[Phylogenetic classification of plant pathogenic mycoplasma].
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Genome, Bacterial↗
Biomedical subjects
L Sun
Publications and source records attributed to L Sun.
[A survey on diabetes mellitus in the staff of electric power system in Baotou city].
According to the diagnostic criteria of diabetes mellituria (DM)set by WHO, a survey of DM and impaired glucose tolerance (IGT) was performed in 10,867 staff of electric power system in Baotou City from August, 1996 to August, 1997. Result indicated that the prevalence rates of DM and IGT were 3.15% and 2.83% respectively. The rates of both DM and IGT increased with age and weight index (P < 0.01 respectively). Both systolic and diastolic blood pressure and serum levels of total cholesterol in persons with DM and IGT were significantly higher than in normal controls (P < 0.01 respectively) which might due to high caloric diet but little physical activity. It is suggested that appropriate caloric diet and physical activities as well as healthy life style should be strictly followed.
Adolescent↗
Development of serial bio-shock tubes and their application.
OBJECTIVE: To design and produce serial shock tubes and further examine their application to experimental studies on blast injury. METHODS: Bio-medical engineering technique was used for the design and development of the serial shock tubes. One thousand four hundred and fifty nine animals (757 rats, 105 guinea pigs, 335 rabbits, 240 dogs and 22 sheep) were then used to test the wounding effects of the shock tubes. RESULTS: Three types of bio-shock tubes, that is, large-, medium- and small-scale shock tubes were made in our laboratory. The large-scale shock tube is 39 meters long; the inner diameter of the test section is 1 meter; and the maximum overpressure in the driving section is 10.3 MPa. A negative pressure could be formed by means of the reflected rarefactive wave produced by the end plate. The medium-scale shock tube is 34.5 meters long; the maximum overpressure in the driving section is 22 MPa; the test section is designed to be a knockdown, showing 5 basic types with inner diameter of 77 to 600 millimeters, which could be used for researches on overpressure, explosive decompression, underwater explosion, and so on. The small-scale shock tube is 0.5 meter long with the maximum endured overpressure of 68.6 MPa. Results from animal experiments showed that this set of shock tubes could induce various degrees of systemic or local blast injury in large or small animals. CONCLUSIONS: This set of bio-shock tubes can approximately simulate typical explosive wave produced by nuclear or charge explosion, and inflict various degrees of blast injury characterized by stability and reproducibility. Therefore, they can meet the needs of blast research on large and small animals.
Animals↗
The correlation between immune rejection and osteoinduction of allogeneic bone grafting.
OBJECTIVE: To evaluate the relationship between the immune rejection and the osteoinductive potential of bone allograft. METHODS: Allogeneic and syngeneic fresh bone, autolyzed antigen-extracted bone, bone matrix gelatin and demineralized bone matrix were implanted into the muscle of mice, and immunological tests, histological observation and alkaline phosphatase assay were performed. RESULTS: Three and 6 weeks after implantation, all kinds of allogeneic implants activated immune rejection, among them, fresh bone induced the most vigorous immune rejection and bone matrix gelatin caused the weakest response. Allogeneic autolyzed antigen-extracted bone, bone matrix gelatin and demineralized bone matrix inhibited proliferation of the lymphocytes in vitro and bone matrix gelatin had the most powerful inhibiting effect. Both allogeneic and syngeneic autolyzed antigen-extracted bone, bone matrix gelatin, and demineralized bone matrix induced heterotopic osteogenesis in vivo and bone matrix gelatin had the best osteoinductive capacity. CONCLUSION: There is a negative correlation between immune rejection to bone allograft and osteoinductive capacity of the graft.
Animals↗
[Influence of ligustrazine-contained peritoneal dialysate on efficiency of dialysis].
OBJECTIVE: To observe the influence of ligustrazine on efficiency of peritoneal dialysis. METHODS: A prospective, self-controlled study was adopted, 24 stable continuous ambulatory peritoneal dialysis (CAPD) patients were divided into 4 groups according to their peritoneal membrane solute transport types identified by peritoneal equilibration test (PET), the high transport group (H group, 4 cases), the high-average transport group (Ha group, 11 cases), the low-average transport group (La group, 8 cases) and the low transport group (L group, 1 case). After treated with standard dialysis for 2 weeks, patients were treated by peritoneal dialysis with ligustrazine (240 mg/d) contained dialysate for another 2 weeks, and changes on mean net ultrafiltration volume (UF) per exchange, and urea kinetics (KT/V) per week of patients were observed. RESULTS: After ligustrazine treatment, the UF and KT/V raised significantly, P < 0.01. In comparison of groups with different transportation, except change on UF of the H group was insignificant, increment of both parameters before and after treatment were significant (P < 0.01 or 0.05). CONCLUSION: By adding ligustrazine in standard dialysate can enhance the efficiency of peritoneal dialysis, raise the UF, so is worth further study.
Adult↗
[Isolation and identification of Triterpenoid compounds in the fruits of Chaenomeles lagenaria (Loisel.) Koidz].
OBJECTIVE: The fruit of Chaenomeles lagenaria is a commonly used drug in Chinese traditional medicine. It is especially effective on rheumatism. The current work is to find out the chemical basis of its pharmacological activity. METHOD: All compounds were extracted with organic solvents and separated by silica gel column or thin layer chromatography, and then purified by recrystalization. The structures were elucidated on the basis of chemical reactions and spectral data analysis. RESULT: In addition to the compounds reported in our previous work, three triterpenoid compounds were separated and identified as 3-O-acetyl ursolic acid, 3-O-acetyl pomolic acid and betulinic acid respectively. CONCLUSION: It is obvious that triterpenoid compounds are dominant among the chemical constituents of C. lagenaria. But it is still to be clarified whether they are the chemical basis of the drug's pharmacological activity.
Drugs, Chinese Herbal↗
[A macroscopic and microscopic study of the relationship between the superior lateral pterygoid muscle and the disc of the temporomandibular joint].
OBJECTIVE: To find out the relationship between the superior lateral pterygoid muscle (SLP) and the disc of the temporomandibular joint. METHODS: The cadavers consisted of 47 TMJ specimens from old humans, were used for the macroscopic and microscopic study. RESULTS: (1) The SLP may insert to the disc, the capsule, the anterior discal attachment of TMJ and to the condyle; (2) On average, 52% of the SLP fibres insert to the condyle, 10% to the articular disc, 24% to the capsule and 14% to the anterior attachment of the disc; (3) There is no association between displacement of disc and the proportion of the SLP insert to the disc; (4) The SLP fibres are jointed into the disc fibres by node or tendon, or jointed and to end. CONCLUSION: The majority of the SLP inserts to the condyle and the contraction of the little part of the SLP, which insert to the disc, should not result in the anterior displacement of the disc.
Female↗
[Retroperitoneal laparoscopic unroofing of renal cyst: use of close method].
OBJECTIVE: To study the close method of retroperitoneal laparoscopic unroofing of renal cyst. METHOD: A close method retroperitoneal laparoscopic unroofing of renal cyst was attempted in 35 cases between May 1995 and December 1996. The age of the patients ranged from 30 to 72 and the cyst size from 4.0 to 9.3 cm. RESULTS: The operative procedure took around 50 minutes. After a 1 - 18 month follow up, we observed the disappearance of all renal cysts. CONCLUSION: The laparoscopic procedure renders less trauma and discomfort to the patients and may be better indicated for symptomatic, simple renal cysts.
Adult↗
[Surgical treatment of infective endocarditis].
OBJECTIVE: To summarize the experience of surgical treatment of infective endocarditis in 28 patients. METHOD: Open heart surgery under cardiopulmonary bypass was performed in all patients: valve replacement (24), VSD repair and tricuspid annuloplasty (3), and Bentall (1) 17 mechanical and 7 homograft valves were placed. RESULT: Two died in hospital, 4 died from infection, 1 had periprosthetic leakage and incompetence respectively. 22 survivors showed improved heart function. CONCLUSION: Combined medication and surgical treatment is superior to antibiotic treatment in long-term survival and convalescence. Infective reccurrence, reinfection and advanced heart failure are major risk factors after operation.
Adolescent↗
[Quantitative determination of fenfluramine hydrochloride and its tablets by high performance liquid chromatography].
Fenfluramine hydrochloride and its tablets were determined with high performance liquid chromatography by using an analytical column (25 cm x 0.46 cm i.d.) packed with Hypersil BDS C18 (5 microns), a UV detector at 264 nm and V(acetonitrile): V(0.4 mol/L ammonium acetate): V(triethylamine) = 30:70:2 as eluent. The quantitative determination was performed with caffeine as the internal standard. The internal standard method showed good linearity in the mass concentration range of 0.1-0.5 g/L with r = 0.9999. The average recovery of fenfluramine tablets was 99.98%. This method is simple, rapid, sensitive and reproducible.
Appetite Depressants↗
[Studies on pyridonecarboxylic acids as antibacterial agents. XIV. Synthesis and structure-activity relationships of 7,8-disubstituted-1-cyclopropyl-6-methyl-1,4-dihydro-4-oxo-3-quinoline carboxylic acids].
Eighteen pyridonecarboxylic acids, characterized by a methyl group at the C6-position instead of the usual fluorine atom, cyclopropyl at the N1-position, substituted amino groups at the C7-position, and some substituted groups (hydrogen, chlorine, nitro and amino) at the C8-position, were synthesized. The in vitro antibacterial activity of these compounds were tested, and the structure-activity relationships were also discussed. The results of the study showed that the activity of compounds 22 and 24 were less potent than that of ciprofloxacin against S. aureus, S. epidermidis, E. coli and P. aeruginosa, while they were 2-100 times more potent than ciprofloxacin against K. pneumoniae, S. marcescens, A. calcoacetous, E. aerogenes, S. typhi and S. typhimurium.
Anti-Infective Agents↗
[Genetic analysis of deltamethrin resistance in Culex pipiens pallens].
AIM: To analyse the genetic character of deltamethrin resistant laboratory strain (resistant factor being 518) of Cx. pipiens pallens. METHODS: Genetic studies were made of deltamethrin-susceptible and-resistant strains of Cx. pipiens pallens with LC-P curve constructed from the response of fourth instar larvae to deltamethrin treatment, and the resistance mechanisms were analysed with synergetic tests in PB, DEF and TPP. RESULTS: The resistant factors of F1 generation from cross and reciprocal cross are respectively 154.8 and 159.2; the LC-P curve of F1 generation gets near to that of resistant parents, D = 0.625; there exist no obvious platform in 50% mortality of BC generation and 25% and 75% mortality of F2 generation, and there are larger differences between the determining curve and theoretical curve in both BC and F2 generations, P < 0.01; the synergetic ratios of PB, DEF and TPP are 27.13, 1.22 and 1.05. CONCLUSION: Deltamethrin resistance of Cx. pipiens pallens is controlled by two or more autosomal genes, and the main gene involved is incompletely dominant; multi-functional oxidase is mainly responsible for the resistance.
Animals↗
[Cloning and characterization of melanin biosynthesis genes from Streptomyces lincolnensis 78-11].
Using mel C1-C2 gene from pIJ702 as probe to hybridize wity chromosome DNA of S. lincolnensis 78-11, a series of positive bands were found, including a 3.2 kb BanHI fragment and a 2.6 kb SphI fragment. So a gene library of S. lincolnensis, containg 3.0-3.5 kb BamHI fragment, was constructed. Melanin biosynthesis genes, mel C1 and mel C2, were then cloned and the fragment, inserted in recombinant plasmid pRSB336 were sequenced. Among five ORFs of the 3152 bp BamHI fragment, mel C1 and mel C2 were highly homologous to the respective genes of the other three strains of Streptomyces, morever, the product of mel C2 gene from S. lincolnensis 78-11 was slightly homologous to tyrosinase from human-being by 17.3% and from rat by 24.5%. All of the above results indicated that mel C1, mel C2 and orf 3 constitute the melanin biosynthesis operon of S. lincolnensis. In the further study of the cloned melanin biosynthesis genes of S. lincolnensis 78-11, recombinant plasmids, pPZ518 and pPZ519, which contain promoter of neo gene and mel gene in different orientation respectively, were constructed, and then were used to transform S. lividans TK23. 12 transformants of pPZ518, selected at random, secreted light brown pigment in R2YE culture medium, but all transformants of pPZ519 and pES1 were white.
Amino Acid Sequence↗
Regulation of K+ and Ca++ channels by a family of neuropeptide Y receptors.
We examined the ability of rat Y1, Y2 and Y4 neuropeptide Y (NPY) receptors to regulate K+ and Ca++ channels expressed in Xenopus oocytes and HEK 293 cells, respectively. Stimulation of all three receptors with NPY or related peptides activated inwardly rectifying K+ currents resulting from the expression of rat GIRK1/CIR in frog oocytes. These effects were inhibited by pertussis toxin treatment. The effects of activating Y1 receptors were antagonized competitively by BIBP3226, SR120819A and GW1229. The effects of Y2 receptor activation were not blocked by these drugs, and the effects of Y4 receptor activation were only blocked by GW1229. Activation of all three NPY receptors also inhibited human alpha-1B Ca++ channels stably expressed in HEK293 cells. The effects of agonists at all three receptors were blocked by pertussis toxin treatment and were voltage dependent. Activation of all three types of NPY receptors produced much smaller inhibition of human alpha-1E Ca++ channels also stably expressed in HEK293 cells. These results suggest that NPY receptors can regulate K+ and Ca++ channels and that these effects may be responsible for the observed effects of NPY on neuronal excitability and synaptic transmission.
Animals↗
Platelet activation with combination of ionophore A23187 and a direct protein kinase C activator induces normal secretion in patients with impaired receptor mediated secretion and abnormal signal transduction.
Defects in signal transduction mechanisms may underlie the impaired aggregation and secretion in patients with congenital platelet function defects (CPD). Both protein kinase C (PKC) induced pleckstrin phosphorylation and cytoplasmic Ca2+ mobilization play a major role in secretion. We postulated that combined platelet activation with a cell permeable direct PKC activator 1,2-dioctanoyl-sn-glycerol (DiC8) and ionophore A23187, which possibly bypass the steps involved in the intracellular synthesis of two major mediators (inositol trisphosphate, diacylglycerol), may induce normal dense granule secretion in patients with impaired receptor mediated secretion. We studied eight CPD patients with abnormal aggregation and secretion in response to several different surface receptor-mediated agonists despite the presence of normal dense granule contents. Receptor mediated Ca2+ mobilization and/or pleckstrin phosphorylation were abnormal in seven patients. Platelet activation with a combination of ADP (8 microM) with DiC8 (200 microM) or A23187 (10 microM) improved secretion in four patients. However, platelet activation with a combination of 200 microM DiC8 with 10 microM A23187, or 100 microM DiC8 with 5 microM A23187 induced normal secretion in platelet-rich plasma in all patients. These studies suggest that in such patients with CPD the ultimate process of exocytosis or secretion per se is intact and impaired secretion results from abnormalities in early signal transduction events, possibly upstream of diacylglycerol formation and calcium mobilization. Detailed studies are needed to delineate the specific abnormalities in these heterogenous patients with signal transduction defects.
Adolescent↗
Analysis of 74 kb of DNA located at the right end of the 330-kb chlorella virus PBCV-1 genome.
This report completes a preliminary analysis of the sequence of the 330,740-bp chlorella virus PBCV-1 genome, the largest virus genome to be sequenced to date. The PBCV-1 genome is 57% the size of the genome from the smallest self-replicating organism, Mycoplasma genitalium. Analysis of 74 kb of newly sequenced DNA, from the right terminus of the PBCV-1 genome, revealed 153 open reading frames (ORFs) of 65 codons or longer. Eighty-five of these ORFs, which are evenly distributed on both strands of the DNA, were considered major ORFs. Fifty-nine of the major ORFs were separated by less than 100 bp. The largest intergenic distance was 729 bp, which occurred between two ORFs located in the 2.2-kb inverted terminal repeat region of the PBCV-1 genome. Twenty-seven of the 85 major ORFs resemble proteins in databases, including the large subunit of ribonucleotide diphosphate reductase, ATP-dependent DNA ligase, type II DNA topoisomerase, a helicase, histidine decarboxylase, dCMP deaminase, dUTP pyrophosphatase, proliferating cell nuclear antigen, a transposase, fungal translation elongation factor 3 (EF-3), UDP glucose dehydrogenase, a protein kinase, and an adenine DNA methyltransferase and its corresponding DNA site-specific endonuclease. Seventeen of the 153 ORFs resembled other PBCV-1 ORFs, suggesting that they represent either gene duplications or gene families.
Chlorella↗
Expression of transforming growth factor beta type III receptor suppresses tumorigenicity of human breast cancer MDA-MB-231 cells.
Transforming growth factor beta (TGF-beta) promotes tumor progression in some model systems including human breast cancer cells. In this study, we report that human breast cancer cell lines express reduced amounts of TGF-beta type III receptor (RIII) when compared with untransformed human mammary epithelial cells. Consequently, we examined whether expression of RIII in human breast cancer MDA-MB-231 cells could reduce TGF-beta's tumor promoting activity by sequestering active TGF-beta isoforms produced by the cells. A tetracycline-repressible human RIII expression vector was stably transfected into the cell line. RIII expression in a pool of transfected clones and a single clone was found to be reversibly repressed by tetracycline treatment. Expression of RIII reduced the amount of active TGF-beta1 and TGF-beta2 in the conditioned medium. The medium conditioned by control cells showed a significantly higher growth inhibitory effect than that conditioned by RIII-transfected cells on the growth of the mink lung epithelial CCL64 cells. A conditioned medium collected from RIII-transfected cells treated with tetracycline significantly increased its growth inhibitory activity to that of control cells. Expression of RIII also reduced tumor incidence and growth rate in two separate experiments when the cells were inoculated in athymic nude mice. Treatment of the mice with tetracycline repressed RIII expression in the tumors generated by RIII-transfected cells and increased tumor incidence and growth rate. These results suggest that TGF-beta RIII can reduce tumorigenicity of MDA-MB-231 cells apparently by sequestering TGF-beta isoforms produced by these cells.
Animals↗
Platelet signal transduction defect with Galpha subunit dysfunction and diminished Galphaq in a patient with abnormal platelet responses.
G proteins play a major role in signal transduction upon platelet activation. We have previously reported a patient with impaired agonist-induced aggregation, secretion, arachidonate release, and Ca2+ mobilization. Present studies demonstrated that platelet phospholipase A2 (cytosolic and membrane) activity in the patient was normal. Receptor-mediated activation of glycoprotein (GP) IIb-IIIa complex measured by flow cytometry using antibody PAC-1 was diminished despite normal amounts of GPIIb-IIIa on platelets. Ca2+ release induced by guanosine 5'-[gamma-thio]triphosphate (GTP[gammaS]) was diminished in the patient's platelets, suggesting a defect distal to agonist receptors. GTPase activity (a function of alpha-subunit) in platelet membranes was normal in resting state but was diminished compared with normal subjects on stimulation with thrombin, platelet-activating factor, or the thromboxane A2 analog U46619. Binding of 35S-labeled GTP[gammaS] to platelet membranes was decreased under both basal and thrombin-stimulated states. Iloprost (a stable prostaglandin I2 analog) -induced rise in cAMP (mediated by Galphas) and its inhibition (mediated by Galphai) by thrombin in the patient's platelet membranes were normal. Immunoblot analysis of Galpha subunits in the patient's platelet membranes showed a decrease in Galphaq (<50%) but not Galphai, Galphaz, Galpha12, and Galpha13. These studies provide evidence for a hitherto undescribed defect in human platelet G-protein alpha-subunit function leading to impaired platelet responses, and they provide further evidence for a major role of Galphaq in thrombin-induced responses.
Blood Platelets↗