Contractile effect of α,β-methylene ATP on the guinea-pig isolated trachea

The effects of alpha,beta-methylene adenosine 5'-triphosphate (alpha,beta-methylene ATP), 2-chloroadenosine and R-PIA (N6-(L-2-phenylisopropyl)-adenosine) and their interaction with dipyridamole, indomethacin, 8-phenyl-theophylline, diazepam and other agonists of central or peripheral benzodiazepine receptors were studied on the guinea-pig isolated trachea. alpha,beta-methylene ATP exerted contractile effects on the guinea-pig isolated trachea; - log EC50 and E(max) values were 8.86 +/- 0.19 and 31.3 +/- 2.3 (n = 31) (% vs acetylcholine 10(-3) M) respectively. In comparison with other purinergic receptor agonists, the rank order of potency was: alpha,beta-methylene ATP greater than 2-chloroadenosine greater than R-PIA. alpha,beta-methylene ATP and 2-chloroadenosine had significantly (P less than 0.05) greater efficacy (E(max)) than R-PIA. Indomethacin (3 x 10(-6) M) and 8-phenyltheophylline (10(-7) to 10(-5) M) significantly reduced the contractile effect of 2-chloroadenosine and R-PIA but did not affect alpha,beta-methylene ATP-induced contraction. Conversely, dipyridamole significantly reduced (10(-7) M) or suppressed (10(-6) M) the contractile effects of alpha,beta-methylene ATP whereas it only partially reduced (10(-6) M) the contractile effects of high concentrations of 2-chloroadenosine or R-PIA. Diazepam potentiated the efficacy of alpha,beta-methylene ATP. The E(max) (% vs acetylcholine 10(-3) M) values were 26.1 +/- 2.0 (n = 10) in control conditions and 45.9 +/- 4.6 (n = 5; P less than 0.05) in the presence of diazepam 10(-5) M. Diazepam did not modify the contractile effects of 2-chloroadenosine or R-PIA. Ro5-4864 (10(-7) to 10(-5) M), an agonist of peripheral benzodiazepine receptors, potentiated the contractile effects of alpha,beta-methylene ATP to the same extent as diazepam. Clonazepam, an agonist of central benzodiazepine receptors, did not modify these effects. Antagonists of central (flumazenil) or peripheral (RP 52028) benzodiazepine receptors had no influence on the interaction between diazepam or Ro-4864 and alpha,beta-methylene ATP. In conclusion, alpha,beta-methylene ATP exerts on guinea-pig isolated trachea a contractile effect which is not modified by indomethacin and 8-phenyltheophylline, but is reduced by dipyridamole. It is suggested that this effect might involve P2 chi receptor stimulation.     

An unusual case of twin birth with two live infants delivered in two consecutive years, at a 36-day interval

The paper describes the obstetric management of an unique case of twin, bicorial, biamniotic pregnancy in which the second twin born 36 days after the first. Both twins are living today.     

Separation of diffusion and perfusion in intravoxel incoherent motion MR imaging

Intravoxel incoherent motion (IVIM) imaging is a method the authors developed to visualize microscopic motions of water. In biologic tissues, these motions include molecular diffusion and microcirculation of blood in the capillary network. IVIM images are quantified by an apparent diffusion coefficient (ADC), which integrates the effects of both diffusion and perfusion. The aim of this work was to demonstrate how much perfusion contributes to the ADC and to present a method for obtaining separate images of diffusion and perfusion. Images were obtained at 0.5 T with high-resolution multisection sequences and without the use of contrast material. Results in a phantom made of resin microspheres demonstrated the ability of the method to separately evaluate diffusion and perfusion. The method was then applied in patients with brain and bone tumors and brain ischemia. Clinical results showed significant promise of the method for tissue characterization by perfusion patterns and for functional studies in the evaluation of the microcirculation in physiologic and pathologic conditions, as, for instance, in brain ischemia.     

消瘀片对实验性高血脂症兔的治疗作用研究

目的:观察消瘀片对实验性高血脂症兔的治疗作用。方法:雄性新西兰兔高脂饲养8周形成实验性高血脂症,然后分组连续给予消瘀片12周,测定给药后6和12周时的血脂变化。结果:消瘀片0.16～0.32g/(kg·d)口服6～12周后,可使血清TC、TC、LDL-C和apoB含量明显降低,apoAI/apoB比值升高,尤其大剂量组的作用更为显著,单味中药丹参或山楂提取物的降血脂作用不如消瘀片。结论:消瘀片对已形成的高血脂症兔具有明显的降血脂作用。     

Osteoinductivity assay of the variability of repeated extractions of bone morphogenetic proteins from bovine bone at different times

BOrthobiologicsLaboratory ,DepartmentofOralMaxillofacialSurgery,FacultyofDentistry ,UniversityofToronto ,Canada (HuZH ,SeanA .F .PeelandCameronM .L .Clokie)DepartmentofOrthopaedicSurgery,TheAffiliatedSecondHospital,KunmingMedicalCollege ,1Mayuan ,Kunming ,Yunnan6 5 0 10 1,China (HuZH) Correspondingauthor:Tel:86 871 5 35 12 81 2 5 95 ,E mail:zminghu @hotmail.comonemorphogeneticproteins (BMPs)aremembersoftransforminggrowthfactor (TGF )superfamilyencodingpolypeptidesthatshareco…