Characterization of liposome suspensions by flow cytometry

Novel approaches to drug delivery and induction of immune responses using liposomes have received much attention in recent years. Liposomes, however, are not a singular entity, but can be produced with a diverse group of phospholipids that form microspheres of different sizes, physical structure, electrochemical characteristics, and most importantly, physiologic properties. The purpose of this study was to establish the usefulness of flow cytometry as a convenient, rapid method for assessing the relative size and uniformity of liposomal preparations. Liposomes were made from phospholipid suspensions by sonication alone, or sonication followed by microemulsification. Forward laser light scatter (FSC) analysis of liposomal preparations by flow cytometry indicated that microemulsification produced homogeneous, small vesicles which were less than 1 micron in diameter, compared to the more heterogeneous sized liposomes generated by sonication alone. Transmission electron micrographs of the liposomal preparations were used to confirm the FSC results and showed that liposomes prepared by microemulsification were homogeneous, unilamellar vesicles which exhibited a mean diameter of 99.8 nm, whereas the sonicated-only preparation was more heterogeneous in size, exhibiting a mean diameter of 154.1 nm. Analysis of various liposome preparations by FSC during a 9 week storage period showed that small vesicles were relatively stable. We conclude that flow cytometry using FSC analysis provides a rapid, reproducible and convenient method to evaluate the relative size, uniformity and stability of liposomes.     

双—对二甲氨基苯甲醛缩二胺类希夫碱合成、表征及抗菌活性

目的：合成双－对二甲氨基苯甲醛缩二胺类希夫碱,并对其抗菌活性进行研究。方法：以对二甲氨基苯甲醛和二胺类为原料,经缩合反应,制得4种相应希夫碱。结果：结构经元素分析、红外光谱、核磁共振谱确定,4种化合物均未见文献报道,抗菌活性测试表明,它们具有一定抗菌活性。结论：乙酸是催化剂,对缩合反应有利,希夫碱化合物具有一定抗菌活性。     

Validation of procedures of rehabilitation after cerebrovascular accident]

There are several methodological difficulties in the assessment of the effectiveness of rehabilitation in stroke patients. Obviously, double-blind studies are not possible, and only single-blind procedures can used. It is difficult to control for non specific effects, such as spontaneous recovery, patient's and therapist's motivation, social environment. It is necessary to assess the effect non only at the level of impairments, but also on disability and handicap. However, there are now accumulating data in the literature suggesting that stroke rehabilitation has a significant, although mild, effectiveness. Patients treated in specialized stroke rehabilitation units obtain a better outcome, in terms of independence in daily-life activities, than those treated in general wards. They also have shorter hospitalisation durations and are more frequently able to return home. Treatment effectiveness is related to intensity and duration of rehabilitation, and also to stroke severity. Patients with moderate impairments seem to benefit more from treatment than patients with mild or severe deficits. However, significant improvements can still be obtained in very severe cases, and even late (up to two years) post stroke. Similarly, rehabilitation of cognitive deficits (aphasia and unilateral neglect) has also been found efficient in most studies, even if the beneficial effect is relatively small. Aphasic patients treated by speech therapists improve more than patients treated by non specialized therapists or by family members who received a short training. One limitation of neglect rehabilitation is the inconsistent generalisation of treatment effects to daily-life situations. These data are encouraging but further research is needed to find out what precisely works, and how, in the "black box" of rehabilitation.     

Proceedings of the Symposium ‘Angiotensin AT1 Receptors: From Molecular Physiology to Therapeutics’: FUNCTIONS OF ANGIOTENSIN PEPTIDES IN THE ROSTRAL VENTROLATERAL MEDULLA

• 1 It was first shown several years ago that the rostral part of the ventrolateral medulla (VLM) contains a high density of receptor binding sites for angiotensin II (AngII). In the present paper we briefly review recent studies aimed at determining the actions of both exogenous and endogenous angiotensin peptides in the rostral VLM, as well as their specific sites of action.
• 2 The results of these studies have shown that angiotensin peptides can excite pressor and sympathoexcitatory neurons in the rostral VLM, but do not appear to affect non-cardiovascular neurons in this region.
• 3 It is known that pressor neurons in the rostral VLM include both catecholamine and non-catecholamine neurons. There is evidence that, at least in conscious rabbits, both of these types of neurons are activated by AngII. The specific endogenous angiotensin peptide or peptides that affect pressor neurons in the rostral VLM have not yet been definitively identified.
• 4 It is also possible that different angiotensin peptides may have different effects on pressor neurons in the rostral VLM, mediated by different receptors. Further studies will be needed to define these different functions as well as the specific receptors and cellular mechanisms that subserve them.

     

New non-cocaine-containing topical anesthetics compared with tetracaine-adrenaline-cocaine during repair of lacerations

OBJECTIVE: To compare the effectiveness of three new topical anesthetics that do not contain cocaine (prilocaine-phenylephrine, tetracaine-phenylephrine [tetraphen], and tetracaine-lidocaine-phenylephrine) to that of tetracaine-adrenaline-cocaine (TAC) during laceration repair in children. DESIGN: Prospective, randomized, double-blind clinical trial. SETTING: The emergency department of an urban children's hospital. PARTICIPANTS: Children 1 year of age or older with a laceration /= 5 years of age using a visual analogue scale (VAS). Suture technicians, research assistants, and parents also scored pain using a seven-point Likert scale. In addition, suture technicians completed an anesthetic effectiveness scale. RESULTS: There was consistently no difference demonstrated between the effectiveness of tetraphen and that of TAC for each outcome measure of each observer group. A statistically significant difference was seen among anesthetics when comparing VAS and Likert scale scores of suture technicians and Likert scale scores of research assistants. Based on post hoc analyses, these statistically significant differences were between TAC and prilocaine-phenylephrine (suture technician VAS and Likert scale) and between TAC and tetracaine-lidocaine-phenyl-ephrine (suture technician Likert scale), but not between TAC and tetraphen. When power analyses were performed using alpha = 0.05 and beta = 0.20, it was possible to detect a difference of 1.2 VAS units for each of the observer groups. Based on anesthetic effectiveness scale scores, the three new topical preparations collectively performed significantly better on the face and scalp than on the extremities (relative risk = 1.83; 95% confidence interval 1.20 < relative risk < 2.79). CONCLUSION: This study demonstrated the effectiveness and safety of three new non-cocaine-containing topical anesthetics. Consistently, there was no statistical difference demonstrated between the effectiveness of tetraphen and that of TAC for each outcome measure of each observer group. Tetraphen offers an effective alternative to TAC during laceration repair in children.     

Imaging of blunt chest trauma

In western European countries most blunt chest traumas are associated with motor vehicle and sport-related accidents. In Switzerland, 39 of 10,000 inhabitants were involved and severely injured in road accidents in 1998. Fifty two percent of them suffered from blunt chest trauma. According to the Swiss Federal Office of Statistics, traumas represented in men the fourth major cause of death (4 %) after cardiovascular disease (38 %), cancer (28 %), and respiratory disease (7 %) in 1998. The outcome of chest trauma patients is determined mainly by the severity of the lesions, the prompt appropriate treatment delivered on the scene of the accident, the time needed to transport the patient to a trauma center, and the immediate recognition of the lesions by a trained emergency team. Other determining factors include age as well as coexisting cardiac, pulmonary, and renal diseases. Our purpose was to review the wide spectrum of pathologies related to blunt chest trauma involving the chest wall, pleura, lungs, trachea and bronchi, aorta, aortic arch vessels, and diaphragm. A particular focus on the diagnostic impact of CT is demonstrated. Received: 29 November 1999; Accepted: 28 January 2000     

同种异体大鼠小肠移植中监测CD4+ T细胞和CD8+ T细胞数比值的意义

目的 探讨CD4+T细胞数/CD8+T细胞数作为大鼠同种异体小肠移植急性免疫排斥反应指标的可行性.方法 选取健康雄性成年SD、Wistar大鼠建立同种异体小肠移植模型,于大鼠术前和术后1、3、5、7、9d共6个时间段静脉取血,应用免疫荧光染色技术及流式细胞仪检测CD4+T细胞和CD8+T细胞百分率,并计算其比值.同期取移植小肠标本做组织学检测.结果 术后CD4+T细胞数和CD8+T细胞数比值前期增高后期降低.组织病理学检测发现术后小肠移植物的排斥反应由轻到重,术后第5天始CD4+T细胞数和CD8+T细胞数比值与急性免疫排斥反应程度呈正相关.结论 CD4+T细胞和CD8+T细胞数比值作为大鼠同种异体小肠移植术后急性免疫排斥反应的监测指标的可行性较大.     

兰索拉唑与莫沙必利联合治疗反流性食管炎的临床观察

目的 观察兰索拉唑与莫沙必利联合治疗反流性食管炎的临床效果.方法 89例反流性食管炎患者随机分为两组,治疗组50例用兰索拉唑和莫沙必利,对照组39例用盐酸雷尼替丁胶囊,观察治疗前及治疗后4、8周的临床症状改善情况和内镜变化.结果 用药4周时,治疗组反酸、恶心及胸骨后疼痛治疗有效率分别为78%、84%、82%,与对照组比较差异有统计学意义(P＜0.05).用药8周结束时,治疗组反酸、恶心及胸骨后疼痛全部改善,总有效率分别是98%、98%和93%,明显优于对照组的64%、81%和73%(均P＜0.05);内镜4周、8周复查治疗组与对照组食管黏膜病损愈合率分别为84%和62%,96%和77%,差异有统计学意义(P＜0.05).结论 兰索拉唑、莫沙必利联合用药是治疗反流性食管炎安全、有效的方法.