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Biomedical subjects

S Lin

Publications and source records attributed to S Lin.

At least 325 records · Page 18Linked to original sources
PubMed1998

Effects of delta-9-tetrahydrocannabinol and (R)-methanandamide on open-field behavior in rats.

This study compared the effects of (R)-methanandamide, an analog of the mammalian brain constituent anandamide, and delta-9-tetrahydrocannabinol on the open-field behavior of male Sprague-Dawley rats. Rats were individually housed with free access to food and water. Animals were treated with 0, 1, 3, and 5.6 mg/kg delta-9-tetrahydrocannabinol given i.p. 30 min pre-session; and 0, 3, 10, and 18 mg/kg (R)-methanandamide, 15 min pre-session. The behavioral categories recorded were ambulation (the number of squares crossed), rearing (the number of times the rat stood erect on its hind-legs), latency (the time in seconds to leave the starting area, the circle in the center of the field), circling (the number of times the animal turned around its vertical axis, 0.5 point given for each 180 degrees turn), grooming (the number of cleaning bouts), urination and defecation (the number of urination spots and fecal boli deposited during the 5 min observation period). Delta-9-tetrahydrocannabinol was more potent than (R)-methanandamide, but otherwise the effects of delta-9-tetrahydrocannabinol and (R)-methanandamide were similar, with one exception; whereas delta-9-tetrahydrocannabinol produced dose-related increases in circling, (R)-methanandamide did not increase circling over the doses examined. The delta-9-tetrahydrocannabinol-induced increase in circling was blocked by the central cannabinoid receptor CB1 antagonist SR 141716. The differential effects with regard to circling may indicate that there are qualitative behavioral differences in the effects of delta-9-tetrahydrocannabinol and (R)-methanandamide.

Analysis of Variance↗
PubMed1998

Mechanisms of the therapeutic effect of astragalus membranaceus on sodium and water retention in experimental heart failure.

OBJECTIVE: To investigate the therapeutic effect of Astragali on sodium and water retention in aortocaval fistula-caused experimental congestive heart failure and its involved mechanisms. METHODS: In aortocaval fistula-caused chronic (5 wk), heart failure rats treated with and without Astragali 1.0 g/day intraperitoneally, changes of cardiac and renal function, renal response to atrial natriuretic peptide (ANP) were examined. Dot blot analysis was used to determine the effect of Astragali on hypothalamic arginine vasopresin (AVP) mRNA expression, and mRNA expressions of aortic and renal AVP V1a receptor, renal AVP V2 receptor and aquaporin-2 (AQP2) were simultaneously detected by RT-PCR method. RESULTS: Rats with aortocaval fistula impaired cardiac and renal functions evidenced by higher right atrial pressure (RAP), left ventricular end-diastolic pressure (LVEDP), lower + dP/dtmax of left ventricle, glomerular filtration rate (GFR), renal plasma flow (RPF), urine volume (UV), urinary sodium excretion (UNaV) and free water clearance (CH2O) compared with sham-operated control (P < 0.05). There was no change in serum sodium, hematocrit and plasma osmolality. Astragali could remarkably improve the cardiac and renal functions. Dot blot analysis demonstrated upregulated hypothalamic AVP mRNA expression in this experimental heart failure. The AVP V1a receptor mRNA level of aortic arch and renal medulla were reduced, while in renal cortex it was elevated. The mRNA expressions of AVP V2 receptor and AQP2 were increased in renal cortex while decreased in medulla. Astragali could partially or completely correct those abnormal mRNA expressions. Analysis on plasma atrial natriuretic peptide (ANP), urinary cyclic guanidino monophosphate excretion (UcGMP V), urinary cyclic guanidino monophosphate excretion/plasma atrial natriuretic peptide (UcGMP V/pANP), and further correlation and linear regression analysis between UcGMP V and plasma ANP showed that there was blunted renal response to ANP in heart failure rat, and astragali could improve the renal reaction to ANP significantly. CONCLUSION: Chinese herb, astragali have therapeutic effects on sodium and water retention in aortocaval fistula-induced heart failure, the mechanisms of which might be the improvement of cardiac and renal functions, partly correction of abnormal mRNA expressions of AVP system and AQP2, and amelioration of blunted renal response to ANP.

Animals↗
PubMed1998

Down-regulation of PTH/PTHrP receptor in the kidney of patients with renal impairment.

OBJECTIVE: To investigate whether the down-regulation of renal parathyroid hormone/parathyroid hormone related protein (PTH/PTHrP) receptor messenger ribonucleic acid (mRNA) expression is a general phenomenon in patients with different stages of renal disease, besides chronic renal failure. METHODS: Twenty-five patients were divided into the following groups: (1) chronic glomerulonephritis with normal renal function (GNN) (2) chronic glomerulonephritis with moderate renal insufficiency (GNI) (3) severe chronic renal failure undergoing maintenance dialysis (CRF) (4) acute renal failure during oliguric phase (ARF) (5) normal control without renal suffering (NC). Using relatively quantitative reverse transcription/polymerase chain reaction (RT/PCR) method, we investigated PTH/PTHrP receptor mRNA expression in renal specimens obtained through biopsy or operation. The levels of plasma C-terminal PTH, serum phosphorus and calcium were also observed at the same time. RESULTS: Plasma C-terminal PTH levels in GNI, CRF and ARF patients were 1.90, 9.73 and 8.63 times higher than those in NC. However, the difference between GNN and NC was insignificant. CRF and ARF patients also presented obviously elevated serum phosphorus (1.61, 1.86 vs 1.14 mmol/L) and reduced serum calcium (1.82, 1.71 vs 2.26 mmol/L) compared with that in the control. These two parameters for GNN and GNI patients were normal. The levels of PTH/PTHrP receptor mRNA (corrected by beta-actin mRNA) in the kidney of GNN, GNI, CRF and ARF patients was markedly decreased by up to 35.7%, 68.5%, 77.9% and 92.2%, respectively. CONCLUSIONS: The down-regulation of renal PTH/PTHrP receptor mRNA occurs much earlier than the changes of renal function, plasma PTH, serum phosphorus and calcium in the course of human renal disease.

Adolescent↗
PubMed1998

[Determination of taurine in foods by high performance liquid chromatography].

Taurine (2-aminoethanesulfonic acid) was quantitated by reversed-phase liquid chromatography on a C18 resolve column (ZOBAX ODS) using a mobile phase of methyl alcohol-phosphate buffer (pH = 4.9). L-glutamine was used as the internal standard. Before separation, the sample was extracted with 0.2 mol/L sulfosalicylic acid solution and cleaned up with dual ion exchange column chromatography. The amino acid was derived with o-phthalaldehyde to form an amino acid adduct which was monitored at 340 nm by UV detector. The HPLC method for taurine analysis in foods showed the precision (relative standard deviation) is better than 5%. The recoveries are more than 95% and the detection limit is 12 ng of taurine.

Animals↗
PubMed1998

Gene expression of receptor for advanced glycosylation end products and its modulation by aminoguanidine in diabetic kidney tissue.

OBJECTIVE: To explore the relationship between receptor for advanced glycosylation end products (RAGE) gene expression in the kidneys of diabetic rats and the role of aminoguanidine on it. METHODS: Among four groups of rats, 2 groups received streptozotocin (STZ) to induce diabetics (DM) and were followed by either aminoguanidine (AG) treatment for 12 weeks or no therapy. Two groups of normal rats in which one received AG and the other given water served as control (Con). Reverse transcription-polymerase chain reaction (RT-PCR) was used to measure the amount of receptor of advanced glycosylation and products (RAGE) messenger RNA (mRNA) expression. RESULTS: After 4 weeks of diabetes inducement, RAGE mRNA levels showed a continuous increase up to 12 weeks both in diabetic renal cortex and medulla compared with mRNA levels at the end of 2 weeks. The RAGE mRNA levels in renal cortex and medulla of control rats did not change significantly with age. AG as the prototype inhibitor of advanced glycosylation end products (AGEs) formation, when administered to diabetic rats for 4 weeks, had no visible effect on the alterations of renal RAGE mRNA in diabetes. By continuous administration up to 8 weeks, those alterations of RAGE mRNA both in diabetic renal cortex and medulla were all ameliorated [P < 0.05, (diabetes without AG) versus (diabetes with AG)]. In addition, diabetic animals had a progressive increase in urinary protein excretion compared to control rats from week 4 onwards. Similarly, after 8 weeks diabetic rats had significantly higher glycated Hb (GHb) (DM without AG vs Con: 7.71 +/- 0.22% vs 2.95 +/- 0.52% P < 0.001). AG treatment for 8 weeks decreased GHb by 24.78% and retarded the rate of rise in albuminuria in diabetic rats as compared with that in untreated diabetic rats (DM with AG vs DM without AG: 22.04 +/- 0.91 micrograms/24 h vs 70.25 +/- 13.05 micrograms/24 h, P < 0.001). CONCLUSIONS: Gene expression of RAGE in renal cortex and medulla was altered in diabetic rats and excessive gene expression of RAGE in kidney tissue may enhance the interactions between advanced glycosylation end products (AGEs) and its receptor (RAGE) which would contribute to the development of diabetic nephropathy. Cumulative AGEs play an important role in increasing RAGE gene expression in vivo. The decrease of AGEs level by AG therapy ameliorate the abnormal regulation of RAGE gene expression.

Animals↗
PubMed1998

[Epidemiological characteristics of tuberculosis patients complicated with diabetes in Shanghai].

OBJECTIVE: To understand the epidemiological trends and characteristics of tuberculosis patients complicated with diabetes in Shanghai. METHOD: All the registered tuberculosis (TB) cases from 1992 to 1997 in Shanghai were included in the analysis. The new registration rates and percentages of TB cases complicated with diabetes were calculated. RESULT: The new registration rate of the cases increased from 0.70/100,000 in 1992 to 2.10/100,000 in 1997 with an annual increase rate of 24.57%. The cases with the complication accounted for 4.86% in 1997. Diabetes tends to be more prevalent among TB patients in urban area. The greater the age, the more diabetes were found in TB patients. A significant difference was also observed between sex. Bacillary positive rate and percentage of infiltration type were higher, and cavity was more common in cases with the complication. The percentage of cases with relapse was also higher. CONCLUSION: The complication of diabetes significantly affected the epidemiological trend of TB in Shanghai. The diagnosis of diabetes in TB patients should be enforced, and short-course chemotherapy targeting the cases should be investigated.

Age Factors↗
PubMed1998

[Clinical study on active factors of vascular endothelial cells in acute cerebral infarction patients and therapeutical effect of activating blood stasis].

OBJECTIVE: To investigate the level of plasma tissue plasminogen activator (tPA), plasminogen activator inhibitor (PAI), 6-keto-prostaglandin F1 alpha(PGF1 alpha), thromboxane B2(TXB2), factor VIII related antigen (VIII R:Ag) in acute cerebral infarction (ACI) patients with different TCM syndrome-type and the therapeutical effect of activating blood stasis (ABS). METHODS: Plasma fibrolysin system, prostaglandin system, and VIII R:Ag of 20 healthy subjects and 66 ACI patients were determined. The 45 of 66 cases were treated with ABS randomly and prospectively, 20 cases were treated by difibrase batroboxobin (DF-521), only 25 cases were treated by DF-521 together with Heart-Brain Mixture (HBM), on activating blood stasis mixture, concurrently. RESULTS: (1) The activity of tPA, ratio of tPA/(tPA + PAI) and level of PGF1 alpha decreased significantly, the level of VIII R:Ag increased remarkably in ACI patients than those of the controlled subjects. (2) Between Differentiation of Deficiency and Excess Syndromes, the level of above index changed more remarkably in the case with Excess Syndrome. Insignificant change of index shown in Deficiency cases except activity of tPA. (3) No more improvement of nerve impairment was shown between group of DF-521 together with HBM and DF-521 alone within 30 days. However, the improvement of index such as level of VIII R:Ag, ratio of tPA/(tPA + PAI) and TXB2/PGF1 alpha showed significant change between the beginning and end of treatment of DF-521 with HBM group. CONCLUSIONS: The vascular endothelial impairment was more serious in ACI patients with Excess than those with Deficiency Syndrome. DF-521 combining with HBM could protect vascular endothelial cells and improve the fibrolytic system and prostaglandin system.

6-Ketoprostaglandin F1 alpha↗
PubMed1998

[Follow-up study on influence of Sini Decoction to living quality of patients after percutaneous transluminal coronary angioplasty].

OBJECTIVE: To determine the influence of Sini Decoction (SND) on living quality of patients after percutaneous transluminal coronary angioplasty (PTCA). METHODS: Randomized case-control clinical trail was conducted to evaluate the living quality of 40 post-PTCA patients before and after SND treatment by scoring. RESULTS: The scores in physical symptoms, sense of well-being, depression, satisfaction of life and work capacity of patients after PTCA were improved significantly as compared with before PTCA, P < 0.05-0.01. Scores of patients received SND treatment were higher than those untreated with SND in the first three criteria, P < 0.05, particularly on relieving palpitation and dyspnea. CONCLUSION: SND is helpful to improve the living quality of patients after PTCA.

Angioplasty, Balloon, Coronary↗
PubMed1998

[Effect of hyperbaric oxygen on cerebral microcirculation and tissue cells in animals with cerebral ischemic injury].

Changes of cerebral microcirculation and tissue cells after Hyperbaric Oxygen (HBO) exposure were observed in 136 gerbils with cerebral ischemia by observation of meningeal microcirculation pathological study in cerebral tissues and determination of Na, K-ATPase. It is indicated that HBO may be helpful in improving microcirculatory dynamics and other microcirculatory functions, and enhancing cerebral tissue cell activity and cell function, as well as increasing oxygen content. It is suggested that HBO (250 approximately 300kPa) may play a role in protecting vessel endothelial cells and nerve cells.

Adenosine Triphosphatases↗
PubMed1998

[Blepharospasm and hemifacial spasm treated with botulinum A toxin injection].

OBJECTIVE: To study the efficacy of botulinum A toxin (BTA) injections for the treatment of blepharospasm and hemifacial spasm (HFS). METHODS: Twelve patients with blepharospasm and thirty eight patients with HFS were treated with BTA local injections (2.5 U to 5 U for each injection). RESULTS: Of the fifty patients, ten (86.7%) in blepharospasm and thirty two (84.2%) in HFS were completely relieved, two (13.3%) and five (13.2%) were remarkably relieved respectively, zero and one (2.6%) were partial relieved respectively. All patients experienced relief from spasm. The duration of the effect in blepharospasm were 10 to 24 weeks (mean, 18 weeks) and in HFS 14 to 32 weeks (mean, 22 weeks). The local side effects were transient and mild, including minor facial paralysis in eight patients, ptosis in four patients and tearing in four patients. No systemic adverse and allergic reactions were noted. CONCLUSION: Botulinum A toxin local injection is a safe, effective and simple means for the treatment of blepharospasm and HFS.

Adult↗
PubMed1998

[Simultaneous determination of the enantiomers of verapamil and norverapamil in plasma by high performance capillary electrophoresis].

An analytical method has been developed to determine simultaneously plasma concentration of the enantiomers of verapamil and its major metabolite, norverapamil, using capillary zone electrophoresis. Trimethyl-beta-cyclodextrin was selected as chiral selector. Good separation was achieved under the conditions as below: Running electrolyte was pH 2.5, 60 mmol.L-1 phosphate buffer containing 60 mmol.L-1 trimethyl-beta-cyclodextrin; capillary: 30 cm x 75 microns (ID), coated; setpoint of capillary temperature: 20 degrees C; detector: UV 200 nm; injection: electromigration at 12 kV for 7 s; running voltage: 14 kV. Solvent of sample was doubly deionized water. The migration times of enantiomers were less than 12 min. The good linear range was from 300.0 ng.ml-1 to 2.50 ng.ml-1. Relative standard deviations of assay accuracy and precision were less than 12%. It fits for routine therapeutic monitoring as it is highly efficient, rapid, sensitive, with less solvent and sample consumption and automation.

Electrophoresis, Capillary↗
PubMed1998

[Protective and antioxidative effect of 2(3)tert-butyl-4-hydroxyanisole against cytotoxicity induced by doxorubicin in mice].

The protective and antioxidative effects of 2(3)tert-butyl-4-hydroxyanisole (BHA) against cardiotoxicity and hepatotoxicity induced by doxorubicin in mice were investigated. After pretreatment with different oral doses of BHA, doxorubicin 30 mg.kg-1 was given i.p. Serum GPT, GOT, LDH and CK were determined, and the mortality rate of animals was observed. Quinone reductase (QR), glutathione-S-transferases (GSTs) and glutathione reductase (GR) were determined on tissue cytosols with enzyme dynamic methods. Malondialdehyde (MDA) was measured by the method of thiobarbituric acid. Compared with the doxorubicin group, the serum GPT, GOT, LDH, CK and the mortality rate of mice were significantly decreased by BHA pretreatment, and BHA was shown to inhibit the increase of MDA induced by doxorubicin (P < 0.01 and P < 0.0001). Administration of BHA resulted in increased activities of QR, GSTs and GR in the myocardium and liver (P < 0.05 or P < 0.0001). These results suggest that BHA has protective effect against the toxicity induced by doxorubicin via the induction of QR, GSTs and GR activities and anti-lipid peroxidation.

Animals↗
PubMed1998

[The design and clinical application of an apparatus for monitoring neuromuscular transmission function during operation under general anaesthesia].

This paper introduces a monitoring system of musle relaxant in action during the operation under general anaesthesia. The design of the monitor is based on measurement of acceleration. It consists of an acceleration transducer, a nerve stimulator and a microcomputer unit. The transducer can be fastened to the thumb, and the signal of the thumb movement in response to ulnar nerve stimulation is measured and registered in the computing unit. In clinical practice, it has been proved that this new apparatus can achieve reliable evaluation of nuromuscular transmission function and improve the quality of anesthesia in patients care during surgical operation.

Anesthesia, General↗
PubMed1998

Identification and preliminary characterization of PCNA gene in the marine phytoplankton Dunaliella tertiolecta and Isochrysis galbana.

The gene coding for proliferating cell nuclear antigen (PCNA) was identified in Dunaliella tertiolecta (Chlorophyceae) and Isochrysis galbana (Prymnesiophyceae). Southern blot hybridization using a PstI fragment of rat PCNA gene (pCR-1) as a probe showed that there is apparently a single copy of this gene per haploid genome in both species. On the Northern blot pCR-1 probed a single messenger RNA for each species of a molecular size close to rat PCNA mRNA (1.1 kilobases [kb]). Polymerase chain reaction (PCR) with a set of degenerated primers produced a fragment of about 610 base pairs [bp] from genomic DNA of both species; the PCR products appeared close in size to the amplified from rat PCNA and hybridized to the pCR-1 probe. Further analysis with reverse transcription-PCR (RT-PCR), cloning, and sequencing revealed a complementary DNA of a similar size (616 and 576 bp) that possesses an open reading frame encoding 205 and 192 amino acids, respectively, for Dun (D. tertiolecta) and Iso (I. galbana). Surprisingly, the polypeptides deduced from the two cDNA shared no higher homology to each other (71%) than to animals such as Xenopus (Dun 72%; Iso 73%), rat (Dun 73%; Iso 74%), and human (Dun 73%; Iso 74%), and to higher plants such as soybean (Dun 78%; Iso 72%), Zea mays (Dun 77%; Iso 73%), and rice (Dunn 77%; Iso 72%), although D. tertiolecta has a higher homology (77%) to the Prasinophyceae alga Tetraselmis chiu than does I. galbana (71%). The homology to PCNA in budding and fision yeasts (63% and 53%, respectively) is also lower than to animals and higher plants. It is thus suggested that with regard to PCNA genes, the three algae are as different from each other as they are from higher plants and animals. In a partially synchronized exponential culture of D. tertiolecta grown with a photocycle of 12 h light and 12 h dark, the abundance of the transcript appeared to be low at hours 3 and 9 (hour 0 = the onset of light period), and increased about 2- to 3-fold at hours 15 and 21 (i.e., during the dark period). Western blotting and immunofluorescence analysis on concurrent diel samples showed an over 2-fold increase in PCNA protein abundance (in proportion to total cellular protein) and the percentage of cells labeled by PCNA antibody. A similar trend was found for I. galbana grown under the same conditions. The results suggest that the gene transcription was in pace with PCNA synthesis, which was lower in the light period when G1 phase was dominant and higher in the dark period when S (and probably G2 and early M) phase was dominant, and that the expression of this gene may be regulated at the transcriptional level in these two algae.

Amino Acid Sequence↗