Dysfunction of phrenic pacemakers induced by metallic rescue blankets

BOISSEL, N., et al. : Dysfunction of Phrenic Pacemakers Induced by Metallic Rescue Blankets. Phrenic pacing can restore diaphragmatic contractions in patients with central respiratory paralysis. It relies on radiofrequency transmission of energy from an external unit to implanted receivers through circular coil antennas. The case of a patient is reported in whom severe hypoventilation occurred following the use of a metallic rescue blanket. The phenomenon was confirmed in two subsequent patients and during benchmark tests. Possible mechanisms include reflection and diffusion of high frequency waves by a Faradaylike effect. Patients with implanted devices relying on telemetric control or powering, and their care givers, should be warned against the use of metallic rescue sheets.     

Gastrointestinal toxicity associated with nonsteroidal anti-inflammatory drugs. Epidemiologic and economic issues.

The large body of literature on the gastrointestinal side effects of NSAIDs has shown consistently that populations can be identified that have a markedly elevated risk for these iatrogenic conditions. These groups include the elderly, persons with prior history of peptic ulcer disease and its complications, persons receiving anticoagulant and corticosteroid therapy, and persons who require long-term NSAID therapy, especially at high dose. It is possible that several comorbidities (e.g., rheumatoid arthritis) predispose patients to gastrointestinal complications caused by NSAIDs, but few studies have adjusted carefully for the possibility that concomitant medication use (e.g., oral anticoagulants, corticosteroids) or increased NSAID dose may account best for apparent association of comorbidities as a risk factor for serious gastrointestinal events. The role of H. pylori infection in affecting the risk of complicated ulcer disease among NSAID users remains to be fully elucidated. Low-dose aspirin for cardioprotective use is associated with an increased risk for PUBs; when used concomitantly with NSAIDs, this increases the risk of PUBs above that of the NSAID itself. Apart from the physical toll NSAID-related gastrotoxicity places on the patient, there are considerable economic consequences to patients, providers, and society. This cost presents a subject for research for those interested not only in improving the quality of patient care, but also in the prudent use of health care resources.     

Primary mediastinal large B-cell lymphoma: optimal therapy and prognostic factor analysis in 141 consecutive patients treated at Memorial Sloan Kettering from 1980 to 1999

Primary mediastinal large B-cell lymphoma (PMLBL) is a distinct clinicopathological entity with unclear prognostic factors and optimal treatment approach. To elucidate an optimal treatment and identify predictive factors, a retrospective analysis of 141 consecutive patients was undertaken. Patients received cyclophosphamide, hydroxydaunomycin, Oncovin, prednisone (CHOP)-like therapy, the non-Hodgkin lymphoma (NHL)-15 regimen or upfront autologous stem cell transplantation (ASCT) on Institutional Review Board approved trials or according to the institutional guidelines. Evaluation included lactate dehydrogenase, International Prognostic Index (IPI) assessment, computed tomography scan and gallium imaging. With a median follow-up of 10.9 years, event-free survival (EFS) and overall survival (OS) was 50% and 66% respectively. EFS/OS for CHOP/CHOP-like, NHL-15 and upfront ASCT was 34/51%, 60/84% and 60/78% respectively. CHOP/CHOP-like regimens had inferior EFS and OS versus NHL-15 or upfront ASCT (P < 0.001). A total of 23% of patients received radiotherapy. Multivariate analysis revealed the following outcome predictors: for EFS, greater than or equal to two extranodal sites and initial therapy received (NHL-15 or upfront ASCT); for OS, only initial therapy with NHL-15. We conclude: (i) dose-dense chemotherapy with NHL-15 may be superior to CHOP for PMLBL; (ii) The impact of consolidative radiotherapy requires randomised controlled trials; (iii) The age-adjusted IPI did not predict survival in this analysis; (iv) high-dose chemotherapy/ASCT should be reserved for upfront anthracycline-based therapy failure or in clinical trials for high-risk patients.     

Comparison of methods to detect recent HIV type 1 infection in cross-sectionally collected specimens from a cohort of female sex workers in the Dominican Republic

Interest in estimating HIV-1 incidence using specimens obtained as part of cross-sectional surveys has led to the development of new methods to detect recent HIV-1 infection through the testing of a single anti-HIV-positive specimen. These assays are based on quantitative and qualitative differences in anti-HIV-1 antibodies between recent and long-standing infections. An ongoing vaccine preparedness study enrolled female sex workers in the Dominican Republic. Specimens from women found to be HIV positive at baseline were tested for recent HIV-1 infection using the detuned assay, avidity index, and BED-CEIA assay. An unweighted kappa statistic in pairwise comparisons was used to estimate the correlation of recent HIV-1 infection detection by the three methods. Nineteen (3.9%) of 482 women were positive for HIV-1 infection. The incidence of HIV infection was 1.4% [95% confidence interval (CI): 0.2, 5.3], 0.9%(95% CI: 0.1, 4.4), and 1.0%(95% CI: 0.1, 4.4) using detuned assay, avidity index, and BED-CEIA techniques, respectively. The overall agreement between both detuned assay and avidity index and detuned assay and BED-CEIA was 94%(kappa = 0.8, 95% CI; 0.3, 1.0). The correlation was highest between BED-CEIA and avidity index methods (100%; kappa = 1.0). All three methods performed similarly in detecting recent HIV-1 infection in this region dominated by clade B HIV-1 infection. Although incidence estimates were slightly higher using the detuned assay method, they were not significantly different. These assays may be of value in both clinical research and practice. The utility of individual assays for recent infection detection will depend upon operating characteristics, HIV-1 subtype limitations, and selection of appropriate assay cutoff values.     

Decreased bone mineral density during low dose glucocorticoid administration in a randomized, placebo controlled trial

OBJECTIVE: While osteoporosis and bone fractures are clearly recognized side effects of high dose glucocorticoids, the effect of low dose glucocorticoids remains controversial. We investigated the effect of 3 months of low dose hydrocortisone on bone mineral density (BMD). METHODS: Subjects, 18 to 55 years old with chronic fatigue syndrome and no medical or psychiatric illness requiring medication, were randomized in a double blind, placebo controlled trial to receive oral hydrocortisone, 13 mg/m2 body surface area every morning and 3 mg/m2 every afternoon (25 to 35 mg/day, equivalent to about 7.5 mg prednisone/day) or placebo for 12 weeks. Before and after treatment BMD of the lumbar spine was measured by dual energy x-ray absorptiometry. RESULTS: We studied 23 subjects (19 women, 4 men). For the 11 hydrocortisone recipients there was a mean decrease in BMD: mean change from baseline of the lateral spine was -2.0% (95% CI -3.5 to -0.6. p = 0.03) and mean change of the anteroposterior spine was -0.8% (95% CI -1.5 to -0.1, p = 0.06). Corresponding changes for the 12 placebo recipients were +1.0% (95% CI -1.0 to 3.0, p = 0.34) and +0.2% (95% CI -1.4 to 1.5, p = 0.76). CONCLUSION: A 12 week course of low dose glucocorticoids given to ambulatory subjects with chronic fatigue syndrome was associated with a decrease in BMD of the lumbar spine. This decrease was statistically significant in lateral spine measurements and nearly so in anteroposterior spine measurements.     

Abnormal flow volume loops in patients with intrathoracic Hodgkin's disease

STUDY OBJECTIVES: To study the incidence of upper airway obstruction, as measured on the flow volume loop (FVL), in patients with bulky mediastinal Hodgkin's disease; to correlate the FVL with CT of the chest; and to follow the changes in the FVL after treatment of the tumor. DESIGN: Retrospective study of pulmonary function tests (PFTs) and chest CTs performed as part of a clinical trial for Hodgkin's disease. SETTING: Memorial Sloan-Kettering Cancer Center, a comprehensive cancer care center. PATIENTS: Twenty-five patients (15 men and 10 women; age range, 20 to 57 years) with bulky mediastinal Hodgkin's disease enrolled in a clinical trial of chemotherapy followed by external beam radiation therapy. MEASUREMENTS AND RESULTS: Fourteen of 25 patients (56%) had an abnormal FVL prior to therapy; after chemotherapy, only 7 of 25 patients (28%) had an abnormal FVL. The abnormal patterns seen were either those typical of fixed obstruction or variable extrathoracic obstruction. No patient had a pattern typical of variable intrathoracic obstruction. On chest CT scan, 16 patients had grade-I tracheal deformity; 6 had grade-II deformity, and 3 had grade-III deformity. All three patients with grade-III deformity had a fixed obstruction pattern, as did three patients with a grade-I pattern. Patients with a fixed pattern on FVL had significant decreases in inspiratory and expiratory flow rates. CONCLUSION: FVL abnormalities suggesting upper airway obstruction occurred in > 50% of patients with bulky mediastinal Hodgkin's disease. A fixed pattern of obstruction was associated with the lower flow rates and severe tracheal distortion on CT; these patients may warrant special attention prior to general anesthesia or invasive procedures. Asymptomatic patients with abnormal FVLs but normal tracheal profiles need not undergo extensive evaluation. No patients showed the expected pattern typical of intrathoracic obstruction, but rather the major effect was on the inspiratory loop. The authors speculate on the mechanism for this unexpected finding.     

Fulminant EBV(+) T-cell lymphoproliferative disorder following acute/chronic EBV infection: a distinct clinicopathologic syndrome

This study describes the clinicopathologic features of 5 patients who developed a fulminant Epstein-Barr virus (EBV)-positive clonal T-cell lymphoproliferative disorder (LPD) after acute EBV infection. One additional patient developed a similar disorder in the setting of long-standing chronic active EBV infection. Detailed immunophenotyping, in situ hybridization for EBV early RNA-1 (EBER1) and polymerase chain reaction (PCR) analyses for immunoglobulin (Ig) heavy chain and T-cell receptor (TCR)-gamma gene rearrangements were performed on paraffin-embedded tissue from all patients. In addition, EBV strain typing and detection of the characteristic 30-bp deletion of the latent membrane protein-1 (LMP-1) gene were performed by PCR. Controls included 8 cases of uncomplicated infectious mononucleosis (IM). Patients included 4 males and 2 females with a median age of 18 years (2-37 years). Three patients were Mexican, 2 were white, and 1 was of Asian descent. All presented with fever, hepatosplenomegaly, and pancytopenia; 5 were previously healthy, but had a clinical history of a recent viral-like upper respiratory illness (1 week to 2 months), and 1 patient had documented chronic active EBV infection for 7 years. Serologic data for EBV were incomplete but titers were either negative or only modestly elevated in 3 cases. In 1 case serology was consistent with severe chronic active EBV infection. In the remaining 2 cases serologic studies were not performed. All patients died within 7 days to 8 months of presentation with T-cell LPD. On histologic examination, the liver and spleen showed prominent sinusoidal and portal lymphoid infiltrates of CD3(+), beta F1(+), EBER1(+) T cells lacking significant cytologic atypia. Two cases were CD4(+), 2 cases were CD8(+), and 2 cases had admixed CD4(+) and CD8(+) cells without clear subset predominance. All were TIA-1(+), CD56(-). Only rare B cells were noted. Marked erythrophagocytosis was present. Molecular analysis revealed identical T-cell clones in 2 or more sites (liver, spleen, lymph node) in 5 cases. All patients carried type A EBV; 4 cases had wild-type EBV-LMP, and 2 showed the 30-bp deletion. This fulminant T-cell LPD after acute/chronic EBV infection is characterized by hepatosplenomegaly, often without significant lymphadenopathy, fever, liver failure, pancytopenia, and erythrophagocytosis indicative of a hemophagocytic syndrome. EBV serology may be misleading, with lack of elevated titers. The presence of an EBER1(+) T-cell infiltrate with scant B cells should alert one to this diagnosis. Although cytologic atypia is minimal, studies for T-cell clonality confirm the diagnosis. (Blood. 2000;96:443-451)