The chronotropic effect of acetylcholine in the presence of vecuronium and atracurium A study in the isolated perfused rabbit heart

The bradycardia produced by 1 microgram acetylcholine in the isolated perfused rabbit heart, in the presence of vecuronium and atracurium, was studied and compared with control. Vecuronium at a concentration of 2.5 micrograms/litre and atracurium 6 micrograms/litre did not enhance the negative chronotropic effect of acetylcholine. Atracurium produced a statistically significant inhibition of the negative chronotropic effect of acetylcholine.     

Teaching of medical ethics

Teaching medical ethics in Manchester within the introductory course of obstetrics and gynaecology is a joint activity with the Centre for Social Ethics and Policy. This interdisciplinary teaching has evolved through lecture sessions with small-group discussions dealing with topics of interest in human reproduction. The small-group discussion have been replaced by an open debate conducted by the students. Their own involvement and participation and an exposure to the disciplines of the humanities has broadened their approach to different ways of problem-solving of these real issues.     

Endoscopic fistulotomy and biliary drainage as the ultimate palliative treatment for obstruction due to malignant tumors of the papilla of Vater

Summary This report describes the technique and results of endoscopic fistulotomy as a drainage procedure in cases of malignant obstruction of the biliary system from bulky and friable growths in the papilla of Vater. Fistulotomy, coupled with insertion of stents, was successful in seven of eight patients and was associated with relief of jaundice. It is suggested that the method be applied when conventional transpapillary insertion of stents is impossible either due to distortion of the papilla or bleeding of the growth on touch.     

The effect of prior back surgery on surgical outcome in patients operated on for lumbar spinal stenosis a matched-pair study

Summary It has been widely observed that the outcome after repeat lumbar surgery is rarely comparable to that of primary surgery. In particular, the results of repeat surgery for lumbar spinal stenosis (LSS) have not been favourable. We used a matched-pair format in an attempt to decrease the confounding factors so as to determine as exactly as possible the effect of prior back surgery on the LSS patients surgical outcome. The matching criteria were sex, age, myelographic findings, major symptom, and duration of symptoms. From one group of 251 patients without prior back surgery (SO patients) and another of fifty-three patients with one preceding back operation (RS patients), forty-one similar matched patients pairs (one SO and one RS-patient) were formed.There were 8 female and 33 male pairs. The mean age of the SO patients was 51.6 and of the RS patient 51.4 years, and the mean follow-up time was 4.6 and 4.4 years. The assessment of outcome was based on a subjective disability questionnaire. The SO patients fared significantly better than the RS patients (32.1 versus 41.3, P = 0.026). A short time interval between operations in the RS patients had a worsening effect on outcome, but this trend was not significant.We concluded that one preceding back operation had a worsening effect on the outcome of patients operated on for LSS. As a whole, the results of RS patients were unfavourable. The proper time for achieving good surgical results in LSS patients is the initial operation.     

Galanin gene expression declines with adulthood in the cholinergic fields of the horizontal diagonal band of male rats

The neuropeptide galanin (GAL) influences leaming and memory processes, perhaps by inhibiting cholinergic function. We recently reported that, in the rat, the nucleus of the horizontal limb of the diagonal band (HDB) exhibits the highest level of GAL mRNA coexpression by basal forebrain (BF) cholinergic neurons and, in the HDB, virtually all GAL mRNA-expressing neurons correspond to the cholinergic cell type. Since GAL gene expression is induced across puberty in many brain regions, we used in situ hybridization histochemistry and quantitative autoradiography to assess GAL gene expression across the rostro-caudal extent of the HDB in prepubertal and adult male rats and to determine whether GAL gene expression is also regulated during maturation in this BF region. Our results show that the number of GAL mRNA-expressing cells per section is significantly reduced in the HDB with adulthood. Post-hoc analysis indicated that these age-associated differences in the number of GAL mRNA-expressing cells per section could be ascribed to the rostral and central subregions of the HDB. Age-related differences in the labeling intensity of GAL mRNA-expressing neurons were also detected in the rostral and central subregions of the HDB. No age-associated differences in GAL gene expression were found in the caudal HDB subregion. These results suggest that: (1) in contrast to other brain regions, GAL gene expression in the cholinergic BF may be negatively regulated by factors concomitant with puberty; and (2) the inhibition of cholinergic function by cosecreted GAL may be enhanced prior to puberty within cholinergic neurons of the rostral and central aspects of the HDB.     

Comparative effects of plateletderived growth factor-BB and insulin-like growth factor-I, individually and in combination, on periodontal regeneration in Macaca fascicularis

Platelet-derived growth factor (PDGF) and insulin-like growth factor I (IGF-I) in combination have previously been shown to enhance periodontal regeneration. The objective of this study was to further characterize the biological effects of this combination of growth factors in non-human primates and compare the effects to those of each growth factor individually. Ligature-induced periodontitis was initiated in 10 cynomolgus monkeys. After periodontal lesions were established, surgery was performed, and either a methylcellulose gel vehicle or vehicle containing 10 μg each of either PDGF-BB, IGF-I or both PDGF-BB and IGF-I was applied to exposed root surfaces. Biopsies were taken 4 and 12 wk after treatment and the extent of periodontal regeneration was assessed by histomorphometry. At both 4 and 12 wk vehicle-treated lesions generally revealed minimal osseous defect fill (ODF) (8.5±2.1% and 14.5±5.7%, respectively) and new attachment (NA) (34.1±5.2% and 26.6±10.5%, respectively). IGF-I treatment did not significantly alter healing compared to vehicle in any parameter at both 4 and 12 wk. PDGFBB-treated sites exhibited significant (p<0.05) regeneration of NA (69.6±12.0%) at 12 wk; trends for PDGF-BB treatment effect were also observed in other parameters at 4 and 12 wk. although these increases were not statistically significant. Treatment with PDGF-BB/IGF-I resulted in 21.6±5.1 % and 42.5±8.3% ODF at 4 and 12 wk, respectively, and 64.1±7.7% and 74.6±7.4% NA at 4 and 12 wk, respectively (all significantly greater than vehicle, p<0.05). The results from this study demonstrated that: 1) IGF-1 alone at the dose tested did not significantly alter periodontal wound healing; 2) PDGF-BB alone significantly stimulated NA, with trends of effect on other parameters; and 3) the PDGF-BB/IGF-I combination resulted in significant increases in NA and ODF above vehicle at both 4 and 12 wk.     

FRACTURE OF ABUTMENT SCREW SUPPORTING A CEMENTED IMPLANT-RETAINED PROSTHESIS WITH EXTERNAL HEXAGON CONNECTION: A CASE REPORT WITH SEM EVALUATION

One of the causes of implant failures in cemented implant-retained prostheses is the fracture of abutment screw or UCLA abutment. This article reports a case of simultaneous fracture of two UCLA abutments screws occurring in an implant-supported prosthesis placed in the mandibular molar region. The fractured structures were examined under scanning electron microscopy to investigate the probable causes of the failure, which were not related to failures on materials or fabrication of the screws, but rather were due to shear forces. The misfit in cemented prostheses may be the most likely cause of shear force generation.     

帕罗西汀对抑郁模型大鼠不同脑区环磷酸腺苷反应元件结合蛋白的影响

目的探讨帕罗西汀在不同用药时间对抑郁模型大鼠海马、前额叶皮质环磷酸腺苷反应元件结合蛋白（CREB）磷酸化（p-CREB）及总蛋白（t-CREB）水平的影响。方法成年雄性SpragueDawley大鼠36只，随机分为6组：对照组、抑郁模型组（以下简称模型组）、抑郁模型＋用药1d组（以下简称用药1d组）、抑郁模型＋用药1周组（以下简称用药1周组）、抑郁模型＋用药2周组（以下简称用药2周组）和抑郁模型＋用药4周组（以下简称用药4周组），每组各6只。抑郁模型的制作为强迫大鼠游泳4周，每天1次，每次15min。帕罗西汀的剂量为10m∥kg体质量，灌胃给药，时间分别为1d和1，2，4周，每天1次，于每次游泳前用药。采用Westernblot法检测各组大鼠海马及前额叶皮质的p-CREB和t-CREB水平。结果（1）模型组及用药1d、1周组大鼠海马p-CREB水平明显低于对照组（P〈0．01），用药2，4周组大鼠海马p-CREB水平与对照组的差异无统计学意义（P〉0．05）；模型组及各用药组海马t-CREB水平与对照组的差异无统计学意义（P〉0．05）。（2）模型组及用药1d和1，2周组大鼠前额叶皮质p-CREB水平均明显低于对照组（P〈0．05），用药4周组与对照组的差异无统计学意义（P〉0．05）。模型组及用药1d、1周组大鼠前额叶皮质t-CREB水平与对照组的差异无统计学意义（P〉0．05），用药2，4周组大鼠前额叶皮质t-CREB水平均明显高于对照组（P〈0．05或P〈0．01）。结论慢性强迫游泳导致大鼠海马及前额叶皮质CREB活性降低，长期使用帕罗西汀可逆转此效应，提高抑郁大鼠前额叶皮质的CREB水平。