Biomedical subjects
Publications and source records attributed to C C Lin.
A relatively simple method of obtaining high resolution chromosomes from amniotic fluid cells is described. The elongated chromosomes are achieved by adding ethidium bromide (5 micrograms/ml) to the culture 4 1/2 hours before harvesting and the high resolution banding can be produced by usual banding procedures.
Chromosomal analysis of 1000 spermatozoa from 33 normal men was performed using in vitro fertilization of zona-free golden hamster eggs. The frequency of abnormal sperm complements was 8.5%: 5.2% were aneuploid and 3.3% had a structural chromosome abnormality. The frequencies of hyperhaploid (2.4%) and hypohaploid (2.7%) sperm complements were not significantly different and all chromosome groups were represented among the aneuploid complements. The majority (22/33) of structurally abnormal complements had a chromosome break. The percentages of X and Y-bearing sperm were 53.9% and 46.1%, which is significantly different from the expected one to one ratio.
An infant with an interstitial deletion of chromosome 16 is reported. He showed severe psychomotor retardation and multiple congenital anomalies (craniofacial dysmorphism, cleft palate, endocardial cushion defect, preaxial polydactyly of one hand, low total ridge count). Unbanded chromosome studies following amniocentesis failed to identify the deletion. This case is very similar to other cases in the literature which were reported first by Fryns et al. (1977).
An epidemiological study on the association between oral contraceptive (OC) use and circulatory system disease (CSD) mortality undertaken in Taiwan by proxy interview of closest family members of 306 deceased cases, 305 deceased controls, and 611 healthy neighborhood controls indicated that the relative risk between the cases and health controls was 0.98 (0.62-1.54) and that between cases and health controls was 0.82 (0.56-1.21). Use of OC by Taiwanese women has not produced any overwhelming adverse effects on CSD mortality.
We examined three eyes with retinoblastoma that had clinical evidence of calcification. The light and electron microscopic study of the retinoblastoma cells from these eyes disclosed an intramitochondrial calcium deposition after plasmalemma disruption. Morphologically, calcium deposits initially occur as needle-like structures gathered within the mitochondrial membrane. With progressive necrotic liquefaction of tumor cells, microbodies develop a central calcified cone surrounded by an electron-translucent zone with coarse needle-like calcium deposition on the surface.
Two human neuroendocrine tumor cell lines derived from a colon carcinoma contain either numerous double minute chromosomes (COLO 320 DM) or a homogeneously staining marker chromosome (COLO 320 HSR). We found amplification and enhanced expression of the cellular oncogene c-myc in both COLO 320 DM and HSR cells, and we were able to show that the homogeneously staining regions of the COLO 320 HSR marker chromosome contain amplified c-myc. From previous and present karyotypes, it appears that the homogeneously staining regions reside on a distorted X chromosome. Therefore, amplification of c-myc has been accompanied by translocation of the gene from its normal position on chromosome 8 (8q24). Because double minute chromosomes were features of primary cultures from the original tumor, it seems reasonable to suspect that amplification of c-myc may have contributed to tumorigenesis.
The incidence of hepatitis in a general open population of Asian adults was estimated for the first time in this study. A group of 2445 students were first tested when they enrolled at National Taiwan University in 1977; approximately one third were susceptible to hepatitis A and another third to hepatitis B. Most of these students (92%) were retested shortly before their graduation in 1981 to determine the frequency of serologic conversions and clinical hepatitis which had occurred in the 3 1/2 years since they had entered the university. Among 704 susceptible to hepatitis A, 12 (1.7%) had undergone serologic conversions, 33% of which were associated with clinical illness diagnosed as hepatitis. Among 738 susceptible to hepatitis B, 39 (5.3%) had undergone serologic conversions, 12.8% of which were associated with clinical hepatitis. The annual incidence of new infections was 0.5% for hepatitis A and 1.5% for hepatitis B. An additional eight students among the 17 who had clinical hepatitis had no associated conversion of hepatitis A or hepatitis B markers, and were considered to have non-A, non-B hepatitis. No factors could be identified which were predictive of hepatitis risk. No difference in incidence was observed according to sex, type of residence, place of food consumption, or receipt of acupuncture or blood transfusion. Among the 39 students who experienced hepatitis B infections while at the university, there were 2.7% who became hepatitis B surface antigen (HBsAg) carriers. Thus the carrier frequency following hepatitis B infection among Chinese adults is the same or lower than that among Caucasian adults.
Pig--mouse somatic cell hybrids were obtained by fusing pig lymphocytes with mouse cells of the RAG (HPTR-) line using polyethylene glycol. The expression of pig superoxide dismutase (SOD-1) activity in 11 hybrid clones as well as in the parental cells was investigated. Seven hybrid clones positive for the expression of pig SOD-1 displayed the corresponding parental RAG and pig bands of SOD-1 plus a heteropolymeric band of intermediate electrophoretic mobility. The positive and negative expression of pig SOD-1 was concordant with the retention and loss of pig chromosome No. 9, suggesting that the gene for pig SOD-1 is located on the chromosome No. 9 of the domestic pig.
Pig--mouse somatic cell hybrids were obtained from fusion of HPRT--mouse cells (RAG) and pig lymphocytes. The pig-mouse hybrids examined apparently retained on the average only 9 to 15 pig chromosomes. Seven of the hybrid clones were karyotyped to determine the pig chromosome constitution, and the same hybrid clones were tested electrophoretically for the expression of pig hypoxanthine-guanine phosphoribosyltransferase (HPRT), glucose-6-phosphate dehydrogenase (G6PD), and alpha-galactosidase (alpha-GAL) phenotypes. All five of the hybrid clones which had retained the pig X-chromosome exhibited concordant expression of pig HPRT, G6PD, and alpha-GAL enzymes. These data indicate that the genes HPRT, G6PD, and alpha-GAL are located on the X-chromosome of the domestic pig.
We describe a new type of gamma delta beta-thalassemia in four generations of a family of Scotch-Irish descent. The proposita presented with hemolytic disease of the newborn, which was characterized by a microcytic anemia. Initial restriction endonuclease analysis of the DNA showed no grossly abnormal patterns, but studies of polymorphic restriction sites and gene dosage revealed an extensive deletion that removed all the beta- and beta-like globin genes from the affected chromosome. In situ hybridization of chromosome preparations with radioactive beta-globin gene probes showed that only one 11p homolog contained the beta-globin gene cluster in the affected family members.
Explore the source record for details and available documents.
A randomized double blind placebo controlled efficacy trial of hepatitis B immunoglobulin (HBIG) for prevention of the mother to infant transmitted HBsAg carrier state was conducted in Taiwan where the carrier rate in the general population is 15% to 20%. HBIG was given immediately after birth to infants of e antigen positive HBsAg carrier mothers and all infants were followed for at least 15 months. Among 61 placebo recipients the carrier rate was 92%; compared with 26% among 57 infants who received 0.5 ml HBIG at birth, three months and six months and 54% among 67 infants who received a single 1.0 ml dose of HBIG at birth only. Efficacy was 71% and 42% respectively for the two treatment schedules. The most common response of HBIG-treated infants was passive-active immunization which was 27% in single dose group and 61% in three doses group. Some of the infants who became carriers were probably infected as HBIG protection waned and we expect that higher efficacy can be achieved by HB vaccine in conjunction with HBIG.
A prevalence survey for arthritis among the general adult population of a rural island off the coast of China revealed a prevalence of rheumatoid arthritis (RA) of no more than 0.3% compared with 1.0% among Americans in the National Health Examination Survey (NHES). The frequency of clinical ankylosing spondylitis (AS) (0.2%) appears to be higher than expected, although limited data are available for comparison. No clinically unusual features of these diseases were recognized.
Immunoglobulin G, A, and M (IgG, IgA and IgM) levels were measured in paired maternal and cord serum samples from 18 pregnancies with intrauterine growth retardation (IUGR) and 55 with normal growth (adequate-for-gestational-age pregnancies) delivered vaginally at 36 weeks' gestation or later. Cord blood levels of IgG, IgA, and IgM in IUGR infants were found significantly lower than those in infants with adequate-for-gestational-age growth. Lower Lower levels of cord IgG in IUGR may be due to a defect in the active transport of IgG across the placenta. Lower levels of cord IgM and IgA suggest an impairment of synthesis of immunoglobulins in the IUGR infants. There was no difference in cord immunoglobulin concentrations between infants with intrapartum fetal heart rate (FHR) decelerations and those without FHR decelerations in either the IUGR or the adequate-for-gestational-age group. No difference was observed in maternal immunoglobulin concentrations among the study groups.
We investigated the effect of globin gene amplification on alpha-globin gene expression. Chinese hamster ovary cells were transformed with a plasmid containing the human alpha-globin gene linked to a functional dihydrofolate reductase gene, and the transformed cells were selected with increasing concentrations of methotrexate in the culture medium. A cell clone which was resistant to 0.1 mM methotrexate showed a 500-fold amplification of the transformed alpha-globin and DHFR genes. Both genes expressed high levels of their respective mRNAs. The mRNAs were functional and were translated to alpha-globin and DHFR proteins. Thus, one strategy for globin gene therapy is to achieve a high copy number of the transformed globin genes.
A method of plotting growth rate of the biparietal diameter against the concurrent size of the biparietal diameter was used to assess risk of intrauterine growth retardation. The technique does not require knowledge of gestational age of the fetus. Therefore, it is uniquely useful for patients with unknown or uncertain menstrual dates who present relatively late in pregnancy when a reliable estimate of gestational age cannot be sonographically obtained. One hundred twenty-one patients were studied. Ninety-seven percent of the fetuses who demonstrated a normal rate of growth were either appropriate or large for gestational age by weight. Thirty-five percent of the fetuses who had a subnormal rate of growth of the biparietal diameter were intrauterine growth retarded by weight. The data presented support the use of this technique for assessing the risk for intrauterine growth retardation, when an accurate estimate of gestational age account be made.
Explore the source record for details and available documents.
Fetal outcome was evaluated in 157 hypertensive pregnant women whose underlying disease had been established by renal biopsy. The patients had pathologic diagnoses of preeclampsia (95), nephrosclerosis (23), nephrosclerosis with superimposed preeclampsia (13), interstitial and tubular nephropathy (seven), and normal findings (six). Pregnancy outcome in this selected group of patients was extremely poor, with the perinatal mortality rate being 134 per 1,000. There were 21 perinatal deaths; three quarters of these were stillbirths, and most were encountered below the fiftieth weight percentile and before 30 weeks' gestation. In addition 22% of the infants were small for gestational ages, and 40% of the infants were born before term. Most of the perinatal mortality (81%) was in women with preeclampsia. The worst fetal outcome was encountered in multiparous preeclamptic women, over 50% of whom manifested nephrotic-range proteinuria during pregnancy. Despite the presence of hypertension throughout most of their gestation, women with nephrosclerosis alone had the best fetal survival rate.