Ouabain resistance conferred by expression of the cDNA for a murine Na+, K+-ATPase alpha subunit   总被引：13，自引：0，他引：13  

R B Kent  J R Emanuel  Y Ben Neriah  R Levenson  D E Housman 《Science (New York, N.Y.)》1987,237(4817):901-903

The molecular basis for the marked difference between primate and rodent cells in sensitivity to the cardiac glycoside ouabain has been established by genetic techniques. A complementary DNA encoding the entire alpha 1 subunit of the mouse Na+- and K+-dependent adenosine triphosphatase (ATPase) was inserted into the expression vector pSV2. This engineered DNA molecule confers resistance against 10(-4) M ouabain to monkey CV-1 cells. Deletion of sequences encoding the carboxyl terminus of the alpha 1 subunit abolish the activity of the complementary DNA. The ability to assay the biological activity of this ATPase in a transfection protocol permits the application of molecular genetic techniques to the analysis of structure-function relationships for the enzyme that establishes the internal Na+/K+ environment of most animal cells. The full-length alpha 1 subunit complementary DNA will also be useful as a dominant selectable marker for somatic cell genetic studies utilizing ouabain-sensitive cells.  相似文献   

STUDIES ON THE PERIPHERAL BLOOD IN PATIENTS WITH THERMAL BURNS. 1. THROMBOCYTOPENIA     

Macdonald AH  Levenson SM  Davidson CS  Tagnon HJ  Taylor FH 《Science (New York, N.Y.)》1944,99(2582):519

  相似文献   

ABNORMAL NITROGEN METABOLISM IN BURNS     

Taylor FH  Levenson SM  Davidson CS  Adams MA  Macdonald H 《Science (New York, N.Y.)》1943,97(2523):423-424

  相似文献   

Chronic cervical compressive myelopathy in horses: clinical correlations with spinal cord alterations     

JV YOVICH  RA LeCOUTEUR†  DH GOULD† 《Australian veterinary journal》1991,68(10):326-334

Histological examination was performed on the cervical spinal cord from 13 horses with chronic cervical compressive myelopathy of 4 to 29 months duration. Structural alterations were correlated with clinical features. At the level of compression, the spinal cord was grossly deformed. Histological alterations included nerve fibre swelling and degeneration, occasional spheroids, astrocytic gliosis, increased macrophage activity and increased perivascular collagen. Myelin degeneration or loss at the level of the compressive lesion was greatest in the ventral and lateral funiculi and less consistently present in the dorsal funiculi. Asymmetry of lesions in the dorsal funiculi was associated with asymmetry of clinical signs in 5 horses. Histological alterations in areas of Wallerian degeneration were similar to that at the level of spinal cord compression, except that perivascular collagen was not increased. Wallerian degeneration was present cranial to the compressed site in the superficial portions of the lateral funiculi and in the middle of the dorsal funiculi. Caudal to the compressed site it was present in the ventral funiculi adjacent to the ventral median fissure and in the middle of the lateral funiculi. Deformation of the spinal cord did not correlate with the severity or duration of clinical signs but was positively correlated with the amount of perivascular collagen increase. The amount of nerve fibre swelling was not correlated with the severity of clinical signs but was negatively correlated with their duration. A rapid loss of nerve fibres apparently occurred early in the course of compression, since there was a marked decrease in the amount of nerve fibre swelling and Marchi stained degenerating myelin with increasing clinical duration.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

信阳地区杂交水稻高产高效益栽培模式的研究与应用     

河南信阳农专“双高”开发课题组 《杂交水稻》1993,(1):27-29

河南信阳地区提出了该地区杂交水稻大面积亩产６００公斤以上的最佳栽培模式为：适栽组合应以汕优６３为主;苗栽１．８～２万穴,两段育秧,亩施纯氮１０～１８公斤;钙镁磷肥５０公斤,多效唑１６０克左右;普及一喷三防技术．１９９２年在固始县,罗山县、满川县共推广７．１３万亩,增产１２６３．３６万公斤,增收８８４．３５万元．  相似文献   

Measurement of cardiac output by transesophageal Doppler ultrasonography in anesthetized dogs: comparison with thermodilution     

T Lazic  DH Riedesel  RB Evans 《Veterinary anaesthesia and analgesia》2003,30(2):104-105

Thermodilution (TD) is the standard method for cardiac output (CO) monitoring in human medicine. Although called the ‘gold standard’, TD is related to numerous complications and data misinterpretations. Recently, a noninvasive, continuous, ultrasound‐based technique for CO measurement has been developed (Hemosonic 100, Arrow Intl). This study compared transesophageal Doppler ultrasonography (TED) for measuring CO with TD in anesthetized dogs. In this study, ten dogs were used to simultaneously measure CO by TED and TD. All dogs were pre‐medicated with acepromazine at 0.1 mg kg^?1 IM, induced with thiopental at 10 mg kg^?1 IV, and maintained on isoflurane at end‐tidal concentrations of 1.3%. Baseline and four different levels of CO were used for comparison. Low CO levels were induced by caudal vena cava occlusion. High CO levels were induced by the constant IV infusion of dopamine, dobutamine, or norepinephrine. Each level of CO allowed one comparison between TED and TD. Forty‐nine paired comparisons of CO were determined ranging from 0.73 to 10.9 L minute^?1. Simple linear regression was used to determine the correlation between the two techniques. Correlation coefficient (r²) was 0.53. Bland and Altman statistical method was used for assessing agreement between the two methods. The difference between the TD and TED when all data were included was 0.82 (bias) ± 1.63 L minute^?1 (mean ± SD). At low CO levels (baseline and caudal vena cava occlusion), the correlation coefficient was 0.77, bias was 0.35 ± 0.64 L minute^?1. At high CO levels (dopamine, dobutamine, or norepinephrine), the correlation coefficient was 0.39. It was concluded that TED was not a reliable monitoring method in determining CO when positive inotropes were used. TED might have importance in situations of low CO values; however, further investigation is warranted.  相似文献   

A comparison of anesthetic risk factors and outcomes in light and draft horses     

CB  Riley †  DH Riedesel  ‡  IR Dohoo†  CL Hatfield†  S Clinch† 《Veterinary anaesthesia and analgesia》2003,30(2):113-114

As a result of anatomic and physiologic differences, draft breeds may be at greater risk of developing anesthetic complications. The aim of the study was to evaluate and compare anesthetic management of draft (DR) and light (LT) horses. A case‐matched retrospective study of 371 clinical case records of DR (124 cases) and LT (247 cases) horses presented for general anesthesia between 1991 and 1998 was performed. Data were tabulated and comparisons were made using Student's t‐test (significance p < 0.05). Prior to induction, there were significant differences in mean body weight, rectal temperature, PCV, RBC, and serum TP concentration between DR and LT breeds. There were differences in mean doses of pre‐operative butorphanol (LT 21 µg kg^?1; DR 17 µg kg^?1), induction guaifenesin (LT 99 mg kg^?1; DR 88 mg kg^?1), and intraoperative ketamine (LT 0.35 mg kg^?1; DR 0.56 mg kg^?1) required. There were no significant differences in the mean doses of pre‐operative xylazine, detomidine, or induction barbiturate administered. The mean, average, and maximum concentrations of inspired halothane were significantly higher for DR than for LT horses. Draft horses received 33% less intraoperative IV fluids (8.2 mL kg^?1 hour^?1) than LT horses. Mean anesthetic duration, time to extubation, and standing recovery were not significantly different. Induction complications were not reported for either group. Rates of occurrence of intraoperative bradycardia, hypercarbia, hypoxemia, and metabolic acidosis (SBE, TCO₂, and bicarbonate concentration) did not differ significantly. Average MAP was greater in DR horses, but neither the degree nor the mean duration of hypotension differed between DR and LT horses. Mean PaO₂ was significantly lower in DR (246 mm Hg, 32.8 kPa) than in LT (305 mm Hg, 40.7 kPa) breeds. Draft horses were at greater relative risk of hypoventilation than LT horses. The greater MAP and requirement for halothane and intraoperative ketamine may indicate problems in achieving and maintaining a surgical plane of anesthesia. Draft horses may be at a greater risk of ventilation–perfusion mismatching.  相似文献   

Retraction     

Lezcano N  Mrzljak L  Levenson R  Bergson C 《Science (New York, N.Y.)》2006,314(5806):1681

  相似文献   

Toll‐like receptor and related cytokine mRNA expression in bovine corpora lutea during the oestrous cycle and pregnancy          下载免费PDF全文

JE Gadsby  AM Tyson Nipper  HA Faircloth  M D'Annibale‐Tolhurst  J Chang  PW Farin  IM Sheldon  DH Poole 《Reproduction in domestic animals》2017,52(3):495-504

Improving our understanding of the mechanisms controlling the corpus luteum (CL) and its role in regulating the reproductive cycle should lead to improvements in the sustainability of today's global animal industry. The corpus luteum (CL) is a transient endocrine organ composed of a heterogeneous mixture steroidogenic, endothelial and immune cells, and it is becoming clear that immune mechanisms play a key role in CL regulation especially in luteolysis. Toll‐like receptors (TLR) mediate innate immune mechanisms via the production of pro‐inflammatory cytokines, especially within various tissues, although the role of TLR within CL remains unknown. Thus, the objectives of this study were to characterize TLR mRNA expression in the CL during the oestrous cycle and in pregnancy (day 30–50), and to examine the role of TLR signalling in luteal cells. Corpora lutea were collected at various stages of the cycle and pregnancy and analysed for TLR and cytokine mRNA expression. In addition, luteal cells were cultured with the TLR4 ligand (lipopolysaccharide, LPS) for 24 h to evaluate the role of TLR4 in regulating luteal function. Toll‐like receptors 1, 2, 4, 6, tumour necrosis factor alpha (TNF), interferon gamma (IFN‐G), and interleukin (IL)‐12, mRNA expressions were greatest in regressing CL compared with earlier stages (p < .05), whereas no change was observed for IL‐6 mRNA expression. Cytokine mRNA expression in cultured luteal cells was not altered by LPS. Based on these data, one or more of the TLRs found within the CL may play a role in luteolysis, perhaps via pro‐inflammatory cytokine mRNA expression.  相似文献   

Phytoplankton community structure and the drawdown of nutrients and CO2 in the southern ocean     

KR Arrigo  DH Robinson  DL Worthen  RB Dunbar  GR DiTullio  M VanWoert  MP Lizotte 《Science (New York, N.Y.)》1999,283(5400):365-367

Data from recent oceanographic cruises show that phytoplankton community structure in the Ross Sea is related to mixed layer depth. Diatoms dominate in highly stratified waters, whereas Phaeocystis antarctica assemblages dominate where waters are more deeply mixed. The drawdown of both carbon dioxide (CO2) and nitrate per mole of phosphate and the rate of new production by diatoms are much lower than that measured for P. antarctica. Consequently, the capacity of the biological community to draw down atmospheric CO2 and transport it to the deep ocean could diminish dramatically if predicted increases in upper ocean stratification due to climate warming should occur.  相似文献