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Biomedical subjects

R Li

Publications and source records attributed to R Li.

At least 559 records · Page 31Linked to original sources
PubMed1990

[The measurement of radial bone mineral content in children].

The bone mineral contents of radius of 255 boys and 243 girls (7 to 16 year old of the Han nationality, living in Chengdu) were measured with Bone Mineral Analyzer (Type:SPA-I). The standard values of g/cm was made. There was a positive correlation between the value in boys or girls and chronological age, height or weight. The coefficients were respectively 0.83, 0.77, 0.64 in boys and 0.82, 0.82, 0.82 in girls (P less than 0.005). At the age of 13 (in boys or in girls) the value of the g/cm was the highest.

Adolescent↗
PubMed1990

[A short revision of the species group Pegomya acklandi, with description of a new species (Anthomyiidae, Diptera)].

A key to 1 Japanese and 18 Chinese species of the Pegomya acklandi group, including 1 new species, is given below: 1(4) Apical border of the lateral lobe of 5th sternite with an angular notch. 2(3) Hairs on the basal part of surstylus rather thick and numerous; inner side of the twig of surstylus with a tubercle; apex of postgonite hook-like. ... Pegomya densipilosa Li et Deng, 1984. 3(2) Basal part of surstylus with sparse hairs; postgonite bluntly rounded at the apex ... P. rhagolobos Li et Deng, 1984. 4(1) No angular notch on the apical border of the lateral lobe of 5th sternite. 5(10) Aedeagus of fork type. 6(9) Lateral lobe of the 5th sternite with an arch of long setae. 7(8) Arch of long setae of the lateral lobe of 5th sternite in 2 rows and the apex extremely expanded; acrophallus with a hook bent to the paraphallus at the distal end; A3 twice as long as its width ... P. semiannula Li et Deng, 1984. 8(7) Lateral lobe of 5th sternite cone-shaped; acrophallus pointed apically and slightly curved; A3 as long as its width ... P. laterisetiata Deng et Li, 1988. 9(6) Setae on the lateral lobe of 5th sternite rather sparse and short; a strong seta behind the cerca; acrophallus with a small hook at the distal end; A3 as long as its width ... P. unimediseta Deng et Li, 1988.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

Pre-mRNA splicing mutants of Schizosaccharomyces pombe.

A collection of temperature sensitive (ts-) mutants was prepared by chemical mutagenesis of a wild type Schizosaccharomyces pombe strain. To screen the ts- mutants for pre-mRNA splicing defects, an oligodeoxynucleotide that recognizes one of the introns of the beta-tubulin pre-mRNA was used as a probe in a Northern blot assay to detect accumulation of intron sequences. This screening procedure identified three pre-mRNA splicing mutants from 100 ts- strains. The three mutants are defective in an early step of the pre-mRNA splicing reaction; none accumulate intermediates. The precursors that accumulate at 37 degrees C are polyadenylated. Analysis of the splicing of another pre-mRNA showed that the mutations are not specific for beta-tubulin. The total RNA pattern in the three splicing mutants appears to be normal. In addition, the amounts of the spliceosomal snRNAs are not drastically changed compared to the wild type and splicing of pre-tRNAs is not blocked. Genetic analyses demonstrate that all three splicing mutations are tightly linked to the ts- growth defects and are recessive. Crosses among the mutants place them in three complementation groups. The mutants have been named prp1, prp2 and prp3.

Crosses, Genetic↗
PubMed1989

Specific recognition nucleotides and their DNA context determine the affinity of E2 protein for 17 binding sites in the BPV-1 genome.

The DNA context of nucleotides that a protein recognizes can influence the strength of the protein-DNA interaction. Moreover, in prokaryotes, understanding the quantitative differences in binding affinities that result in part from the DNA context is often important in describing regulatory mechanisms. Nevertheless, these issues have not been a major focus yet for the investigation of protein-DNA interactions in eukaryotes. In this study, we explored the binding specificity and the range of affinities that the BPV-1 E2 transcriptional activator has for DNA. Because E2 binding sites are positioned near several different BPV-1 promoters, such quantitative information may be important to understand transcriptional regulatory mechanisms in BPV-1. Gel retardation assays and DNA footprinting were used to quantitate the affinities of the E2 binding sites in the viral genome. In the process, five sites were discovered, which, on the basis of sequence, had not been predicted previously to interact with the E2 protein. Equilibrium and kinetic studies show that the range of E2 affinities of the 17 sites varied over 300-fold. The sequence elements responsible for E2 recognition of DNA were determined by missing contact analysis of several sites and a point mutation analysis of one site. The results presented show that the affinity of an E2 binding site is to a large extent determined by the availability of specific contacts, but the data also strongly suggest that DNA structure plays an important role.

Animals↗
PubMed1989

[Study of the relation of the typology of nephrotic syndrome and red cell C3b receptor, T cell function].

This paper reports the determined results of rosette rates of red cell C3b receptor and active rosette (Ea) rates of T lymphocyte in 39 cases of nephrotic syndrome. Typology of nephrotic syndrome according to TCM differentiation symptoms, all the 39 cases were divided into three types: (1) 13 cases of deficiency of Qi of the Spleen with stagnancy of dampness; (2) 9 cases of deficiency of Yang of the Spleen and Kidney; (3) 17 cases of deficiency of Yin of the Liver and Kidney. The results showed that the red cell C3b receptor rosette rate and Ea rosette rate in 39 cases of nephrotic syndrome were significantly lower than those in the control. The difference between the two groups was very obvious (P less than 0.001) among the three types. The rosette rates of both in the deficiency of Qi of the Spleen and deficiency of Yang of the Spleen and Kidney were markedly decreased than those in the control (P less than 0.001). Whereas, the red cell C3b receptor rosette rate was lower than that in the control (P less than 0.01), and T cell Ea rosette rate showed no statistical difference (P greater than 0.05) in the deficiency of Yin of the Liver and Kidney. There was a close relationship between the immune dysfunction of red cell and the pathogenesis in nephrotic syndrome. There was markedly relationship between the pathogenesis of deficiency of Yang of the Spleen and Kidney and deficiency of Qi of Spleen with stagnancy of dampness and T cell immune dysfunction. While the Ea level in deficiency of Yin of the Liver and Kidney was closely correlated with the control. Probably this type was nephrotic nephrosis which had been treated with TCM-WM.

Adolescent↗
PubMed1986

Expression of the three influenza virus polymerase proteins in a single cell allows growth complementation of viral mutants.

Transformed cell lines derived from murine C127 cells were constructed that express the influenza virus RNA-dependent RNA polymerase proteins (PA, PB1, and PB2). Cell lines that express only one or all three of the proteins were tested for their ability to complement temperature-sensitive viral mutants incubated at the nonpermissive temperature. Two cell lines were isolated that express all three polymerase genes and complement the growth of PB2 temperature-sensitive mutants at the nonpermissive temperature. One of these lines also complemented PA temperature-sensitive mutants. The viral titers obtained in these two cell lines were 12-fold to 1000-fold higher than the viral titers obtained upon growth of the corresponding temperature-sensitive mutant in C127 cells at the nonpermissive temperature.

Animals↗
PubMed1986

Hexachlorobenzene levels in multimedia environmental samples from selected chemical production plants.

A sampling and analysis program was conducted to determine hexachlorobenzene (HCB) levels in air, water, soil and sediment. Nine industrial plants were selected, representing six major industries: perchloroethylene, trichloroethylene, carbon tetrachloride, chlorine, triazine herbicides and pentachloronitrobenzene. Of the six industries sampled, higher concentrations of HCB were associated with the production of perchloroethylene, trichloroethylene and carbon tetrachloride. In the one plant that produced only carbon tetrachloride, HCB levels were quite low. HCB concentrations were relatively high in samples from the pentachloronitrobenzene plant, i.e., low microgram/m3 range in air and generally over 100 micrograms/g along roads within the plant. Very low levels of HCB were associated with plants producing chlorine and triazine herbicides. Several different waste-disposal methods were used at the perchloro- and trichloroethylene plants that were sampled. The highest level of HCB was detected in air and soil at the plant using on-site landfill and open-pit storage. High HCB levels were detected in loading and transfer areas at plants using off-site disposal methods. Lower HCB levels were found at plants using on-site incineration, but downwind air concentrations were elevated above background at these plants. Production of perchloro- and trichloroethylene by low-temperature oxychlorination and incineration of liquid bottom wastes resulted in high levels (micrograms/m3) of HCB in the air but relatively low levels in the effluent water.(ABSTRACT TRUNCATED AT 250 WORDS)

Chemical Industry↗