Kinase activation and transformation by NUP214-ABL1 is dependent on the context of the nuclear pore

Genetic alterations causing constitutive tyrosine kinase activation are observed in a broad spectrum of cancers. Thus far, these mutant kinases have been localized to the plasma membrane or cytoplasm, where they engage proliferation and survival pathways. We report that the NUP214-ABL1 fusion is unique among these because of its requisite localization to the nuclear pore complex for its transforming potential. We show that NUP214-ABL1 displays attenuated transforming capacity as compared to BCR-ABL1 and that NUP214-ABL1 preferentially transforms T cells, which is in agreement with its unique occurrence in T cell acute lymphoblastic leukemia. Furthermore, NUP214-ABL1 differs from BCR-ABL1 in subcellular localization, initiation of kinase activity, and signaling and lacks phosphorylation on its activation loop. In addition to delineating an unusual mechanism for kinase activation, this study provides new insights into the spectrum of chromosomal translocations involving nucleoporins by indicating that the nuclear pore context itself may play a central role in transformation.

Urgent coronary bypass surgery for failed percutaneous coronary intervention in the stent era: Is backup still necessary?

BACKGROUND

Current practice guidelines for performance of percutaneous coronary intervention (PCI) in the United States mandate availability of on-site surgical backup. With the decreasing frequency of urgent coronary bypass surgery (UCABG) with newer technologies, it is unclear whether such backup continues to be necessary.

METHODS

A database of 5655 consecutive patients undergoing PCI at a single center between August 1, 1992, and December 31, 1997, was analyzed. Outcomes were determined as well as clinical, lesion, and procedural characteristics of patients during 4 time periods preceding and during use of coronary stenting.

RESULTS

Frequency of UCABG for failed PCI decreased from 2.2% to 0.6% in the most recent time period (P <.01) with no change in incidence of in-hospital death or myocardial infarction. Incidence of stenting progressively increased to 72% in the latest period. Patients requiring UCABG had a higher prevalence of acute coronary syndromes (95%) and type B lesions (79%), but these characteristics were also common in patients who did not undergo UCABG. Although coronary stents were available during the last 3 periods studied, only 30% of UCABG patients had lesions or complications amenable to stenting, and stenting attempts in these patients were all unsuccessful. Despite stenting and use of perfusion balloons and intra-aortic balloon pumps, only 40% of patients having UCABG were stable and pain free on transfer to the operating room.

CONCLUSIONS

Although use of UCABG for a failed PCI is currently very low, there are no satisfactory predictors, patients requiring UCABG are frequently clinically unstable, and availability of stenting does not reliably eliminate the need for UCABG or result in a decrease in mortality. This small group of patients continues to require readily available surgical standby.

Stenting for in-stent restenosis: A long-term clinical follow-up

We studied the feasibility, safety, and short- and long-term outcomes of treating coronary in-stent restenosis with primary restenting. Thirty-one patients (32 lesions) were treated. Eleven patients had adjunctive rotational atherectomy. Clinical follow-up was obtained in all 31 patients at a mean of 9.1 +/- 5.5 months by direct phone contact with the patients, medical records, and subsequent hospitalization for recurrent symptoms and/or revascularization. There were no cardiac deaths or myocardial infarctions. In native vessels (26 patients), repeat target lesion revascularization was required in eight patients (31%); two other patients (7.7%) had angina and were treated medically. All vein graft lesions had recurrent restenosis. Significant predictors of recurrent clinical events were lesions in vein grafts, multivessel disease, and use of higher poststent deployment inflation pressures. Primary restenting for in-stent restenosis in native vessels is a safe approach with good short-term outcome. Recurrent restenosis remains a problem, as it does with other devices, particularly in vein graft lesions and in patients with multivessel disease. Restenting for in-stent restenosis should probably be used selectively. Cathet. Cardiovasc. Intervent. 48:143-148, 1999.

Frey syndrome: treatment with temporoparietal fascia flap interposition

There is a 10% to 48% reported incidence of clinically significant gustatory sweating after parotid surgery or injury. Various medical and surgical treatments have been used in the attempt to treat this socially embarrassing condition. These treatments are not always effective and often have unwanted risks and adverse effects. They also do not address the post-parotidectomy defect. Prevention of Frey syndrome and correction of the postoperative contour deformity after parotidectomy have recently been achieved by interposition of temporoparietal fascia flap between the parotid gland and the cheek skin flap at the time of parotidectomy. This article presents the first report (to our knowledge) of an established case of Frey syndrome being treated with temporoparietal fascia flap interposition.

Detecting and differentiating white from red coronary thrombus by angiography in angina pectoris and in acute myocardial infarction

To determine the ability to detect thrombus by angiography, angioscopy was performed before angiography in patients undergoing interventional procedures and the data collected in a blinded fashion. These data demonstrated that the sensitivity of angiography to detect white thrombus was 50% and the specificity was 95%, whereas the sensitivity and specificity to detect red thrombus was 100%, respectively; the positive and negative predictive value of detecting thrombus in general was 89% and 83%, respectively.

Incidence and characteristics of preventable iatrogenic cardiac arrests

We studied the contribution of iatrogenic illness to cardiac arrest among patients hospitalized in 1981 in a university teaching hospital. During this 1-year period, 28 (14%) of 203 arrests in which resuscitation was attempted followed an iatrogenic complication. Seventeen (61%) of the 28 patients died. The demographic characteristics of patients with iatrogenic arrest did not differ strikingly from those of other patients who arrested. However, patients with iatrogenic arrest were less likely to be in cardiogenic shock or to have suffered an acute myocardial infarction prior to arrest. They were more likely to survive to discharge from the hospital and to be taking digoxin or antiarrhythmic medication prior to arrest. Among the 28 cases of iatrogenic cardiac arrest, 18 (9% of all arrests) might have been prevented by stricter attention to the patient's history, findings on physical examination, and laboratory data. The most common causes of potentially preventable arrest were medication errors and toxic effects (44%) as well as suboptimal response by physicians to clinical signs and symptoms (28%), most frequently dyspnea and tachypnea. Rapid, appropriate response to abnormal drug levels, to electrocardiographic signs of adverse drug effects, and to signs and symptoms of congestive heart failure or toxic effects from digoxin might decrease the incidence of cardiac arrest among hospitalized patients.

Partial dehiscence of a porcine prosthesis in association with aortic annular separation producing a false aneurysm of the ascending aorta

A 44-year-old man developed intermittent left bundle branch block followed by complete heart block 18 months after aortic valve replacement, and aortic insufficiency and hemolytic anemia 5 years postoperatively. These abnormalities were associated with operative findings (7 years after aortic valve replacement) of total disruption of the aorta at the level of the aortic annulus. Echocardiographic findings of an enlarged and unusually shaped "aortic root" and angiographic findings of abnormally high origin of the coronary arteries relative to the valve ring, which should have suggested the diagnosis 2 years prior to successful surgical repair, are presented.