Atypical simple bone cysts of the jaws. II: A possible association with benign fibro-osseous (cemental) lesions of the jaws

Four cases are described of simple bone cysts of the mandible arising concurrently with benign fibro-osseous (cemental) lesions. Previous reports of such findings, and a possible relationship to the so-called 'cementoma' of the long bones, are considered. The relevance of this to the aetiology is addressed, and it is suggested that at least some cases diagnosed as simple bone cysts are closely related to the fibro-osseous lesions.     

Cardiac Rehabilitation in the United States

Coronary heart disease (CHD) is a significant cause of morbidity and mortality in the United States (US). In addition to this, many of the risk factors of CHD, such as obesity, sedentary lifestyle, diabetes mellitus, and poor nutrition, are disproportionately high in the US. Despite the many known benefits of cardiac rehabilitation (CR), referral and participation rates in these programs are paradoxically low. Over the course of this review, we will discuss some of the many benefits of CR, some of the risk factors for CHD in the US, and factors that affect referral and participation in these programs.     

17q-linked frontotemporal dementia-amyotrophic lateral sclerosis without tau mutations with tau and alpha-synuclein inclusions

BACKGROUND: Frontotemporal dementia (FTD) is a clinically heterogeneous condition that can be associated with clinical manifestations of an extrapyramidal disorder or motor neuron disease. A range of histologic patterns has been described in patients with FTD. The most common familial form of this condition is caused by mutations in the microtubule-associated protein tau gene (MAP tau) and is associated with neuronal or glial tau inclusions. OBJECTIVES: To determine the clinical, anatomic, and pathological features of San Francisco family A and to map the mutation responsible for disease in this family. DESIGN: A systematic clinical, neuropsychologic, neuroimaging, and chromosome segregation analysis of San Francisco family A was performed. A pathological and biochemical assessment of a family member was made. SETTING: Family study. PATIENTS: San Francisco family A, with FTD, variable extrapyramidal symptoms, and prominent motor neuron disease. Afflicted family members do not have a MAP tau coding or splice regulatory sequence mutation, and the MAP tau is genetically excluded. MAIN OUTCOME MEASURES: Comparison of clinical, neuropsychologic, neuroimaging, and linkage findings of San Francisco family A with other familial forms of FTD and amyotrophic lateral sclerosis (ALS). RESULTS: The most probable location for the mutation responsible for this condition is on chromosome arm 17q, distal to the MAP tau. All previously identified susceptibility loci for FTD and ALS are excluded. Autopsy findings from an afflicted family member show distinctive tau and alpha-synuclein inclusions. Another unique feature is that the insoluble tau protein consists predominantly of the 4R/0N isoform. CONCLUSION: The condition affecting members of San Francisco family A is clinically, pathologically, and genetically distinct from previous familial forms of FTD and ALS.     

Batrachotoxin blocks saltatory organelle movement in electrically excitable neuroblastoma cells

Batrachotoxin has been reported to inhibit fast axonal transport. We have examined the effect of batrachotoxin on saltatory organelle movements in N115 neuroblastoma cells (a model of fast axonal transport) using time-lapse video intensification microscopy. Batrachotoxin (0.1–1.0 μM) inhibits saltatory organelle movement. Contrary to previously published hypotheses, this inhibition of intra-axonal movement depends upon the action of batrachotoxin on action potential Na⁺ channels. Evidence for this conclusion is: (1) the range of concentrations of batrachotoxin which inhibit saltatory organelle movement is consistent with the dose-response curve for the activation of action potential Na⁺ channels by batrachotoxin in N18 neuroblastoma cells¹⁰; (2) tetrodotoxin, which blocks action potential Na⁺ channels, prevents the inhibition of organelle movements by batrachotoxin; (3) batrachotoxin has no effect on saltatory movement in cells, including some neuroblastoma cell lines, which lack action potential Na⁺ channels; and (4) in Na⁺-free or low Na⁺ media, batrachotoxin does not block organelle movement. We suggest that changes in internal ion concentrations which follow the influx of Na⁺ are responsible for the inhibition of fast axonal transport by batrachotoxin.     

Residency training as technology matures a survey of radiology residents' training experiences

RATIONALE AND OBJECTIVES: The aim of the study is to assess radiology resident training experience in cardiac magnetic resonance imaging (MRI), positron emission tomography (PET), obstetrical (OB) ultrasound (US), carotid US, and barium esophagram. MATERIALS AND METHODS: One hundred eighteen radiology residents completed surveys. Surveys assessed resident year of residency training, hospital size, program affiliation with an academic institution, state, performance of the examinations listed, number of examinations performed per week, and number of weeks spent on rotations for each modality. The study was approved by the institutional review board and was Health Insurance Portability and Accountability Act (HIPAA) compliant. t-Test and chi-square test were performed, and results were analyzed for statistical significance. RESULTS: Most (94 respondents; 80%) respondents were third-year residents, 101 residents (86%) stated their program was affiliated with an academic institution, 92 residents (78%) performed cardiac MRI, 104 (88%) performed PET, 84 (71%) performed OB US, 71 (60%) performed carotid US (one did not respond), and all performed esophagrams (although one did not respond). Only performance of cardiac MRI and PET correlated positively with a larger average hospital size (P < .01). Residents at an academically affiliated program were significantly more likely to perform cardiac MRI (P < .05). Geographic region significantly affected likelihood of performance of cardiac MRI only. CONCLUSION: Such factors as hospital size, academic institution affiliation, and geography affect radiology resident training, particularly for such maturing applications as cardiac MRI and PET. This information may be useful in attempts to standardize radiology residency training.     

Natural killer-like T-cell lymphomas: aggressive lymphomas of T-large granular lymphocytes [see comments]

Natural killer (NK)-like T cells are major histocompatibility complex- unrestricted cytotoxic T cells that are surface CD3-positive, express NK-cell antigens, and rearrange their T-cell receptor. Most neoplasms arising from this T-cell subpopulation have been a chronic lymphoproliferative disease referred to as T-large granular lymphocyte (LGL) leukemia. Only 10 NK-like T-cell lymphomas have been described in detail previously; this study presents the clinicopathologic features of six others and distinguishes these lymphomas from T-LGL leukemia. All patients presented with B-symptoms and often had marked hepatosplenomegaly without significant peripheral lymphadenopathy. Four of the six patients were immunosuppressed. All had CD3, CD8, CD56- positive tumors, presumably of hepatosplenic (n = 3), intestinal (n = 1), pulmonary (n = 1), or nodal (n = 1) origin. Three patients had lymphomatous bone marrow infiltrates, and four had peripheral blood involvement by neoplastic large lymphocytes, some of which had a blastic appearance or resembled virocytes. Azurophilic granules, ultrastructurally corresponding to cytoplasmic dense core and/or double density granules, were seen in all cases. T-cell clonality was shown in five tumors by Southern blot analysis, and three had abnormal karyotypes. Two untreated patients died 20 days after presentation, and three patients who received combination chemotherapy died within 5 months of presentation. One patient remains in complete remission 22 months after treatment. These findings suggest NK-like T-cell lymphomas are aggressive, are clinicopathologically distinct from T-LGL leukemia, and should be in the differential diagnosis of extranodal T-cell lymphoproliferations, including those in immunosuppressed patients. Furthermore, the LGL morphology, phenotype, and tissue distribution of some NK-like T-cell lymphomas suggest they arise from thymic- independent T cells of the hepatic sinusoids and intestinal mucosa.     

Role of perfluorochemical emulsions in the treatment of myocardial reperfusion injury.

Perfluorochemicals are substances with small particle size, low viscosity, and high oxygen-carrying capacity. The role of one perfluorochemical preparation. Fluosol, an emulsion of two perfluorocarbons, a detergent Pluronic F-68 (poloxamer 188), and phospholipids on myocardial reperfusion injury was investigated in a closed-chest canine model of regional ischemia. Intracoronary and intravenous infusions of Fluosol in the perireperfusion period significantly reduced infarct size and improved ventricular function in animals that were examined for up to 2 weeks after reperfusion. Fluosol preserved endothelial structure and endothelium-dependent relaxation of large and small vessels. Fluosol reduced neutrophil plugging of capillaries and attenuated neutrophil infiltration into the reperfused bed. Ex vivo studies of neutrophil function demonstrated apparent suppression of chemotaxis and lysozyme degranulation in cells from animals that were treated with Fluosol. However, treatment of cells in vitro manifested enhanced superoxide anion production within 5 minutes of incubation even with low concentrations of Fluosol. This effect was found to be almost entirely attributable to the detergent, Pluronic F-68. The stimulation of neutrophils by Fluosol was found to result directly from phagocytosis and indirectly from activation of the complement cascade. These findings suggest that perfluorochemicals may provide a novel form of therapy to enhance myocardial salvage after successful reperfusion. The mechanism appears to be due to stimulation and subsequent "deactivation" of neutrophils peripherally, which thereby reduces their cytotoxic potential in the reperfused myocardium. The role of the oxygen-carrying ability of the perfluorocarbons in the reduction of reperfusion injury remains to be determined. In a pilot study in human beings, Fluosol that was used as adjunctive therapy with angioplasty has also been shown to improve regional ventricular function. Clinical trials with perfluorochemical emulsions appear warranted to determine the role of reperfusion injury in limiting myocardial salvage in patients who are undergoing pharmacologic or mechanical reperfusion.