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Biomedical subjects

S M Chuang

Publications and source records attributed to S M Chuang.

At least 37 records · Page 2Linked to original sources
PubMed1996

Primary ovarian carcinoid tumor.

Pure primary ovarian carcinoid tumors are uncommon and only 21 cases have been recorded in the literature. In the past 15 years, we have seen two cases. One was a strumal carcinoid and the other, the case presented here, was a primary ovarian carcinoid tumor arising from the left ovary of a 25-year-old woman who had no carcinoid syndrome. The tumor was made up of pure carcinoid tumor without other teratomatous elements. On light microscopy the neoplasm, composed of uniform tumor cells, was arranged in solid nests or a trabecular pattern. The differential diagnosis included granulosa cell tumor. However, the strongly argyrophilic, chromogranin staining and ultrastructural presence of neurosecretory granules confirmed the diagnosis of primary ovarian carcinoid tumor. After a careful survey of the contralateral ovary and the gastrointestinal tract, the patient underwent a left oophorectomy. Her postoperative course was uneventful. The literature and the pathologic findings are reviewed and discussed, along with the differential diagnosis and treatment of primary ovarian carcinoid tumor.

Adult↗
PubMed1995

Correlation of cytogenetic results with immunophenotype, genotype, clinical features, and ras mutation in acute myeloid leukemia. A study of 235 Chinese patients in Taiwan.

Of 235 consecutive patients with de novo acute myeloid leukemia (AML), clonal chromosomal abnormalities were detected in 151 (64%) of them. Twenty-four of the 71 patients with M2 AML had t(8;21), 35 of the 36 M3 patients had t(15;17), and 11 of the 45 M4 leukemia disclosed inv(16). Six of the eight patients with 11q23 abnormality had M4 or M5 subtype of leukemia. The incidence of t(15;17) and t(8;21) was higher in our patients than in patients from most Western countries. Immunophenotyping was performed on 197 patients. Patients with t(15;17) were associated with negativity to HLA-DR, CD11b, and CD34. Patients with t(8;21) expressed CD13 and CD33 less frequently than other patients, but all showed CD15 positivity. Coexpression of lymphoid-associated antigens on the leukemic blasts was detected in 52 patients (26%), including all 7 patients with t(9;22), 3 of the 8 patients with t/del(11)(q23), 2 of the 25 patients with t(15;17), and 2 of the 22 patients with t(8;21). Seven (35%) of the 20 patients coexpressing lymphoid markers showed immunoglobulin heavy chain or T-cell receptor beta-chain gene rearrangements, while only 2 (4%) of the 53 patients without lymphoid antigen expression did so. Patients with inv(16), t(8;21), and t(15;17) had a better prognosis than other patients. Of all surface antigens tested, only CD15, CD11b, and HLA-DR were of prognostic value: CD15 with a higher complete remission (CR) rate and CD11b or HLA-DR with a shorter CR duration. N-ras mutations were detected in 7 (18%) of the 40 patients in the study, including two of the three patients with inv(16). This study demonstrated differences in clinical features, immunophenotypes, and genotypes among different cytogenetic subgroups.

Adolescent↗
PubMed1995

Consistent presence of isochromosome 7q in hepatosplenic T gamma/delta lymphoma: a new cytogenetic-clinicopathologic entity.

Peripheral T-cell lymphoma (PTL), which is characterized by hepatosplenic presentation and the gamma/delta T-cell receptor (TCR) phenotype on the malignant cells, is a rare but distinct subtype of non-Hodgkin's lymphomas. Little is known about the chromosomal changes in these lymphomas. We report the cytogenetic analysis of three patients who had neoplastic proliferation of T gamma/delta cells in the spleen, bone marrow, and liver, but not in lymph nodes or skin. Isochromosome 7q and trisomy 8 were observed in all three patients. Isochromosome 7q as the sole abnormality has been previously reported in one patient with similar clinicopathologic features. It is suggested that i(7q) is a primary, nonrandom chromosomal abnormality in hepatosplenic T gamma/delta PTL.

Adult↗
PubMed1995

Ultrasonographic scanning of placental thickness and the prenatal diagnosis of homozygous alpha-thalassaemia 1 in the second trimester.

In order to evaluate the association between placental thickness (PT) and fetal homozygous alpha-thalassaemia 1 before the appearance of classic ultrasound findings of haemoglobin (Hb) Bart's hydrops fetalis, a total of 473 pregnancies were collected. The control group included 422 normal pregnancies with a gestational age from 14 to 23 weeks and the study group included 51 affected fetuses in the same gestational period. Fetal biparietal diameter (BPD) and PT were measured by high-resolution ultrasound. PT was evaluated against BPD. In the control group, the PT generally increased in parallel with the advancement of gestational age. All PT measurements in the study group were above the mean PT of their respective gestational week in the control group. Forty-six (90 per cent) of the pregnancies in the study group had PT larger than the mean plus two standard deviations of the control group. This study suggests that ultrasound measurement of PT may be a useful aid in the prenatal diagnosis of Hb Bart's hydrops fetalis before its classic findings become apparent in the late second trimester or third trimester.

Female↗
PubMed1995

Prenatal diagnosis by transabdominal chorionic villus sampling in the second and third trimesters.

From October 1989 through December 1993, 124 pregnant women (114 in the second trimester and 10 in the third trimester) underwent transabdominal chorionic villus sampling (CVS) for prenatal molecular or cytogenetic diagnosis. The mean gestational age was 18.2 weeks. Indications for CVS comprised single gene disease (72%), fetal anomalies detected by ultrasound (17%), advanced maternal age (6%), and previous siblings with chromosomal aberration (5%). Among the 89 fetuses at risk for single gene disease, 20 were diagnosed as affected by DNA analysis. Among the 35 fetuses at risk for chromosomal anomaly, 4 had trisomy, 3 had a 45,XO karyotype and 2 had a structural chromosomal abnormality. The miscarriage rate was 1.8% (2/114) and the spontaneous preterm birth rate was 2.4% (3/124). No maternal or other fetal complications occurred. This study suggested that second- and third trimester CVS is a safe and useful method for prenatal diagnosis.

Abnormalities, Multiple↗
PubMed1995

Acute leukemic transformation of myelodysplastic syndrome--immunophenotypic, genotypic, and cytogenetic studies.

The clinical and biological characteristics of myelodysplastic syndrome (MDS) in acute leukemic transformation were studied in 23 patients. All had myeloid transformation according to FAB criteria, but coexpression of lymphoid-associated antigens was detected in five of the 20 patients who underwent an immunophenotypic study. Rearrangement of the immunoglobulin heavy chain gene was also observed in one of the five patients who coexpressed lymphoid markers and that of the T-cell receptor beta chain gene in another one. None had pure lymphoid transformation. Clonal chromosomal abnormalities were noted in 12 (63%) of the 19 patients who underwent cytogenetic study, most commonly - 7 (six patients or 32%). In the 18 patients who underwent serial analyses both at MDS diagnosis and at acute transformation, seven (39%) underwent karyotypic evolution. The most common new or additional aberrations were +8 and +21. N-ras gene mutation was detected in two of the nine patients at acute leukemic transformation. The median interval from diagnosis of MDS to onset of acute transformation was 10 months (1-36 months). Patients with a normal karyotype at diagnosis had a significantly longer chronic phase duration than those with chromosomal abnormalities (median of 20 months vs. 5 months). However, all had a short survival time after diagnosis of acute leukemia, whether chromosomal anomalies were present or not.

Adolescent↗
PubMed1995

Prevalence of permanent primary congenital hypothyroidism in Taiwan.

The purpose of this study was to find the prevalence of permanent primary congenital hypothyroidism in Taiwan. From January 1988 to December 1990, there were 991,132 live births in Taiwan. Of these, 329,891 neonates were screened for primary congenital hypothyroidism. Fifty-seven cases of permanent primary congenital hypothyroidism were confirmed. Hence, the prevalence of permanent primary congenital hypothyroidism in that period in Taiwan was 1 in every 5,788 live births. There was a female preponderance with a female to male ratio of 1.7. Of 54 infants who had a thyroid scan, 36 were found to have an ectopic thyroid gland, while 11 were found to have dyshormonogenesis. Among the 57 infants, one case with a delayed rise in the serum thyrotropin level was missed on initial screening. When compared with other studies, these data suggest that the prevalence of permanent primary congenital hypothyroidism varies in different ethnic groups throughout the world.

Congenital Hypothyroidism↗
PubMed1994

Malignant fibrous histiocytoma of the broad ligament.

Malignant fibrous histiocytoma of the broad ligament origin is extremely rare. We report a case of a 64-year-old female with a broad ligament tumor mass, who underwent complete excision of the mass, total hysterectomy, and bilateral salpingo-oophorectomy. Pathology showed a malignant fibrous histiocytoma of the broad ligament. The postoperative course was uneventful and no radiation or chemotherapy was given. She has been carefully monitored for 16 months and is without recurrence.

Broad Ligament↗
PubMed1994

Recurrent Down's syndrome due to maternal ovarian trisomy 21 mosaicism.

A family with three children who had Down's syndrome and one healthy child is reported. Cytogenetic studies of the peripheral blood revealed trisomy 21 in the affected children, and normal karyotypes in both the parents and the healthy child. However, a biopsy of the mother's right ovary showed a mosaic trisomy 21 cell line (8/20 cells). By DNA polymorphism analysis, segregation of trisomy oogonia appeared to be the cause of recurrent trisomy 21.

Adult↗
PubMed1994

Amniocentesis in mothers who are hepatitis B virus carriers does not expose the infant to an increased risk of hepatitis B virus infection.

Sixty-seven pairs of mothers with hepatitis B virus (HBV) surface antigen (HBsAg) and their infants were divided into two study groups to determine the effect of amniocentesis on intrauterine HBV infection. In the first study group (35 pairs), the infant's HBsAg status in cord blood was studied and the results were compared with those obtained in the cord blood from 65 infants born to HBsAg-positive women who did not have an amniocentesis. In the second study group (32 pairs), the HBV status of the infants was studied at the age of three months to five years and compared with the HBV status of 3,454 infants in the National HBV Prevention Program. In the first study group, one sample (2.9%) was weakly positive for HBsAg; while in the first control group, two (3.1%) were positive. In the second study group, three (10%) infants were positive for HBsAg. The failure rates of immunoprophylaxis in the second study and control groups were similar (9.4% vs 11% for HBsAg carrier mothers; 30% vs 14% for HBe antigen-positive carrier mothers). This suggested that genetic amniocentesis did not increase the risk of intrauterine HBV infection.

Adult↗
PubMed1994

Increased level of second trimester maternal serum chorionic gonadotropin in pregnancy with a fetus affected by homozygous alpha-thalassemia 1.

With enzyme immunoassay, maternal serum chorionic gonadotropin (MShCG) level was determined in 58 pregnancies affected with fetal homozygous alpha-thalassemia 1. In 40 pregnancies with a gestational age of 10 to 14 weeks, 8 (20%) had an MShCG level above 2.5 multiples of the median (MoM); while in the other 18 pregnancies with a gestational age of 15 to 23 weeks, 14 (78%) had a level above 2.5 MoMs and none had a level below the median. Homozygous alpha-thalassemia 1 of the fetus was associated with an elevated MShCG. Therefore in second-trimester screening for Down's syndrome by measurement of MShCG, homozygous alpha-thalassemia 1 should also be considered if elevated MShCG levels are found.

Adult↗
PubMed1994

Cytogenetic studies, ras mutation, and clinical characteristics in primary myelodysplastic syndrome. A study on 68 Chinese patients in Taiwan.

Cytogenetics and clinical features were studied for 68 Chinese patients with primary myelodysplastic syndrome (MDS). Ras mutation was analyzed in 25 of them. Thirty-four patients (50%) had clonal chromosomal abnormalities at initial analysis. The most common cytogenetic aberrations were -7, +8, 5q-, and 20q-, which occurred in 11 (16.2%), seven (10.3%), five (7.4%) and three patients, respectively. The incidence of -7 was higher and that of 5q- lower in our patients than in patients from most other geographic areas. The 17 patients with multiple chromosomal abnormalities had a significantly shorter median survival (9 months) than the 34 patients with normal karyotype (33 months) and the 17 patients with patients with single anomalies (26 months). Evolution to acute leukemia occurred in 20 patients (29%) after a median interval of 8 months following the diagnosis. Patients with multiple cytogenetic changes at initial analysis or in subsequent studies had a significantly higher frequency of acute transformation than others (55% vs. 18.6%, p = 0.007); the same was not true if only the data of initial study were considered. Serial cytogenetic studies are important in patient follow-up. N-ras mutation was detected in 5 (20%) of 25 patients within the study. There was no correlation between the gene mutation and acute transformation. But combing the data of N-ras mutation and cytogenetics, patients with either the N-ras mutation or clonal chromosomal abnormalities were at significantly higher risk for developing acute leukemia than those with neither of the changes (77% vs. 25%).

Adolescent↗
PubMed1994

Prevalence and molecular studies of thalassemia in five aboriginal groups in Taiwan.

A total of 1,342 blood samples from five aboriginal groups in Taiwan, comprising 522 of the Ami, 246 of the Bunum, 227 of the Atayal, 214 of the Paiwan and 133 of the Yami group, were collected. A complete blood count was performed in each case. In subjects with a mean corpuscular volume < 85 fl or hemoglobin (Hb) < 12 gm% (female) or 13 gm% (male), quantitation of Hb A2 and DNA analysis of alpha- and beta-globin genes were performed. Alpha-thalassemia was diagnosed by Southern hybridization of subject's DNA to alpha-, and zeta-globin gene fragments, and to Lo probe if needed. DNA from beta-thalassemia carriers was studied by polymerase chain reaction and direct sequencing. In the Ami, 42 (8.2%) were alpha-thalassemia 1 carriers, 42 (8.2%) were alpha-thalassemia 2 carriers, one had Hb H disease, and four (0.8%) were beta-thalassemia carriers. In the Bunun, one (0.2%) was an alpha-thalassemia 1 carrier, and two (0.4%) were alpha-thalassemia 2 carriers. In the Atayal, one (0.2%) was an alpha-thalassemia 1 carrier. In the Paiwan, seven (3.3%) were alpha-thalassemia 1 carriers, and one (0.5%) was an alpha-thalassemia 2 carrier. In the Yami, none were either alpha- or beta-thalassemia carriers. Diverse genetic origin, intragroup breeding and malarial selection may play a role in the significant differences of thalassemia prevalences both between the Chinese and the aborigines, and among different groups of aborigines.

Female↗
PubMed1993

Alpha-thalassemia in the four major aboriginal groups in Taiwan.

A total of 1309 unrelated blood samples from four major Taiwan aboriginal groups, including 522 of the Ami, 246 of the Bunun, 227 of the Atayal, and 214 of the Paiwan groups, were collected. Subjects with a mean corpuscular volume below 85 fl and Hb A2 values below 3.5% were further studied with Southern hybridization to determine the status of alpha-globin genes. In the Ami, 43 (4.1%) chromosomes had alpha-thalassemia 1 and 43 (4.1%) had alpha-thalassemia 2. Of the 43 alpha-thalassemia 1 chromosomes, 33 were of the Thailand, one of the Philippine, and nine of the Southeast Asian deletion. Of the 43 alpha-thalassemia 2 chromosomes, 42 were of the type I rightward deletion and one was of leftward deletion. In the Bunun group, one chromosome (0.2%) was of the Thailand deletion and two (0.4%) were of type I rightward deletion. In the Atayal group, only one chromosome (0.2%) was of the Philippine deletion. In the Paiwan group, four chromosomes (0.9%) were of the Southeast Asian deletion and three (0.7%) were of the Thailand deletion. Among the four groups, the Ami had the highest prevalence of alpha-thalassemia, which was also higher than that of the Chinese living in Taiwan.

Blotting, Southern↗
PubMed1993

Cytogenetic characterization of Epstein-Barr virus-associated T-cell malignancies.

Recently, Epstein-Barr virus (EBV) infection has been found not only to be associated with Burkitt lymphoma and nasopharyngeal carcinoma but also with some T-cell malignancies. Cytogenetic studies were performed on four Chinese patients with EBV-associated T-cell neoplasms: three peripheral T-cell lymphomas and one large granular lymphocyte leukemia with coexpression of T-cell antigen. Clonal chromosomal abnormalities were detected in all four patients. Rearrangements of chromosome 7 were observed in three patients: one at 7p22, one at 7q35 or 36, and the remaining one at both sites. The last patient also had a chromosomal abnormality involving 14q11. Trisomy of part of the 1q segment was detected in two patients. The results revealed that the chromosomal abnormalities in these patients were similar to those observed in other T-cell lymphomas. Further studies on more patients are necessary to find out whether there are specific chromosomal aberrations in EBV-associated T-cell neoplasms.

Adolescent↗
PubMed1993

Comparison of clinical and biologic features between myeloid and lymphoid transformation of Philadelphia chromosome positive chronic myeloid leukemia.

Analysis of clinical and biologic features of chronic myeloid leukemia (CML) in blast crisis (BC) was performed on 36 patients: 25 had myeloid and 11 had lymphoid transformation. The median duration from diagnosis to onset of BC was significantly shorter in patients with lymphoid BC (6 months) than in those with myeloid BC (41 months). Patients in lymphoid transformation showed better response to therapy and had a significantly longer median survival time after BC than patients with myeloid transformation (56% vs 0% and 10 months vs 4 months, respectively). The leukemic cells from all the patients with lymphoid BC showed B-cell immunophenotype, confirmed by the presence of immunoglobulin (Ig) heavy chain gene rearrangements in the five patients studied. Two of the eight patients with complete marker study expressed myeloid-associated antigens on the blasts. A high incidence of CD7 expression (7/17 or 41%) was found in patients with myeloid BC, but none of the patients who had DNA analysis showed rearrangement of T-cell receptor beta chain gene. Chromosomal abnormalities +8, +19, +21, and i(17q) were detected only in the patients with myeloid BC but not in those with lymphoid BC. Combined analysis of the patients in this series and those reported previously has revealed a statistically significant difference in the distribution of bcr breakpoints between myeloid and lymphoid BC: the bcr breakpoints in more than half of the patients with myeloid crisis were mapped to Zone 2 while those in patients with lymphoid crisis occurred most frequently in Zone 3.

Adolescent↗