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2.
Article in Chinese | MEDLINE | ID: mdl-29996217

ABSTRACT

Objective: The present study was represented by di-(2-ethylhexyl) phthalate (DEHP), to explore the role of thyroid hormones (THs) disruption in the connection of placenta and neurodevelopmental toxicity. Methods: During fetal mice neural tube closed (pregnancy 9.5 days, E9.5d) to begin synthesis of THs (E15.5 d), all pregnant mice were administered with different concentration of DEHP (0、10、50、200 mg/kg) by gavage once a day(10 mice per group). All pregnant mice were conducted with BrdU administration in E14d by subcutaneous injection. Seven pregnant mice from each group were scarified after anesthesia in E15.5 d, serum and amniotic fluid were collected to determinate the levels of THs(T(3), T(4), FT(3) and FT(4)) by the automatic biochemical analyzer, detecting fetal mice placental protein expression of monocarboxylate transporter 8 (MCT8), organic anion transporting polypeptide 1C1 (OATP1C1) and deiodinaseⅡ&Ⅲ (DIO(2), DIO(3)) by Western blot. Each group of the remaining three pregnant mices were killed after anesthesia in E18d, take the male fetal brain, BrdU immunohistochemistry was used to detect the proliferation and migration of fetal brain cortical neurons. Results: There was no abnormalities in diet, water intake, body weight and general activity of pregnant mice in each treatment group, and there were no difference in the general physiolo. Results There was no abnormalities in diet, water intake, body weight and general activity of pregnant mice in each treatment group, and there were no difference in the general physiological development status of body weight, brain weight, brain body ratio between the mice of each group. There was no statistically significant differences in serum T(3), T(4), FT(3), FT(4) and amniotic fluid FT(4) in pregnant mice of each group (P>0.05), Compared with the control group, the FT(3) levels in the amniotic fluid of the DEHP 50 and 200 mg/kg groups were significantly decreased(P<0.05). Compared with the control group, the placental MCT8 and DIO(2) protein levels of male fetal mice in the DEHP 50 and 200 mg/kg group decreased, and the level of OATP1C1 protein in 200 mg/kg group decreased(P<0.05), and there was no statistically significant difference in DIO(3) protein levels among all groups (P>0.05). Compared with the control group, the number of BrdU positive cells in the cerebral cortex of male mice in DEHP 200 mg/kg group decreased, 56.5% was distributed in VZ-SVZ layer, and the percentage of BrdU positive cells in the IZ layer of 50 mg/kg group increased (P<0.05). Conclusion: DEHP 50, 200 mg/kg may affect the proliferation and migration of neural cells in the developing brain, which may be related to its interference with thyroid hormone by placental transport.


Subject(s)
Diethylhexyl Phthalate/pharmacology , Neurodevelopmental Disorders/chemically induced , Placenta/drug effects , Placental Hormones , Thyroid Gland/drug effects , Animals , Female , Male , Mice , Pregnancy , Thyroid Hormones
3.
Article in Chinese | MEDLINE | ID: mdl-28614919

ABSTRACT

Objective: To investigate the effects of developmental exposure to DEHP on learning and memory of mice. Methods: Male littermates of ICR mice randomly assigned to five experimental groups (n=14 for each condition) on PND4 to receive distilled water, vehicle and 10, 50 and 200 mg/ (kg·d) DEHP from PND5 to PND38 by gavage, weighing and recording body weight of mice. Open field task were conducted on PND 26 and Morris water maze task were begun from PND30 to PND 37 to evaluate spontaneous exploration activity and emotion, spatial learning and memory performance of pubertal mice, respectively. On PND39, all animals were killed and hippocampi were isolated on ice, then total proteins of hippocampus were extracted, followed by determining the expression of PSD95 and synapsin I by western blotting. Results: 200 mg/ (kg·d) DEHP significantly reduced the growth of body weight of mice and the time staying in the central area in open field, prolonged the time searching the hidden platform in Morris water maze (P<0.05) . 50 mg/ (kg·d) DEHP didn't change the growth of body weight and the emotion (P>0.05) , but reduced the percent of time and distance in the target quadrant during the probe trial of mice in Morris water maze (P<0.05) . The results of western blotting showed that DEHP significantly reduced the expression of PSD95 in hippocampus of mice with all dose groups (P<0.01) , but only 200 mg/ (kg·d) DEHP reduced the expression of synapsin I (P<0.05) . Conclusion: Developmental exposure to DEHP can damage the development of synapse in hippocampus, adversely impacting spatial memory performance of mice at a dose that are insufficient to significantly influence the general development and result in anxiety.


Subject(s)
Diethylhexyl Phthalate/toxicity , Fetal Development/drug effects , Maze Learning/drug effects , Memory/drug effects , Animals , Anxiety , Diethylhexyl Phthalate/administration & dosage , Hippocampus , Male , Mice , Mice, Inbred ICR
4.
Article in Chinese | MEDLINE | ID: mdl-27682481

ABSTRACT

Objective: To explore the effect of BDNF pathway on lambda-cyhalothrin interfering estrogen promoting the expression of PSD95 in hippocampus neurons. Methods: HT22 cell line were used to, treating with lambda-cyhalothrin (LCT, 50 µmol/L) , 17ß-Estradiol (E2, 10 nmol/L) , LCT (50 µmol/L) +TrkB FC (20 µg/ml) , E2 (10 nmol/L) +TrkB FC (20 µg/ml) , LCT (50 µmol/L) +ICI182 780 (1 µmol/L) , E2 (10 nmol/L) + ICI182 780 (1 µmol/L) , LCT (50 µmol/L) +E2 (10 nmol/L) for 24 h. MTT kit was used to detect cell viability. Post-synaptic Density 95 protein expression was measured by western blot. ELISA assay was used to detect the level of brain derived neurotrophic factor (BDNF) of culture supernatant and cell. Results: Campared to Sham, LCT or E2 could promote the expression of PSD95 LCT+ICI could reduce the expresion of BDNF (P<0.05) , campared to LCT, LCT+TrkB FC could reduce the expression of PSD95 and LCT+ICI cound reduce the expresion of BDNF (P<0.05) , campared to E2, E2+TrkB FC could reduce the expression of PSD95 and E2+ICI could reduce the expression of BDNF (P<0.05) , campared to E2, LCT+ E2 could reduce the expression of PSD95 and BDNF (P<0.05) . Conclusion: BDNF pathway plays a key role in E2 promoting the expression of PSD95 in neural cells. Although LCT alone has a similar effect on E2. LCT could disrupt the promotion of E2 on PSD95 expression via BDNF pathway.


Subject(s)
Brain-Derived Neurotrophic Factor/metabolism , Estradiol/pharmacology , Hippocampus/drug effects , Nitriles/toxicity , Pyrethrins/toxicity , Cell Line , Estrogens , Neurons , Post-Synaptic Density/metabolism
5.
Nat Mater ; 14(10): 1013-9, 2015 Oct.
Article in English | MEDLINE | ID: mdl-26322718

ABSTRACT

Acoustic metamaterials offer great flexibility for manipulating sound waves and promise unprecedented functionality, ranging from transformation acoustics, super-resolution imaging to acoustic cloaking. However, the design of acoustic metamaterials with exciting functionality remains challenging with traditional approaches using classic acoustic elements such as Helmholtz resonators and membranes. Here we demonstrate an ultraslow-fluid-like particle with intense artificial Mie resonances for low-frequency airborne sound. Eigenstate analysis and effective parameter retrieval show two individual negative bands in the single-size unit cell, one of which exhibits a negative bulk modulus supported by the monopolar Mie resonance, whereas the other exhibits a negative mass density induced by the dipolar Mie resonance. The unique single-negative nature is used to develop an ultra-sparse subwavelength metasurface with high reflectance for low-frequency sound. We demonstrate a 0.15λ-thick, 15%-filling ratio metasurface with an insertion loss over 93.4%. The designed Mie resonators provide diverse routes to construct novel acoustic devices with versatile applications.

6.
Genet Mol Res ; 13(1): 2032-8, 2014 Mar 24.
Article in English | MEDLINE | ID: mdl-24737428

ABSTRACT

Intervertebral disk disease is a common clinical disorder manifested by pain, ataxia, paresis, motor paralysis, and sensorimotor paralysis. The clinical features, diagnosis, and treatment of cervical and thoracolumbar disk disease have been unclear until now. In this study, some differentially expressed genes were identified, and a network was constructed based on these genes. Through the statistical analysis of nodes and the contrast of 2 more connectivity nodes, it was found that the nodes in the network are in an important position and play key roles. Several of these genes, including MAP2K6, MAP2K3, and MAPK14, belong to the MAP kinase family, and several genes, including RHOBTB2, RHOQ, and RHOH, belong to the RHO family. Therefore, we hypothesize that the development of intervertebral disk disease is related to MAP and RHO family proteins.


Subject(s)
Gene Expression Profiling , Intervertebral Disc Degeneration/genetics , Intervertebral Disc Displacement/genetics , Intervertebral Disc/metabolism , Computational Biology/methods , Databases, Nucleic Acid , Gene Expression Regulation , Gene Regulatory Networks , Humans , Molecular Sequence Annotation
7.
Eur Rev Med Pharmacol Sci ; 17(14): 1951-7, 2013 Jul.
Article in English | MEDLINE | ID: mdl-23877861

ABSTRACT

BACKGROUND: Iliac bone graft harvesting is a common procedure in spinal surgery and trauma center for spinal fusion and nonunion of the extremities. AIM, PATIENTS AND METHODS: To compare the pain and cosmetic outcomes of patients undergoing iliac crest anatomical reconstruction using equivalent iliac crest allograft (R group) with those of patients without reconstruction of the iliac crest defect (NR group), a prospective nonrandomized controlled study was conducted. RESULTS: In R group, the intensity and prevalence of pain were significantly lower than those in NR group. Cosmetic outcome and satisfaction score were also significantly improved in R group. One patient of R group suffered from lipolysis and superficial infection which healed by regular dressing change for two weeks. There were no cases of allograft displacement, implant loosening, internal fixation breakage or immunological rejection. Seven patients in NR group had significant pain related to the tenting of skin over the defect. Radiologic incorporation of pelvis was documented in all patients except four having partial re-sorption of the allograft. Early fibrous healing and the late creeping substitution were noted in all patients of R group. CONCLUSIONS: Equivalent iliac crest allograft provides an effective alternative for iliac crest anatomical reconstruction, leading to reduced donor site pain and better cosmesis.


Subject(s)
Ilium/anatomy & histology , Ilium/transplantation , Transplant Donor Site/anatomy & histology , Adolescent , Adult , Bone Transplantation/adverse effects , Disability Evaluation , Female , Humans , Ilium/diagnostic imaging , Male , Middle Aged , Pain Measurement , Pain, Postoperative/epidemiology , Prospective Studies , Radiography , Spinal Fusion , Transplant Donor Site/diagnostic imaging , Treatment Outcome
8.
Phys Rev E Stat Nonlin Soft Matter Phys ; 84(4 Pt 2): 046406, 2011 Oct.
Article in English | MEDLINE | ID: mdl-22181282

ABSTRACT

Including the ion-gyroradius effect, a general low-frequency kinetic dispersion equation is presented, which simultaneously takes account of a field-aligned current and temperature anisotropy in plasmas. Based on this dispersion equation, kinetic Alfvén wave (KAW) instability driven by the field-aligned current, which is carried by the field-aligned drift of electrons relative to ions at a drift velocity V(D), is investigated in a high-ß plasma, where ß is the kinetic-to-magnetic pressure ratio in the plasma. The numerical results show that the KAW instability driven by the field-aligned current has a nonzero growth rate in the parallel wave-number range 0

9.
J Acoust Soc Am ; 130(5): 2738-45, 2011 Nov.
Article in English | MEDLINE | ID: mdl-22087902

ABSTRACT

This study investigates the propagation of Lamb waves in phononic-crystal plates in the form of a sandwich-layered structure. The composite plates are composed of periodic layers bilaterally deposited on both sides of the homogeneous core layer. Using the analyses of the band structures and the transmission spectra, it is revealed that the core layer may induce significant modulations to the lower-order Lamb modes. The modulations are ascribed to the reshaped particle displacement fields of the eigenmodes. Prominently, the core layer made of soft material (rubber) combines the identical eigenmodes of the periodic layers into a pair of asymmetric and symmetric modes in which case the periodic layers vibrate independently. However, the core layer made of hard material (tungsten) or medium hardness material (silicon) couples the periodic layers tightly, in which case the composites vibrate as a whole. In addition, it is found that the phononic band gaps are very sensitive to the thickness of the core layer; this could be indispensable to practical applications such as bandgap tuning.


Subject(s)
Acoustics/instrumentation , Sound , Crystallization , Elasticity , Equipment Design , Models, Theoretical , Motion , Signal Processing, Computer-Assisted , Time Factors , Vibration
10.
J Acoust Soc Am ; 129(3): 1157-60, 2011 Mar.
Article in English | MEDLINE | ID: mdl-21428478

ABSTRACT

This study investigates the temperature-tuned band gaps of Lamb waves in a one-dimensional phononic-crystal plate, which is formed by alternating strips of ferroelectric ceramic Ba(0.7)Sr(0.3)TiO(3) and epoxy. The sensitive and continuous temperature-tunability of Lamb wave band gaps is demonstrated using the analyses of the band structures and the transmission spectra. The width and position of Lamb wave band gaps shift prominently with variation of temperature in the range of 26 °C-50 °C. For example, the width of the second band gap increases from 0.066 to 0.111 MHz as the temperature is increased from 26 °C to 50 °C. The strong shift promises that the structure could be suitable for temperature-tuned multi-frequency Lamb wave filters.


Subject(s)
Acoustics/instrumentation , Barium Compounds , Ceramics , Epoxy Compounds , Sound , Strontium , Temperature , Titanium , Crystallization , Elastic Modulus , Equipment Design , Finite Element Analysis , Models, Theoretical , Motion , Time Factors
11.
Eur J Clin Nutr ; 64(9): 1007-13, 2010 Sep.
Article in English | MEDLINE | ID: mdl-20571496

ABSTRACT

BACKGROUND/OBJECTIVES: The purpose of this study was to investigate whether vitamin B(6) supplementation had a beneficial effect on inflammatory and immune responses in patients with rheumatoid arthritis (RA). SUBJECTS/METHODS: This was a single-blind co-intervention study performed at the Division of Allergy, Immunology and Rheumatology of Chung Shan Medical University Hospital, Taiwan. Patients were diagnosed with RA according to the 1991 American College of Rheumatology criteria for RA. Patients were randomly allocated into two groups: control (5 mg/day folic acid only; n=15) or vitamin B(6) (5 mg/day folic acid plus 100 mg/day vitamin B(6); n=20) for 12 weeks. Plasma pyridoxal 5'-phosphate (PLP), serum folate, inflammatory parameters (that is, high-sensitivity C-reactive protein (hs-CRP), erythrocyte sedimentation rate (ESR), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-alpha)) and immune parameters (that is, white blood cell, total lymphocyte, T-cell (CD3), B-cell (CD19), T-helper cell (CD4), T-suppressor (CD8)) were measured on day 1 (week 0) and after 12 weeks (week 12) of the intervention. RESULTS: In the group receiving vitamin B(6), plasma IL-6 and TNF-alpha levels significantly decreased at week 12. There were no significant changes with respect to immune responses in both groups except for the percentage of total lymphocytes in the vitamin B(6) group when compared with week 0 and week 12. Plasma IL-6 level remained significantly inversely related to plasma PLP after adjusting for confounders (beta=-0.01, P=0.01). CONCLUSIONS: A large dose of vitamin B(6) supplementation (100 mg/day) suppressed pro-inflammatory cytokines (that is, IL-6 and TNF-alpha) in patients with RA.


Subject(s)
Arthritis, Rheumatoid/drug therapy , Arthritis, Rheumatoid/immunology , Cytokines/blood , Vitamin B 6/administration & dosage , Vitamin B Complex/administration & dosage , Arthritis, Rheumatoid/blood , B-Lymphocytes/immunology , B-Lymphocytes/metabolism , Biomarkers/blood , C-Reactive Protein/metabolism , Cytokines/immunology , Dietary Supplements , Dose-Response Relationship, Immunologic , Female , Humans , Interleukin-6/blood , Male , Middle Aged , Pyridoxal Phosphate/blood , Single-Blind Method , T-Lymphocytes/immunology , T-Lymphocytes/metabolism , Tumor Necrosis Factor-alpha/blood , Vitamin B 6/blood , Vitamin B Complex/blood
12.
Methods Find Exp Clin Pharmacol ; 32(9): 631-44, 2010 Nov.
Article in English | MEDLINE | ID: mdl-21225014

ABSTRACT

The aim of this study was to compare the protective effects of three traditional Chinese herbal medicines (ligustrazine, kakonein and Panax notoginsenosides) on multiple organs in a rat model of severe acute pancreatitis (SAP) and to explore the underlying mechanisms. The mortality rates in all three treated groups were significantly lower than the control group (P < 0.05). All three herbal medicines significantly alleviated the pathological changes in the pancreas, liver and kidney in SAP rats, induced pancreatic acinar cell apoptosis and effectively prevented the apoptosis of cells in the liver and kidney; however, no obvious lung protection was observed. Panax notoginsenosides showed better pancreatic protection than ligustrazine and kakonein, while kakonein displayed a better role in improving liver and kidney function. The protective effects of ligustrazine were somewhat more comprehensive.


Subject(s)
Isoflavones/pharmacology , Pancreatitis/drug therapy , Pyrazines/pharmacology , Saponins/pharmacology , Acute Disease , Animals , Apoptosis/drug effects , Disease Models, Animal , Drugs, Chinese Herbal , Ginsenosides/pharmacology , Kidney/drug effects , Kidney/pathology , Liver/drug effects , Liver/pathology , Male , Panax/chemistry , Pancreas/drug effects , Pancreas/pathology , Pancreatitis/complications , Rats , Rats, Sprague-Dawley , Severity of Illness Index
13.
J Med Genet ; 46(2): 86-93, 2009 Feb.
Article in English | MEDLINE | ID: mdl-18835857

ABSTRACT

BACKGROUND: Chromosome 15q11-13 contains a cluster of imprinted genes essential for normal mammalian neurodevelopment. Deficiencies in paternal or maternal 15q11-13 alleles result in Prader-Willi or Angelman syndromes, respectively, and maternal duplications lead to a distinct condition that often includes autism. Overexpression of maternally expressed imprinted genes is predicted to cause 15q11-13-associated autism, but a link between gene dosage and expression has not been experimentally determined in brain. METHODS: Postmortem brain tissue was obtained from a male with 15q11-13 hexasomy and a female with 15q11-13 tetrasomy. Quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) was used to measure 10 15q11-13 transcripts in maternal 15q11-13 duplication, Prader-Willi syndrome, and control brain samples. Southern blot, bisulfite sequencing and fluorescence in situ hybridisation were used to investigate epigenetic mechanisms of gene regulation. RESULTS: Gene expression and DNA methylation correlated with parental gene dosage in the male 15q11-13 duplication sample with severe cognitive impairment and seizures. Strikingly, the female with autism and milder Prader-Willi-like characteristics demonstrated unexpected deficiencies in the paternally expressed transcripts SNRPN, NDN, HBII85, and HBII52 and unchanged levels of maternally expressed UBE3A compared to controls. Paternal expression abnormalities in the female duplication sample were consistent with elevated DNA methylation of the 15q11-13 imprinting control region (ICR). Expression of non-imprinted 15q11-13 GABA receptor subunit genes was significantly reduced specifically in the female 15q11-13 duplication brain without detectable GABRB3 methylation differences. CONCLUSION: Our findings suggest that genetic copy number changes combined with additional genetic or environmental influences on epigenetic mechanisms impact outcome and clinical heterogeneity of 15q11-13 duplication syndromes.


Subject(s)
Aneuploidy , Brain/metabolism , Chromosomes, Human, Pair 15/genetics , Epigenesis, Genetic , Gene Dosage/genetics , Adolescent , Adult , Angelman Syndrome/genetics , Angelman Syndrome/metabolism , DNA Methylation , Female , Gene Duplication , Gene Expression , Humans , Male , Prader-Willi Syndrome/genetics , Prader-Willi Syndrome/metabolism , Syndrome
14.
Nanoscale Res Lett ; 4(10): 1153-1158, 2009 Jun 17.
Article in English | MEDLINE | ID: mdl-20596374

ABSTRACT

The intrinsically core/shell structured La(0.6)Sr(0.4)MnO(3) nanoparticles with amorphous shells and ferromagnetic cores have been prepared. The magnetic, dielectric and microwave absorption properties are investigated in the frequency range from 1 to 12 GHz. An optimal reflection loss of -41.1 dB is reached at 8.2 GHz with a matching thickness of 2.2 mm, the bandwidth with a reflection loss less than -10 dB is obtained in the 5.5-11.3 GHz range for absorber thicknesses of 1.5-2.5 mm. The excellent microwave absorption properties are a consequence of the better electromagnetic matching due to the existence of the protective amorphous shells, the ferromagnetic cores, as well as the particular core/shell microstructure. As a result, the La(0.6)Sr(0.4)MnO(3) nanoparticles with amorphous shells and ferromagnetic cores may become attractive candidates for the new types of electromagnetic wave absorption materials. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s11671-009-9374-y) contains supplementary material, which is available to authorized users.

15.
Calcif Tissue Int ; 83(5): 308-14, 2008 Nov.
Article in English | MEDLINE | ID: mdl-18843436

ABSTRACT

The aim of this study was to assess the efficacy and safety of strontium ranelate in the treatment of postmenopausal women with osteoporosis in Taiwan. In this 12-month multicenter, randomized, double-blind, placebo-controlled study, 125 women with osteoporosis were randomly given either strontium ranelate 2 g daily or placebo. Lumbar spine, femoral neck, and total-hip bone mineral density (BMD) and biochemical markers of bone turnover were measured; adverse events and tolerability were recorded and assessed. Subjects treated with strontium ranelate showed significant increases in BMD of 5.9% at the lumbar spine, 2.6% at the femoral neck, and 2.7% at the total hip, while the placebo group exhibited no significant change at 12 months. Serum level of a formation marker (bone-specific alkaline phosphatase) was also significantly increased at 6 and 12 months. Thus, although the sample size and the treatment duration of this study could not show its effect of reducing osteoprotic fractures, strontium ranelate showed bone protection effects by increasing BMD and concentrations of a bone formation marker. Safety assessment revealed adverse events were mild and not significantly different from placebo.


Subject(s)
Bone Density Conservation Agents/therapeutic use , Bone Density/drug effects , Calcium/therapeutic use , Organometallic Compounds/therapeutic use , Osteoporosis, Postmenopausal/drug therapy , Thiophenes/therapeutic use , Vitamin D/therapeutic use , Aged , Biomarkers/blood , Bone Density Conservation Agents/administration & dosage , Bone Density Conservation Agents/adverse effects , Calcium/administration & dosage , Double-Blind Method , Female , Humans , Middle Aged , Organometallic Compounds/administration & dosage , Organometallic Compounds/adverse effects , Taiwan , Thiophenes/administration & dosage , Thiophenes/adverse effects , Vitamin D/administration & dosage
16.
Pak J Biol Sci ; 11(20): 2423-7, 2008 Oct 15.
Article in English | MEDLINE | ID: mdl-19137853

ABSTRACT

To evaluate the genetic polymorphisms and to search for available molecular markers for Liangshan semi-wool sheep, 15 microsatellite markers of 187 samples were amplified by multiplex PCR. A total of 133 alleles were detected, with the number of alleles ranging from 6 (BM2830) to 15 (McM130), giving a mean No. of 8.87 alleles per locus. The total and mean effective allele No. were 64.29 and 4.29, respectively. The observed heterozygosity and expected heterozygosity were from 0.4486 (McM130) to 0.8877 (BMS1678) and 0.5704 (BMS0887) to 0.8373 (McM130), respectively. Mean observed heterozygosity and mean expected heterozygosity were 0.672 and 0.7536. Polymorphism information content values were from 0.5202 (BMS0887) to 0.8183 (McM130) and mean polymorphism information content of the 15 microsatellite loci was 0.7184. All 15 microsatellite loci were highly polymorphic, which showed that there were rich genetic polymorphisms at these detected microsatellite loci in Liangshan semi-wool sheep. Comparison of allele distributions among loci did not reveal consistent shapes. Distributions were centralized in some cases, whereas in others some kind of skewness was evident. Complex evolution at these loci is an important factor in the irregularity of microsatellite distributions.


Subject(s)
Microsatellite Repeats , Sheep/genetics , Alleles , Animals , Genetic Variation , Genetics, Population , Heterozygote , Homozygote , Sheep/classification , Species Specificity
17.
Phys Rev E Stat Nonlin Soft Matter Phys ; 67(2 Pt 2): 027402, 2003 Feb.
Article in English | MEDLINE | ID: mdl-12636869

ABSTRACT

The acceleration of energetic electrons has long been one of the most outstanding problems in astrophysics and space physics, and some recent observations from space satellites show that low-frequency electromagnetic fluctuations in the auroral ionosphere and magnetosphere can often be identified as the kinetic Alfvén modes. A model of nonlinear kinetic Alfvén waves is presented here, in which the effect of electron collisional dissipation has been taken into account. The result is a dissipative solitary kinetic Alfvén wave (DSKAW), which can produce a local shocklike structure with a net electric potential drop and which can thereby accelerate efficiently the electrons to the order of the local Alfvén velocity. Since Alfvénic fluctuation is the most common electromagnetic activity in extensive cosmic plasma environments, the present result suggests that the DSKAW could play an important role in the acceleration and energization of cosmic plasmas.

18.
J Hum Hypertens ; 16(11): 805-13, 2002 Nov.
Article in English | MEDLINE | ID: mdl-12444542

ABSTRACT

Suboptimal management of hypertension is often a result of poor patient compliance in the form of missed doses of their antihypertensive medication. This multicentre, randomised, double-blind, parallel-group trial was designed to compare the persistence of the antihypertensive efficacy of the amlodipine and nifedipine gastrointestinal therapeutic system (GITS) after two 'missed doses', and also to compare the drugs' overall efficacy and safety in Asian patients with mild-to-moderate essential hypertension. Following a 2-week placebo run-in period, 222 patients were randomised to receive either amlodipine (5 mg daily, increased after 6 weeks if necessary to 10 mg daily, n=109) or nifedipine GITS (30 mg daily, increased after 6 weeks if necessary to 60 mg daily; n=113) for 12 weeks. A placebo was then substituted for further 2 days with continuous ambulatory blood pressure (BP) monitoring. The increases in the last 9 h of mean ambulatory BP on day 2 after treatment withdrawal were significantly less with amlodipine than with nifedipine GITS: 4.4+/-7.0 vs 11.2+/-11.3 mmHg for systolic BP (P

Subject(s)
Amlodipine/therapeutic use , Antihypertensive Agents/therapeutic use , Hypertension/drug therapy , Nifedipine/therapeutic use , Asia, Southeastern , Blood Pressure Monitoring, Ambulatory , Dose-Response Relationship, Drug , Double-Blind Method , Drug Administration Schedule , Humans , Hypertension/physiopathology
19.
Environ Pollut ; 115(1): 81-7, 2001.
Article in English | MEDLINE | ID: mdl-11586775

ABSTRACT

The presence of butyltin compounds was investigated for the first time in selected lakes, rivers and coastal environments of China. Aqueous samples were pretreated by the technique of headspace solid phase micro-extraction after hydride generation with sodium tetrahydroborate (NaBH4). Quantitative measurement of tributyltin (TBT), dibutyltin (DBT) and monobutyltin (MBT) concentrations were accomplished by capillary gas chromatography with flame photometric detector using quartz surface-induced luminescence. Experimental data demonstrated the widespread occurrence of butyltin compounds in the Chinese aquatic environment. In some locations, the concentrations of TBT were higher than the acute and chronic toxicity threshold of sensitive fresh water or marine organisms. Although DBT and MBT (which mainly come from the degradation of TBT), are less toxic, their occurrence can still affect the ecosystem over a long time frame.


Subject(s)
Organotin Compounds/analysis , Trialkyltin Compounds/analysis , Water Pollutants, Chemical/analysis , China , Chromatography, Gas , Ecosystem , Environmental Monitoring , Photometry
20.
Jpn Circ J ; 65(7): 673-7, 2001 Jul.
Article in English | MEDLINE | ID: mdl-11446504

ABSTRACT

N-methyl-1-deoxynojirimycin (NMDN), an a-glucosidase inhibitor, reduces myocardial infarct size by reducing the glycogenolytic rate through inhibition of the alpha-1,6-glucosidase of glycogen-debranching enzyme in the heart, in addition to possessing an antihyperglycemic action by blocking alpha-1,4-glucosidase in the intestine. Ischemic preconditioning (PC), which markedly reduces the size of the myocardial infarct, is known to reduce the activity of phosphorylase and reduce the glycogenolytic rate. Therefore, it was hypothesized that a combination of pharmacological inhibition of glycogenolysis by an alpha-1,6-glucosidase inhibitor, NMDN, and PC could markedly reduce myocardial infarct size more than NMDN or PC alone. Japanese white rabbits without collateral circulation were subjected to a 30-min coronary occlusion followed by 48-h reperfusion. The infarct sizes as a percentage of area at risk were significantly reduced by pre-ischemic treatment with either 100mg/kg of NMDN or PC of 5 min ischemia and 5 min reperfusion alone (15.9+/-2.0%, n=8, and 10.3+/-1.2%, n=8, respectively) as compared with the control (43.9+/-2.2%, n=8). However, the combination of 100mg/kg of NMDN and PC significantly reduced the infarct size (4.9+/-1.2, n=8) compared with NMDN or PC alone. Another 40 rabbits, also given 100mg of NMDN, PC, NMDN+PC or saline before ischemia (n=10 in each group), were killed for biochemical analysis after 30 min of ischemia. NMDN and PC preserved the glycogen content and attenuated the lactate accumulation, respectively, as compared with the control. However, the combination of NMDN and PC preserved significantly more glycogen and significantly reduced lactate accumulation than either NMDN or PC alone. The combination of NMDN and PC markedly reduced the myocardial infarct size more than either process alone. The marked preservation of glycogen and marked attenuation of lactate accumulation by the combination of NMDN and PC suggest that the mechanism for this effect of NMDN+PC is related to the inhibition of glycogenolysis.


Subject(s)
1-Deoxynojirimycin/analogs & derivatives , 1-Deoxynojirimycin/pharmacology , Glycoside Hydrolase Inhibitors , Ischemic Preconditioning, Myocardial , Myocardial Infarction/therapy , 1-Deoxynojirimycin/administration & dosage , Animals , Combined Modality Therapy , Disease Models, Animal , Enzyme Inhibitors/administration & dosage , Enzyme Inhibitors/pharmacology , Glycogen/metabolism , Heart Ventricles/metabolism , Heart Ventricles/pathology , Ischemia/metabolism , Ischemia/pathology , Lactic Acid/metabolism , Myocardial Infarction/pathology , Myocardial Infarction/prevention & control , Rabbits
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