Prevalence of antibodies to HTLV-I/II in blood donors and risk populations in South China.
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Blood Donors↗
Biomedical subjects
S Lin
Publications and source records attributed to S Lin.
Plasma antioxidants and lipid peroxidation in acute myocardial infarction and thrombolysis.
OBJECTIVES: The aim of this study was to investigate the balance between prooxidative and protective mechanisms in patients with acute myocardial infarction (AMI) throughout streptokinase (STK) therapy. METHODS: Patients who presented to coronary care unit within 3 hours of infarction were followed. Blood was collected before, 2 and 24 hours post STK. Plasma lipid peroxidation was analyzed by a free radical generating system (AAPH) and malondialdehyde equivalents and conjugated dienes quantitated. Plasma vitamins A, E and beta-carotene, were analyzed by HPLC. Patients' results were compared with those from age-matched, healthy control subjects. RESULTS: In 38 patients with AMI, baseline plasma antioxidant vitamin concentration was reduced compared with a healthy control group. Upon STK therapy, there was a significant drop in plasma vitamin E concentration. Successful reperfusion was followed by an increased plasma oxidizability. Plasma lipids were not significantly different in the AMI patients except for a lower HDL-cholesterol concentration. CONCLUSIONS: Patients with AMI showed a drop in plasma antioxidant vitamins. Upon thrombolysis, there was an enhanced lipid peroxidation. These alterations indicate the significance of free radical generation processes in reperfusion injury in AMI patients, and suggest the potential involvement of antioxidants in the management of AMI treated by thrombolysis.
Aged↗
Tetravinyl-tetramethylcyclo-tetrasiloxane (tetravinyl D4) is a mutagen in Rat2lambda lacI fibroblasts.
Small fragments of silicone gels injected intraperitoneally have been used to induce plasmacytomas in genetically susceptible mice. Silicone oils, in contrast to silicone gels, are apparently not tumorigenic in the mouse plasmacytoma system. The reason for this difference as well as the mechanism of silicone gel-induced plasmacytoma development is poorly understood. We chose to examine the possibility that low molecular wt silicone compounds such as siloxanes, leaking from the complex silicone gel matrix into the surrounding tissue, may be mutagenic. We postulate that this mutagenicity may be a critical determinant of the plasmacytoma inducing potency of silicone gels. Six siloxane compounds, either linear or cyclic di-, tri-, or tetrasiloxanes substituted with methyl or vinyl moieties, were selected as model compounds to study mutagenicity in Rat2lambda lacI fibroblasts in vitro. Using phage lambda-derived lacI/lacZ genes as target/reporter genes to quantitate mutagenesis, and gamma-cyclodextrin as vehicle to effectively deliver siloxanes, we found that exposure to 50 microM of tetravinyl-tetramethylcyclo-tetrasiloxane (tetravinyl D4) resulted in a modest 1.7-fold increase of mutant frequencies over controls in Rat2lambda lacI cells. In related toxicity experiments, tetravinyl D4 was shown to perturb lipid membranes leading to a loss of cytosolic glutathione (GSH), which by itself resulted in a 1.5-fold increased mutant rate in Rat2lambda lacI cells. We conclude that certain siloxanes may act as direct mutagens in mammalian cells. In addition, siloxane-induced mutagenicity may be enhanced by the depletion of intracellular GSH caused by the interaction of lipophilic siloxanes with cell membranes.
Animals↗
Utrophin is a regeneration-associated protein transiently present at the sarcolemma of regenerating skeletal muscle fibers in dystrophin-deficient hypertrophic feline muscular dystrophy.
Utrophin, an autosomal homologue of dystrophin, has been suggested as a possible therapeutic replacement of dystrophin in Duchenne or Becker muscular dystrophies (DMD/BMD). We have undertaken this study to examine the expression of utrophin in the skeletal muscle of dystrophin-deficient cats, a spontaneous animal model for dystrophinopathy. Dystrophin was normal in size, but very low in quantity by immunohistochemistry and Western blot. Utrophin was heterogeneously overexpressed at extrajunctional sarcolemma of regenerating muscle fibers, as defined by overexpression of the myogenic markers: vimentin, desmin, and developmental isoform of myosin heavy chain (MHCd). Muscle regeneration occurred in 6 stages as assessed by fiber size, and immunolabeling of desmin, vimentin, and MHCd. Differential developmental patterns of utrophin, alpha-sarcoglycan, and beta-dystroglycan expression were seen with an increase followed by a decrease and with changes in their respective location. These results suggest that utrophin is a regeneration-associated protein. It can functionally replace dystrophin in anchoring dystrophin-associated proteins (DAPs). However, the expression of utrophin and its anchored DAPs is restricted to the period of muscle regeneration and tends to decrease in late stages. This study therefore suggests a novel role of utrophin during skeletal muscle regeneration.
Animals↗
Effects of maternal work activity during pregnancy on infant malformations.
This article examines the association between two birth defects, neural tube defects and oral cleft defects, and maternal physical work demands during the periconceptional period. A case-control study was conducted by comparing exposure characteristics of mothers of malformed infants, as ascertained from the New York State Congenital Malformations Registry (n = 520), with mothers of non-malformed infants (n = 1154). Case groups were further subdivided on whether infants had additional defects. Occupational exposure information was collected from a self-administered questionnaire, and demographic variables from vital records. The results showed no general differences between cases and controls in most variables. However, those infants with cleft defects plus additional defects tended to have a marginally increased risk (odds ratio = 1.76; 95% confidence interval, 1.02-3.21) in relation to maternal jobs requiring standing (> or = 75% of time). We suggest that exposure assessment be improved and defects subdivided for future studies.
Case-Control Studies↗
Whole-cell immunolocalization of nitrogenase in marine diazotrophic cyanobacteria, trichodesmium spp
The mechanism by which planktonic marine cyanobacteria of the genus Trichodesmium fix N2 aerobically during photosynthesis without heterocysts is unknown. As an aid in understanding how these species protect nitrogenase, we have developed an immunofluorescence technique coupled to light microscopy (IF-LM) with which intact cyanobacteria can be immunolabeled and the distribution patterns of nitrogenase and other proteins can be described and semiquantified. Chilled ethanol was used to fix the cells, which were subsequently made permeable to antibodies by using dimethyl sulfoxide. Use of this technique demonstrated that about 3 to 20 cells (mean +/- standard deviation, 9 +/- 4) consecutively arranged in a Trichodesmium trichome were labeled with the nitrogenase antibody. The nitrogenase-containing cells were distributed more frequently around the center of the trichome and were rarely found at the ends. On average 15% of over 300 randomly encountered cells examined contained nitrogenase. The percentage of nitrogenase-containing cells (nitrogenase index [NI]) in an exponential culture was higher early in the light period than during the rest of the light-dark cycle, while that for a stationary culture was somewhat constant at a lower level throughout the light-dark cycle. The NI was not affected by treatment of the cultures with the photosynthetic inhibitor dichloro 1,3'-dimethyl urea or with low concentrations of ammonium (NH4Cl). However, incubation of cultures with 0.5 &mgr;M NH4Cl over 2 days reduced the NI. The IF technique combined with 14C autoradiography showed that the CO2 fixation rate was lower in nitrogenase-containing cells. The results of the present study suggest that (i) the IF-LM technique may be a useful tool for in situ protein localization in cyanobacteria, (ii) cell differentiation occurs in Trichodesmium and only a small fraction of cells in a colony have the potential to fix nitrogen, (iii) the photosynthetic activity (CO2 uptake) is reduced if not absent in N2-fixing cells, and (iv) variation in the NI may be a modulator of nitrogen-fixing activity.
Journal Article↗
Impact of fundoplication on bolus transit across esophagogastric junction.
This study analyzed the effect of fundoplication on the mechanics of liquid and solid bolus transit across the esophagogastric junction (EGJ). The squamocolumnar junction was endoscopically clipped in seven controls, seven hiatal hernia patients, and seven patients after laparoscopic Nissen fundoplication. Concurrent manometry and fluoroscopy were done during swallows of liquid barium and a 13-mm-diameter marshmallow. The EGJ opening, pressure gradients, transit efficacy, and axial motion were measured. The axial motion of the EGJ was reduced in the fundoplication and hiatal hernia patients. The opening dimensions at the squamocolumnar junction were similar among groups, but in each case the constriction limiting flow to the stomach was at the hiatus and this was substantially narrowed with fundoplication. As a result, liquid intrabolus pressure was increased and marshmallow transit frequently required multiple swallows. We conclude that fundoplication limits the axial mobility of the EGJ and leads to a restricted hiatal opening. These alterations decrease the efficacy of solid and liquid transit into the stomach and are potential causes of dysphagia in this population.
Adult↗
Retinoic acid-receptor activation of SP-B gene transcription in respiratory epithelial cells.
Retinoids are known to play important roles in organ development of the lung. Retinoids exert their activity by modulating the expression of numerous genes, generally influencing gene transcription, in target cells. In the present work, the mechanism by which retinoic acid (RA) regulates surfactant protein (SP) B expression was assessed in vitro. RA (9-cis-RA) enhanced SP-B mRNA in pulmonary adenocarcinoma cells (H441 cells) and increased transcriptional activity of the SP-B promoter in both H441 and mouse lung epithelial cells (MLE-15). Cotransfection of H441 cells with retinoid nuclear receptor (RAR)-alpha, -beta, and -gamma and retinoid X receptor (RXR)-gamma further increased the response of the SP-B promoter to RA. Treatment of H441 cells with RA increased immunostaining for the SP-B proprotein and increased the number of cells in which the SP-B proprotein was detected. An RA responsive element mediating RA stimulation of the human SP-B promoter was identified. RAR-alpha and -gamma and RXR-alpha but not RAR-beta or RXR-beta and -gamma were detected by immunohistochemical analysis of H441 cells. RA, by activating RAR activity, stimulated the transcription and synthesis of SP-B in pulmonary adenocarcinoma cells.
Adenocarcinoma↗
Influence of hepatocyte growth factor/scatter factor on the metastatic phenotype of B16 melanoma cells.
B16 melanoma cells selected in mice for liver-specific metastasis (B16-LS9) overexpress a constitutively active form of the hepatocyte growth factor/scatter factor receptor (HGF/SFr), the product of the c-met proto-oncogene. HGF/SF can affect both invasion and growth of receptive cells. In fact, we show that overexpression of c-met in B16-LS9 cells results in a higher inducibility of two different proteolytic activities (uPA and gelatinase), in correlation with a stronger invasive and motility response to HGF/SF treatment. However, HGF/SF treatment inhibits growth of B16 cells, which might appear in contradiction with the observation that c-met overexpression and constitutive activation seems to be required for efficient liver colonization. However, this apparent discrepancy is resolved by the finding that liver-derived, but not lung-derived factor(s), can efficiently rescue B16-LS9 cells from the growth inhibitory effects of HGF/SF, while not changing their motility response. Therefore, overexpression of c-met in B16-LS9 cells might give a specific advantage in liver colonization, because specifically at this site B16-LS9 cells can take full advantage of the positive effects exerted by HGF/SF stimulation on motility and invasion, while the negative effects on growth are counteracted by other paracrine factor(s).
Animals↗
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↗
Web slinkies, getting unkinked.
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Computer Communication Networks↗
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↗
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↗
[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↗
[Progress in the study of neurosurgery China].
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Brain Neoplasms↗
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↗
Coexistence of Creutzfeldt-Jakob disease and Alzheimer's disease in the same patient.
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Alzheimer Disease↗
[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↗