KPC型碳青霉烯酶分子进化及与底物结合自由能分析

目的 分析KPC-2、KPC-5和KPC-10型碳青霉烯酶的分子进化及与10种β-内酰胺类药物的结合自由能.方法 用MEGA 4.1软件中的Minimum Evolution法分析KPC-2、KPC-5和KPC-10型碳青霉烯酶的分子进化,用ArgusLab 4.1软件中的Dock模块作这3种酶与10种β-内酰胺类药物的分子对接,并计算酶与底物的结合自由能（△G）.结果 有碳青霉烯酶活性的A类β-内酰胺酶在同一簇且保守性较好,无碳青霉烯酶活性的普通A类β-内酰胺酶则在另一簇.KPC-2、KPC-5和KPC-10型碳青霉烯酶与碳青霉烯类药物结合自由能均下降,且降幅居前,它们的结合自由能比第三代头孢类抗生素更低.结合自由能较高的为氨曲南和克拉维酸.结论 KPC型碳青霉烯酶对碳青霉烯类药物的催化能力高于对第三代头孢类抗生素的催化能力,对氨曲南和克拉维酸的催化活性最低.     

Effect of transcutaneous electrical nerve stimulation on onset of axillary plexus block

We examined the effect of high frequency transcutaneous electrical nerve stimulation on the onset of brachial plexus block. Three groups of patients scheduled for surgery of the hand had a local anaesthetic block performed with 40 ml mepivacaine 1.5% using the axillary approach. After injection of the local anaesthetic transcutaneous electrical nerve stimulation was applied for 15 min either to the median nerve or the ulnar nerve; no stimulation was applied in the control group. Before and for 45 min after, the injection of local anaesthetic touch perception, pin prick, motor strength andskin temperature were tested by a blinded investigator in the areas supplied by the median, musculocutaneous, radial and ulnar nerves. There were no differences in the onset of block between the groups. Thus, the frequency-dependent action of local anaesthetics could not be demonstrated.     

Effect of awake Carotid Endarterectomy under local anaesthesia on peri-operative blood pressure: blood pressure is normalised when carotid stenosis is treated under local anaesthesia

Summary Background. Carotid Endarterectomy can be performed under local, regional or general anaesthesia. One of the most important effects of the type of anaesthetic used is on the systemic blood pressure. Although variations in blood pressure during and following carotid endarterectomy have been studied previously, the effects of awake carotid endarterectomy under local anaesthesia on blood pressure and its comparison with similar procedures under similar types of anaesthesia have not.Methods. Peri-operative blood pressure measurements were collected from the records of 25 consecutive patients for each of the following five procedures; Carotid Endarterectomy under general anaesthesia (CEAGA), Anterior Cervical Discectomy and Fusion under general anaesthesia (ACDF), Cerebral Angiography under local anaesthesia (ANG), Carotid Endarterectomy patients under local anaesthesia who were symptomatic (CEALAS) and Carotid Endarterectomy patients under local anaesthesia who were asymptomatic (CEALAA). The recordings were then analysed to find out if there were any clinically significant variations in peri-operative blood pressure.Findings. There is a significant and consistent difference when the pre-operative value was compared with the 4 hour and 24 hour post-operative recordings between the local and general anaesthetic groups for carotid endarterectomy. Carotid endarterectomy reduces the systolic and diastolic blood pressures post-operatively when performed under local anaesthesia and only the diastolic pressure was reduced when performed under general anaesthesia.Conclusion. The study provides evidence about the effect of carotid endarterectomy on the systemic blood pressure and its variations when performed under different types of anaesthesia. There is significant post-operative reduction in both the systolic and diastolic blood pressure values and the intraoperative fluctuation is minimal when local anaesthesia is used. Further studies are required to find out how this affects the long-term blood pressure and clinical outcome of the patient.     

Effect of the experience of surgical chairpersons on departmental National Institutes of Health funding

Background

Experience and application of recruitment packages can be critical in leadership efforts of surgical chairpersons in promoting research, although attrition of these efforts can happen over time due to lack of new resources. We aimed to examine the impact of experience of surgical chairpersons on departmental National Institutes of Health (NIH) funding.

Methods

Experience as a chairperson defined as the number of years spent as an interim or permanent chair was abstracted from the department Web site (US medical schools only). The NIH funding (US dollars) of the departments were obtained from the Blue Ridge Medical Institute (www.brimr.org). The change in NIH funding from the immediate previous financial year (2010–2009 and 2011–2010) was used to classify chairpersons into four groups: group 1 (−/−), group 2 (−/+), group 3 (+/+), and group 4 (+/−) for analysis.

Results

Median NIH funding were $1.9 (0.7–6) million, $1.8 (0.6–5) million, and $1.7 (0.7–5) million for 2009, 2010, and 2011, respectively, and the median experience as a surgical chairperson was 6 y (3–10). Recent chairpersons (<1 y) inherited departments that usually lost NIH funding (62%) and were frequently unable to develop a positive trend for growth over the next fiscal year ([−/−] n = 4 and [+/−] n = 2, 75%). Chairpersons who held their positions for 4–6 y were most likely to be associated with trends of positive funding growth, whereas chairpersons >10 y were most likely to have lost funding (66%, P = 0.07).

Conclusions

Provision of new development dollars later in their tenure and retention of chairpersons might lead to more positive trends in increase in NIH funding.