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Biomedical subjects

L Lin

Publications and source records attributed to L Lin.

At least 145 records · Page 8Linked to original sources
PubMed1999

[Preventive effect of endothelin-1 mRNA antisense oligonucleotide on acute myocardial ischemic arrhythmia in rats].

Acute myocardial ischemia was induced by occlusion of the anterior descending of left coronary artery (LAD) in rats; the resultant arrhythmia in 1 h after LAD occlusion was evaluated. In order to prevent expression of endothelin-1 mRNA, human endothelin-1 mRNA antisense oligonucleotide (ET-1 AS-ODN) was intravenously injected 2 h before LAD occlusion. The effect of AS-ODN on plasma ET-1 concentration and the acute ischemic arrhythmia were observed. The results showed that plasma ET-1 was significantly decreased in rats pretreated with AS-ODN, and both the incidence and severity of the acute ischemic arrhythmia were decreased dose-dependently as compared with normal saline control and sense oligonucleotide control, indicating that ET-1 AS-ODN could prevent acute myocardial ischemic arrhythmia and that endogenous endothelin-1 may play an important role in the development of acute ischemic arrhythmia in rats.

Animals↗
PubMed1999

[Clinical study on hyperthyroidism of yang hyperactivity type due to yin deficiency treated by jiakang ning capsule].

OBJECTIVE: To investigate the effect of Jiakang Ning (JKN) capsule on hyperthyroidism. METHODS: Eighty-five cases of hyperthyroidism were divided into JKN group (24 cases), JKN with low dose Tapazol group (35 cases) and Tapazol control group (26 cases) at random. The effects were evaluated by total effective rate, using principal symptoms, body weight, EKG, thyroid hormone and atrial natriuretic peptide (ANP) after 6 months. RESULTS: The total effective rates of three groups were 83.8%, 97.1%, 88.5% respectively, and there were insignificant difference among them statistically (P > 0.05). The first two groups had better effect in principal symptoms than Tapazol control group (P < 0.05). There were similar results in adjusting thyroid dysfunction and abnormal EKG, decreasing ANP and increasing body weight among those three groups (P > 0.05). CONCLUSION: The effect on hyperthyroidism treatment by JKN capsule was satisfactory. The combination of Chinese herbs with western medicine could enhance the curative effect of hyperthyroidism without obvious side-effects.

Adolescent↗
PubMed1999

[Ankylosing spondylitis in Shantou: clinical experience in fifteen years].

OBJECTIVE: To evaluate the clinical features of ankylosing spondylitis (AS) in Shantou area and improve the diagnostic level and therapeutic effect. METHODS: Clinical and laboratory data, and the methods and effects of therapy were analyzed. Some patients were followed up. RESULTS: 94% of the cases had an insidious onset. Low back pain or discomfort, peripheral arthritis, positive "4" test and pressing tenderness over the sacroiliac joints and lumbar spine were the frequent symptoms and signs. The degree of sacroiliitis and involvement of hip and spine were related to the disease duration. However, hip joint involvement in juvenile onset AS did not relate to the disease duration. Some cases with disease duration as long as 16 years still remained at II of degree sacroiliitis. Clinical improvement was more obvious in the first two years of treatment. Although some patients came to a standstill condition after this period, yet the disease activity might still relapse with withdrawal of the treatment. The rate of adhering to the treatment for 1, 2, and over 5 years was 34.6%, 28.4%, and 10.3% respectively. The radiological changes frequently did not parallel with the clinical manifestations. CONCLUSION: Early diagnosis is of importance in improving the prognosis of AS and adherence to slow-acting anti-rheumatic drug therapy is beneficial in disease controlling. A follow up of more than 3 years is necessary to estimate the therapeutic efficacy, and the radiological change is the key indicator. AS is a heterogenic disease and the risk factors for prognosis should be further studied.

Adolescent↗
PubMed1999

[Protective effect of endothelin receptor subtype A antagonist BQ610 on the ultrastructure of acute ischemic myocardium in cats].

OBJECTIVE: To observe the effects of endothelin receptor subtype A antagonist BQ610 on acute ischemic myocardial injury by electronic microscopy to study whether endogenous endothelin is involved in the pathogenesis of acute myocardial ischemia. METHODS: Acute myocardial ischemia was induced by ligation of the left anterior descending coronary artery (LAD) in 12 cats, and BQ610 was immediately injected into the occluded LAD. Controls received normal saline (NS) injection. The ultrastructure of ischemic myocardium and non-ischemic myocardium were observed 30 min after LAD ligation. RESULTS: As compared wtih NS controls, BQ610 significantly protected the acute ischemic myocardium from ultrastructural injury, including cardiac muscle fiber swelling, myofibril disorganization and breakdown, mitochondrial swelling and endothelial swelling. In general, the non-ischemic myocardial ultrastructure was normal. CONCLUSIONS: The results indicate that endogenous endothelin, through endothelin receptor subtype A, plays an important role in ultrastructure injury of acute ischemic myocardium in cats.

Acute Disease↗
PubMed1999

[Relationship of nitric oxide and immunal function of the patients with acute hepatitis and hepatic cirrhosis].

The interleukin-12(IL-12), interleukin-10(IL-10), tumor necrosis factor(TNF) and nitric oxide (NO) levels in serum of 90 patients with hepatitis and cirrhosis were measured by the method of ELISA and colorimeter. The levels of IL-12, IL-10 and NO in serum of the patients with hepatitis were in close proximity to the level of healthy control, but the TNF level was significantly higher than that of healthy control. The IL-12, IL-10, TNF and NO levels in serum of the patients of hepatic cirrhosis were significantly higher than that of healthy control and patients with hepatitis. The results suggested that the NO level was not related with the hepatic damage of acute hepatitis. The dysfunction of immunology in the patients with cirrhosis was related with the increase of NO level.

Adult↗
PubMed1999

[The relationship between the thin-layer chromatographic retention values and the molecular structures of a group of amino acids by using back-propagation artificial neural networks].

The relationship between the thin-layer chromatographic retention values and the molecular structures of fifteen amino acids was studied by using back-propagation artificial neural networks (ANNs). In this paper, firstly, lots of parameters of amino acids have been determined, accumulated and computed. Then, correlation coefficients of all parameters were computed by taking advantage of correlation analysis. Taking the correlation coefficient approaching one as the criteria in the correlation analysis, all parameters were classified into three kinds. Three parameters were selected from each kind, respectively, to consist of one group. Then, the optimized groups of parameters, which have clearer physicochemical meanings, were used as the inputting parameters of artificial neural networks. Correlation coefficients of experimental retardation values and those calculated by using ANNs were computed and showed good agreement. The present work shows that the ANNs method may take an important role in the study of the relationship between TLC behavior and compound structure.

Amino Acids↗
PubMed1999

[The relationship between thin-layer chromatographic retention values and molecular structures of phenol and aniline derivatives].

The Rf values of 24 phenol and aniline derivatives were determined on silica gel layer with three solvent mixtures of hexane-ethyl acetate in different proportions as the mobile phases. The compounds were divided into two species having different features by using the oblique factor analysis. It was found that in the first species there is no methyl group on their benzene rings and in the second all have methyl group in their benzene rings, which results in higher Rf values of the latter than those of the former. It was also found that the sequence of the groups on the benzene rings which make the Rf values of the compounds higher was --CH3 >--OH >--NH2 and the compounds having the ortho-substituted groups give the higher Rf values than para- and meta-substituted ones due to the formation of hydrogen bond within their molecules. The multi-parameter regression analyses of Rf values with the topological indexes degree B and M for the two species showed rather good correlation between the TLC retention values and the molecular structure of the compounds. The findings are of great practical significance.

Aniline Compounds↗
PubMed1999

[Enantiomeric resolution of trans-1,2-disubstituted cyclopropane by high performance liquid chromatography].

The enantiomeric resolution of racemic mixtures of thirteen trans-1,2-disubstituted cyclopropane was achieved with HPLC by using Chiralcel OD and Chiralcel OJ as chiral stationary phase and hexane/2-propanol mixtures with different concentrations as eluent. The chromatographic parameters of these racemates on Chiralcel OD and Chiralcel OJ columns were examined. The results showed that enantiomeric resolution ability of the racemic mixtures of trans-1,2-disubstituted cyclopropane on Chiralcel OD and Chiralcel OJ was strongly dependent on the site and the property of substituents on the benzene cycle. On the other hand, some racemated of trans-1,2-disubstituted cyclopropane with aliphatic group were also separated on the columns. The results showed that the chiral recognition process was the sum of all the possible chiral interaction (the dipole-dipole, hydrogen bond-hydrogen bond and pi-pi interactions) between the chiral stationary phase and trans-1,2-disubstituted cyclopropane. This method has been applied to identify the optical purity of trans-1,2-disubstituted cyclopropane.

Chromatography, High Pressure Liquid↗
PubMed1999

[The postoperative complications and management of excimer laser in situ keratomilleusis].

OBJECTIVE: To evaluate the safety of excimer laser in situ keratomilleusis (LASLK) METHODS: The postoperative complications in 699 eyes of LASIK were observed and statistically analyzed. RESULTS: The haze, halo, growth of corneal epithelium under valve, the foreign body under valve, the fold of corneal valve, infection, decentralization, irregular astigmatism, valvular damage, low contrast sensibility, undercorrection and over correction, the psychological dysopia, glaucoma, fluctuating visual acuity and the loss of the best corrected visual acuity were found. CONCLUSION: LASIK has it's advantages of accurate manipulation, extensive range of correction and rapid recovery, but some of the complications resulting from this operation are so difficult to treat that careful consideration should be given before using this technique.

Adolescent↗
PubMed1999

[Research on applications of micromachine technology in medical engineering].

This paper presents the basic concept of micromachines. The development aim and Key technology of medical micromachine Research are discussed here too. Besides, this Paper introduces some typical application research of micromachines, which may have actual reference Value for the future development of medical engineering.

Artificial Organs↗
PubMed1999

[The research of distributed HRV analysis system based on DCOM].

This article introduces the meaning of Distributed Component Object Model(DCOM), which used network communication protocol to replace the local process communication to reach the aim of Distributed Computing, then it discusses the significance of HRV analysis, and finally it presents the system we developed.

Computer Communication Networks↗
PubMed1998

The effect of 4,4'-diisothiocyanato-stilbene-2,2'-disulfonate on CO2 permeability of the red blood cell membrane.

It has long been assumed that the red cell membrane is highly permeable to gases because the molecules of gases are small, uncharged, and soluble in lipids, such as those of a bilayer. The disappearance of 12C18O16O from a red cell suspension as the 18O exchanges between labeled CO2 + HCO3- and unlabeled HOH provides a measure of the carbonic anhydrase (CA) activity (acceleration, or A) inside the cell and of the membrane self-exchange permeability to HCO3- (Pm,HCO-3). To test this technique, we added sufficient 4, 4'-diisothiocyanato-stilbene-2,2'-disulfonate (DIDS) to inhibit all the HCO3-/Cl- transport protein (Band III or capnophorin) in a red cell suspension. We found that DIDS reduced Pm,HCO-3 as expected, but also appeared to reduce intracellular A, although separate experiments showed it has no effect on CA activity in homogenous solution. A decrease in Pm,CO2 would explain this finding. With a more advanced computational model, which solves for CA activity and membrane permeabilities to both CO2 and HCO3-, we found that DIDS inhibited both Pm,HCO-3 and Pm,CO2, whereas intracellular CA activity remained unchanged. The mechanism by which DIDS reduces CO2 permeability may not be through an action on the lipid bilayer itself, but rather on a membrane transport protein, implying that this is a normal route for at least part of red cell CO2 exchange.

4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid↗
PubMed1998

cDNA sequence and chromosomal localization of mouse Dlgh3 gene adjacent to the BRCA1 tumor suppressor locus.

Membrane associated guanylate kinase homologues (MAGUKs) function in tumor suppression and receptor clustering pathways presumably by modulating signaling events at the interface of the membrane cytoskeleton. The p55 subclass of MAGUKs includes two novel cDNAs that were originally identified by virtue of their genomic location to human chromosome 17q12-21 where the BRCA1 tumor suppressor gene has been mapped. The predicted primary structure of the human MPP3 contains a single copy of the PDZ domain, an SH3 motif, and a carboxy-terminal guanylate kinase-like domain. Here we report the full-length coding cDNA sequence of the mouse homologue of MPP3. The translated amino acid sequence of murine Dlgh3 contains 568 amino acids that show 87% sequence identity with the human MPP3 protein. Northern blot analysis shows abundant expression of a approximately 3.0 kb transcript of Dlgh3 in mouse brain and skeletal muscle, and a relatively less abundant approximately 5.0 kb transcript in skeletal muscle, testis, kidney, and lung. Using an interspecific backcross panel, the Dlgh3 gene was mapped to a segment of mouse chromosome 11 that is conserved with human chromosome 17q12-21. The close proximity of murine Dlgh3 gene to the BRCA1 locus and the high conservation of the primary structure of human and murine proteins provide a framework for testing the role of Dlgh3 in cell proliferation pathways using the mouse as a model system.

Amino Acid Sequence↗
PubMed1998

At least four loci and gender are associated with susceptibility to the chemical induction of lung adenomas in A/J x BALB/c mice.

Four putative quantitative trait loci (QTLs) that influence susceptibility to the induction of lung adenomas by urethane in an F2 cross between A/J and BALB/cOlaHsd have been mapped. Following microsatellite typing of mice with resistant and susceptible phenotypes at 97 microsatellite marker loci, a major locus was identified on chromosome 18 with a lod score of 15. This was responsible for an 8- to 10-fold increase in tumor multiplicity in males and females, respectively, having the AA and CC genotypes at the D18Mit188 marker locus. It mapped close to Dcc (deleted in colorectal cancer). A locus on chromosome 4 (lod score 6.5) had the resistant allele in strain A/J and the susceptible allele in BALB/c, with a 14-fold difference in tumor multiplicity between mice of the AA and CC genotypes. This mapped close to the Cdkn2a (cyclin-dependent kinase inhibitor 2A) locus, which is commonly deleted in mouse lung tumors. Two loci with smaller effects (lod scores 3.03 and 3.25) were identified on chromosomes 1 and 11. There was also significant sexual dimorphism in tumor multiplicity both among 151 F2 hybrids and among 52 mice resulting from a backcross to strain A/J, with males having higher tumor counts than females.

Adenoma↗
PubMed1998

A CLOCK polymorphism associated with human diurnal preference.

A single nucleotide polymorphism located in the 3' flanking region of the human CLOCK gene was investigated as a predictor of diurnal preference in a population-based random sample of 410 normal adults. Morningness-eveningness preferences were determined using the 19-item Home-Ostberg questionnaire. Subjects carrying one of the two CLOCK alleles, 3111C, had a significantly lower mean Horne-Ostberg score. The distribution of scores was clearly shifted toward eveningness for these subjects. The score difference was independent of age, sex and ethnic heritage, thus making population stratification effects unlikely to explain this difference. These subjects had a substantial 10- to 44-minute delay in preferred timing for activity or sleep episodes. We suggest that the identified polymorphism or another tightly linked polymorphism within the CLOCK gene or its regulatory elements may be responsible for the finding.

Adult↗
PubMed1998

In vitro anti-human immunodeficiency virus (HIV) activity of the chromanone derivative, 12-oxocalanolide A, a novel NNRTI.

The three chromanone derivatives, (+)-, (-)-, and (+/-)-12-oxocalanolide A (2), were evaluated for in vitro antiviral activities against HIV and simian immunodeficiency virus (SIV). The compounds were determined to be inhibitors of HIV-1 reverse transcriptase (RT) and exhibited activity against a variety of viruses selected for resistance to other HIV-1 nonnucleoside RT inhibitors. They are the first reported calanolide analogues capable of inhibiting SIV.

Acquired Immunodeficiency Syndrome↗
PubMed1998

Thin-layer chromatography of mycotoxins and comparison with other chromatographic methods.

This paper highlights the status of thin-layer chromatography (TLC) of mycotoxins in various sample matrices. The outstanding merits of TLC in the field of the qualitative and quantitative determination of mycotoxins have been briefed. A comparison between different TLC methods and TLC with HPLC, enzyme-linked immunosorbent assay and GC methods, etc. is made, in general.

Chromatography↗