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1.
OBJECTIVES: solders containing chromophores and proteins enhance the strength of lasered anastomoses. Methylene blue (MB) solder anastomoses in vitro are strong but no in vivo work has been reported. We used an MB solder in vivo and studied the effects of two laser powers on patency and histological appearance. DESIGN, MATERIALS AND METHODS: two groups of 15 rabbits had unilateral end-to-end carotid anastomoses (1.5-2.0 mm) formed using three stay sutures and MB solder. Group 1 anastomoses were formed at 5.7 Wcm(-1) and Group 2 at 2.8 Wcm(-1). The vessels were examined at various points by necropsy for patency and gross macroscopic appearance, with subsequent histological examination. RESULTS: group 2 showed patency of 93.3% v 0% ( p<0.001) endothelialisation of 100% v 26.6% ( p<0.001), giant cell formation 0% v 40.0% ( p<0.01), but stenosis was not significantly different (0% v 13.3% p=0.06). Group 2 showed a higher rate of intimal hyperplasia (IH) (66.6% v 20.0% p<0.05) but neither group exhibited thermal injury or aneurysm formation. CONCLUSIONS: laser soldered microvascular anastomoses were formed in vessels of 1.5-2.0 mm with a high degree of patency. A relationship appears to exist between laser power and anastomotic patency. Methylene blue fading has the potential to act as a switch against over exposure and a visual indicator of solder activation. 相似文献
2.
The amplitude of the leading edge of the a-wave of the human electroretinogram (ERG) was compared with predictions from a computational model of the light-induced responses of rod mammalian receptors. According to this model, a linear process describes the amplitude and time course of the response to relatively low flash intensities and at brief times after the onset of the flash. At higher flash intensities, a nonlinear process, described by the Naka-Rushton function or a saturating exponential, is involved. The primary focus here is on intensity-response data recorded with a clinical ganzfeld apparatus. The leading edge of the rod a-wave recorded from normal observers and patients with congenital stationary night blindness (CSNB) was described by a linear process for flash intensities up to the maximum available flash intensity, 2.0 log scot td-sec. This finding is consistent with the model of the rod's response. It suggests, however, that when ERGs are recorded with clinical systems limited to 2.0 log scot td-sec, these data cannot be used to distinguish between changes in the parameters (eg, semisaturation intensity versus maximum response) of the human rod receptors. Responses to flash intensities up to 3.4 log scot td-sec were recorded using a custom, high-intensity ganzfeld system. Both the linear and nonlinear components of the model were needed to fit the ERGs recorded with this system. This suggests that changes in different receptor parameters can be distinguished with higher intensity flashes. 相似文献
3.
A L Hartley J M Birch P A McKinney V Blair M D Teare J Carrette J R Mann C A Stiller G J Draper H E Johnston et al. 《Journal of epidemiology and community health》1988,42(3):235-242
The Inter-Regional Epidemiological Study of Childhood Cancer (IRESCC) collected interview and medical information relating to the child's past medical experiences from parents of 555 children diagnosed with cancer and parents of 1110 unaffected matched controls. No significant associations emerged overall for ante-natal care, place and mode of delivery, length of gestation, birth weight, condition at birth, special care, neonatal procedures or breast-feeding. Few risk factors relating to previous illnesses and medication were found, although increasing numbers of illnesses appeared to be associated with an increased risk of childhood cancer, particularly acute lymphoblastic leukaemia. A highly significant excess of case children had not been immunised (p = 0.005). In general, these results indicate that past medical experiences have little influence on the development of cancer in children. 相似文献
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The pharmacology of GR203040, a novel, potent and selective non-peptide tachykinin NK1 receptor antagonist. 总被引:2,自引:2,他引:0 下载免费PDF全文
D. T. Beattie I. J. Beresford H. E. Connor F. H. Marshall A. B. Hawcock R. M. Hagan J. Bowers P. J. Birch P. Ward 《British journal of pharmacology》1995,116(8):3149-3157
1. The in vitro and in vivo pharmacology of GR203040 ((2S, 3S)-2-methoxy-5-tetrazol-1-yl-benzyl-(2-phenyl-piperidin-3-y l)-amine), a novel, highly potent and selective non-peptide tachykinin NK1 receptor antagonist, was investigated in the present study. 2. GR203040 potently inhibited [3H]-substance P binding to human NK1 receptors expressed in Chinese hamster ovary (CHO) and U373 MG astrocytoma cells, and NK1 receptors in ferret and gerbil cortex (pKi values of 10.3, 10.5, 10.1 and 10.1 respectively). GR203040 had lower affinity at rat NK1 receptors (pKi = 8.6) and little affinity for human NK2 receptors (pKi < 5.0) in CHO cells and NK3 receptors in guinea-pig cortex (pKi < 6.0). With the exception of the histamine H1 receptor (pIC50 = 7.5). GR203040 had little affinity (pIC50 < 6.0) at all non-NK1 receptors and ion channels examined. Furthermore, GR203040 produced only weak inhibition of Na+ currents in SH-SY5Y neuroblastoma and superior cervical ganglion cells (pIC50 values < 4.0). GR203040 produced only weak antagonism of Ca(2+)-evoked contractions of rat isolated portal vein (pKn = 4.1). The enantiomer of GR203040, GR205608 (2R, 3R)-2-methoxy-5-tetrazol-1-yl-benzyl-(2-phenyl-piperidin-3-y l)-amine), had 10,000 fold lower affinity at the human NK1 receptor expressed in CHO cells (pKi = 6.3). 3. In gerbil ex vivo binding experiments, GR203040 produced a dose-dependent inhibition of the binding of [3H]-substance P to cerebral cortical membranes (ED50 = 15 micrograms kg-1 s.c. and 0.42 mg kg-1 p.o.). At 10 micrograms kg-1 s.c., the inhibition of [3H]-substance P binding was maintained for > 6 h. In the rat, GR203040 was less potent (ED50 = 15.4 mg kg-1 s.c.) probably reflecting, at least in part, its lower affinity at the rat NK1 receptor. 4. In guinea-pig isolated ileum and dog isolated middle cerebral and basilar arteries, GR203040 produced a rightward displacement of the concentration-effect curves to substance P methyl ester (SPOMe) with suppression of the maximum agonist response (apparent pKB values of 11.9, 11.2 and 11.1 respectively). 5. In anaesthetized rabbits, GR203040 antagonized reductions in carotid arterial vascular resistance evoked by SPOMe, injected via the lingual artery (DR10 (i.e. the dose producing a dose-ratio of 10) = 1.1 micrograms kg-1, i.v.). At a dose 20 fold greater than its DR10 value (i.e. 22 micrograms kg-1, i.v.), significant antagonism was evident more than 2 h after GR203040 administration. 6. In anaesthetized rats, GR203040 (3 and 10 mg kg-1, i.v.) produced a dose-dependent inhibition of plasma protein extravasation in dura mater, conjunctiva, eyelid and lip in response to electrical stimulation of the trigeminal ganglion. 7. It is concluded that GR203040 is one of the most potent and selective NK1 receptor antagonists yet described, and as such, has considerable potential as a pharmacological tool to characterize the physiological and pathological roles of substance P and NK1 receptors. GR203040 may also have potential as a novel therapeutic agent for the treatment of conditions such as migraine, emesis and pain. 相似文献
6.
A series of novel, highly potent and selective agonists for the kappa-opioid receptor. 总被引:4,自引:4,他引:0 下载免费PDF全文
A. G. Hayes P. J. Birch N. J. Hayward M. J. Sheehan H. Rogers M. B. Tyers D. B. Judd D. I. Scopes A. Naylor 《British journal of pharmacology》1990,101(4):944-948
1. This paper describes the opioid receptor pharmacology and in vivo activity of several novel benzene-acetamidopiperidine and benzeneacetamidopiperazine analogues. 2. These compounds all showed potent, naloxone-reversible, full agonist activity in the field-stimulated rabbit vas deferens, indicating that they are kappa-opioid agonists; but showed very little activity in the rat or hamster vas deferens, indicating good selectivity with regard to mu- and delta-opioid receptors. 3. They were all potent antinociceptive agents, the most potent compound, GR 103545, having an ED50 value in the mouse abdominal constriction test of 0.25 micrograms kg-1 s.c. The compounds also produced sedation and diuresis, but had little effect on respiration rate or gastrointestinal motility. 4. It is concluded that the seven novel compounds described are all potent and selective agonists for the kappa-opioid receptor. 相似文献
7.
A survey was conducted among the 1990 members of the Vitreous Society in order to measure their acceptance of pneumatic retinopexy. They were asked which treatment they would prefer should they suffer a hypothetical detachment. The choices were limited to pneumatic retinopexy or scleral buckling (encircling or segmental). The majority of respondents selected a scleral buckling procedure for a phakic retinal detachment with two adjacent superior temporal quadrant tears. Surgeons who had been in practice for 10 years or less (median for entire group = 10 years) were significantly more likely to select a pneumatic retinopexy procedure. As the details of the hypothetical detachment became more complicated with myopia, additional tears, vitreous hemorrhage, or lattice degeneration with a positive family history, the respondents selected a scleral buckling procedure with greater frequency, and the differences between the choices of the surgeons became nonsignificant. This survey shows that many surgeons feel pneumatic retinopexy is an acceptable alternative to buckling surgery in select cases. There were no trends by geographic location. 相似文献
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10.
R L Weinsier L D James B E Darnell N H Wooldridge R Birch G R Hunter A A Bartolucci 《The American journal of clinical nutrition》1992,56(1):44-49
The separate effects of energy restriction and weight loss on serum lipids were studied in 24 postmenopausal moderately obese women before and after weight loss of greater than 10 kg to normal weight. Fasting serum triglycerides (TGs), total cholesterol (TC), high-density-lipoprotein (HDL) and low-density-lipoprotein (LDL) cholesterol, and insulin were measured at the end of four 10-d in-hospital phases, two before and two after weight loss: phase I, stable weight; phase II, 3350 kJ/d(800 kcal/d), followed by outpatient weight loss; phase III, 3350 kJ/d (800 kcal/d); and phase IV, stable weight. Diet composition and exercise were constant the entire study. Energy-restriction effect was determined by comparing average values in stable-weight phases (I and IV) with low-energy phases (II and III); weight-loss effect was determined by comparing values in obese phases (I and II) with reduced-weight phases (III and IV). Energy restriction lowered TG, TC, LDL cholesterol, the LDL-HDL cholesterol ratio, and insulin and raised HDL cholesterol (all P less than 0.05). Weight loss lowered TG, TC, LDL cholesterol, and insulin (all P less than 0.01) but did not change HDL cholesterol or the LDL-HDL cholesterol ratio. The results suggest that reduction to a weight-steady nonobese state significantly lowers TG, TC, and LDL cholesterol but does not improve HDL cholesterol or the LDL-HDL cholesterol ratio. 相似文献