CD34 expression is regulated reciprocally with adhesion molecules in vascular endothelial cells in vitro

Freshly cultured vascular endothelial cells express the CD34 antigen in a diffuse cell surface pattern with some concentration on microvilli. Expression is downregulated with proliferation in continuous culture and undetectable after nine population doublings but can be maintained by restraining cell proliferation and promoting cell contact. Expression of CD34 at the antigen and mRNA levels on early passage cells is rapidly downregulated by interleukin-1 beta (IL-1 beta), interferon-gamma (INF-gamma), and tumor necrosis factor-alpha (TNF- alpha) under conditions in which these ligands upregulate the adhesion molecules: endothelial leukocyte adhesion molecule 1 (ELAM-1) and intracellular adhesion molecule 1 (ICAM-1). This reciprocal pattern of expression and the topographic distribution of CD34 molecules on the lumenal interdigitated microprocesses of adjacent endothelial cells in vivo suggest that CD34 might have a negative modulating role on adhesion functions of endothelia.     

Arg-Gly-Asp-dependent occupancy of GPIIb/IIIa by applaggin: evidence for internalization and cycling of a platelet integrin

Using indirect immunofluorescence microscopy we examined the distribution and cycling of GPIIb/IIIa after binding to applaggin, a high-affinity Arg-Gly-Asp (RGD)--containing ligand. Resting, unfixed platelets were incubated with applaggin for 30 minutes at 37 degrees C, and bound applaggin was detected by an affinity-purified rabbit anti- applaggin antibody. Examination of intact cells showed a rim pattern for applaggin, consistent with its binding to the platelet surface. Staining of Triton X-100--permeabilized cells showed an intracellular pool of applaggin. Competition of applaggin binding by either AP-2, an anti-GPIIb/IIIa monoclonal antibody (MoAb) that blocks fibrinogen binding, or the synthetic peptide RGDW eliminated both surface and intracellular staining, indicating that applaggin is binding to GPIIb/IIIa in an RGD-dependent manner. Inhibition of platelet activation by PGE1 and theophylline had no effect on the observed staining patterns, indicating that cellular activation is not required for surface binding and subsequent internalization. To evaluate whether occupancy of functional binding sites on GPIIb/IIIa is required for internalization, we used mAb15, an anti-GPIIIa antibody that neither blocks fibrinogen binding nor induces the expression of ligand-induced binding sites on GPIIb/IIIa. In these studies mAb15 was internalized in a manner analogous to both AP-2 and applaggin, showing that occupancy of the RGD binding site is not required to initiate receptor internalization. To estimate the size of the newly internalized pool of applaggin, 125I-applaggin--binding studies were performed. Displacement of bound 125I-applaggin by excess unlabeled applaggin or EDTA showed that at least 17% of bound applaggin was nondisplaceable when binding was performed under conditions permitting membrane flow and internalization. These data indicate that GPIIb/IIIa is internalized in unstimulated platelets independent of cellular activation or occupancy of the functional binding site(s) of GPIIb/IIIa by RGD-containing ligands. Thus, internalization of GPIIb/IIIa may represent a mechanism by which the surface expression of this adhesion receptor is regulated.     

Robotically assisted laparoscopy for paraaortic lymphadenectomy: technical description and results of an initial experience

Objective

The objective of this study is to demonstrate the feasibility of robotically assisted laparoscopy paraaortic lymphadenectomy (PAL), isolated or combined with another procedure using different surgical approaches.

Methods

From February 2007 to December 2010, 53 patients underwent paraaortic lymphadenectomy up to the left renal vein. We used three different approaches with three different positions for the robot in relation to the surgical procedure (isolated transperitoneal PAL, isolated extraperitoneal PAL, or transperitoneal PAL combined with another procedure). Thirty-nine patients underwent isolated lomboaortic lymphadenectomy and 14 a combined procedure. Information concerning installation time, operative time, peri- and postoperative complications, blood loss, lymph node count, and conversion rate was recorded.

Results

For the whole population, mean installation time was 33?±?18?min, mean operative time was 197?±?81?min, and mean hospital stay was 3.9?±?2.8?days. We observed 15.1% lymph node involvement at definitive pathology. Between isolated trans- and extraperitoneal PAL, only body mass index (BMI, 27.4 versus 22?kg/m²) was significantly different. No difference was observed concerning mean number of lymph nodes or hospital stay. We observed statistical difference between combined and isolated PAL concerning mean operative time (256 versus 160?min), mean number of lymph nodes (7.8 versus 14.6), and hospital stay (5.9 versus 2.9?days).

Conclusions

Although laparoscopic robotic-assisted PAL is a safe and feasible procedure, lymph node staging seems to be better if the procedure is isolated. In case of combined procedures, the surgical approach should be modified regarding patient BMI and the associated procedure, to increase lymph node count.     

National survey of quality assurance activities for pharmacy-prepared sterile products in hospitals.

The results of a survey of pharmacy department activities for quality assurance in the preparation of sterile drug products in short-term, nonfederal hospitals are reported. A questionnaire was mailed in March and April 1991 to pharmacy directors at hospitals that had indicated in ASHP's 1990 national survey of pharmaceutical services that they had formal quality assurance processes for intravenous admixture preparation. The adjusted gross sample size was 465. The net response rate was 71% (330 usable replies). Nearly all respondents indicated that sterile drug products were prepared extemporaneously in their departments; 61% reported batch preparation of such products. Both pharmacists and pharmacy technicians prepared sterile products. Respondents identified which guidelines were used in developing departmental policies and procedures for sterile product preparation. Specific areas were identified in which educational programs for pharmacists are needed; the most frequently indicated area (85%) was principles of aseptic technique. A majority of respondents used the following means for the orientation and training of personnel who prepare sterile products: aseptic technique lectures or videotapes, on-the-job training, written policies and procedures, and direct observation of technique. Almost all of the respondents (99%) had laminar-airflow hoods in their departments. Three fourths of those respondents indicated that laminar-airflow hoods were located in a limited-access room. Half of the respondents reported that laminar-airflow hoods were located certified every six months and that prefilters were changed monthly. Less than one third sampled environmental areas for microbial contamination. Less than one third of the surveyed hospitals routinely sampled sterile products for microbial contamination or pyrogens. Almost half indicated the absence of policies and procedures for testing chemical purity, drug concentration, sterility, pyrogenicity, or the environment for sterile preparations. Few respondents indicated the use of sterilization techniques other than microbial filtration, which was used by 32% of pharmacies involved in extemporaneous preparation and 16% of those involved in batch preparation. About 90% of the respondents used published references and manufacturers' recommendations to determine expiration dating. This survey revealed that certain quality assurance procedures related to pharmacy-prepared sterile products need major improvement.     

Recurrent pulmonary embolism after Greenfield filter placement

Three patients with documented recurrent pulmonary embolism with an inferior vena cava (IVC) Greenfield filter in place were examined with contrast-material-enhanced cavography. Mechanisms for recurrent pulmonary embolism were found to be propagation of thrombus through the filter struts, occlusion of the IVC at the level of the filter, and loss of contact of the filter hooks with a portion of the caval wall.     

Percutaneous biliary drainage: complications of 118 consecutive catheterizations

We have reviewed our experience with 118 biliary catheterization procedures in 109 patients from 1979 to 1984. Major complications (septic shock, hemorrhage, subphrenic abscess, and formation of an arteriovenous fistula) occurred in five patients (4.2%), three of whom died (2.5%). Minor complications occurred in 41 patients. Our success rate using the procedure was 97%. The complications that occurred are described.     

Satellite in vitro fertilization: The Oregon experience

Objective: This study was designed to compare the results of preliminary evaluation, ovarian hyperstimulation, and monitoring of patients at a distant in vitro fertilization satellite center with those treated at the main campus of the program.Study design: Fifty-four patients completing oocyte retrieval cycles at the Eugene satellite Oregon Health Sciences University in vitro fertilization program for the period Jan. 1, 1991, through Dec. 31, 1993, were compared with 222 patients at the main campus for age, peak estradiol level, number of oocytes, retrieved, number of embryos, clinical pregnancy rate, and pregnancy outcome.Results: There were no statistically significant differences between the Eugene in vitro fertilization satellite center and the main campus for any of the factors analyzed with the exception of clinical pregnancy rate. The clinical pregnancy rate per cycle at the Eugene satellite center was 39% while the Portland main campus rate was 23% (p = 0.027), presumably because of a larger number of couples with severe male factor infertility at the central site.Conclusion: A distant in vitro fertilization satellite program was highly successful in the Oregon experience. In addition to greater convenience to the patients, the program was highly comparable to main campus program in measured parameters of ovarian hyperstimulation, oocyte retrieval, number of embryos, and pregnancy rate.     

眩晕的神经放射学特征

眩晕患者的诊断过程始于对病史以及随后的全身体格检查和神经系统检查的准确评价。这步骤通常能够识别确切的病因，或者至少可鉴别周围性眩晕和中枢性眩晕。神经放射学检查必须作为选择性诊断手段加以考虑，包括CT、MRI、MR血管造影（MRA）以及血管造影术。对于周围性眩晕、良性阵发性位置性眩晕、迷路炎、Meniere病、外淋巴瘘、局部外伤、中毒性迷路炎、急性中耳炎和慢性中耳渗液等疾病的诊断而言，影像学技术的作用是有争议的。CT和MR可用来排除其他病理学原因和证实诊断。分辨率和增加和能够增强迷路内液的特殊MRI序列的应用，使我们能够对迷路的结构和病理学变化进行更详细地分析。T1和T2对比序列检查都是必需的。当怀疑中耳类以及在外伤后眩晕随访时，需要进行高分辨率CT检查。中枢性眩晕的病因很多，包括椎基底循环血管病变、多发性硬化、偏头痛相关性眩晕、小脑和脑干肿瘤以及中枢神经系统感染，其中脑缺血和多发性硬化最为常见。在这些情况下，影像学检查应该是强制性的。CT能够诊断大多数小脑出血以及小脑和脑干的急性缺血，增强的MRI已经证实是检测后颅窝病病变最为敏感的工具。弥散加权MRI能够比常规MRI更早地显示急性缺血性改变。MRA能提供类似血管造影片的颅内血管图像。有证据表明，有时可避免进行侵入性的血管造影术。MRA的分辨率不如传统的血管造影术，还可能受到活动和其他伪影的影响。选择性的后循环血管造影通常对治疗决策有提示作用。