for dementia in a population with large variation in educational backgrounds.

Age Factors↗
PubMed1995

Variability of day 3 follicle-stimulating hormone levels in eumenorrheic women.

OBJECTIVE: To assess the intercycle variability of early follicular follicle-stimulating hormone (FSH) and estradiol (E2) levels in eumenorrheic women according to age. STUDY DESIGN: Forty-eight female volunteers with regular menstrual cycles were studied. Serum samples were obtained on cycle day 3 in multiple cycles over a one-year period. Serum was also obtained on consecutive cycle days 2, 3 or 4 in a single cycle in 20 participants. All samples were assayed for FSH and E2 by radioimmunoassay. RESULTS: In women under 40 years of age, all initial day 3 FSH levels were < 20 mIU/mL, and 15% of subjects had a subsequently elevated day 3 FSH level (> or = 20 mIU/mL) within the year. In eight women 40-44 years of age, 75% had an initial day 3 FSH level < 20 mIU/mL, but half of them subsequently had an elevated level, > 20 mIU/mL, within the year. Between cycle days 2, 3 and 4, FSH (coefficient of variation [CV] = 14.8%, 95% confidence interval (CI) = 11.4-18.3%) varied less than E2 (CV = 31.1%, 95% CI = 21.5-40.6%). CONCLUSION: A single day 3 FSH level < 20 mIU/mL is highly predictive of all subsequent values within a year and occurred only in women under 40. An FSH level drawn on cycle day 2 or 4 will probably be within 18% of the day 3 value, but the E2 level may vary by up to 40%.

Adult↗
PubMed1995

Active corpus luteum function at pre-, peri- and postimplantation is essential for a viable pregnancy.

Luteal-phase estrogen and progesterone concentrations were measured every other day and used to monitor the corpus luteum activity. The patterns of estrogen and progesterone concentrations were compared relative to the day of endogenous human chorionic gonadotropin (hCG) detection (defined as the day of implantation). The relationship between estrogen and progesterone and hCG concentrations was studied in 71 viable pregnancies, 12 clinical abortions, five preclinical abortions and 84 non-pregnant cycles after IVF/ET. Although all patients received luteal-phase progesterone support (25-50 mg/ml), low late luteal-phase progesterone concentrations of < 30 ng/ml from day + 11 to day + 15 were found in 64 patients (17% of viable pregnancies, 33.3% of clinical abortions, 60% of preclinical abortions and 53.6% of non-pregnant cycles) day + 1 was the day of retrieval). Implantation always occurred before or on day + 13 and 86% of pregnant cycles implanted on day + 8 to day + 11. Viable pregnancies had significantly higher mean progesterone concentrations on day + 3 to day + 7 (pre-implantation) and on day + 9 to day + 15 (postimplantation) than those of non-pregnant cycles or abortions. On the day of implantation, the mean +/- standard of deviation of estrogen (pg/ml) and progesterone (ng/ml) levels for viable pregnancies, clinical abortion and preclinical abortions were 314 +/- 210, 40.5 +/- 25; 226.7 +/- 246, 48.7 +/- 31; and 39.6 +/- 24.5, 28.6 +/- 24.5, respectively. On the same day, 73.2% of viable pregnancies, 41.7% of clinical abortions, and 20% preclinical abortions had a progesterone concentration > 30 ng/ml; 73.2% of viable pregnancies, 41.7% of clinical abortions and 20% of preclinical abortions had an estrogen concentration > 100 pg/ml. Although not precluding implantation completely, late luteal-phase hormonal deficiencies may impair endometrial growth and might ultimately lead to failure or abnormal implantation. A viable pregnancy requires not only a functional corpus luteum in the early luteal phase to develop a receptive endometrium, but also a responsive corpus luteum in the late luteal phase to support pregnancy. The time of implantation is critical. Implantation that occurs before the demise of the corpus luteum will facilitate a normal pregnancy.

Abortion, Induced↗
PubMed1994

Performance on a dementia screening test in relation to demographic variables. Study of 5297 community residents in Taiwan.

OBJECTIVE: To examine the relation between performance on a dementia screening test and the demographic variables of age, education, gender, and urban vs rural residency. DESIGN: Community survey with cluster sampling. SETTING: One urban and one rural community from each of four geographic regions in Taiwan, Republic of China. PARTICIPANTS: A total of 5265 nondemented individuals approximately equally divided between men and women and between urban and rural residency with a range in age from 41 to 88 years and in education from 0 to 20 years. MAIN OUTCOME MEASURE: Score on a Chinese adaptation of the Mini-Mental State Examination. RESULTS: Lower test scores were associated with older age and less education. The decrease in score with age was faster among participants who had never attended school. Better performance by men and by urban residents was found only among participants with fewer than 6 years of schooling. In this group, the magnitudes of sex and residency differences were comparable among those subjects aged 41 to 64 years and those aged 65 to 88 years. Women who had never worked outside of the home performed poorer than those who had worked outside of the home. CONCLUSIONS: The influence of educational background on test performance is most evident in individuals with less education. Commonly used dementia screening tests may be unfair to poorly educated individuals, especially women and rural residents. Efforts should be made to develop ecologically relevant cognitive tests for the intended study populations. To help distinguish test bias from different rates of cognitive decline, the study populations should include individuals in predementia age ranges.

Adult↗
PubMed1994

Endometrial secretory proteins enhance early embryo development.

PURPOSE: To evaluate the role of endometrial stromal cells and their secretory proteins in early embryo development, two-celled CB6F1 mouse embryos were cultured alone or cocultured with human endometrial stromal cells in various culture conditions. RESULTS: The percentage of embryo blastocyst formation, hatching, and outgrowth was significantly greater in (1) coculture with endometrial stromal cells than in a cell-free control when both coculture and control were carried out in protein-free medium or in RPMI 1640 plus 10% fetal calf serum; (2) coculture with hormone (i.e., progesterone plus relaxin)-treated cells than in coculture with hormone-nontreated cells; and (3) media supplemented with isolated endometrial secretory proteins than in media supplemented with BSA (0.35%). Embryo development was not found to be significantly different in coculture and in media supplemented with endometrial secretory protein. CONCLUSION: Our data provides credence to the theory that endometrial stromal cells enhance embryo development by secreting specific proteins that are beneficial to embryo growth in vitro.

Animals↗
PubMed1994

Ectopic pregnancies after in vitro fertilization and embryo transfer.

OBJECTIVE: Our objective was to analyze the risk factors, stimulation characteristics, and future fecundity of patients with ectopic pregnancies after in vitro fertilization (IVF). METHODS: We retrospectively evaluated all cases of ectopic pregnancy occurring between January 1989 and March 1993 (Cornell series 1 to 17). A case-control group of intrauterine pregnancies was used for comparison of the stimulation and transfer characteristics. RESULTS: Twenty-seven of 1123 pregnancies (2.4%) were ectopic, following 2812 fresh IVF embryo transfers, while 8 of 105 pregnancies (7.6%) were ectopic, following 405 frozen-thawed embryo transfers. Tubal factor was the cause of infertility in the majority (85.7%) of ectopic pregnancies. No difference was found between the ectopics and the matched controls in stimulation and transfer characteristics. Thirty ectopic pregnancies were ampullary, two were interstitial, two were cervical, and one was heterotopic. Twenty of the patients subsequently underwent 29 IVF attempts, with a pregnancy rate of 41.4% per transfer. CONCLUSIONS: Ectopic pregnancy after IVF appears to be related to preexisting tubal pathology; embryo transfer of cryopreserved thawed embryos in a natural cycle may result in a higher ectopic rate in these patients; in subsequent IVF cycles the intrauterine pregnancy rate of these patients is not decreased.

Adult↗
PubMed1994

Transient unilateral hypoglossal nerve palsy: a case report.

Transient unilateral hypoglossal nerve palsy is very rare. We report an 81-year-old woman with right hypoglossal nerve palsy who recovered in 4 weeks without specific treatment. Extensive investigations did not disclose a cause for her hypoglossal nerve palsy. We believe that hypoglossal nerve palsy may sometimes be self-limited, just as Bell's palsy is.

Aged↗
PubMed1994

Syncope as the presenting symptom of nasopharyngeal carcinoma.

Syncope is a rare symptom of nasopharyngeal carcinoma, a common tumor in Taiwan. We describe two patients with nasopharyngeal carcinoma who presented with frequent syncopal attacks five months before the diagnosis was made. We postulate that the mechanism of syncope is involvement of the glossopharyngeal or vagal nerve by para-pharyngeal extension of the tumor.

Aged↗