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Biomedical subjects

C Li

Publications and source records attributed to C Li.

At least 1,135 records · Page 63Linked to original sources
PubMed1991

A clinical and experimental study on all-trans retinoic acid-treated acute promyelocytic leukemia patients.

Fifty patients with acute promyelocytic leukemia (APL) have been treated with all-trans retinoic acid (RA). In vitro induced differentiation of primarily cultured bone marrow cells from the patients, colony-forming unit granulocyte-macrophage (CFU-GM) and L-CFU colony-forming assays, and karyotype analysis were performed over the treatment course. The very high bone marrow complete remission (CR) rate (94%) suggested that all-trans RA was superior to conventional chemotherapeutic regimens for the treatment of APL. The leukemic clone was reduced by RA-induced terminal differentiation and loss of proliferation capacity of leukemic cells. Relapse after CR in about 40% of patients was the major reason for the failure of the RA treatment. Patients who relapsed after a chemotherapy-maintained CR could be effectively reinduced to second CR by RA. However, if relapse occurred after a CR maintained by both RA and chemotherapy, the sensitivity of newly emerged leukemic clones to RA was greatly reduced. Therefore, it is suggested that RA should be replaced by conventional chemotherapy as soon as CR is achieved. Laboratory studies proved valuable in selecting cases for RA therapy and in predicting therapeutic effects and prognosis.

Adolescent↗
PubMed1991

Cloning of a cellular factor, interleukin binding factor, that binds to NFAT-like motifs in the human immunodeficiency virus long terminal repeat.

Human immunodeficiency virus (HIV) gene expression is regulated by both general transcription factors and factors induced by activation of T lymphocytes such as NF-kappa B and the nuclear factor of activated T cells (NFAT). Within the HIV long terminal repeat (LTR), two purine-rich domains between nucleotides -283 and -195 have homology to a regulatory region found in the interleukin 2 promoter, which binds NFAT and other cellular factors. In the HIV LTR, this region has been demonstrated to have both positive and negative regulatory effects on HIV gene expression. In an attempt to clone genes encoding cellular factors that bind to these NFAT-like elements in the HIV LTR, we used lambda gt11 expression cloning with oligonucleotides corresponding to these binding motifs. A ubiquitously expressed cDNA encoding a 60-kDa protein, which we termed interleukin binding factor (ILF), binds specifically to these purine-rich motifs in the HIV LTR. This factor also binds to similar purine-rich motifs in the interleukin 2 promoter, through with lower affinity than to HIV LTR sequences. Sequence analysis reveals that the DNA binding domain of ILF has strong homology to the recently described fork head DNA binding domain found in the Drosophila homeotic protein fork head and a family of hepatocyte nuclear factors, HNF-3. Other domains found in ILF include a nucleotide binding site, an N-glycosylation motif, a signal for ubiquitin-mediated degradation, and a potential nuclear localization signal. These results describe a DNA binding protein that may be involved in both positive and negative regulation of important viral and cellular promoter elements.

Amino Acid Sequence↗
PubMed1991

Amelioration of bleomycin-induced pulmonary fibrosis in hamsters by combined treatment with taurine and niacin.

Interstitial pulmonary fibrosis induced by bleomycin (BL) involves the production of reactive oxygen species and the impairment of repair of damaged epithelial cells. We have shown previously that taurine or niacin treatment partially attenuates BL-induced lung fibrosis in hamsters and that the two agents probably act through different mechanisms. In the present investigation, we have demonstrated that taurine and niacin in combination provide nearly complete protection against BL-induced pulmonary fibrosis. Based on the findings of this investigation, it is suggested that combined treatment with taurine and niacin offers the potential for a novel pharmacological approach in the prevention of lung fibrosis in humans.

Administration, Oral↗
PubMed1991

Assignment of the gene for cyclic AMP-response element binding protein 2 (CREB2) to human chromosome 2q24.1-q32.

The regulatory element TGACGTCA is found upstream of a number of viral and cellular genes. This element has been demonstrated to mediate cyclic AMP induction of cellular genes and activation of viral genes. A group of closely related cellular genes known as cyclic AMP-response element binding proteins (CREB) or activating transcription factor (ATF) have been found to bind to this motif and mediate activation by cyclic AMP and the adenovirus E1A protein. One of these genes, CREB1, was previously mapped to human chromosome 2q32.3-q34. Southern blot analysis of genomic DNA from a panel of mouse-human somatic cell hybrids indicated that the CREB2 gene, another member of this family, also resides on human chromosome 2. In situ hybridization further regionalized this gene to 2q24.1-q32. Thus, the genes for CREB1 and CREB2 that have only limited DNA sequence homology map to a similar region of the long arm of chromosome 2, though whether they are part of a gene cluster is unclear.

Activating Transcription Factor 2↗
PubMed1991

Hybrid biomechanical assist for acute biventricular failure.

It is now clear dynamic cardiomyoplasty alone will not be able to support patients in severe cardiogenic shock. On the other hand, implantable univentricular electromechanically driven devices for permanent circulatory support are undergoing early clinical trials. Because of the potential for existing or subsequent biventricular failure and to avoid the need to implant two space-occupying mechanical devices, hybrid biomechanical assist devices could have certain advantages. To evaluate the feasibility of supporting profound biventricular failure, utilizing the combination of dynamic cardiomyoplasty and mechanical ventricular assistance, six dogs underwent simultaneous right latissimus dorsi cardiomyoplasty and left heart bypass. Microspheres were embolized into the pulmonary artery resulting in pulmonary hypertension and acutely impairing the right ventricle. The left ventricle was unloaded via a centrifugal Biomedicus pump. To create severe biventricular failure, the aorta was cross-clamped and potassium cardioplegia was infused into the aortic root to achieve a flaccid diastolic arrest of the heart. Infusion of microspheres into the pulmonary artery resulted in a dose-dependent increase in pulmonary artery pressure. Stimulation of the cardiomyoplasty under these conditions showed a 25.9 +/- 7.9% (S.E.M.) (p less than 0.05, paired t-test) increase in mean pulmonary artery flow. There was a corresponding increase of 6.75 +/- 10.6% in the centrifugal pump flow. Following diastolic arrest, the mean pulmonary artery and centrifugal pump flows increased 90.8 +/- 11.5% (p less than 0.001) and 16.4 +/- 12.1%, respectively. These preliminary results suggest this approach could be a useful alternative to patients who require long-term biventricular support.

Acute Disease↗
PubMed1991

The remodelling of skeletal muscle for indefatigable hemodynamic work.

Skeletal muscle possesses inherent plasticity of gene expression. Low frequency pulse-train stimulation can remodel the biochemical machinery that confers physiological expression and fatigue resistance approaching that of the myocardium. This fatigue-resistant muscle can generate sufficient force to meet the power requirements for useful cardiac work. This ultimate goal is currently being pursued in models of cardiomyoplasty and muscle-powered cardiac assist devices. In this article, we review the three major subcellular systems subserving canine skeletal muscle transformation and compare them to those of cardiac muscle. The magnitude of the problem of clinical heart failure and the feasibility of fatigue-resistant skeletal muscle joining the therapeutic armamentarium are addressed. The adaptation and transformation of fast-twitch skeletal muscle in response to chronic electrical stimulation augers therapeutic potential as an endogenous, readily available power source for myocardial assistance. The basis mechanisms of skeletal muscle fatigue require elucidation to gain a complete and thorough understanding of how to manipulate this property to provide continuous hemodynamic work.

Animals↗
PubMed1991

[Polarographic determination of sulfide in water].

Sulfide has a sensitive polarographic wave in the system of NaOH-EDTA-triethanolamine. The addition of triethanolamine to the system improved the shape of the wave and increased the sensitivity. The peak current was directly proportional to the concentration of sulfide in the range of 0.002-5.000 ppm. The detection limit for water sample was 2 ppb, and the relative standard deviation and recovery were 2.3-7.2% and 94.0-102.0%, respectively. The proposed method is simple, accurate, sensitive and reproducible.

Polarography↗
PubMed1991

A morphological study of primary pulmonary hypertension--an analysis of six autopsy cases.

Six typical autopsy cases of primary pulmonary hypertension are reported. The histopathological features were as follows: medial hypertrophy of the muscular pulmonary arteries, muscularization of arterioles, internal fibrosis and fibroelastosis of muscular pulmonary arteries with typical "onion-skin" configuration, fibrinoid necrosis of the media or necrotizing arteries of muscular pulmonary arteries, and formation of highly characteristic plexiform lesions and dilatation lesions. It is thought that the plexiform lesions seen in all six cases represent morphological changes resulting from pulmonary hypertension rather than congenital abnormalities or thromboembolism.

Adult↗
PubMed1991

[A study of textile noise influence on maternal function and embryo-growth].

Ninety hundred seventy-eight female textile workers exposed to noise (greater than or equal to 85 dB (A)) were recruited as the subjects of observation group, and 402 nonexposed female workers were chosen as the controls (less than 75 dB (A)). According to noise level, the observation group was subdivided into three groups: group 1, 100-104 dB (A), 416 workers; group 2, 95-99 dB, (A), 310 workers; group 3, 85-94 dB (A), 252 workers. Non-conditional logistic regression model was used to exclude the effect of mixed factors, such as age and working life. The result showed that noise-exposure could have some adverse effect on reproductive function of women and embryo growth. The workers exposed to noise had significantly increased incidence rates for irregular menstrual cycle, dysmenorrhea, lumbago, hypertension in pregnancy, threatened abortion, spontaneous abortion, premature labour, dystocia and low birth weight of newborns. When the noise intensity heightened, the sorts of abnormal function of reproduction increased and the risk of incidence raised too. These demonstrated a dose-response relationship between the noise intensity and incidence rate. The noise-working life had significant effects on the incidence of hypertension in pregnancy and prematurity. Although the age had some influence, it was not statistically significant. In terms of the maternal function and embryo growth, the factors in order of risk are: noise intensity greater than working life greater than age.

Abortion, Spontaneous↗
PubMed1991

[The species of titanium in natural water].

The species of titanium in natural water was studied. Sample was filtered with a paper filter and a 0.45 micron membrane filter. The content of titanium in each case was determined by polarography proposed by Li, et al. It was found that the main species for all the tested samples was of the particle form. A supernatant of a river water sample was taken to study the effect of pH on the distribution of titanium species. It was found that pH was an important factor for species distribution. At pH1-2, the particle will change into the dissolved form in a short time; at pH 6-8, the dissolved form will change into the particle form in several days.

Hydrogen-Ion Concentration↗
PubMed1991

[Quantitative analysis of semen Cuscutae].

In this paper, the quantitative analysis of the total flavone in 7 species revealed the contents: Semen Cuscutae Chinensis (3.0%), Semen Cuscutae Australis (3.2%) as compared with Semen Cuscutae Europaea (4.5%). Semen Cuscutae Chinensis has the highest content of polysaccharide of about 5-6%. The experimental results provide a scientific basis the rational use of Semen Cuscutae.

Drugs, Chinese Herbal↗