Quantitative structure-property relationships for vapor pressure of PCDD/Fs.
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Benzofurans↗
Biomedical subjects
Y Yan
Publications and source records attributed to Y Yan.
Effects of L-arginine administration before cardioplegic arrest on ischemia-reperfusion injury.
BACKGROUND: Administration of L-arginine during reperfusion or its addition to cardioplegic solution has been shown to protect myocardium against ischemia-reperfusion injury. This study aimed at evaluating the role of L-arginine in ischemia-reperfusion injury when administered intraperitoneally 24 hours before cardioplegic arrest. METHODS: Two groups of Sprague-Dawley rats (control, n = 10; and L-arginine, n = 10) were studied in an isolated buffer-perfused heart model. Both groups were injected intraperitoneally 24 hours before ischemia. Before experimentation blood samples were collected for cardiac troponin I and cGMP analysis. In the coronary effluents, cardiac troponin I, adenosine, cyclic guanosine monophosphate, and nitric oxide metabolites were assayed. RESULTS: Before heart excision, serum cardiac troponin I concentrations were higher in the L-arginine than in the control group (0.037 +/- 0.01 versus 0.02 +/- 0.05 microg x L(-1); p < 0.05). During reperfusion, cardiac troponin I release was lower in the L-arginine than in the control group (0.04 +/- 0.01 versus 0.19 +/- 0.03 ng x min(-1); p < 0.05). The coronary flow as well as the left ventricular developed pressure were higher in the L-arginine than in the control group before ischemia and remained so throughout the experimentation. CONCLUSIONS: These results indicate that L-arginine administered intraperitoneally 24 hours before cardioplegic arrest reduced myocardial cell injury and seems to protect myocardium against ischemia-reperfusion injury.
Animals↗
Quantitative structure-property relationship studies on direct photolysis of selected polycyclic aromatic hydrocarbons in atmospheric aerosol.
Based on some fundamental quantum chemical descriptors computed by PM3 Hamiltonian, by the use of partial least-squares analysis, a quantitative structure property relationship model for direct photolysis half-lives of 11 polycyclic aromatic hydrocarbons (PAHs) in atmospheric aerosol under UV irradiation was developed. PAHs with great molecular weight (bulkness) tend to photolyze fast, and PAHs with small absolute electronegativity values and large absolute hardness values, tend to photolyze fast.
Atmosphere↗
Quantitative structure-property relationship studies on n-octanol/water partitioning coefficients of PCDD/Fs.
Based on some fundamental quantum chemical descriptors computed by PM3 Hamiltonian, by the use of partial least-squares (PLS) analysis, a significant quantitative structure-property relationship (QSPR) model for logKow of polychlorinated dibenzo-p-dioxins and dibenzo-p-furans (PCDD/Fs) was obtained. The QSPR can be used for prediction. The intermolecular dispersive interactions and thus the bulkness of the PCDD/Fs are the main factors affecting the logKow. The more chlorines in the PCDD/F molecule, the greater the logKow values.
Benzofurans↗
Refractive lensectomy in extreme myopia.
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Acrylic Resins↗
Evaluation of diagnostic criteria for atopic dermatitis: validity of the criteria of Williams et al. in a hospital-based setting.
BACKGROUND: Surveys of the prevalence of atopic dermatitis (AD) have been carried out world-wide, but the results vary widely. The differences probably result from the use of different diagnostic criteria. Williams et al. proposed minimum, simplified, diagnostic criteria that require no invasive test and are easy to use. Pilot studies in European countries showed their suitability for implementation both in hospitals and in the community, and their high sensitivity and specificity. OBJECTIVES: To evaluate the potential practical value of the criteria of Williams et al. in the Chinese population. METHODS: The criteria of Hanifin and Rajka (gold standard), Williams et al. and Kang and Tian were applied and compared in 111 patients with AD and 121 control subjects with other skin diseases in three out-patient centres in China. RESULTS: The criteria of Williams et al. showed a similar diagnostic efficiency to that of the gold standard, with the sensitivity, specificity and kappa value reaching 95.50%, 97.52% and 0.93, respectively. No significant difference was found between the criteria of Williams et al. and those of Kang and Tian (chi2 = 0.69, P > 0.05). 'Onset under the age of 2 years', a criterion of Williams et al. could be used in subjects of any age. CONCLUSIONS: The diagnostic efficiency of the criteria of Williams et al. was basically similar to those of Hanifin and Rajka and of Kang and Tian in our out-patient settings. However, those of Williams et al. were easier to apply and required no invasive tests.
Adolescent↗
Lack of effect of gender on retinopathy in the mouse.
BACKGROUND: The reported effect of gender on retinopathy of prematurity has been controversial. The goal of this study was to determine the effect of gender on oxygen-induced retinopathy in a mouse model. METHODS: Oxygen-induced retinopathy was produced in C57BL6 mice by exposure to 75% oxygen from postnatal day (P) 7 for 5 days. Animals were returned to room air on P12 and killed on P17-21. Gender was determined by inspection. Retinopathy was evaluated by a retinopathy scoring system and by quantifcation of extraretinal neovascular nuclei on retinal sections. RESULTS: Both males and females developed similar degrees of retinopathy. Males had a median total retinopathy score of 9 (25th, 75th quartile: 8, 11) and females had score of 9 (25th, 75th quartile: 7, 10). Retinal subscores of blood vessel growth, blood vessel tufts, extraretinal neovascularzation, haemorrhage and blood vessel tortuosity were similar in both groups. Males and females had a similar number of neovascular nuclei on retinal sections. CONCLUSIONS: Gender does not alter the development of oxygen-induced retinopathy in the C57BL6 mouse.
Animals↗
Transparent morphology of the thoracoabdominal wall.
The transverse rectus abdominis myocutaneous (TRAM) flap has become the gold standard for autologous breast reconstruction in the last decade. The deep inferior epigastric perforator (DIEP) flap is a refinement of the conventional myocutaneous flap, which is based on anatomic studies of the abdominal wall. These authors have performed a transparent morphologic study of the abdominothoracic wall, in order to visualize the vessel architecture and relationships. The methodology of specimen processing, the anatomic findings, and modifications of surgical incisions are illustrated and discussed.
Abdominal Muscles↗
Functional screening yields a new beta-1,4-endoglucanase gene from Heterodera glycines that may be the product of recent gene duplication.
Clones with secreted cellulolytic activity were identified when a cDNA library constructed from poly A(+) RNA of preparasitic second-stage juveniles of Heterodera glycines, the soybean cyst nematode, was expressed in the Escherichia coli SOLR strain and overlaid with a carboxymethylcellulose (CMC) substrate. Twenty CMC-degrading clones were analyzed, and all were either identical or strongly similar to a beta-1,4-endoglucanase gene (HG-eng-2), previously isolated from H. glycines. A subgroup of identical "HG-eng-2-like" clones had considerable differences in the 5' untranslated region compared with HG-eng-2 and were designated HG-eng-3. One H. glycines genomic clone contained HG-eng-2 and HG-eng-3 full-length genes, separated by a distance of approximately 8 kb, and a second genomic clone contained two copies of HG-eng-2, separated by approximately 6.5 kb, suggesting the presence of endoglucanase gene clusters in H. glycines. The HG-eng-2 and HG-eng-3 genes were in opposite transcriptional orientation, with considerable nucleotide differences in their 5' flanking regions. The highly conserved nucleotide sequence in the introns and exons and their close proximity within the genome suggest that HG-eng-2 and HG-eng-3 are the products of recent gene duplication and inversion.
Amino Acid Sequence↗
Na+-K+-Cl- cotransporter in rat focal cerebral ischemia.
In cultured neurons, the authors previously demonstrated that the Na+-K+-Cl- cotransporter is significantly stimulated by elevated extracellular potassium and glutamate, which are important factors in cerebral ischemic damage. These findings led the authors to hypothesize that stimulation of the cotransporter after ischemia might result in Na+, K+, and Cl- influx, and might contribute to neuron damage. In the current study, the authors investigated such a role of the Na+-K+-Cl- cotransporter in focal cerebral ischemia. Cerebral ischemia was induced by 2-hour occlusion of the left middle cerebral artery (MCA) and 24-hour reperfusion in male spontaneously hypertensive rats (SHRs). Immunocytochemical staining and immunoblotting revealed an up-regulation of expression of the cotransporter protein in neurons in cortex at 24 hours of reperfusion. Artificial cerebral spinal fluid (aCSF) or 100 micromol/L bumetanide (a cotransporter inhibitor) in aCSF were continuously microdialyzed through a microdialysis probe into left cortices throughout 2-hour MCA occlusion and 24-hour reperfusion. Compared with the aCSF-treated group, infarction volume was significantly reduced in the bumetanide-treated group (25%, P < 0.05). In addition, brain water content in the bumetanide-treated brains was decreased by 70% (P < 0.05). These results strongly suggest that the Na+-K+-Cl- cotransporter may play an important role in cerebral ischemic neuronal damage.
Animals↗
Impact of transrectal ultrasound guided prostate biopsy on quality of life: a prospective randomized trial comparing 6 versus 12 cores.
PURPOSE: Recent studies advocating an increase in the number of cores of sextant transrectal ultrasound guided biopsy of the prostate to improve the cancer detection rate often have not addressed the impact on quality of life. We performed a prospective randomized trial comparing 6 to 12 prostate biopsy cores to determine the impact on the cancer detection rate, pain and morbidity, and quality of life. We report the impact on health related and screening specific quality of life in men undergoing 6 versus 12 core transrectal ultrasound guided prostate biopsy. MATERIALS AND METHODS: We prospectively randomized 244 men with a mean age plus or minus standard deviation of 65 +/- 8 years, serum total prostate specific antigen between 2.5 and 20.0 ng./ml., and/or digital rectal examination findings suspicious of cancer to undergo 6 or 12 core peripheral zone tissue biopsy. Of the men 71 (29%) were black. All patients completed a self-administered questionnaire before, and 2 questionnaires 2 and 4 weeks after the procedure. Health related quality of life was measured using 2 subscales (emotional well-being and role limitation due to physical health) of the short form 36-Item Health Survey. Screening specific quality of life was addressed by questions on the functional consequences of the procedure (return to daily activity, work-employment and sports-exercise). Health related and screening specific quality of life responses were compared in the groups. RESULTS: After controlling for cancer diagnosis, patient age, race, education, report of pain and baseline emotional well-being there was no significant difference in the mean change in emotional well-being scores at 2 and 4 weeks in the 6 and 12 core groups (p = 0.7 and 0.3, respectively). Similarly after controlling for these factors and baseline role limitation due to physical health there was no significant difference in the mean change in role limitation due to physical health scores at 2 and 4 weeks in the 2 groups (p = 0.3 and 0.5, respectively). There was no difference in the percent of men returning to routine daily activity (p = 0.6), work-employment (p = 0.5) or sports-exercise (p = 0.3) at 0 to 1, 2 to 3 and 4 to 7 days or longer than 1 week after the procedure in the groups. CONCLUSIONS: Doubling the sextant biopsy does not affect the quality of life in regard to emotional well-being, role limitation due to physical health, or return to routine daily activity, work-employment or sports-exercise.
Aged↗
[Effect of a complex tea on reducing blood lipid in rabbits].
In order to observe the effect of a complex tea composed of tea, ginkgo leaf, red koji and fructus lycii on reducing blood lipids in experimental rabbits, 40 rabbits weighted from 1.5 to 2.0 kg were divided randomly into 5 group: (I) normal control group, (II) hyperlipidemia model(positive control), (III) green tea control group, (IV) low dose complex tea group, and (V) high dose complex tea group. Blood triglyceride(TG), cholesterol(TC), lower density lipoprotein(LDL) and high density lipoprotein(HDL) were measured before experiment and 6.12 weeks later. Then the pathological changes of heart, aorta and liver were observed. After 12 weeks of experiment, the results showed that, (1) hyperlipidemia characterized by high TC has been induced by high-fat feeds in group II, (2) the complex tea can reduce body weight and eliminate the lipids deposition in aorta and liver. (3) the complex tea can decrease serum TG, TC,LDL and increase serum HDL in the high complex tea group. The results indicate that the complex tea is more effective than green tea on reducing blood lipids in experimental rabbits.
Animals↗
[Repair of medial collateral ligament defect of knee joint with transposition of great adductor muscular tendon pedicled vessels].
OBJECTIVE: To study the effect of transposition of great adductor muscular tendon pedicled vessels in repairing the medial collateral ligament defect of knee joint. METHODS: From September 1991 to September 1999, on the basis study of applied anatomy, 30 patients with the medial collateral ligament defect were repaired with great adductor muscular tendon transposition pedicled vessels. Among them, there were 28 males and 2 females, aged 26 years in average. RESULTS: Followed up for 17 to 60 months, 93.3% patients reached excellent or good grades. No case fell into the poor grade. CONCLUSION: Because the great adductor muscular tendon is adjacent to the knee joint and similar to the knee ligament, it is appropriate to repair knee ligament. Transposition of the great adductor muscular tendon pedicled vessels is effective in the reconstruction of the medial collateral ligament defect of knee joint.
Adolescent↗
[Identification of seeds of Cuscuta australis and C. chinensis by TLC and HPLC].
Identification of seeds of Cuscuta australis R. Br. and C. chinensis Lam. was carried out by TLC and HPLC. Polyamide membrane was used as stationary phase, MeOH-HOAc-H2O and CHCl3-MeOH-HOAc were used as mobile phase for TLC. For HPLC, Hypersil-ODS column was used; the mobile phase was MeOH-0.025 M H3PO4; the flow rate was 1.0 ml.min-1; detection wavelength was 360 nm; and column temperature was 40 degrees C. Both methods represented significant identification characteristics, and were simple, accurate and reproducible.
Chromatography, High Pressure Liquid↗
Captopril improves retinal neovascularization via endothelin-1.
PURPOSE: The purpose of this study was to determine the effect of an angiotensin converting enzyme inhibitor, captopril, on oxygen-induced retinopathy (OIR) in the mouse. Endothelin-1 (ET-1) expression is assessed in a mouse model of OIR. METHODS: OIR was produced in C57BL6 mice. Captopril (0.5mg/kg/d SC) was given from P7 (post natal day 7) for 5 days. Retinopathy was assessed by a retinal scoring system and by quantification of extra retinal neovascular nuclei on retinal sections at P17 to P20. The expression of ET-1 was determined using a reverse transcriptase polymerase chain reaction. RESULTS: Pups treated with captopril during hyperoxia had a lower median retinopathy score of 4.5 (25th, 75th quartile: 3, 6.4) compared with animals exposed to hyperoxia alone with median score 9.5 (25th, 75th quartile: 7.1, 10.4; P < 0.001). The pups treated with captopril during hyperoxia had significant reduction in number of nuclei extending beyond the inner limiting membrane (15.8 +/- 16.7, mean +/- SD) when compared with the animals exposed to hyperoxia only (50.4 +/- 28.0; P < 0.01). ET-1 expression in the retina increased 4.1-fold from P7 to P12 and a 1.9-fold increase from P12 to P17. Overall, there was an 8-fold increase in ET-1 expression from P7 to P17. Hyperoxia increased ET-1 expression by 2.1-fold at P12 over room air-reared animals. At P17, there was a 2.9-fold increase in retinal ET-1 expression when compared with room air. At P17, there was a 6.2-fold suppression in ET-1 expression in captopril-treated animals when compared with the oxygen only-treated animals. CONCLUSIONS: Captopril reduces retinal neovascularization in a mouse model of oxygen-induced retinopathy. ET-1 expression is increased from P7 to P17, altered by hyperoxic exposure and relative hypoxic recovery and modulated by captopril in a mouse model of OIR.
Angiotensin-Converting Enzyme Inhibitors↗
[Evaluation of historical exposure to silica dust for the workers employed in geologic exploration industry].
OBJECTIVE: To evaluate their level of exposure to silica dust in the workers employed in geologic exploration industry using a quantitative method. METHODS: Monitoring data of exposure to silica dust since 1950s were collected for the workers in various jobs from the factories and mines of the bureaux of geological exploration in the nine provinces, with 30,000 pieces of figures in total. Job title and history of employment were determined for 1,627 employees. Levels of exposure to silica dust in various factories and mines were estimated based on the data mentioned-above, including amount of respirable dust, total dust in the lungs, and proportion of free silica dust to the total silica dust. RESULTS: Concentration of total silica dust was 14 mg/m3 in average in the factories and mines, with a range of 29 mg/m3 during the earlier years to 3 mg/m3 in recent years, and that of respirable silica dust was 3 mg/m3, in average, with (28.0 +/- 8.2)% of free silica dust. Different indices of exposure to silica dust were calculated for individuals, based on their history of employment and level of exposure. CONCLUSION: Assessment of exposure to silica dust during the past years, based on the monitoring data, could provide basis for evaluation of dose-response relationship.
Air Pollutants, Occupational↗
The effect of herbs on cerebral energy metabolism in cerebral ischemia-reperfusion mice.
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Animals↗
[Study of mechano-sensitive K+ channel in cerebral microvascular endothelial cells from rats].
This study was conducted to gain an understanding of the electrophysiologic characteristics of cerebral microvascular endothelial cells. The stress response of the potassium ion channel in cerebral microvascular endothelial cells was explored. We developed a model of the opening shear stress effect device and used it for calculation of shear stress. The cultured cerebral microvascular endothelial cells from rats were seeded on glass slide of 1 cm x 1 cm. K+ ion channel current was recorded by Patch-Clamp amplifier of Axonpatch 200A type and whole cell Patch-Clamp technique. The inward rectifier potassium current of cerebral microvessel endothelial cells has been elicited by flow stimulus of 1.1 dynes/cm2 shear stress, and there is good relationship between the current and voltage changing. The various stress responses of the cerebral vascular endothelial cells are related to the stress sensitive potassium ion channels of cellular membrane.
Animals↗