Review of Currently Available GP IIb/IIIa Inhibitors and Their Role in Peripheral Vascular Interventions.

The glycoprotein IIb/IIIa (GP IIb/IIIa) antagonists are the most recent additions to the antiplatelet agents available to the interventional radiologist. The currently available GP IIb/IIIa antagonists are abciximab, eptifibatide, and tirofiban. These medications have demonstrated excellent safety and efficacy in the setting of coronary arterial interventions. The fundamental benefit of the GP IIb/IIIa antagonists lies in their unique mechanism of action: the ability to prevent platelet aggregation, thrombus formation, and distal thromboembolism while preserving initial platelet binding to damaged vascular surfaces. A paucity of data exists regarding the role of GP IIb/IIIa inhibitors in peripheral vascular interventions. The GP IIb/IIIa antagonists would theoretically provide excellent antiplatelet therapy in patients undergoing any of a variety of endovascular interventions during which thrombosis or thromboembolism may endanger distal perfusion in patients with peripheral vascular disease. The goal of this summary is to review the indications for use, pharmacology, and evidence for efficacy of the GP IIb/IIIa antagonists in hopes of translating these data for application in the peripheral arterial circulation. Further research is necessary to determine how these agents may be safely used in combination with other anticoagulants or with stents, efficacy compared with standard regimens, success at preventing distal thromboembolism, and cost effectiveness.

Sex differences in prefrontal volume with aging and Alzheimer's disease.

We used volumetric magnetic resonance imaging to examine sex differences in prefrontal tissue volumes of healthy aged and patients with Alzheimer's disease (AD). Healthy subjects had greater total prefrontal volume than AD, and men had greater total prefrontal volume than women (ps < or = 0.02). This was true for both gray and white matter volumes. There were no interactions between group and sex for total prefrontal volume. An exploratory analysis of each group suggested that sex differences in both gray and white matter in healthy aging are not sustained in AD.

Variable platelet response to low-dose ASA and the risk of limb deterioration in patients submitted to peripheral arterial angioplasty.

A group of 100 patients with intermittent claudication (70 male, 30 female), treated with I00 mg ASA per day, were followed over 18 months after elective percutaneous balloon angioplasty. Platelet function was monitored over a period of 12 months by corrected whole blood aggregometry (CWBA). Upon stimulation by arachidonic acid (AA), adenosine diphosphate (ADP) and collagen, CWBA-results were obtained by an electronic acquisition and evaluation system correcting for hematocrit and platelet count of the blood sample. All patients showed a completely inhibited platelet response to AA stimulation. Comparison of the CWBA-results with clinical parameters revealed that reocclusions at the site of angioplasty occurred exclusively in male patients for which CWBA failed to prove an inhibition of aggregation upon both agonists, ADP and collagen, and for these patients the risk of complication is at least 87% higher (p = 0.0093). Only 40% of male patients show the expected effect of ASA on in vitro platelet aggregation at any given point in time and CWBA is capable of predicting those male patients which are at an elevated risk of reocclusion following peripheral angioplasty.

Significant association of strictures and internal fistula formation in Crohn's disease.

Intestinal inflammation in Crohn's disease (CD) may be complicated by the occurrence of strictures and fistulae. The pathogenesis of fistula formation is unknown. We therefore wanted to determine whether mechanical factors might contribute to the development of fistulae. Furthermore, we tried to define the path of internal fistulae through the muscular layer. For this purpose, surgical resection specimens from 42 consecutive patients with CD were prospectively studied. In gross examination the whole bowel was cut into circumferential cross sections 0.3 cm thick. Abnormal areas were histologically examined. Strictures were found in 38 patients (90.5%), and fistulae were observed in 27 (64.3%) patients. In 11 (40.7%) specimens fistulae were found within a stricture, in 15 (55.6%) at the proximal end, and in 1 (3.7%) no stricture was found. In 7 (25.9%) cases with fistulae, herniated mucosa was found within the muscularis propria or the subserosa. In 7 (25.9%) cases a blood vessel was identified near a fistula traversing the muscularis propria. From these findings we conclude that that mechanical factors may contribute to fistula formation. This is further supported by the fact that fistulae appear to traverse the muscular layer along piercing vessels.

Influence of hematocrit and platelet count on impedance and reactivity of whole blood for electrical aggregometry.

Previous studies have shown that differing qualities of blood specimen seem to influence whole blood electrical aggregometry (WBEA), making it difficult to standardize the method. The aim of this study was to investigate the impact of hematocrit (HCT) and platelet count (PLC) on in vitro platelet aggregation in citrated whole blood (CWB) in order to compensate for their possible effects on impedance aggregometry. Red blood cells and blood platelets were isolated from fresh citrated whole blood taken from 15 healthy donors (mean age = 26 years) and recombined to 20 physiologically relevant combinations of hematocrit and platelet count (HCT: 20-50, PLC: 100-500). Platelet aggregability was measured using WBEA with three different triggers. A special-purpose software package was used in this study, ensuring proper calibration, acquisition, and evaluation of analogue to digital converted data, allowing the calculation of a set of characteristic parameters of each impedance curve. Most of the linear regressions showed that all parameters significantly depend on HCT and PLC. Furthermore, we found interactions of both variables, making it impossible to focus on the effects of one of the investigated variables only. The outcome of this study is a set of dependences, allowing the calculation of regressions for in vitro aggregation in whole blood, enabling a comparison of blood of any quality with each other, regardless of the variables HCT and PLC. Together with the previously defined dependence of sample age on WBEA data, this step should help to make this technique a more reliable and practicable clinical tool, making it suitable for daily routine investigations.

[Diagnostic and therapeutic video thoracoscopy: conversion rate and costs]. / Diagnostische und therapeutische Videothoracoskopie: Umsteigeraten und Kosten.

With the further development of new surgical techniques, that allow for the performance of a variety of standard diagnostic and therapeutic procedures in a less invasive fashion, it is instructive to look at the complications of these new techniques, in order to define their role for general thoracic surgery. 372 patients have been treated by means of video-assisted thoracic surgery (VATS) between 1/1992 and 12/1994. A total of 934 open thoracic procedures were performed in the same time frame, 399 out of them for the same chest disorders as treated by VATS alternatively. In 40 cases (10.7%) the endoscopic procedure had to be converted to an open thoracotomy. The main reasons for conversion were inability to locate or resect lesions due to a deep or central position (n = 13), requirement of further resection (n = 10), adhesions (n = 9), fibrinopurulent empyema (n = 5), bleeding (n = 2) and single-lung-ventilation failure (n = 1). The mean operation time was significantly shorter with VATS compared to open procedures, except for decortications. The mean hospital stay was 4.2 days in the endoscopic and 7.9 days in the thoracotomy group. Cost analysis for both techniques included expenses for disposable instruments, the operation room, anesthesia, and total hospital charges. Higher costs for instruments for VATS procedures were compensated by shorter chest drainage, less postoperative need for analgetics and a significantly shorter hospital stay.(ABSTRACT TRUNCATED AT 250 WORDS)

[Long-term results of the Wilhelm denervation operation in epicondylitis humeri radialis (tennis elbow)]. / Langzeitergebnisse nach Denervationsoperation nach Wilhelm bei Epicondylitis humeri radialis (Tennisarm).

Fourteen patients with epicondylitis humeri radialis, resistant to conservative therapy were surgically treated according to Wilhelm's procedure at the II. Department of Plastic Surgery, University of Vienna. The mean follow-up period was 7.6 years (1 to 14 years). This study demonstrates a marked improvement of the symptoms after operative treatment, hence it follows that Wilhelm's procedure can be recommended in patients resistant to conservative therapy.

Intra-arterial methylprednisolone infusion in treatment-resistant graft-versus-host disease.

Acute graft-versus-host disease (GVHD) is a potentially fatal complication following allogeneic hematopoietic stem cell transplant. Standard primary therapy for acute GVHD includes systemic steroids, often in combination with other agents. Unfortunately, primary treatment failure is common and carries a high mortality. There is no generally accepted secondary therapy for acute GVHD. Although few data on localized therapy for GVHD have been published, intra-arterial injection of high-dose corticosteroids may be a viable option. We treated 11 patients with steroid-resistant GVHD using a single administration of intra-arterial high-dose methylprednisolone. Three patients (27%) died periprocedurally. Four patients (36%) had a partial response to intra-arterial treatment and were discharged on total parenteral nutrition and oral medication. Four patients (36%) had a complete response and were discharged on oral diet and oral medication. No immediate treatment or procedure-related complications were noted. Twenty-seven percent of patients survived long-term. Our preliminary results suggest that regional intra-arterial treatment of steroid-resistant GVHD is a safe and potentially viable secondary therapy in primary treatment-resistant GVHD.

Analysis of recorded biomedical book and journal use in the Yale Medical Library. II. Subject and user relations.

Cancelled charge slips collected over a one-year period supply the data for this analysis of circulation in the Yale Medical Library. Full-time teaching faculty are the heaviest users of journal literature, and students, of monograph literature. Faculties of Medical School departments are compared in terms of their use of material in individual subjects. Subject literatures are analyzed in terms of groups of users borrowing from them. The extent to which journal titles used by medical students are also used by Medical School faculty is examined. One of the products of the study is a rank list of journal titles used in the Library. Results are presented in several tables.

Analysis of recorded biomedical book and journal use in the Yale Medical Library. I. Date and subject relations.

Analysis of book and journal circulation is based on cancelled charge slips collected over a one-year period in the Yale Medical Library. About two-fifths of material circulated were monographs. Books and journals in seven subject fields provided over half of the circulation. Approximately two-thirds of both books and journals used had been published during the most recent nine years. A subject-by-subject examination of the ratio of books to journals circulating revealed that, in subjects where proportionally more journals than books were taken out of the Library, books were of more recent imprint dates than were journals, contrary to the overall pattern. Date distribution of books and journals by subject was also studied. Results are illustrated with graphs and tables.

Influence of UW solution on in vitro platelet aggregability.

Bleeding problems in orthotopic liver transplantation (OLT), starting immediately after reperfusion of the graft, are complicating the outcome of transplantation. Platelets may be involved in this situation, but there is still a lack of information about the influence of UW solution on platelet function. We evaluated the effect of UW solution on in vitro platelet aggregability in healthy volunteers using whole blood electrical aggregometry and concluded, that UW solution causes impaired platelet aggregability and may contribute to bleeding problems during OLT. The mechanism of impairment remains unclear, since central pathways as well as membrane receptors seem to be involved. Furthermore, our data support the necessity of extended flushing of the liver graft after reperfusion.

Routine diagnosis with PhastSystem compared to conventional electrophoresis: automated sodium dodecyl sulfate-polyacrylamide gel electrophoresis, silver staining and western blotting of urinary proteins.

The recent introduction of the PhastSystem, an automatic electrophoresis and staining system with precast gradient-gels, allows rapid and reproducible analysis of proteinuria in patients suffering from renal injury. A routine method for sodium dodecyl sulfate-polyacrylamide gradient gel electrophoresis (SDS-PAGE) and silver staining of unconcentrated urine specimens in the PhastSystem is described and compared to our conventional "macro"-method with self-cast SDS-polyacrylamide gradient gels. The method described for the PhastSystem using 0.3 microL sample volumes and an 8-25% polyacrylamide gradient gel leads to highly reproducible results within 1.5 h. Before electrophoresis urine specimens were neither concentrated nor dialyzed. Samples with a protein concentration exceeding 5 mg/mL had to be diluted 1:5 (v/v). Analysis and documentation of PhastGels appeared as easy as with our conventional SDS-PAGE. Protein bands could reliably be identified by Western blotting. Urine and serum proteins, separated in PhastGels, were electrophoretically transferred to nitrocellulose and detected with specific antibodies against human albumin, transferrin, alpha-1-antitrypsin and IgG. Comparison of several standard kits for molecular weight determination revealed considerable differences concerning the quality of protein separation patterns. Availability of precast gels and automatization of SDS-PAGE and staining allows easy standardization of urine SDS-PAGE among clinical routine laboratories.