Biomedical subjects
C C Lin
Publications and source records attributed to C C Lin.
Quantitative analysis in the oxytocin challenge test.
A quantitative analysis of the oxytocin challenge test (OCT) was carried out in 305 women to evaluate: (1) the intrauterine pressures evoked during the oxytocin infusion, (2) when fetal heart rate (FHR) decelerations are likely to occur, (3) the type and amount of decelerations which are significant, and (4) what clinical events and laboratory parameters correlate with the OCT. If contractions are evoked at a rate of three per 10 minutes, the pressure profile mimics normal labor. The first FHR deceleration is likely to occur between the second and third effective contraction. A deceleration/contraction ratio greater than or equal to 10% significantly forecasts an abnormal FHR during parturition and an increased chance of a cesarean section.
Reverse banding on chromosomes produced by a guanosine-cytosine specific DNA binding antibiotic: olivomycin.
Characteristic reverse fluorescent banding patterns (R bands) on human, bovine, and mouse metaphase chromosomes are produced by treating chromosome preparations directly with olivomycin. With the DNA in solution, the repeating polymer poly[d(G-C)] - poly[d((G-C)] (where G is guanine and C is cytosine) enhanced the fluorescence of olivomycin, while the antibotic fluorescence was not affected by the alternating polynucleotide poly]d(A-T)] - poly[d(A-T)] (where A is adenine and T is thymine). Calf thymus DNA, with an intermediate G-C content of about 40 percent, showed a smaller fluorescence enhancement in the presence of olivomycin as was observed for the synthetic polynucleotide poly[d(G-C)] - poly [d(G-C)]. The closely related antibiotic chromomycin A3 showed the same results as were obtained with olivomycin either in the solution interaction with specific DNA's or with the netaphase chromosome preparations. The production of R bands by these G-C-specific DNA binding antibiotics lends credence to the suggestion that the arrangement of the nucleotide sequences along the chromosome is a primary determinant for the appearance of fluorescent bands.
Pyrimidinylpropenamides as antitumor agents. Analogues of the antibiotic sparsomycin.
A series of pyrimidinylpropenamides 9 and their oxidation products 10 was prepared, as analogues of sparsomycin (1), for antitumor evaluation. Syntheses involved condensation of the appropriate amino alcohol 5 with acid 8. The resulting sulfides 9 were then oxidized with NaIO4 or H2O2 to sulfoxides 10. Activity was studied in lymphocytic leukemia P-338 and KB cell culture. With the exception of the n-decyl analogue, all of the deoxygenated compounds 9 were inactive regardless of the stereochemical form. In the sulfoxide series 10, those compounds prepared with an L configuration at the asymmetric carbon were also inactive. The completely racemic sulfoxides, on the other hand, displayed substantial antitumor activity (ILS = 37-61% in P-388; ED50 = 1.2-2.4 mug/ml in KB) suggesting that both the presence of a sulfoxide moiety and a D configuration at the chiral carbon atom were structural requirements for a positive antitumor response. There appeared to be a large tolerance for the group substituted at the sulfoxide moiety, however.
Discrete spiral modes in disk galaxies: Some numerical examples based on density wave theory.
Discrete growing spiral modes are calculated, on the basis of principles of stellar dynamics, according to the recently developed asymptotic theory of density waves for spiral structure in galaxies. From the growth rates obtained, it appears likely that several spiral modes coexist in a given disk galaxy. General properties of these modes are described for two galaxy models, and some of their important observational implications are discussed.
Interchromosomal duplication for the short arm of chromosome no. 9: report of three cases due to a familial translocation t(9; 11) and one case with a de novo 47, XX, +9p karyotype.
Four cases of the 9p duplication syndrome are described. Three affected sibs resulted from a maternal t(9;11) translocation and have a duplication of the segment 9p13 leads to 9pter. They have the typical facies, hands and other features of the syndrome but are relatively mildly retarded. The fourth case has a de novo duplication of the short arm of chromosome 9. Her features are also typical although she is more retarded, particularly in expressive speech, than the other three individuals and had club feet. These observations further confirm the distinctive clinical features of this type of duplication, and support previous suggestions that the severity is roughly correlated with the length of the duplicated segment.
A (9;17) translocation, 46 chromosomes. Repository identification No. GM-988.
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Hyphal wall chemistry in Apodachlya.
Hyphal walls were isolated from the Oomycete, Apodachlya sp. Microscope examination of wall preparations showed that they were clean and relatively free of cellulin granules. The principal wall constituents, accounting for more than half of wall weight, were beta-glucans with 1,3- and 1,6-glucosidic linkages. Apparently chitin was the second most abundant wall constituent (18%) and cellulose accounted for less than 10% of wall weight. Protein was a significant wall constituent (6.4%), and protein hydrolysis demonstrated nearly all common amino acids plus hydroxyproline; additionally, the unusual amino acid, hydroxylysine was tentatively identified. The lipid and ash constituents were small (1.7and 0.4%, respectively) and no particular significance was assigned to them. The possible occurrence of wall glycoproteins and the relationship between wall chemistry and systematics in Apodachlya and related genera were discussed.
Chromosome analysis on 930 consecutive newborn children using quinacrine fluorescent banding technique.
Chromosome analysing using quinacrine fluorescence was performed on 930 consecutive newborn infants. The total incidence of major chromosome aberrations including numerical changes of the sex chromosomes, and structural changes of autosomes, was 0.54%. Incidence of XYY (0.4%) and XXY (0.2%) were relatively higher as compared to other studies. About 0.75% of the newborn infants were found to have a variable bright fluorescent band located on the proximal area of the short arm (p11) rather than on the proximal long arm (q11) of chromosome No. 3. Attempts were also made to record the variable fluorescent regions on 7 autosomes and the Y chromosome.
Unstable spiral modes in disk-shaped galaxies.
The mechanisms for the maintenance and the excitation of trailing spiral modes of density waves in diskshaped galaxies, as proposed by Lin in 1969 and by Mark recently, are substantiated by an analysis of the gas-dynamical model of the galaxy. The self-excitation of the unstable mode in caused by waves propagating outwards from the corotation circle, which carry away angular momentum of a sign opposite to that contained in the wave system inside that circle. Specifically, a simple dispersion relationship is given as a definite integral, which allows the immediate determination of the pattern frequency and the amplification rate, once the basic galactic model is known.
The prevalence of alpha-antitrypsin heterozygotes (Pi MZ) in patients with obstructive pulmonary disease.
An increased incidence of intermediate deficiency of serum alpha1-antitrypsin resulting from Pi phenotype MZ has been reported in patients with chronic obstructive pulmonary disease (COPD) by some laboratories but not confirmed by others. Prevalence of Pi MZ was determined in patients with COPD among 502 subjects referred to a pulmonary function testing laboratory in a region with low concentrations of air pollutants. Control prevalences were obtained from 930 randomly selected subjects in the same community as well as from patients without COPD referred to the laboratory. Depending on criteria used to define COPD, 155 to 306 subjects had COPD. Pi MZ prevalence in subjects with COPD varied from 1.5 to 4 times the prevalence in the community control group and in the patients without COPD. This difference approached significance or was significant. Because Pi MZ was present in only 3.5 to 4.5 per cent of patients with COPD, Pi MZ is not a major factor in the etiology of COPD in this community. The higher incidence of Pi MZ inpatients with COPD reported by other investigators may be explained by small sample size, bias in selection of study or control population groups, or the development of COPD from interaction between Pi MZ and air pollutants or other factors not present in this community.
[Prevalence survey of primary lung cancer in Taiwan].
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Differential fluorescent staining of human chromosomes with daunomycin and adriamycin--the d-bands.
Human chromosome preparations were treated with a group of anthracycline antibiotics. Well-defined, orange-red fluorescent bands were observed on chromosomes after the slide was stained with daunomycin and adriamycin but not with nogalamycin. The characteristic differential bands appeared to be similar to the banding patterns obtained by the quinacrine techniques. Interaction of these antibiotics with DNA could provide information on the general mechanism of fluorescent banding. Further, these bands (D-bands) appeared to be more stable than the Q-bands and may have some usefulness for routine clinical cytogenetic analysis.
Synthesis of sparsomycin analogs as potential antitumor agents.
No information is available on the structural requirements for the antitumor activity of sparsomycin, an antibiotic obtained from the fermentation broth of Streptomyces sparsogenes. Its high in vivo and in vitro activity, novel structure, and uncommon mode of action have, therefore, suggested the synthesis of analogs. This report describes the preparation and screening of a series of N-substituted 3-aryl acrylamides which are closely related to sparsomycin. Three compounds exhibited some tumor inhibition but insufficient to warrant further testing.
Derepression in Saccharomyces cerevisiae can be dissociated from cellular proliferation and deoxyribonucleic acid synthesis.
A method has been developed that permits precise control of release from catabolite repression in Saccharomyces cerevisiae. It consists of transferring cells growing exponentially on 5% glucose to derepression medium at high cell density. Derepression then proceeds with reproducible kinetics and is complete within 6 to 7.5 h for various intra- and extramitochondrial markers, in the absence of any substantial increase in cellular dry weight or protein. Nuclear (and mitochondrial) deoxyribonucleic acid synthesis can be interrupted in certain thermosensitive (cdc) mutants at the nonpermissive temperature; a shift to this temperature before the onset of derepression has no effect on its outcome.
Quinacrine fluorescence and Q-banding patterns of human chromosomes. I. Effects of varying factors.
Various factors involved in the production of "Q-bands" have been studied. It was found that a Zeiss standard WL fluorescent microscope required a shorter exposure time for photography as compared to a Zeiss photomicroscope. The minimal exposure time was obtained when the standard WL microscope was equipped with a UV light source containing a DC powered mercury burner and a concave mirror. Further, the pH and type of water used in the staining, washing and mounting of the slide were also important factors in producing clear and well differentiated "Q-bands". It also appears that the factors involved in the production of "Q-bands" effect the enhancement or quenching of fluorescence by poly d(A-T)-poly d(A-T) and salmon sperm DNA or poly dG-poly dC respectively. This preliminary report also suggests that DNA or polynucleotides with a specific base sequence may play an important role in Q-banding patterns on chromosomes.
An (8;12) translocation, balanced, 46 chromosomes. Repository identification No. GM-213.
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The derepression of delta-aminolevulinate synthetase in yeast.
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