Biomedical subjects
Publications and source records attributed to C C Lin.
A technique for avian leukocyte culture and chromosome analysis is described. The method is simple and allows karyotypic analysis by a variety of chromosome banding methods. It is applicable to a wide variety of species and may be useful in determining the genetic sex of monotypic species in captivity or for population studies of specimens in the wild.
Attempts were made to adapt human long-term B lymphoblastoid cell lines to prolonged growth in serum-free, chemically defined media. A newly described medium, which is an enriched modification of Dulbecco's modified Eagle's medium containing additional amino acids and vitamins, was used. The serum is totally replaced by albumin, transferrin, and soybean lipid. The cell lines were all adaptable from RPMI 1640 over a period of time during which the 10% fetal bovine serum (FBS) concentration was reduced and then eliminated in successive steps. After 3 to 6 wk minor alterations in cell shape and adhesion were noted without significant histological changes. Growth characteristics were comparable in the new medium provided a double initial inoculum was used. A panel of cell surface markers, including surface immunoglobulins, Ia antigens, Fc and complement receptors, and T and B erythrocyte rosettes, all showed no altered expression. Molecular genotyping of Ia antigens was carried out by 3-D gel electrophoresis. The antigens showed their full polymorphism without change and were shed into the new culture medium without alteration. Chromosome analysis was performed on Q-banded karyotypes from one of the lines and showed no alteration resulting from the change to serum-free conditions. Thus long-term B lymphoblastoid cell lines can be adapted to prolonged growth in serum-free medium. This will facilitate the assay and isolation of cell products regulating lymphocyte function and the identification and characterization of cell surface molecules free of interference from undefined serum components.
Some realistic galaxy models have been found to support discrete unstable spiral modes. Here, through the study of the relevant physical mechanisms and an extensive numerical investigation of the properties of the dominant modes in a wide class of galactic equilibria, we show how spiral structures are excited with different morphological features, depending on the properties of the equilibrium model. We identify the basic dynamical parameters and mechanisms and compare the resulting morphology of spiral modes with the actual classification of galaxies. The present study suggests a dynamical basis for the transition among various types and subclasses of normal and barred spiral galaxies.
To determine the incidence of infections with hepatitis B virus (HBV) among Chinese preschool children, 1,510 children (mean age, 29 months) were tested for HBV markers; 15.9% were infected with HBV (7.8% positive for hepatitis B surface antigen [HBsAg] and 8.1% positive for antibody to HBsAg) and 84.1% were susceptible when the children were enrolled in the study. The average length of follow-up was 2.1 years among 1,110 children. Among the 924 susceptible children who were followed up, 10.6% had seroconversions for HBV markers, none of which was associated with clinical illness; the annual incidence of HBV infections was 5.0%. Among the 98 children who experienced HBV infections during the study, 23% became HBsAg carriers, and HBsAg persistence was age-related, with most carriers being among the youngest children infected. In contrast, among the children with HBV markers at the time of enrollment, 118 (49.2%) were HBsAg-positive and 86% were still positive on follow-up. The incidence of HBV infections was significantly associated with the frequency of previous injections.
The organizations of the genomes of two related species of Asian deer, the Indian (2n = 6 female, 7 male) and Chinese muntjac (2n = 46), were compared at the cytogenetic and molecular levels. These dramatically different karyotypes preserve little apparent G-banding homology. The difference in chromosome number is coincident with a 22% reduction in haploid DNA content from 2.7 to 2.1 pg in the Chinese and Indian muntjac, respectively. The kinetics of reassociation of the Indian muntjac (equivalent Cot = 4285 M-1. s-1) and Chinese muntjac DNA (equivalent Cot - 4362 M-1.s-1) in 2.4 M tetraethylammonium chloride suggests conservation in amount of "single-copy" DNA. Two middle repetitive DNA sequence classes differ in both amount and in degree of repetition between the two species. A middle repetitive frequency component (935-fold repeated) represents 13% of the Indian muntjac DNA. A similar component (644-fold repeated) represents 17% of the Chinese muntjac DNA. Low repetition DNA sequence components (repeated 5- and 50-fold) represent 30 and 40% of the Indian and Chinese muntjac DNAs, respectively. These differences quantitatively account for the 0.6 pg haploid DNA content variation between species. The deletion of middle repetitive DNA has not substantively altered the distribution of restriction endonuclease DNA base composition classes as defined by buoyant density in cesium chloride. These results represent the first time that middle repetitive DNA has been directly implicated in a chromosome rearrangement within the vertebrates.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
A 29-yr-old pregnant woman presented in her third trimester with severe pancreatitis, hyperlipidemia, and small-for-dates fetus. Studies suggested that her pancreatitis was caused by profound hypertriglyceridemia, which was the result of an underlying lipoprotein disorder exacerbated by pregnancy. Throughout the first 7 wk of hospitalization, attempts to refeed the patient with solid food and various elemental diets resulted in the induction of hypertriglyceridemia and relapses of pancreatitis. Concern for the nutritional status of the mother and the possibility of further growth retardation of the fetus prompted the use of total parenteral nutrition for the last 2 wk of gestation. This treatment was well tolerated by the mother, promptly reversed maternal weight loss, caused a rapid resolution of her pancreatitis, and did not induce further hypertriglyceridemia. This report documents that total parenteral nutrition may be safely and effectively used in the management of hyperlipidemic pancreatitis in pregnancy.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Chromosomal analysis of 240 spermatozoa from 18 normal men was performed using in vitro fertilization of zona-free golden hamster eggs. The frequency of chromosome abnormalities in this population was 9.2% (22/240). Of the abnormal complements, 18 were aneuploid (13 hyperploid and five hypoploid) and four had a chromosome break. The sex ratio of Y-bearing to X-bearing sperm was .68. The frequency and type of sperm chromosome abnormalities is compared with those seen in spontaneous abortions.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Amniotic fluid C-peptide (AFCP), insulin, and glucose levels were measured in 33 diabetic and 126 nondiabetic pregnant women at greater than or equal to 36 weeks' gestation. Levels of AFCP distinguished diabetic from nondiabetic patients more reliably than amniotic fluid (AF) insulin or glucose. Levels of AFCP in diabetic patients correlated well with infant birth weight adjusted for gestational age (large for gestational age greater than adequate for gestational age), degree of diabetic control (fair to poor control greater than good control), or diabetogenic infant morbidity, but did not correlate with classes of diabetes within the limits of the population studied. We conclude that AFCP is a useful prognostic index for predicting fetal outcome in diabetic pregnancies. A level of AFCP of greater than or equal to 1.0 pmoles/ml is associated with an increased risk of macrosomia in infants of diabetic mothers.
This report describes a patient referred at 14 years in 1971, after one year's surveillance by the family physician, for a persistently elevated erythrocyte sedimentation rate, leukopenia, and relative lymphocytosis. Despite the documented myeloproliferative syndrome of seven years, significant physiologic impairment precluding strenuous ranching and rodeo work appeared only in the last six to nine months. Throughout the clinical course characterized by pancytopenia, refractory and somewhat megaloblastic anemia partially responsive to oxymetholone, and subacute myeloblastic leukemia, he showed a persistent double trisomy--48, XY, +8, +21 in bone marrow. This report reiterates the value of chromosome analysis in the study of hematologic disorders and, in addition, emphasizes the need to individualize each patient's prognosis.