A simple method to prepare intact yeast chromosomal DNA for pulsed field gel electrophoresis.
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Chromosomes, Fungal↗
Biomedical subjects
C C Li
Publications and source records attributed to C C Li.
Genetics of subdivided populations and its relationships with certain measures of association.
Unlike inbreeding, population subdivision affects different genotypes differently for multiple alleles, so that the simple relationship between inbreeding and subdivision for two alleles no longer holds for all genotypes. In this communication, the detailed effects of subdivision have been studied for three alleles with results easily generalized to any number of alleles. Then an average effect of subdivision is proposed. This average effect of subdivision is found to play the same role as the inbreeding coefficient for multiple alleles, so that the overall relationship between inbreeding and subdivision may be reestablished again. In the final section, we discuss the relationship of the genetic result with measures of association of square contingency tables arising from epidemiological, social studies, educational and psychological studies.
Alleles↗
Classification of plasma cortisol patterns in normal subjects and in Cushing's syndrome.
The 24-h pattern of half-hourly sampled plasma cortisol in normal human subjects shows a 24-h (circadian) period, which may be variably distorted in patients who suffer from autonomous hypercortisolism (Cushing's syndrome). We have developed a pattern recognition system for computer classification of cortisol time series into the normal class and subclasses of Cushing's syndrome with different etiology ("pituitary" designating pituitary tumor, "adrenal" designating adrenal tumor, and "ectopic" designating tumor elsewhere). Discriminatory features were extracted from Fourier analysis and Karhunen-Loeve expansion coefficients of cortisol time series. Decision functions were trained by the LMSE algorithm and tested by the jack-knife test procedure on a data-base of 90 normal and patient patterns. The classification accuracy for normal, "pituitary," "adrenal," and "ectopic" classes was 100, 98.1, 98.3, and 100%, respectively. Hence this pattern recognition system may be useful as an aid in the differential diagnosis of Cushing's syndrome.
Algorithms↗
p34cdc2 is physically associated with and phosphorylated by a cdc2-specific tyrosine kinase.
The mammalian homologue of the yeast cdc2 gene encodes a 34-kilodalton serine/threonine kinase that is a subunit of M phase-promoting factor. Recent studies have shown that p34cdc2 is also a major tyrosine-phosphorylated protein in HeLa cells and that its phosphotyrosine content is cell cycle regulated and related to its kinase activity. Here, we show that cdc2 is physically associated with and phosphorylated in vitro by a highly specific tyrosine kinase. Tyrosine phosphorylation of cdc2 in vitro occurs at tyrosine 15, the same site that is phosphorylated in vivo. The association between the two kinases takes place in the cytosolic compartment and involves cyclin B-associated cdc2. Evidence is presented that a substantial fraction of cytosolic cdc2 is hypophosphorylated, whereas nuclear cdc2 is hyperphosphorylated. Finally, we show that the tyrosine kinase associated with cdc2 may be a 67-kilodalton protein and is distinct from src, abl, fms, and other previously reported tyrosine kinases.
Amino Acid Sequence↗
Method of path coefficients: a trademark of Sewall Wright.
This address is a tribute to a pioneer of population genetics, including human population genetics. The unique methodology employed by Sewall Wright in many genetic problems is the method of path coefficients. This essay traces the historical landmarks in the development of the path method and then shows how some of the conventional statistical results can be converted into expressions involving path coefficients. The construction of a path diagram to represent such statistical results is explained in terms of examples. In the last section an example of applying the path method to the problem of genetic linkage in a random mating population is given. I hope that, despite the ending of the Sewall Wright era, the path method will continue to serve the scientific world.
Genetics, Population↗
Static anthropometry of civilian Chinese in Taiwan using computer-analyzed photography.
The purpose of this study was to establish a static anthropometric data bank for Chinese civilians in Taiwan using a computer-analyzed photographic method. Stratified random sampling was applied to decide the sampling site; sample size was established by considering standard errors in a pilot study. Then a photographic method was employed in addition to direct measurement of selected body dimensions. In all, 933 subjects were measured. The data were entered via a digitizer into a microcomputer for processing. The resulting anthropometric data bank was organized by age, sex, and occupational groupings. Comparisons with data from previous studies were made, and recommendations for further research presented.
Adolescent↗
[A pathological study of primary malignant lymphomas of the thyroid].
Thirty cases of a primary malignant lymphoma (ML) have been studied clinicopathologically and immunohistochemically. The average age of the patients was 59.1 years, and the ratio of males to females was 1:1.7. According to the Kiel classification of MLs, 53.3% had a low grade malignancy and 46.7% were a high grade malignancy. Therefore, the number with a low or a high grade malignancy was almost equal. Most of the low grade malignancies were ML, centroblastic centrocytic, and most of the high grade malignancies were ML, lymphoblastic. From histopathological and immunohistochemical studies, most cases were considered to be of B-cell origin and two thirds of the cases were regarded as being of a follicular center cell origin. Prognosis was better than that of other MLs. Finally, MLs of the thyroid were found combined more frequently with chronic thyroiditis of the Hashimoto type than malignant epithelial neoplasms.
Adult↗
[Changes of creatine phosphokinase and malondialdehyde in the serum and clinical use of large doses of vitamin C following open heart surgery].
The protective effect of a large dose Vit. C on ischemic myocardium was studied on 10 patients who underwent open heart operation and received 250 mg/kg Vit. C before the start of ECC (Group II). Another 10 similar patients receiving no Vit. C served as a control (Group I). Blood samples were taken from the brachial artery at different time intervals for determination of CPK-MB and MDA in both groups. Considerable increases of serum CPK-MB and MDA in both group I and II were noted. The differences of CPK-MB and MDA concentration between Group I and II were highly significant from 2 to 12 hours postoperatively. The effect of Vit. C in the reduction of the release of CPK-MB and MDA after open heart operation was attributed to its action as an oxygen free radical scavenger, thus decreasing the peroxidation of the lipids present in the cell membrane.
Adolescent↗
Role of beta-receptor in the radix Angelicae sinensis attenuated hypoxic pulmonary hypertension in rats.
Acute pulmonary hypertension was caused by inhalation of 5% O2 in rats. Pulmonary vascular resistance (PVR) increased, but heart rate (HR), cardiac output (CO) and carotid arterial pressure (CAP) were not obviously changed. After an intravenous administration of Radix Angelicae sinensis, the acute pulmonary hypertension induced by inhalation of 5% O2 could be attenuated, but this effect disappeared if propranolol was given before Radix Angelicae sinensis. In chronic experiments, the same results were obtained, but the protective effect of Radix Angelicae sinensis on heart function was not influenced by propranolol. It is suggested that Radix Angelicae sinensis might play a role by stimulating the beta 2-receptor in the prevention of acute and chronic hypoxic pulmonary hypertension. However, prevention of hypertrophy of the right ventricle and enhancement of heart function in chronic hypoxic rats might not be attributed to the beta 1-receptor in the heart.
Adrenergic beta-Agonists↗
Effect of chuanxiongqin (tetrame-thylpyrazine) on microcirculatory perfusion in hamsters and capillary permeability in rats.
The authors continuously observed the effect of Chuanxiongqin on the microcirculation of hamster cheek pouch by use of the Dual-Window Television Automatic Estimating System. It was seen that the caliber of arterioles, the microcirculatory velocity, and blood flow all decreased after local application of noradrenaline and all increased and returned to normal 1 to 30 min after local administration of Chuanxiongqin. Microcirculatory perfusion, however, could not be improved by normal saline or Iluangqi. The effect of Chuanxiongqin on the pulmonary capillary permeability was also investigated in rats. Pulmonary edema was induced in rats by adrenaline administration. Evans blue was injected intravenously and the amount of Evans blue in broncho-alveolar lavage fluid was estimated. It was found that Evans blue was increased in broncho-alveolar fluid of rats with pulmonary edema, and this increase could be lessened by Chuanxiongqin.
Animals↗
[Effect of triptolide on cytokinetics of HeLa cells].
The cytostatic effects of triptolide on HeLa cells in different proliferation stages and cell cycle phases were studied by colony-forming units assay. An exposure of exponential-phase cells to triptolide 0.02-4.00 micrograms/ml for 0.5 h resulted in a biphasic-exponential dose-survival curve (n = 1, D0 = 0.3 micrograms/ml in the most sensitive population; D0 = 2.8 micrograms/ml in the more resistant population). The plateau-phase cells in the same conditions seemed to have lower sensitivity to the drug. The synchronized cells caused by excess TdR double block and the selective detachment of mitotic cells from monolayer were exposed to triptolide 0.06 micrograms/ml for 0.5 h. The sensitivity of cell cycle phases to the drug ranked as follows: S greater than G2, M greater than G1. The result showed that triptolide is one of the cell cycle phase non-specific agents, but more sensitive to S phase cells.
Antineoplastic Agents, Phytogenic↗
Pseudo-random mating populations. In celebration of the 80th anniversary of the Hardy-Weinberg law.
That random mating leads to Hardy-Weinberg distribution of genotypes is well known. This report is to show that, if the deviations from random mating are of a certain pattern, the offspring generation will also be in Hardy-Weinberg proportions. This brings out the fact that random mating is a sufficient condition, not a necessary one, for the attainment of the Hardy-Weinberg proportions. Such nonrandom-mating populations are tentatively said to be pseudo-random mating. Pseudo-random-mating populations exist for both autosomal and sex-linked systems with two or multiple alleles. This report covers the basic case of a two-allele autosomal locus in detail, but the possible extension to two loci and cytonuclear systems have also been mentioned in discussion.
Alleles↗
Identification of the human papillomavirus E2 protein in genital tract tissues.
A 27-kilodalton protein representing approximately 60% of the E2 open reading frame of human papillomavirus type 6 (HPV-6) was synthesized in a bacterial expression system. Affinity-purified polyclonal antibody to this protein detected the probable E2 gene product as a 50-kilodalton protein in most condylomas by Western blot (immunoblot) analysis. The E2-positive condylomas were associated with HPV-6, HPV-11, HPV-16, or unidentified HPVs.
Condylomata Acuminata↗
[Some rare heart manifestations in middle- and old-aged groups of hyperthyroidism].
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Aged↗
Steinberg's new paternity probability.
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Humans↗
A genetical model for vitiligo.
A genetical model is found to provide a good fit to family data on vitiligo. The model postulates that recessive alleles at a set of four unlinked diallelic loci are involved in the causation of the disorder. Under this multiple recessive homozygosis model, for normal X affected families ascertained through the affected parent, the expected segregation probability is .063; the estimated value is 0.53, which is not significantly different from the expected value. For normal X normal families ascertained through an affected offspring, the expected segregation probability is .037; the estimated value is .04.
Age Factors↗
An expository review of two methods of calculating the paternity probability.
There are two methods for calculating the posttests probability of paternity, viz., the nonexclusion probability method (E method) and the paternity index method (lambda method). This report reviews these two methods and explains the reasons behind them, in the hope that it might alleviate the current controversy between the advocates of these two methods. The emphasis throughout the paper is on exposition, using simple examples to illustrate certain principles or properties. A discussion follows the presentation of the two methods. The calculation of the paternity index is based on the genotype (or phenotype) of the accused man; and the value of the paternity index remains the same whether the accusation itself is true or false.
Biometry↗
Estimation of segregation and ascertainment probabilities by discarding the single probands.
The first portion of this communication reiterates the method of discarding single probands for studying the segregation ratio under incomplete ascertainment. The organization of the algebra leads to the second portion, in which the "self-contained" subsets are constructed with respect to both the segregation ratio and the ascertainment ratio. These subsets make a more detailed study of segregation and ascertainment possible.
Genetic Diseases, Inborn↗