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Biomedical subjects

T T Chiu

Publications and source records attributed to T T Chiu.

At least 19 recordsLinked to original sources
PubMed2005

A randomized trial comparing alternative approaches to prenatal diagnosis counseling in advanced maternal age patients.

Prenatal diagnosis (PND) is offered routinely as part of pregnancy care to a large number of women at increased risk of fetal anomalies. Despite an extraordinary growth in the use of PND and significant resource allocation, few studies have examined outcomes of PND counseling, and virtually no research has evaluated the relative efficacy of various approaches to genetic counseling. This study was a randomized trial that compared which counseling methods - individual, group, and use of a decision aid - are effective in PND counseling for women of advanced maternal age (>/=35 years) and their partners. Three hundred and fifty-two women and 225 partners completed pre- and post-intervention questionnaires assessing changes in knowledge, decisional conflict, state anxiety, satisfaction, use of PND, and pregnancy outcomes. All participants showed a significant increase in knowledge and a decrease in decisional conflict post intervention. Those in the group intervention showed a significantly greater increase in knowledge than those in the individual counseling intervention. While high levels of satisfaction were reported by all, those in individual counseling were significantly more satisfied than those receiving group counseling or the decision aid. This study has shown unique benefits with each type of intervention such that women and their partners preferred individual genetic counseling, while they learned best in group-counseling sessions, and experienced the least decisional conflict regarding genetic testing with a decision aid.

Adult↗
PubMed2001

Subjective health measure used on Chinese patients with neck pain in Hong Kong.

STUDY DESIGN: A prospective observational study was conducted on the use of the Chinese version of the Northwick Park Neck Pain Questionnaire. OBJECTIVE: To examine the reliability, validity, and responsiveness of the Chinese version of the Northwick Park Neck Pain Questionnaire in Chinese patients with neck pain in Hong Kong. SUMMARY OF BACKGROUND DATA: There is increasing recognition that patient perspectives are essential both in making medical decisions and in judging the treatment outcomes. A valid Chinese version of a neck disability index questionnaire is urgently needed for effective and reliable evaluation of the treatment outcomes for patients with neck pain. METHODS: Two samples with 532 consecutive adult patients with neck pain from seven physiotherapy outpatient departments in Hong Kong who completed the Northwick Park Neck Pain Questionnaire were observed and measured at different intervals: at the beginning of physiotherapy, at 7 days, at 3 weeks, and 6 weeks after physiotherapy. RESULTS: The questionnaire had good content validity, very good test-retest reliability, and internal consistency (intraclass correlation coefficient, 0.95; Cronbach's alpha, 0.87). It also had good validity (Spearman correlation coefficient of 0.59 when the score was correlated with that of a generic 42-item Chinese health questionnaire) and good responsiveness (effect size of 1.11 at week 6 after treatment began). CONCLUSIONS: The Chinese version of the Northwick Park Neck Pain Questionnaire has been shown to demonstrate very good content validity, a high degree of test-retest reliability, and internal consistency. It also exhibited good construct validity and high sensitivity to changes in severity over time.

Adolescent↗
PubMed2001

Regulation of human oviductin mRNA expression in vivo.

OBJECTIVE: To examine changes in oviductin mRNA expression in oviductal mucosal tissue from fertile women throughout an ovulatory cycle. DESIGN: Semiquantitative reverse-transcriptase-polymerase chain reaction (RT-PCR) analysis of oviductin mRNA. SETTING: University-based obstetrics and gynecology department. SUBJECT(S): Twenty women undergoing laparoscopy for tubal sterilization or hysterectomy for uterine fibroids. INTERVENTION(S): The mucosal layer was isolated from the oviduct tissue, and semiquantitative RT-PCR was performed. MAIN OUTCOME MEASURE(S): The relationship between serum estradiol, luteinizing hormone, and progesterone concentrations and the expression of oviductin mRNA. RESULT(S): There was a significant positive correlation between serum estradiol and luteinizing hormone concentrations and oviductin mRNA expression. There was a significant inverse correlation between serum progesterone concentrations and oviductin mRNA expression. CONCLUSION(S): Little is known about the regulation of human oviductin. This study was the first to examine the relationship between oviductin mRNA expression and serum estradiol and luteinizing hormone and progesterone concentrations in fertile women. Estradiol and luteinizing hormone both have a stimulatory effect on oviductin mRNA in humans, however, it is difficult to determine whether the effects are independent of one another, as the luteinizing hormone surge is dependent on the estradiol increase. Progesterone shows a clear inhibitory effect on oviductin mRNA.

Adult↗
PubMed2001

The effects of follicular fluid and platelet-activating factor on motion characteristics of poor-quality cryopreserved human sperm.

PURPOSE: To evaluate the effects of follicular fluid and platelet-activating factor on sperm motion characteristics of cryopreserved oligospermic and normospermic samples. METHODS: Sperm motion characteristics were evaluated prior to cryopreservation, immediately after thawing and following incubation in human tubal fluid, follicular fluid, or 1-microM platelet-activating factor cultures. Sixteen oligospermic samples and 20 normospermic samples were examined. Sperm motion characteristics were analyzed manually according to WHO criteria (1999) and also with an automated videomicrography system. RESULT(S): Incubation in follicular fluid increased overall motility and the percentage of sperm with fast progressive motility in normospermic but not oligospermic samples. Incubation with platelet-activating factor increased overall motility and the percentage of sperm showing nonprogressive motility in both oligospermic and normospermic samples. CONCLUSION(S): The stimulatory effects of culture in follicular fluid as seen in normospermic samples do not show a significant benefit in oligospermic cryopreserved samples. Platelet-activating factor and follicular fluid increase motility via different mechanisms. Incubation of oligospermic cryopreserved sperm with PAF increases the number of motile sperm, thereby enabling easier identification of viable sperm for intracytoplasmic sperm injection in samples with severe asthenozoospermia.

Cryopreservation↗
PubMed2001

Methodology standards associated with quality reporting in clinical studies in pediatric surgery journals.

BACKGROUND/PURPOSE: Reports of clinical trials often lack adequate descriptions of design and analysis; recent attention has focused on improving this omission so readers can properly assess the strength of the findings and draw their own conclusions. Similar analysis of study design and methodologic standards associated with quality reporting has not been carried out for pediatric surgery journals. METHODS: All studies (n = 642) published in 1998 in Journal of Pediatric Surgery (JPS) and Pediatric Surgery International (PSI), were reviewed for demographic data and study design. The frequency of reporting of 11 basic elements of design and analysis was evaluated in randomized clinical trials (RCT), nonrandomized clinical trials (NRCT), and retrospective cohorts (RC) from JPS by consensus of 2 assessors. RESULTS: Of the 642 studies, 17% of articles (111 of 642) were classified as clinical studies. Sixty-three were comparative studies and consisted of RC (n = 48), NRCT (n = 12), and RCT (n = 3). Two-thirds of articles published were either case reports or case series (431 of 642), and 16% were basic science articles. Demographic analysis showed a wide range of topics addressed, 4 authors per article, and multiple country of origin of authors. More than 66% of all RCT in JPS reported on eligibility criteria, admission before allocation, random allocation, method of randomization, patients' blindness to treatment, treatment complications, statistical analyses, statistical methods, loss to follow-up, and statistical methods; 2 elements of design and analysis, however, were poorly reported: blind assessment of outcome (33%) and power (17%). CONCLUSIONS: There were few randomized, controlled trials in pediatric surgery journals, and further attention should be given to evaluate the causal factors. Nine elements of quality reporting were well reported; however, 2 others were poorly reported; this may improve if editors of pediatric surgical journals provide authors with guidelines on how to report clinical trial design and analysis.

Authorship↗
PubMed2001

Dose-finding study for the use of long-acting gonadotrophin-releasing hormone analogues prior to ovarian stimulation for IVF.

Gonadotrophin-releasing hormone (GnRH) analogues improve the outcome of treatment with IVF by increasing the number and quality of oocytes retrieved and by reducing cycle cancellation rates. Whilst short-acting GnRH analogues are most commonly used, depot preparations are now available that are more convenient for patient use. Some studies have reported that pregnancy rates with depot GnRH analogues are similar to those of short-acting preparations, but others have suggested that the more profound down-regulation seen with depot GnRH analogues results in inferior embryo quality. The purpose of this study was to determine whether a lower than conventional dose of a depot GnRH analogue may be more appropriate for use in ovarian stimulation prior to IVF. Sixty patients were randomized to receive either 3.75 mg (conventional dose) or 1.87 mg (low dose) triptorelin prior to ovarian stimulation for IVF. Suppression was measured using serum concentrations of LH measured 2 and 3 weeks after the administration of the GnRH analogues, the dose of gonadotrophin used and the time to resumption of menses. Mean concentrations of LH were 2.2 +/- 1.0 and 1.1 +/- 0.6 IU/l in the conventional dose group and 3.5 +/- 5.5 and 2.7 +/- 1.9 IU/l in the low dose group (P < 0.05 at 2 and 3 weeks). There were no significant differences between the doses of gonadotrophins used, the number of oocytes and embryos available and the time to resumption of menses, nor in the pregnancy rates. Although the degree of suppression as measured biochemically was more profound with the conventional dose, this did not affect the IVF outcome. The use of a lower dose therefore appears to be equally effective and could contribute to a reduction in the cost of treatment.

Adult↗
PubMed1998

The view from the horizon: strategic partnerships of public health, academic medical centers, and managed care.

The organization and operation of public health departments must change if they are to participate in the evolving health system. Strategic partnerships with academic medicine, academic medical centers, and managed care organizations offer an opportunity to establish and sustain these new roles. A rationale for collaboration and description of the assets each organization contributes to the partnership is described. The experience of the authors in developing such strategic partnerships and other examples from across the country is presented.

Academic Medical Centers↗
PubMed1997

Pregnancies from subzonal insemination of unfertilized oocytes after conventional IVF.

OBJECTIVE: To evaluate the efficacy of subzonal insemination (SUZI) as applied to unfertilized oocytes after initial insemination. METHODS: Unfertilized oocytes at metaphase II obtained after conventional IVF from 14 patients were selected for reinsemination by SUZI. The fertilization rate and pregnancy outcome were assessed. RESULTS: Of the 57 unfertilized oocytes at metaphase II, 10 (17.5%) became fertilized after SUZI. Eight of the 10 (80%) oocytes showed normal fertilization with two pronuclei while the other two (20%) oocytes were polyspermic. Five (35.7%) of the 14 patients had embryo transfer resulting in two (14.3%) pregnancies. One patient had a spontaneous abortion and the other had a live birth at term. CONCLUSION: Reinsemination of unfertilized oocytes by SUZI could be of value when fertilization fails after initial insemination.

Embryo Transfer↗
PubMed1996

Inverse agonistic effect of ICI-174,864 on the cloned delta-opioid receptor: role of G protein and adenylyl cyclase activation.

Previous studies have established that the delta-selective antagonist ICI-174,864 exhibits negative intrinsic activity at the delta-opioid receptors in NG108-15 membranes. To determine whether ICI-174,864 can function as a true inverse agonist in intact cells, its ability to stimulate cAMP accumulation was examined in a human embryonic kidney 293 cell line (293/DOR) expressing the cloned murine delta-opioid receptor. Forskolin-stimulated cAMP accumulation in the 293/DOR cells was dose-dependently suppressed by the delta-selective agonist [D-Pen2, D-Pen5]enkephalin, and such inhibition was abolished by pertussis toxin or the opiate antagonist naloxone. In contrast, ICI-174,864 significantly potentiated the forskolin response. The ICI-174,864-induced enhancement of the forskolin response exhibited dose-dependency and was antagonized by [D-Pen2,D-Pen5]enkephalin and blocked by pertussis toxin. Neither ICI-174,864 nor pertussis toxin elevated the basal level of cAMP accumulation in the absence of forskolin. Other opiate antagonists, such as naloxone and naltrindole, were ineffective in enhancing the forskolin-stimulated cAMP accumulation. Elevation of cAMP levels in response to the activation of Gs (through either ligand-bound receptor or point mutation on alpha(s)) was also potentiated by ICI-174,864. Our results indicate that ICI-174,864 behaves as an inverse agonist in human embryonic kidney 293 cells stably expressing the delta-opioid receptor. The inverse agonistic effect of ICI-174,864 seemed to require Gi proteins and was clearly manifested when adenylyl cyclase was activated.

Cell Line↗
PubMed1995

Activation of type II adenylyl cyclase by the cloned mu-opioid receptor: coupling to multiple G proteins.

Opioid receptors are multifunctional receptors that utilize G proteins for signal transduction. The cloned delta-opioid receptor has been shown recently to stimulate phospholipase C, as well as to inhibit or stimulate different isoforms of adenylyl cyclase. By using transient transfection studies, the ability of the cloned mu-opioid receptor to stimulate type II adenylyl cyclase was examined. Co-expression of the mu-opioid receptor with type II adenylyl cyclase in human embryonic kidney 293 cells allowed the mu-selective agonist, [D-Ala2,N-Me-Phe4,Gly5-ol]enkephalin, to stimulate cyclic AMP accumulation in a dose-dependent manner. The opioid-induced stimulation of type II adenylyl cyclase was mediated via pertussis toxin-sensitive Gi proteins, because it was abolished completely by the toxin. Possible coupling between the mu-opioid receptor and various G protein alpha subunits was examined in the type II adenylyl cyclase system. The opioid-induced response became pertussis toxin-insensitive and was enhanced significantly upon co-expression with the alpha subunit of Gz, whereas those of Gq, G12, or G13 inhibited the opioid response. When pertussis toxin-sensitive G protein alpha subunits were tested under similar conditions, all three forms of alpha i and both forms of alpha o were able to enhance the opioid response to various extents. Enhancement of type II adenylyl cyclase responses by the co-expression of alpha subunits reflects a functional coupling between alpha subunits and the mu-opioid receptor, because such potentiations were not observed with the constitutively activated alpha subunit mutants.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenylate Cyclase Toxin↗
PubMed1994

Calcium requirements for acetylcholine-induced contraction of cat esophageal circular muscle cells.

Esophageal circular muscle cells isolated by enzymatic digestion contracted in response to acetylcholine (ACh) and in response to the protein kinase C (PKC) agonist 1,2-dioctanoylglycerol (1,2 DAG). Both responses were blocked by PKC antagonists but not by calmodulin antagonists. Furthermore, specific PKC activity, measured in the particulate fraction of the muscle, increased in response to cholinergic stimulation, suggesting that ACh-induced contraction is mediated by a PKC-dependent pathway. ACh-induced contraction decreased with decreasing extracellular Ca2+ and was blocked in Ca(2+)-free physiological salt solution (PSS). Similarly, contraction by the nonhydrolyzable GTP analogue guanosine 5'-O-(3-thiotriphosphate) was blocked by removal of Ca2+ from the PSS. Diacylglycerol production in response to ACh was reduced when extracellular Ca2+ was reduced from 2 to 0.5 mM and was abolished in Ca(2+)-free PSS. The response to 1,2-DAG, however, did not significantly change as extracellular Ca2+ or cytosolic Ca2+ was reduced to zero. Heparin (10 micrograms/ml), thapsigargin (3 microM), or the Ca2+ ionophore A-23187 (3 microM) had no effect on 1,2-DAG or ACh-induced contraction in permeable cells. The data suggest that contraction in response to ACh is mediated by influx of extracellular Ca2+ and a PKC-dependent pathway. Ca2+ may be required mainly to activate the phospholipases responsible for production of diacylglycerol, since contraction of esophageal muscle cells in response to 1,2-DAG is Ca2+ independent.

Acetylcholine↗
PubMed1992

A correlation of the outcome of clinical in vitro fertilization with the inositol content and embryotrophic properties of human serum.

PURPOSE: This study was designed to investigate whether the level of myo-inositol (MI) in human serum is critical for embryotrophic activity. METHODS: The embryotrophic properties of human serum were evaluated by the development of postimplantation mouse embryos [in vitro assay of Tam et al. (Fertil Steril 48:834-839, 1987)]. An enzymatic spectrophotometric method using myo-inositol dehydrogenase was used for determination of serum MI. The level of MI detected in serum was compared with the embryotrophic properties and the pregnancy outcome. The effect of MI on the embryotrophic activity of human serum was studied by supplementing the suboptimal serum samples that were unsupportive of embryo growth with extra MI. RESULTS: Serum obtained from patients having successful IVF pregnancies generally supported better development of postimplantation mouse embryos and contained higher levels of inositol, particularly if the serum sample was collected during the IVF treatment cycle. Serum samples obtained from patients with aborted pregnancies, though supporting mouse embryo development, contained significantly lower concentrations of inositol. An improvement of the embryotrophic properties with exogenous inositol supplement was achieved in some but not all of the suboptimal serum samples studied. CONCLUSIONS: It is possible that other factors in addition to inositol are crucial in promoting better embryonic development.

Abortion, Spontaneous↗
PubMed1990

Localization of fucosyl glycoconjugates in human oocytes following insemination for in vitro fertilization.

Human oocytes that failed to cleave after insemination were examined for the presence of fucosyl glycoconjugates in the perivitelline space by staining with Ulex europeaus lectin conjugated to fluorescein isothiocynate. Oocytes that formed two or three pronuclei following first insemination always exhibited positive lectin staining similar to that observed with in vitro fertilized mouse oocytes. Among those oocytes that failed to form any pronuclei after the first insemination attempt, only 5% contained lectin positive substances in the perivitelline space. Upon reinsemination, a higher percentage of those oocytes produced lectin-positive materials, although pronuclei were still absent. The appearance of fucosyl glycoconjugates in these oocytes might be the result of the release of cortical granules triggered by sperm penetration or, more likely, due to spontaneous granule discharge in senescent oocytes.

Female↗
PubMed1990

Controlled ovarian hyperstimulation for in vitro fertilization using buserelin and gonadotropin in patients with previous failed cycles.

Fifteen patients who had had previous unsuccessful in vitro fertilization and embryo transfer (IVF) cycles were treated with intranasal buserelin, a gonadotropin releasing hormone agonist (GnRH-a), commencing in the mid-luteal phase prior to ovarian stimulation in the next cycle. The use of buserelin was associated with the suppression of spontaneous luteinizing hormone (LH) surges (nil versus 6), an increase in gonadotropin requirements (27.3 versus 13.7 ampoules), higher serum estradiol peak levels (8, 154 versus 4,446 pmol/l), more oocytes retrieved (87 versus 20) as well as more embryos being transferred (28 versus 7). In buserelin-treated cycles, 2 pregnancies resulted but no oocyte was recovered in 2 of the 3 poor responders.

Adult↗
PubMed1990

Hospital costs for cocaine-exposed infants.

A retrospective study was done at University Medical Center at Jacksonville for the period November 1988 through October 1989 to estimate the cost of treatment for 207 infants from cocaine-exposed pregnancies, 151 (76%) black and 56 (24%) white. The mean age of the mothers was 26. Twenty-five (12%) infants were admitted into the neonatal intensive care nursery (NICU) and 82 (88%) into the normal nursery where 45% of total days was due to "social hold" pending clearance for discharge by the Florida Department of Health and Rehabilitative Services. Average stay was 21.5 days in the NICU and 6.7 days in the normal nursery. Average costs varied from $36,481 for NICU to $801 for normal nursery in excess of the usual charge for a normal full-term infant. Laboratory fees accounted for the largest percentage (41.5%) of the total cost of hospitalization in the NICU, while rooming charges are the major factor (50.8%) in the normal nursery. Total charges in the 12-month period amounted to $1,057,921 or $5,110 per patient and for a control group $520,251 or $2,513 per patient. A major concern above the cost of treatment is the special education needs when these children enter the school system.

Adolescent↗