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Biomedical subjects

F M Chang

Publications and source records attributed to F M Chang.

At least 19 recordsLinked to original sources
PubMed2006

Infusion of human umbilical cord blood cells protect against cerebral ischemia and damage during heatstroke in the rat.

Intravenously delivered human umbilical cord blood cells (HUCBC) have been previously shown to improve both morphologic and functional recovery of heat-stroked rats. To extend these findings, we examined both the morphologic and functional alterations in the presence of HUCBC or human peripheral mononuclear cells (PBMC) 24 h before initiation of heatstroke. Anesthetized rats, 1 day before the initiation of heatstroke, were divided into three major groups and given the following: (a) serum-free lymphocyte medium (0.3 ml) intravenously; (b) PBMC (5 x 10(6) in 0.3 ml serum-free lymphocyte medium); or (c) HUCBC (5 x 10(6) in 0.3 ml serum-free lymphocyte medium). Another group of rats were exposed to room temperature (26 degrees C) and used as normothermic controls. In vehicle-treated heatstroke rats, their mean arterial pressure, cerebral blood flow, and brain PO(2) were all lower than in normothermic controls after the onset of heatstroke. However, their body temperatures and striatal levels of inducible nitric oxide synthase (iNOS)-dependent NO, ischemia and damage markers (e.g., glycerol, glutamate, and lactate/pyruvate ratio), and neuronal damage in the striatum were all greater. The heatstroke-induced arterial hypotension, cerebral ischemia and hypoxia, and increased levels of iNOS-dependent NO in the striatum were all significantly reduced by pretreatment with HUCBC, but not with PBMC. Moreover, HUCBC were localized by immunohistochemistry and PCR analysis in the injured brain structures and spleen. These findings indicate that HUCBC transplantation, in addition to having therapeutic values, can be a good choice for preventing heatstroke occurrence.

Analysis of Variance↗
PubMed2001

Prenatal diagnosis of twin-twin transfusion syndrome complicated with hydrops fetalis at 14 weeks of gestation.

Twin-twin transfusion syndrome (TTTS) may complicate multiple pregnancy. Monochorionic discordant twins with oligohydramnios and polyhydramnios may be diagnostic. Hydrops fetalis is particularly ominous. All the signs can appear independently at any stage of gestation. However, TTTS with hydrops fetalis in early pregnancy is rare. We report here a case of TTTS complicated with hydrops fetalis diagnosed at 14 weeks of gestation. Our case may be one of the earliest cases of the prenatal diagnosis of TTTS complicated with hydrops fetalis in the literature.

Abortion, Induced↗
PubMed2001

Prenatal diagnosis of cleft palate by three-dimensional ultrasound.

Prenatal diagnosis of cleft palate is very important to prenatal consultation and management after birth. To examine if three-dimensional (3-D) ultrasound (US) is an accurate diagnostic method for clinical use, we analyzed our experience in detecting cleft palate by 3-D US. From June 1996 to January 2000, 21 fetuses with facial clefts were scanned by 2-D US, as well as by 3-D US. The coronal and oblique planes were reconstructed by 3-D US to detect the cleft palate. In addition, level II US was performed to find any possibly associated anomalies. All the scans were recorded on optic disks for final analysis. In our study, the gestational age when prenatal diagnosis was made by US initially was between 20 and 34 weeks. The accuracy for prenatal diagnosis of cleft lip with or without cleft palate by 3-D US was 100%, which was superior to that by 2-D US (p < 0.05). In addition, we proposed a novel method to evaluate the cleft palate systemically by 3-D US. In conclusion, from our study, fetuses with cleft lip combined with or without cleft palate can be easily differentiated by 3-D US. The reconstruction of coronal and oblique planes by 3-D US is a powerful tool for detecting cleft palate.

Cleft Lip↗
PubMed2001

Successful pregnancy by transmyometrial and transtubal embryo transfer after IVF in a patient with congenital cervical atresia who underwent uterovaginal canalization during Caesarean section: case report.

Successful pregnancy in a patient with congenital cervical atresia is a great challenge for assisted reproductive techniques and reproductive medicine. We report a case of successful pregnancy by transmyometrial and transtubal embryo transfer simultaneously after in-vitro fertilization (IVF) in a 33 year-old patient with congenital cervical atresia diagnosed at the age of 18 years. The patient had experienced cyclic abdominal pain and amenorrhoea since she was 13 years old. She had had two unsuccessful attempts to create a new uterovaginal canal in another hospital. At the age of 32 years, she was referred to our unit and had a successful pregnancy after transmyometrial and transtubal embryo transfer. Caesarean section was performed at 36 weeks gestation due to progressive pre-eclampsia and gestational diabetes. A healthy male baby weighing 2812 g was safely delivered. Uterovaginal canalization with amniotic membrane for the covering of the neo-endocervical wall was performed during Caesarean section. Normal menstrual outflow and symptomatic relief have continued for 5 months after the operation. To the best of our knowledge, this is the first reported case of successful pregnancy by transmyometrial and transtubal embryo transfer as well as uterovaginal canalization performed during Caesarean section in a patient with congenital cervical atresia.

Amnion↗
PubMed2001

Quality of life and sexuality changes in postmenopausal women receiving tibolone therapy.

OBJECTIVE: The goal of this study was to investigate the effects of hormone replacement therapy (HRT) and tibolone on the sexuality and quality of life of Taiwanese postmenopausal women. METHODS: Forty-eight postmenopausal women were enrolled and prospectively randomized to receive either HRT or tibolone for 3 months. At the end of the 3-month period, quality of life measures were assessed using the Greene Climacteric Scale and attitudes of sexuality were evaluated using the McCoy Sex Scale. RESULTS: Based on subjective qualitative scores, tibolone treatment was at least as effective as continuous combined HRT in improving quality of life. It also effectively prevented withdrawal bleeding, which may occur during HRT use. Compared with continuous combined HRT, tibolone treatment was also associated with perceived improvement of sexual performance, including general sexual satisfaction, sexual interest, sexual fantasies, sexual arousal and orgasm, with decreased frequencies of vaginal dryness and painful intercourse. CONCLUSIONS: The findings of this study indicate that both tibolone and continuous combined HRT have positive effects on the quality of life of Taiwanese postmenopausal women. Sexuality is affected more by tibolone than by HRT.

Adult↗
PubMed2000

Evolution of exon 1 of the dopamine D4 receptor (DRD4) gene in primates.

The dopamine D4 receptor (DRD4) gene exhibits a large amount of expressed polymorphism in humans. To understand the evolutionary history of the first exon of DRD4-which in humans contains a polymorphic 12bp tandem duplication, a polymorphic 13bp deletion, and other rare variants-we examined the homologous exon in thirteen other primate species. The great apes possess a variable number of tandem repeats in the same region as humans, both within and among species. In this sense, the 12bp tandem repeat of exon 1 is similar to the 48bp VNTR of exon 3 of DRD4, previously shown to be polymorphic in all primate species examined. The Old World monkeys show no variation in length, and a much higher conservation of amino acid sequence than great apes and humans. The New World monkeys show interspecific differences in length in the region of the 12bp polymorphism, but otherwise show the higher conservation seen in Old World monkeys. The different patterns of variation in monkeys compared to apes suggest strong purifying selective pressure on the exon in these monkeys, and somewhat different selection, possibly relaxed selection, in the apes.

Animals↗
PubMed2000

Prenatal diagnosis of alobar holoprosencephaly by two-dimensional and three-dimensional ultrasound.

The aim of this study is to evaluate the sonographic characteristics of alobar holoprosencephaly (AH) in utero. Seventeen cases were diagnosed at 16-30 weeks' gestation by two-dimensional and three-dimensional ultrasound from October 1994 to December 1998. In this series, the prenatal prevalence was 1 out of 415 and the detection rate of AH by prenatal ultrasound was 100%. Eleven cases (64.7%) had concurrent facial anomalies. Cleft lip and hypotelorism were the most common associated facial anomalies (72.7%). Two cases (11.8%) were twin pregnancy with one fetus affected. We present one of the largest series in the literature and compare it with previous reports. From this series, we concluded that: (1) intracranial findings, including monoventricle, fused thalami, and the absence of midline structures, were reliable sonographic characteristics for prenatal diagnosis; (2) cleft lip and hypotelorism seemed to be more common associated facial malformations than cyclopia or cebocephaly with AH; and (3) although three-dimensional ultrasound did not change the diagnosis of AH made by two-dimensional ultrasound in this series, three-dimensional ultrasound does assist in defining the severity and extent of AH.

Adult↗
PubMed2000

Fetal ear assessment and prenatal detection of aneuploidy by the quantitative three-dimensional ultrasonography.

The purposes of this study were to use quantitative three-dimensional (3-D) ultrasonography to establish the normal charts of three fetal ear-growth indexes, (ear length, ear width and ear area), and to validate their efficacy in the prenatal diagnosis of fetal trisomies, either separately or as a combination. Using quantitative 3-D ultrasonography, we performed a prospective study to measure the three fetal ear growth indexes (i.e., ear length, ear width and ear area) in 129 singleton pregnancies, including 122 normal fetuses and 7 trisomies. The ear shape was also evaluated in these fetuses using both 2-D and 3-D ultrasonography. Our results showed that: First, 3-D ultrasonography offers better visualization and easier evaluation of fetal ears than 2-D ultrasonography. Second, when using the quantitative assessment of 3-D ultrasonography, the measurements of ear length, ear width and ear area were all correlated significantly with gestational age in normal pregnancies (r = 0.881, 0.848, and 0.890, respectively). In addition, 3 of 7 fetal trisomies had ear length below the tenth percentile, 1 had ear width below the tenth percentile, and 2 had ear area below the tenth percentile. Furthermore, with the combination of these three measurements, (including ear length, ear width and ear area), the sensitivity in detecting fetal trisomies was elevated to 57.1% and the specificity was 83.2%. In conclusion, 3-D ultrasonography reduces the limitations of 2-D ultrasonography in the evaluation of fetal ears. However, fetal ear measurement may not be used as a single ultrasonographic parameter in identifying aneuploid fetuses. We recommend using the combination of these three ear growth indexes to enhance the detection rate of aneuploidy.

Aneuploidy↗
PubMed2000

Systemic assessment of fetal hemodynamics by Doppler ultrasound.

The aim of our study was to investigate the parameters of fetal circulation of normal pregnancies and their relationship to fetal cardiac output. We performed a cross-sectional study of 315 normal singleton pregnancies between 20 and 40 weeks' gestation without fetal chromosomal or structural malformations. After follow-up to delivery, 212 patients who fit all the criteria were enrolled for final analysis. Blood flow velocity waveforms were obtained from the tricuspid and mitral ventricular inflow, ascending aorta (AAO), pulmonary artery (PA), middle cerebral artery (MCA), renal artery (RA), umbilical artery (UA), descending aorta (DAO), inferior vena cava (IVC) and ductus venosus (DV) using duplex (real-time Doppler) ultrasound (US) scanner. The peak velocity of DV, AAO, PA and MCA were also obtained. At the intracardiac level, the ratio of peak flow velocity of E wave to peak flow velocity of A wave (E:A ratio) of mitral valve (MV) increased more rapidly than tricuspid valve (TV) E:A ratio. For the great vessels, aortic peak velocity remained higher than the pulmonary peak velocity with advancing gestation. The cardiac output closely correlated to the cardiac compliance and flow resistance indices at arterial and venous level. The acceleration time in the fetal arteries increased with advancing gestation in AAO, PA, MCA and DAO, but it decreased in RA and kept constant in UA. In addition, the acceleration time of UA was unrelated to cardiac output. The changes of the fetal intracardiac, arterial and venous impedances were remarkable through the gestation and related to cardiac output. Fetal cardiac output correlated well with the changes of arterial resistance, except with the DAO. The ventricular compliance increased with advancing gestation, especially in the left side, and was highly related to the change of cardiac output. The acceleration time in major arteries positively correlated with the gestational age and cardiac output, except in UA and RA; this indicates the difference of the changes of mean arterial pressure in uteroplacental circulation, fetal organs and great vessels. In conclusion, the fetal cardiac output correlated well with the ventricular compliance and was influenced by both hemodynamic changes in peripheral resistance and mean arterial pressure.

Adult↗
PubMed2000

Assessment of fetal cerebellar volume using three-dimensional ultrasound.

The purposes of this study were to assess the fetal cerebellar volume during normal gestation using three-dimensional (3-D) ultrasound (US) and to establish a normal chart of fetal cerebellar volume using Altman's model of statistics. In total, 231 healthy fetuses were studied for assessment of cerebellar volume using a 3-D US volume scanner. The fetuses to be studied were selected to give a cross-sectional series (i.e., each fetus was examined only once). Polynomial regression analysis was calculated to find the best-fit model using gestational age as the independent variable and cerebellar volume as the dependent variable. Altman's model was used to calculate the age-related reference centiles for the variance of cerebellar volume. In addition, common fetal growth indices, such as biparietal diameter, occipitofrontal diameter, head circumference, abdominal circumference, femur length and estimated fetal weight, were also measured for the correlation between cerebellar volume and these indices. Our results indicated that the fetal cerebellar volume was highly correlated with gestational age in normal pregnancies with the best-fit polynomial regression equation of a second-order (r = 0.91, p < 0.0001). In addition, fetal cerebellar volume in normal gestation is also highly correlated with common fetal growth indices, such as biparietal diameter, occipitofrontal diameter, head circumference, abdominal circumference, femur length and estimated fetal weight (all p < 0.0001). Following the Altman's model, a normal growth chart of fetal cerebellar volume was established for clinical reference. In conclusion, with 3-D US, the assessment of fetal cerebellar volume becomes feasible. We believe that fetal cerebellar volume assessed by 3-D US may be useful in detecting cerebellar hypoplasia and relevant syndromes prenatally.

Cerebellum↗
PubMed2000

Three-dimensional ultrasound in the assessment of fetal cerebellar transverse and antero-posterior diameters.

Fetal cerebellum scanning by prenatal ultrasound (US) is very important for early detection of fetal central-nervous-system anomaly, as well as for the determination of gestational age (GA). Due to the small organ size and the unique shape of the fetal cerebellum (CL), accurate measurement of the dimensions of CL by two-dimensional (2-D) US is not easy if the appropriate plane cannot be reached. With the advent of three-dimensional (3-D) US, the disadvantages of 2-D US in assessing the fetal CL dimensions can be avoided. The purpose of this study was to assess the fetal cerebellar transverse diameter (CTD) and cerebellar antero-posterior diameter (CAD) using 3-D US. First, we compared the reproducibility of 2-D and 3-D US on the assessment of fetal cerebellar dimensions. Second, we prospectively measured CTD and CAD in 223 healthy fetuses using a cross-sectional design with an attempt to establish the normal growth charts of fetal CL. Our results showed 3-D US is superior to 2-D US in the reproducibility test of fetal cerebellar dimensions. In addition, with GA as the dependent variable, polynomial regression analysis showed that the best-fit equations for both CTD vs. GA and CAD vs. GA were the first-order. The best-fit predictive equation of GA by CTD was GA (week) = 9.0281 + 0. 58533 x CTD (mm) (r = 0.95, n = 223, SE = 1.82 weeks, p < 0.0001), and the best-fit predictive equation of GA by CAD was GA (week) = 10. 855 + 1.1672 x CAD (mm) (r = 0.82, n = 223, SE = 3.41 weeks, p < 0. 0001). Furthermore, all the correlation coefficients of CTD or CAD vs. the common fetal growth indexes were also highly significant (all p < 0.0001). In conclusion, our data of fetal CL dimensions assessed by 3-D US may serve as a useful reference in assessing fetal CL growth, dating GA or detecting fetal CL anomalies.

Anthropometry↗
PubMed1999

No association between DRD2 locus and alcoholism after controlling the ADH and ALDH genotypes in Chinese Han population.

BACKGROUND: Recent studies on the genetics of alcoholism have examined the association between alcoholism and the dopamine D2 receptor locus (DRD2); our study of Chinese Han gave negative results (Lu et al., 1996). The different genotypes at the genes encoding the enzymes involved in alcohol metabolism, class one alcohol dehydrogenase (ADH2 and ADH3) and mitochondrial aldehyde dehydrogenase (ALDH2), have previously been shown to confer different predispositions to the development of alcoholism in Chinese Han males (Thomasson et al., 1991; Chen WJ et al., 1996; Chen CC et al., unpublished data). Therefore, association studies of alcoholism in Chinese Han might be more sensitive if controlled for the genotypes of ADH2,ADH3, and ALDH2, when other loci, such as DRD2, are examined. This study employs such controls to evaluate the evidence for an association between alcoholism and TaqI-A and TaqI-B genotypes and haplotypes at DRD2 in the Chinese Han population. METHODS: We studied 213 Chinese Han subjects (128 alcoholics and 85 nonalcoholics) with alcohol dependence defined according to DSM-III-R criteria. RESULTS: Significant linkage disequilibrium was observed between the TaqI-A and TaqI-B sites at the DRD2 locus, as previously seen in smaller samples, but no significant association was observed between these genetic variants at the DRD2 locus and alcoholism in Chinese Han. Several different stratifications by ADH and ALDH2 genotypes were examined; no genotypes or haplotypes at DRD2 differ between alcoholics and nonalcoholics except for a small number of nominally significant p-values which do not constitute significant results given the many tests done, some of which are not independent of one another due to linkage disequilibrium. These tests included considering the high risk (ADH2*1/*1; *1/*2; ADH3*1/*2; *2/*2; and ALDH2*1/*1) and the low risk (ADH2*2/*2; ADH3*1/*1; and ALDH2*1/*2; *2/*2) groups of alcoholics, as well as nonalcoholic controls. CONCLUSIONS: After stratification by the relevant genotypes of ADH2, ADH3, and ALDH2 no significant association exists between the genetic variants at the DRD2 locus and alcoholism in the Chinese Han population.

Alcohol Dehydrogenase↗
PubMed1998

Prenatal sonographic characteristics and Doppler blood flow study in a case of a large fetal mediastinal teratoma.

Although fetal mediastinal teratomas may result in respiratory distress in the neonatal period and lead to perinatal mortality, they are rarely diagnosed prenatally. Furthermore, their impact on fetal hemodynamics has never been described. We report a case of a large fetal mediastinal teratoma prenatally visualized at 38 weeks' gestation by both two- and three- dimensional ultrasound. We also describe the associated changes in the Doppler flow velocimetry, namely, a decrease in cardiac output, prolonged acceleration time in the pulmonary artery and an increase in the umbilical artery S/D ratio. The baby was well at the 5-month follow-up after an operation in the neonatal period. From our case, we believe that accurate prenatal diagnosis and assessment by two- and three-dimensional ultrasound as well as Doppler flow velocimetry may contribute to a better perinatal outcome.

Adult↗
PubMed1998

Prenatal diagnosis of otocephaly using two-dimensional and three-dimensional ultrasonography.

We report a case of the prenatal diagnosis of a very rare anomaly, namely isolated otocephaly, using two-dimensional and three-dimensional ultrasound at 24 weeks of gestation. Two-dimensional ultrasound revealed polyhydramnios, absence of a stomach shadow, hypotelorism and a proboscis-like mass. Three-dimensional ultrasound gave a precise demonstration of the striking craniofacial features of otocephaly including agnathia, synotia, microstomia and protuberance of the nose-mouth fusion. The use of three-dimensional ultrasound provided a whole view of the very rare lethal malformation in utero and contributed significantly to prenatal diagnosis.

Abortion, Legal↗
PubMed1997

Rapid molecular haplotyping of the first exon of the human dopamine D4 receptor gene by heteroduplex analysis.

The dopamine D4 receptor gene (DRD4) and its products are of great interest in many neurospsychiatric disorders. There are at least five expressed polymorphisms in exons 1 and 3, plus rare expressed variants, all of which may have functional relevance. Several studies have described methods for studying the exon 3 polymorphisms, especially the VNTR; fewer reports have documented the exon 1 polymorphisms and variants of DRD4. We report here a simple, rapid, nonisotopic, nondenaturing heteroduplex method for determining the molecular haplotype composed of the two more polymorphic systems of the first exon of DRD4: the 12 bp duplication and 13 bp deletion. This method will facilitate future research on expressed variation of this gene.

Electrophoresis, Polyacrylamide Gel↗