PubMed Health⌕ Search

Biomedical subjects

Y J Lin

Publications and source records attributed to Y J Lin.

At least 127 records · Page 7Linked to original sources
PubMed1987

The three-dimensional structure of trichosanthin molecule.

A model completed recently of two trichosanthin molecules in an asymmetric unit belonging to the monoclinic system is reported. It can be seen that the molecular structure consists of two domains, one large and one small, and that there are some features in the secondary structure. The dissimilarity between two molecules as well as their interactions in an independent unit correlated in a non-symmetric way has been described, moreover, the binding sites of the heavyatom position in the derivatives are also discussed.

Abortifacient Agents↗
PubMed1986

Simplified differential staining of mouse sister chromatids.

Many previously developed methods for sister chromatid exchange (SCE) analysis both in vivo and in vitro have been published during the past decade. Such methods have met with success in many but not all laboratories. These methods often involve expensive, hazardous equipment such as ultraviolet light and mercury lamps, as well as tedious treatments with hot salt solutions, acids or enzymes. The authors have developed an in vivo method using a 50 mg bromodeoxyuridine (BrdU) pellet combined with phosphate buffering at pH 6.8 and the use of a 300 watt, 130 volt inside-frosted incandescent bulb. Slides prepared from mouse bone marrow with this simplified method yielded many cells of excellent quality for SCE analysis, which were found to be highly reproducible.

Animals↗
PubMed1985

Improved light sources for induction of sister chromatid differentiation.

Various light sources, including ultraviolet light, mercury, germicidal, fluorescent, and incandescent lamps, were studied for their ability to induce sister chromatid differentiation (SCD) in rat bone marrow cells. The light sources were used along with Hoechst 33258 and Giemsa stains for SCD induction. When those lamps which emit significant amounts of heat were used, 60 degrees C incubation in 2X SSC was found to be unnecessary for SCD induction. A high wattage lamp, a high ambient temperature, a short distance between the lamp and the slides, or a light with 360 nm wavelength, minimized the required exposure time to the light. The pH value of the mounting buffer was also a significant factor. Fluorescent black light and incandescent lamps were found to be ideal light sources for SCD induction.

Animals↗
PubMed1984

Surfactants: a survey of short-term genotoxicity testing.

The available results for tests on over 200 surfactants in nine short-term genotoxicity assay systems were reviewed. These tests included the Salmonella/microsome mutation assay, bacterial DNA repair tests, mitotic recombination in Saccharomyces cerevisiae, the mouse lymphoma cell-mutation assay, unscheduled DNA synthesis and sister chromatid exchange assays in mammalian cells, mammalian chromosome damage tests in vitro and in vivo, the dominant lethal test in rodents, and mammalian cell-transformation tests. The collected data cover all four major classes of surfactants: anionic, cationic, nonionic and amphoteric. The results of these genotoxicity tests were overwhelmingly negative. Although there were occasional positive results in bacterial or cell-transformation systems, the testing performed to date indicates that surfactants have negligible potential to cause genetic damage. The available data also indicate that none of the assays were incompatible with testing surfactants for genotoxicity.

Animals↗
PubMed1982

Chiasma failures and chromosome association in Rhoeo spathacea var. variegata.

In Rhoeo spathacea var. variegata (2n = 2x = 12), the most frequent meiotic configuration was the chain-of-12 chromosomes (36%) and the second most frequent was the ring-of-12 chromosomes (25.6%). All six possible two-chain situations and eleven of the twelve possible three-chain situations were observed. A maximum of five chains was observed in four cells. The size of chains ranged from on through twelve chromosomes. The mean number of chiasma failures was 1.36 +/- 0.07 per cell and 0.1133 per pair of chromosome arms. Because the observed frequencies of various configurations agree with the expected, which were calculated under the assumption that chiasma failure is equally likely at each of the twelve positions around the ring, it was concluded that chiasma failures occurred at random among the arm-positions. Due to the lengths of arm-pairs in the ring vary considerably, the randomness may mean that chiasma formation was restricted to small terminal regions on all chromosomes.

Chromosomes↗
PubMed1981

Pulmonary absorption of amino acids in the rat: evidence of carrier transport.

To investigate the absorption of nonmetabolized amino acids from the rat lung, 0.1 ml of Krebs-Ringer phosphate solution containing either 14C-labeled 1-aminocyclopentanecarboxylic acid (cycloleucine) or alpha-aminoisobutyric acid (AIB) was administered to anesthetized animals by way of a catheter introduced through a tight-fitting tracheal cannula. After various times, lungs were removed and assayed for the amount of amino acid that remained. Cycloleucine appeared to be absorbed by a combination of at least two processes: saturable carrier-type transport and a nonsaturable process. The saturable process was inhibited to varying degrees by a number of L- and D-amino acids but not by D-ornithine, betaine, 3-O-methyl-D-glucose, phenol red, disodium cromoglycate, or tetraethylammonium. The nonsaturable process appeared to be too rapid to be accounted for by diffusion alone, thus suggesting interaction with a second carrier system of high capacity. Although AIB was a weak inhibitor of cycloleucine transport, it appeared to be absorbed solely by a nonsaturable process at a rate consistent with diffusion through aqueous membrane channels.

Absorption↗
PubMed1980

Chromosome behaviour in Rhoeo spathacea var. variegata.

Rhoeo spathacea var. variegata is unusual in that its twelve chromosomes are arranged in a ring at meiosis. The order of the chromosomes has been established, and each chromosome arm has been designated a letter in accordance with the segmental interchange theory. Chromosomes are often irregularly orientated at metaphase I. Chromosomes at anaphase I are generally distributed equally (6-6, 58.75%) although not necessarily balanced. Due to adjacent distribution, 7-5 distribution at anaphase I was frequently observed (24.17%), and due to lagging, 6-1-5 and 5-2-5 distributions were also observed (10.83% and 3.33% respectively). Three types of abnormal distribution, 8-4, 7-1-4 and 6-2-4 were observed very infrequently (2.92% total), and their possible origins are discussed. Irregularities, such as adjacent distribution and lagging, undoubtedly reduce the fertility of the plant because of the resulting unbalanced gametes.

Anaphase↗
PubMed1979

Fine structure of meiotic prophase chromosomes and modified synaptonemal complexes in diploid and triploid Rhoeo spathacea.

The synaptonemal complex (SC) in the diploid Rhoeo consists of 2 amorphous lateral elements, each about 46.0 nm thick, and one amorphous central element about 30.0 nm thick. The central region is about 115.0 nm wide. SC in the triploid have essentially the same dimensions as those of the diploid; both lateral (46.0 nm) and central (30.0 nm) elements are amorphous, and the central region is about 117.5 nm wide. The coil, observed in both diploid and triploid, is a modified short segment of SC with several twists at the end of a synapsed bivalent that is attached to the nuclear membrane. Serial sections in a diploid cell reveal that a coil extends inwards about 3.5 micron from the nuclear membrane and makes a complete turn at a distance of every 0.5 micron. There is a correlation between the modified ends of SC and terminal chiasmata in Rhoeo. The coils might have a positive role in the process of crossing over, or alternatively might be involved in ring formation by holding chromosome ends together while chiasmata are not involved. SC are present in chromocentres of both diploid and triploid. Chromocentres in diploid and triploid are indistinguishable, and appear to be formed from the aggregation of pericentromeric heterochromatin as a result of translocations which occured close to the centromeres. 3-dimensional hypothetical pachytene configuration of the diploid is presented.

Chromosomes↗
PubMed1976

New method for detecting and quantitating pharmacokinetic drug-drug interactions applied to ethanol-propranolol.

A novel method for detecting and quantitating pharmacokinetic drug-drug interactions is described. The method involves perturbation of an existing steady-state whole blood (or plasma) concentration of one drug by the other drug. The method would allow differentiation of "pharmacokinetic" drug interactions from "pharmacologic" interactions. It is shown that a bolus intravenous injection of propranolol reduced a steady-state arterial blood concentration of ethyl alcohol by 26% in the cat.

Acetaldehyde↗
PubMedDate not supplied

An exploratory study of social support: a cross-cultural comparison of Chinese-, Japanese-, and Anglo-American breast cancer patients.

This paper investigated the nature of social support for Asian- and Anglo-American women post breast cancer treatment. Forty-six Anglo- and Asian-American (13 Anglo-American, 18 Chinese-American and 15 Japanese-American women) women were assessed 6 months to 3 years post-treatment. Assessments consisted of a semi-structured interview plus standardized psychological tests. Three major hypotheses were developed and tested in the study. Results showed: (1) Anglo-American women indicated a greater need for social support than either of the two Asian-American groups in 66% of the categories; (2) no differences were found between the three ethnic groups in receipt of emotional or tangible social support; and (3) the network size and composition differed significantly in 83% of the categories between the Anglo group and at least one of the Asian groups. These differences were in size, mode, and perceived adequacy of social support. Implications for culturally-based clinical practice which emerge from these findings are discussed.

Adult↗