Radiology and the Health Policy Agenda for the American People

Eleven radiologists appointed by the major radiological societies participated for the past 5 years in the development of the Health Policy Agenda for the American People. The Agenda is an action plan to address a wide variety of serious problems in medicine. The first phase involved establishment of 159 principles, broad value statements that were the foundation of the project. Phase 2 involved the development of policy proposals on 38 urgent issues for action in medical science; education; health resources; delivery mechanisms; evaluation, assessment, and control; and payment for services. These proposals are summarized in this report. The activities and recommendations of representatives for the field of radiology are described. The Agenda has been released, and an implementation phase has begun. It will likely be of great importance to the practice of radiology over the next decade. Important issues can be addressed by acting with the coalitions that are being formed from among the more than 150 participating organizations.     

Thrombosed synthetic hemodialysis access fistulas: failure of fibrinolytic therapy

Seven episodes of acute thrombosis occurring in five patients with polytetrafluoroethylene dialysis fistulas were treated with local infusions of low-dose streptokinase. Bleeding from previous dialysis puncture sites necessitated stopping the infusion in six out of seven patients, although in one of these six, the graft reopened. The seventh patient had never been dialyzed through the graft and thrombolysis was achieved without incident. Surgery was avoided in only one patient. The authors contend that in these patients the risks of fibrinolytic therapy outweigh the benefits. Surgical thrombectomy, coupled with intraoperative angiography and possible angioplasty, is the preferred method of treating these patients. Venography prior to the creation of the fistula helps the surgeon avoid diseased vessels and may avert early failure of the fistula.     

Epstein-Barr virus latent membrane protein-1 oncogene deletions: correlations with malignancy in Epstein-Barr virus--associated lymphoproliferative disorders and malignant lymphomas

LMP-1, an Epstein-Barr viral (EBV) latency protein, is considered a viral oncogene because of its ability to transform rodent fibroblasts in vivo and render them tumorigenic in nude mice. In human B cells, EBV LMP-1 induces DNA synthesis and abrogates apoptosis. LMP-1 is expressed in EBV-transformed lymphoblastoid cell lines, nasopharyngeal carcinoma (NPC), a subset of Hodgkin's disease (HD), and in EBV-associated lymphoproliferative disorders (EBV-LPDs). Recently, focused deletions near the 3' end of the LMP-1 gene (del-LMP-1, amino acids 346-355), in a region functionally related to the half-life to the LMP-1 protein, have been reported frequently in human immunodeficiency virus (HIV)- associated HD (100%) and EBV+ Malaysian and Danish peripheral T-cell lymphomas (100%, 61% respectively), but less frequently in cases of HD not associated with HIV (28%, 33%) and infectious mononucleosis (33%). To further investigate the potential relationship of del-LMP-1 to EBV- LPDs associated with immunosuppression or immunodeficiency, we studied 39 EBV-associated lymphoproliferations (10 benign, 29 malignant) from four distinct clinical settings: posttransplant (4 malignant, 1 reactive); HIV+ (18 malignant, 2 reactive); nonimmunodeficiency malignant lymphoma (ML) (7 cases); and sporadic EBV infection with lymphoid hyperplasia (7 cases). The presence of EBV within lymphoid cells was confirmed by EBV EBER1 RNA in situ hybridization or by polymerase chain reaction (PCR) analysis. EBV strain type and LMP-1 deletion status were determined by PCR. EBV strain types segregated into two distinct distributions: HIV+ (9 A; 11 B) and non-HIV (19 A, 0 B), consistent with previous reports. Overall, del-LMP-1 were found in 1 of 5 (20%) Burkitt lymphomas (BL); 17 of 24 (71%) aggressive non- Hodgkin's lymphoma (agg-NHL), and 2 of 10 (20%) reactive lymphoid proliferations. Of the agg-NHLs, del-LMP-1 were present in 4 of 4 PT-ML (100%); 10 of 15 HIV+ ML (67%); and 3 of 5 nonimmunodeficiency malignant lymphoma (ML, 60%). A total of 2 of 7 (28%) sporadic EBV- associated lymphoid hyperplasias contained a del-LMP-1. All del-LMP-1 were identical by DNA sequence analysis. No correlation was identified between the presence of del-LMP-1 and the EBV strain type observed. The high incidence of del-LMP-1 observed in agg-NHLs (71%), in contrast to the relatively low incidence observed in reactive lymphoid proliferations (28%), suggests that the deleted form may be preferentially selected in lymphomatous processes. All posttransplant agg-NHLs contained a del-LMP-1, and a similar frequency of del-LMP-1 was observed in both HIV-associated ML (66%) and nonimmunodeficiency ML (60%), suggesting that impairment of immune function alone is not a requirement for the expansion of malignant cells infected by EBV stains containing the deleted LMP-1 gene.     

Benign prostatic hypertrophy: retrograde transurethral dilation of the prostatic urethra in humans. Work in progress

Retrograde transurethral balloon dilation of the prostatic urethra was performed in five human volunteers with benign prostatic hypertrophy. Each patient underwent cystoscopy, uroflow studies, voiding cystourethrography, retrograde urethrography, and magnetic resonance imaging before dilation and at defined intervals afterward. The longest follow-up to date is 8 months. Patients were given topical anesthetics and mild sedatives, and dilation was performed with a 25-mm urethroplasty balloon catheter inflated at 3-6 atm for 10 minutes. All catheter manipulations were done with a guide wire and under fluoroscopic control. Significant resolution of symptoms of prostatism was seen in four patients. The unsatisfactory results in the last patient were believed to be caused by ineffectual dilation of predominantly middle lobe hypertrophy--a condition that is now regarded as a contraindication to dilation. This technique has promise to replace transurethral resection of the prostate as the treatment of choice for this common male ailment.     

Changes on radiographs of wives of workers exposed to asbestos

Between January and March 1986, 117 wives of insulation workers exposed to asbestos were screened by means of chest radiography, pulmonary function testing, and a detailed questionnaire. The final study group included 93 women over 40 years of age. Eighteen of these (19.4%) demonstrated pleural changes consistent with asbestos exposure, including pleural plaque (88.9%), diaphragm plaque (27.8%), pleural calcification (16.6%), and diffuse pleural thickening (5.5%). In statistical correlation between the groups with normal and abnormal radiographs, the only factor that proved significant was the year of first exposure (the duration of the latent period). Finally, radiographs of the husbands were compared for 17 of the 18 wives with radiographic abnormalities. Fourteen of the husbands (82%) demonstrated more severe radiographic changes than their wives.     

A new torque guide wire

A new guide wire that provides markedly improved torque control is described. It was compared with a conventional guide wire in two models, one simulating a drainage tube with numerous side holes and one, the biliary tree. The new wire was much more easily controlled than the conventional guide wire and passed through both models significantly faster (P less than .01 and P less than .005). Although some deterioration in control was noted when it was inserted through a catheter in vivo, the new torque-control wire still exhibited a definite improvement over conventional wires in directional control.     

1990～1991年北京市城区大气污染与每日居民死亡关系的研究

本研究使用时间序列分析对北京市主要城区（西城区、东城区）１９９０～１９９１年大气污染和每日死亡数进行连续观察，并使用泊松回归模型分析空气中总飘尘（ＴＳＰ）和二氧化硫（ＳＯ２）的对数测定值对每日居民死亡的影响，结果显示：大气污染物有增加每日居民死亡数的危险性，心血管病患者受ＴＳＰ的影响和呼吸系统疾病患者受ＳＯ２的影响比其他疾病患者更大，６５岁及以上老年病人所受影响较大。