Biomedical subjects
Publications and source records attributed to C P Chen.
We report on a rare in utero appearance of urinary bladder perforation, urinary ascites, and bilateral contained urinomas secondary to posterior urethral valves. The findings on prenatal sonography, postnatal voiding cystourethrography, and magnetic resonance imaging are described.
We report the prenatal diagnosis, pathology, cytogenetics, and molecular studies of a retroperitoneal fetus in fetu. Prenatal ultrasonography of the host fetus in the third trimester showed an anencephalic, acardiac mass with identifiable extremities and spine within an intra-abdominal cystic mass. Pathological examination revealed a fetiform mass weighing 20 g with four extremities, digits, vertebral bodies, an oral cavity with developing teeth, primitive male external genitalia, a urinary bladder, a cloaca with an external opening, large intestines, a membranous capsule, and an umbilical cord with one artery, one vein, and Wharton's jelly. Histological examination demonstrated nerve bundles in the fibrocollagenous tissue below the cuboidal surface epithelium of the membranous capsule, and absence of lamina elastica interna and vasa vasorum in the single artery of the umbilical cord. Both the host infant and the fetus in fetu had a normal 46,XY karyotype. Molecular analysis using informative genetic markers showed no genetic difference between the host infant and the fetiform mass. We report this case as an unusual example of fetus in fetu in co-existence with an amnion-like membrane containing nerve bundles and with a well-formed umbilical cord. We demonstrate that fetus in fetu can be diagnosed prenatally if the fetiform mass has well-developed limbs and spine. We emphasize the necessity for suspicion of fetus in fetu when a well-defined encapsulated cystic mass with calcified solid components is detected prenatally in a fetus by ultrasonography.
We report the rare occurrence of a progressive fetal axillary cystic lymphangioma coexistent with an overlying naevus flammeus. The fetus at 22 weeks' gestation was found to have a 37 x 35 mm left axillary multiloculated mass without colour-flow imaging. Amniocentesis showed a normal 46,XX karyotype. Multiple fine-needle aspirations of the mass in the second and third trimesters obtained blood-stained chocolate-coloured fluid containing numerous erythrocytes and lymphocytes but proved ineffective in lessening the progressive growth of the mass. The mother underwent caesarean delivery and a healthy neonate was born with a 141 x 81 mm left axillary cystic lymphangioma and a 50 x 35 mm coexistent naevus flammeus. The neonate was well after simple excision of the lesions. Although cystic lymphangiomas arising in the axilla enlarge progressively during fetal life, our case suggests a good prognosis and except for genetic evaluation, no prenatal intervention is required.
A 34-year-old woman with an abnormal maternal serum screening result and a Down syndrome risk of 1:60 calculated from a maternal serum alpha-fetoprotein (AFP) value of 1.4 multiples of the median (MoM) and a human chorionic gonadotrophin (hCG) level of 4.32 MoM at 18 weeks' gestation was found to have isolated fetal ascites at 23 weeks' gestation. Spontaneous resolution occurred 10 weeks after the initial presentation. After birth, the neonate had generalized cutis marmorata telangiectatica congenita (CMTC), large vascular plaques on the scalp with superficial ulceration and crusts, a small atrial septal defect, a patent ductus arteriosus, hepatomegaly, micrognathia, seizures, an abnormal electroencephalogram, congenital retinal detachment, glaucoma and widely spaced toes. Our patient illustrates that CMTC in utero may be associated with a markedly elevated maternal serum hCG level as well as transitory isolated fetal ascites. However, such associations can be coincidental and further collaborative studies and cases will be necessary before it can be determined that a disproportionately elevated hCG level and transitory isolated fetal ascites are predictive of CMTC in utero.
We report on six cases with CVS-exposed limb-"reduction" defects born in our hospital during a period of 9 years (1986-1994). Four cases were associated with other birth defects. One had an oromandibular-limb hypogenesis syndrome with a cleft lip and jejunal atresia, a second had an oromandibular-limb hypogenesis (Hanhart) syndrome, a third had severe flexion deformity at the hips and hyperextension at the knees with meconium peritonitis and intestinal obstruction, and a fourth had Poland anomaly. Detailed clinical descriptions, prenatal diagnosis, photographs, and radiographs are presented. Our presentation adds to the information on severe limb abnormalities after CVS and suggests CVS-exposed limb defects may be associated with other birth defects resulting from vascular insufficiency or intrauterine compression. We suggest that detailed post-CVS sonographic followups are necessary for each CVS-exposed case to identify not only the possible fetal limb reduction, but also vascular disruption-type malformations and compressive deformities.
Studies on the structures and binding properties of the glycoproteins, purified from human ovarian cyst fluids, will aid the understanding of the carbohydrate alterations occurring during the biosynthesis of blood group antigens and neoplasm formation. These glycoproteins can also serve as important biological materials to study blood group A, B, H, Le(a), Le(b), Le(x), Le(y), T and Tn determinants, precursor type I and II sequences and cold agglutinin I and i epitopes. In this study, the binding property of a cyst glycoprotein from a human blood group Le(a+) nonsecretor individual, that contains an unusually high amount (18%) of sialic acid (HOC 350) was characterized by quantitative precipitin assay with a panel of lectins exhibiting a broad range of carbohydrate-binding specificities. Native HOC 350 reacted well only with three out of nineteen lectins tested. It precipitated about 80% of Ricinus communis (RCA1), 50% of Triticum vulgaris (WGA) and 37% of Bauhinia purpurea aba (BPA) agglutinins, respectively. However, its asialo product had dramatically enhanced reactivity and reacted well with many I/II (Gal beta1 --> 3/4GcNAc), T(Gal beta1 --> 3GalNAc) and Tn(GaNIAc alphaI --> Ser/Thr) active lectins. It bound best to Jacalin, BPA, and abrin-a and completely precipitated all the lectins added. Asialo-HOC 350 also reacted strongly with Wistaria floribunda, Abrus precatorius agglutinin, ricin and RCA1 and precipitated over 75% of the lectin nitrogen added, and moderately with Arachis hypogaea, Maclura pomifera, WGA, Vicia viosa-B4, Codium fragile tomentosoides and Ulex europaeus-II. But native HOC 350 and its asialo product reacted not at all or poorly with Dolichos biflorus, Helix pomatia, Lotus tetra-gonolobus, Ulex europaeus-I, Lens culinaris lectins and Con A. The lectin-glycoform interactions through bioactive sugars were confirmed by precipitin inhibition assay. Mapping the precipitation profiles of the interactions have led to the conclusion that HOC 350 contains a large number of receptors for I/II, T, and Tn active lectins. But in the untreated (or native) substance, most of these determinants are masked by sialic acids.
Unlike the human blood group Sd(a+) Tamm-Horsfall glycoprotein (THGP), the Sd(a-) one lacks terminal GalNAcbeta1--> residues at the nonreducing ends. The binding properties of this glycoprotein and its asialo product with lectins were characterized by quantitative precipitin (QPA) and precipitin inhibition assays. Among 20 lectins tested by QPA, both native and asialo Sd(a-) THGP reacted best with Abrus precatorius and Ricinus communis and completely precipitated the lectin added. They also precipitated well Wistaria floribunda (WFA), Glycine max (SBA), Bauhinia purpurea alba, abrin-a and ricin, all of which recognize the Galbeta1--> 4GlcNAcbeta1--> sequence, although at different strength. The lectin-glycan interactions were inhibited by Galbeta1--> 4GlcNAc and Galbeta1--> 4Glc. When the precipitability of Sd(a-) THGP was compared with that of the Sd(a+) phenotype, the native Sd(a-) THGP exhibited a 40% lesser affinity for WFA, SBA, WGA and mistletoe lectin-I (ML-I). Mapping the precipitation and inhibition profiles of the present study and the results of THGP Sd(a+), it is concluded that Sd(a-) THGP showed a strongly diminished affinity for GalNAcbeta1--> active lectins (SBA and WFA) than the Sd(a+) phenotype.
The prenatal and postnatal findings of a fetus with partial deletion of 3p25 -> pter and duplication of 2p25.3 -> pter are described. The proband postnatally displayed mental and growth retardation, psychomotor delay, microcephaly, ptosis, micrognathia, a narrow palate, and cryptorchidism. All of these anomalies were consistent with those described in 3p- and partial trisomy 2p syndromes, and also frequently seen in patients with other chromosomal disorders. However, the prenatal sonograms revealed unusual shortening of the long bones, a single umbilical artery, and normal development of the skull. Our case suggests that skeletal growth retardation of the long bones may occur earlier than that of the skull in fetuses associated with chromosomal aberrations such as del(3p)/dup(2p). Shortening of the long bones and a single umbilical artery together with other abnormalities detected by prenatal ultrasound thus warrant a fetal cytogenetic study.
We report on a case of duplicated hydrometrocolpos with uterus didelphys, a septate vagina, lower vaginal atresia, a persistent urogenital sinus, left ear agenesis, a single umbilical artery, and an imperforate anus, but without the associated features of McKusick-Kaufman syndrome such as polydactyly and congenital heart defects. Ultrasound-guided fluid aspiration of the fetal intrapelvic cystic mass helped to decompress the distended genital organs, decrease the severity of the urinary tract obstruction, delineate the ultrasonographic image of duplicated hydrometrocolpos to differentiate it from other intrapelvic cystic masses, and obtain fluid for cytological analysis.
The pre- and postnatal findings of a fetus with a de novo del(13)(pter-->q21:) and an occipital encephalocoele are described. Maternal serum alpha-fetoprotein (AFP) screening at 19 weeks' gestation demonstrated a high level of 2.5 multiples of the median (MOM) and ultrasonography at 27 weeks' gestation showed severe intrauterine growth retardation, cardiomegaly, an occipital encephalocoele, and a calvarial defect. Genetic amniocentesis revealed a karyotype of 46,XX,del(13)(pter-->q21:). The proband postnatally displayed additional abnormalities such as microphthalmia, hypertelorism, large low-set ears, and micrognathia. We discuss the association of central nervous system (CNS) malformations with 13q deletions and emphasize that pregnancies with neural tube defects warrant cytogenetic analysis, especially when additional fetal abnormalities and neonatal dysmorphism are observed.
We present the first report of prenatally diagnosed Dandy-Walker malformation with the karyotype of partial trisomy 11 and 22 due to familial translocation t(11;22)(q23;q11) inherited in three generations. We demonstrate that the Dandy-Walker malformation can be an associated congenital malformation of supernumerary der(22)t(11;22) syndrome and emphasize the importance of chromosomal analysis and genetic counselling in the obstetric management of prenatally diagnosed Dandy-Walker malformation.
The therapeutic and side-effect profiles of clozapine differ from those of typical antipsychotic drugs such as haloperidol. Effects on the serotonin system, especially serotonin-2 receptors, may contribute to clozapine's atypicality. We injected rats for 14 days with clozapine (25 mg/kg/day) or haloperidol (2 mg/kg/day), and measured three aspects of the serotonin system in forebrain regions: abundance of serotonin-2A, -2C and -1A receptor messenger RNAs by in situ hybridization histochemistry; serotonin-2A and -1A binding sites using receptor autoradiography, and levels of serotonin and 5-hydroxyindoleacetic acid with high-performance liquid chromatography. Clozapine administration decreased serotonin-2A receptor messenger RNA and the density of [3H]ketanserin binding in cingulate and frontal cortex, but not in piriform cortex. Serotonin-1A receptor expression and serotonin-2C receptor messenger RNA were unchanged in all areas. The treatment markedly decreased serotonin and 5-hydroxyindoleacetic acid concentrations in striatum with similar trends in cortex and hippocampus. Haloperidol administration did not affect the expression of the three serotonin receptors, but was associated with a modest reduction of striatal and hippocampal 5-hydroxyindoleacetic acid. The selective reduction of serotonin-2A receptors confirms earlier findings and supports the view that this receptor may have relevance for the actions of clozapine. The fact that the encoding messenger RNA is decreased shows that the the effect is mediated at the level of gene expression. In contrast, the unchanged serotonin-2C receptor messenger RNA level indicates that the reported loss of serotonin-2C receptors after clozapine treatment is due to translational or post-translational events. The relationship between the reduction in serotonin-2A receptor expression and the altered serotonin metabolism remains unclear.
BACKGROUND: The polymorphic metabolism of debrisoquin and sparteine by cytochrome P450IID6 (CYP2D6) is genetically determined. Determination of the CYP2D6 metabolic phenotype with conventional urine analytic methods is not feasible in anuric patients with renal failure. The possibility of using salivary analysis, with dextromethorphan as a probe drug, to determine the CYP2D6 metabolic phenotype in patients with renal failure was evaluated. METHODS AND RESULTS: One hundred four Chinese patients with renal failure were recruited. All 104 patients were receiving hemodialysis. Saliva was collected before and at 3 hours after each patient took a capsule of dextromethorphan hydrobromide (30 mg). Four patients were excluded because of insufficient samples of saliva. The distribution of logarithms of the metabolic ratios (log[MR]) in the 100 patients appeared to be normal. Administration of quinidine sulfate (200 mg twice daily) to nine of the patients significantly and markedly increased the dextromethorphan metabolic ratios. The metabolic ratios of nine patients pretreated with quinidine were higher than any of the 100 patients with renal failure who did not receive quinidine pretreatment. A metabolic ratio of 33 separated these two groups. Genomic deoxyribonucleic acid was extracted from whole blood in a subset of patients. Polymerase chain reaction (PCR)-based methods were used to detect the CYP2D6 and B mutant genes. Mutant B alleles (which are common in white poor metabolizers) of CYP2D6 genes were not detected in any of the 47 subjects tested. A PCR-based test of cytosine (C188) to thymine (T188) polymorphism at 188 base pairs in exon 1 of CYP2D6 genes was performed in 61 patients. Subjects who were homozygous for C188 had significantly (p = 0.0067) lower log[MR] values than those who were homozygous for T188. CONCLUSIONS: Determination of dextromethorphan metabolic ratios in saliva is feasible in patients with renal failure requiring hemodialysis. All subjects in this study appeared to be "extensive metabolizer" phenotype for CYP2D6, and no poor metabolizer was identified. From the results with quinidine pretreatment, a metabolic ratio of 33 is suggested to be a tentative antimode for identification of poor metabolizers in patients with renal failure.
OBJECTIVE: To examine the risk factors associated with preterm birth in an upper middle class Chinese population. STUDY DESIGN: From March 1994 to February 1995, a total of 301 cases (gestational age between 20 and 37 weeks) and 656 controls (gestational age at or greater than 37 weeks) were recruited at Mackay Memorial Hospital, Taipei, Taiwan. Using a case-control study design, logistic regression was used to examine the relative significance of various risk factors associated with preterm birth. RESULTS: Age and educational level were identified as significant risk factors for preterm birth. Multiple pregnancies, fetal congenital anomalies, placenta previa or abruptio placentae, and preeclampsia were found to be strongly associated with preterm birth (crude odds ratios between 6.37 and 25.89); vaginal bleeding during or after the first trimester, prior history of preterm delivery, and two or more previous first trimester abortions were associated with preterm birth to a lesser extent (crude odds ratios between 1.67 and 2.9). The magnitude of the increased risk associated with these variables in preterm birth did not show change to any great extent after age and educational level were adjusted for. Further stratification of these cases into groups with and without premature rupture of the membranes (PROM), showed that a multiple pregnancy was still the leading risk factor of preterm birth in both groups. Carrying an abnormal fetus was the next important risk factor for preterm birth in cases with PROM, but was less important in the group without PROM. However, placenta previa or abruptio placentae and preeclampsia were the next most important factors in the group without PROM. CONCLUSIONS: Unfavorable current obstetric conditions and a history of more than two prior abortions and preterm delivery were positively associated with preterm birth.
Presynaptic serotonergic markers, serotonin uptake sites, and concentrations of serotonin and 5-hydroxyindoleacetic acid were studied in the frontal and temporal cortex of 20 community-acquired cases of Alzheimer's disease and 16 controls matched for age, sex, postmortem delay, and storage. Clinical assessments, including behavioural symptoms, of the Alzheimer patients were made at 4-month intervals during life. There was significant reduction in the number of serotonin uptake sites in Alzheimer cases in temporal but not frontal cortex. There was no significant alteration in the concentrations of serotonin or 5-hydroxyindoleacetic acid in either region. Alzheimer patients who had persistent depressive symptoms during life had significantly fewer serotonin uptake sites in both cortical areas compared with Alzheimer patients without these symptoms. In addition, Alzheimer patients who were receiving chronic neuroleptic medication had significantly lower concentrations of serotonin in frontal cortex and 5-hydroxyindoleacetic acid in temporal cortex than those patients not receiving such treatment. These data suggest previous studies that reported uniform serotonergic dysfunction may have been subject to unintentional selection of behaviourally disturbed Alzheimer cases or those receiving chronic neuroleptic medication. This study also provides a basis for the treatment of behaviourally disturbed Alzheimer patients with serotonomimetics.
The case of an 18-year-old pregnant woman with cryptococcal meningitis treated with amphotericin B and flucytosine since the third trimester of pregnancy is reported. She delivered a normal baby. The maternal outcome was favorable. There is no evidence of congenital infection in the newborn.
We retrospectively reviewed 27 cases of omphalocele and 15 cases of gastroschisis occurring among 62, 572 deliveries between 1987 and 1994. All cases had undergone prenatal sonographic examinations at a mean gestational age of 28 weeks. In cases of omphalocele, 59.3% (16/27) of fetuses were associated with multiple malformations and 16% (4/25) had chromosomal abnormalities. Among the 4 cases with an abnormal karyotype, three cases were associated with extracorporeal livers and two cases were associated with umbilical cord cysts. Prenatal ultrasound examinations during the second and third trimesters were able to detect 66.7% (18/27) of the cases of omphalocele and 66.7% (10/15) of the cases of gastroschisis. Failure in correctly diagnosing abdominal wall defects by prenatal ultrasound occurred mostly in cases associated with small defects, ruptured omphalocele, multiple fetal anomalies, intrauterine fetal death, twin pregnancies, or cases referred in late gestation. A comparison of perinatal data between omphalocele and gastroschisis reveals fetuses with omphalocele carry higher risks of associated malformations, chromosomal abnormalities, prematurity, and neonatal death. Although fetuses with gastroschisis have higher incidences of oligohydramnios and small for gestational age, the fetal prognosis after pediatric surgery is good.
Prenatal sonographic presentation of toe deformities is associated with fetal aneuploidies. This report presents a second-trimester fetus with large bilateral choroid plexus cysts, clenched hands, separation of the great toe, toe syndactyly, abnormal double maternal serum biochemical screening results, and trisomy 18. We suggest a careful ultrasound screening of the fetal limbs and other organs once a choroid plexus cyst has been identified. If abnormal sonographic findings are present, or if the results of the maternal serum biochemical screening are abnormal, karyotyping should be recommended.