Citations

Although interleukin 1 (IL-1) receptor signaling events in T helper lymphocytes are incompletely characterized, events associated with translocation of the transcription factor NF-kappa B are receptor-proximal assays of ligand-initiated responses. In this report we demonstrate that the transient nature of IL-1-induced NF-kappa B nuclear translocation occurs as a consequence of ligand-induced receptor desensitization. Other receptor-initiated events including induction of I kappa B alpha phosphorylation, expression of c-jun and junB mRNA, and costimulatory effects on IL-2 synthesis also are altered by IL-1 receptor desensitization. IL-1 receptor desensitization is not initiated by tumor necrosis factor, which also stimulates NF-kappa B translocation, and is not a consequence of alterations in either IL-1 receptor expression or binding affinity. In the absence of IL-1, the effects of desensitization are completely reversed within 18 h. Since IL-1 desensitization is initiated under conditions of low receptor occupancy, it is likely that receptor desensitization results from alterations to a receptor-proximal transducer, rather than from direct modification of the IL-1 receptor. These results suggest that the cyclic nature of the events in the T helper lymphocyte activation program can be controlled, in part, by the reversible desensitization of cell surface IL-1 receptors.

Two of the four principal cationic proteins of the eosinophil granule, major basic protein (MBP) and eosinophil peroxidase (EPO), were shown to be platelet agonists. Both MBP and EPO evoked a dose-dependent nonlytic secretion of platelet 5-hydroxytryptamine in unstirred platelet suspensions even in the presence of 10 microM indomethacin. MBP also evoked secretion of platelet alpha granule and lysosome components. Secretion by MBP and EPO was inhibited by 1 microM PGE1, but the nature of the inhibition differed from that observed with thrombin. Thus, MBP and EPO can be classified as strong platelet agonists with a distinct mechanism of activation.

Purpose To compare low-dose (30 Gy) radiotherapy (RT) with observation (OBS) in limited-stage aggressive lymphoma patients achieving complete remission (CR) after chemotherapy, and to measure conversion from partial response (PR) to CR with high-dose (40 Gy) RT. Patients and Methods From 1984 to 1992, stage I (with risk factors) and II adults with diffuse aggressive lymphoma in CR after eight cycles of cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) were randomly assigned to 30 Gy involved-field RT or OBS. PR patients received 40 Gy RT. Results Among 172 CR patients, the 6-year disease-free survival (DFS) was 73% for low-dose RT versus 56% for OBS (two-sided P = .05). Failure-free survival (two-sided P = .06), and time to progression (two-sided P = .06) also favored RT. Intent-to-treat analyses yielded similar results. No survival differences were observed. Three RT versus 15 OBS patients relapsed in initial disease sites. At 6 years, failure-free survival was 63% in PR patients; conversion to CR did not significantly influence clinical outcome. Conclusion For patients in CR after CHOP, low-dose RT prolonged DFS and provided local control, but no survival benefit was observed. The majority of PR patients were event-free at 6 years despite residual radiographic abnormalities. Future efforts should be directed toward improved imaging and more effective systemic therapies.

AbstractRadioligand binding assays can be used to characterize receptors in their natural environment (wild type) as well as those transfected into cell lines. They can be used to study receptor dynamics and localization, to identify novel chemical structures that interact with receptors, and to define ligand activity and selectivity. The technique thus serves as a valuable adjunct to other pharmacological and molecular biological approaches. This unit describes the major issues involved in developing a binding assay, such as selecting a radioligand, tissue preparation, optimization of assay parameters, and separation of bound from free ligand. Methods for analysis of the binding data are carefully considered, and tips for troubleshooting a binding assay are also provided.

Abstract One hundred fifty‐six arthroscopic transglenoid multiple suture repairs were performed for chronic anterior shoulder instability. In 150 shoulders (96% follow‐up), the outcome with respect to recurrence of instability and the Bankart Score was determined a minimum of 2 years and a mean of 4.1 years after surgery (range, 2 to 8.2 years). During the follow‐up interval, 11 shoulders (7.3%) redislocated. Fourteen other shoulders (9.3%) had at least one episode that we interpreted as recurrent subluxation. Shoulders with a Bankart lesion and younger patients had a higher probability of recurrent instability ( P < .05). We concluded that this method is most effective in shoulders without a Bankart lesion and in patients older than 25 years of age (regardless of pathology).

OBJECTIVESThere are options available to patients newly diagnosed with vestibular schwannoma. Our institution employs stereotactic radiosurgery, microsurgical removal, and watchful waiting. There are no studies in the literature examining which of these treatment options patients are choosing.STUDY DESIGN AND SETTINGUsing retrospective chart review from January 2000 through December 2001, we noted several variables and patients’ initial treatment choices.RESULTSDuring the 24‐month study period, 139 patients were seen at our institution with a new diagnosis of vestibular schwannoma and made a clear initial treatment choice. Of these, 32 (23%) patients elected watchful waiting; 51 (36%) underwent stereotactic radiosurgery, and 56 (40%) underwent surgical removal. Surgical excision correlated with younger age and larger tumor size.CONCLUSIONSOur initial hypothesis, that patients choosing treatment would choose stereotactic radiosurgery more than 50% of the time, was untrue for the time course studied.SIGNIFICANCEThis is the first study to examine patient choice in treatment of vestibular schwannoma.

AbstractWe compared the angiogenic potential of bone marrow plasma and the expression of vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), and their receptors on plasma cells from patients with monoclonal gammopathy of undetermined significance (MGUS), smoldering multiple myeloma (SMM), and newly diagnosed multiple myeloma (NMM). Cytokine and cytokine-receptor expression was studied by bone marrow immunohistochemistry, quantitative reverse transcription-polymerase chain reaction (RT-PCR) on sorted plasma cells, and quantitative Western blot analysis. Bone marrow angiogenic potential was studied using a human in vitro angiogenesis assay. The expression levels of VEGF, bFGF, and their receptors were similar among MGUS, SMM, and NMM. Sixty-one percent of NMM samples stimulated angiogenesis in the in vitro angiogenesis assay compared with SMM (0%) and MGUS (7%) (P &lt; .001). Importantly, 63% of MGUS samples inhibited angiogenesis compared with SMM (43%) and NMM (4%) (P &lt; .001). The inhibitory activity was heat stable, not overcome by the addition of VEGF, and corresponded to a molecular weight below 10 kd by size-exclusion chromatography. Our results suggest that increasing angiogenesis from MGUS to NMM is, at least in part, explained by increasing tumor burden rather than increased expression of VEGF/bFGF by individual plasma cells. The active inhibition of angiogenesis in MGUS is lost with progression, and the angiogenic switch from MGUS to NMM may involve a loss of inhibitory activity. (Blood. 2004; 104:1159-1165)