Elevated circulating angiogenic progenitors and white blood cells are associated with hypoxia-inducible angiogenic growth factors in children with sickle cell disease.

We studied the number and function of angiogenic progenitor cells and growth factors in children aged 5-18 years without acute illness, 43 with Hemoglobin SS and 68 with normal hemoglobin. Hemoglobin SS subjects had at least twice as many mononuclear cell colonies and more circulating progenitor cell than Control subjects. Plasma concentrations of erythropoietin, angiopoietin-2, and stromal-derived growth factor (SDF)-1α were significantly higher in children with Hemoglobin SS compared to Control subjects. In a multivariate analysis model, SDF-1α concentration was found to be associated with both CPC number and total white blood cell count in the Hemoglobin SS group, suggesting that SDF-1α produced by ischemic tissues plays a role in mobilizing these cells in children with Hemoglobin SS. Despite having a higher number of angiogenic progenitor cells, children with Hemoglobin SS had slower migration of cultured mononuclear cells.

Cardiac neuroendocrine tumor with absence of sustentacular cells: immunohistochemical and ultrastructural findings.

A 68-year-old male presented with increased shortness of breath and intermittent chest pain. Cardiac catheterization along with echocardiogram imaging demonstrated 3-vessel coronary artery disease with severe left ventricular dysfunction and critical aortic stenosis. During coronary artery bypass surgery, a tumor was identified at the sulcus between the aorta and the right atrial appendage. This highly vascular tumor extended over the right coronary artery, prompting biopsy and further resection. Light microscopic evaluation showed packets of uniform round neoplastic cells without evidence of necrosis or increased mitotic figures. Immunohistochemical studies were positive for synaptophysin and weakly positive for chromogranin. Pankeratin, S-100, and GFAP stains were all negative. Ultrastructural examination of the neoplasm demonstrated numerous electron-dense secretory granules within the cytoplasm of the tumor cells. These secretory granules varied in size from 60 to 210 nm, with halos encircling many of them, suggesting the likelihood of epinephrine or norepinephrine granules. Within the specimen, abundant vascular spaces were identified, but no sustentactular cells were present. The patient agreed to undergo genetic testing, and a mutation in the succinate dehydrogenase complex subunit B (SDHB) was identified. This confirmed the molecular diagnosis of hereditary paraganglioma/pheochromocytoma syndrome. Now two years out from surgery, this patient continues to be asymptomatic in spite of the fact that his tumor was only partially resected.

Dynamic nuclear polarization and nuclear magnetic resonance in the vicinity of edge states of a 2DES in GaAs quantum wells.

Nuclear magnetic resonance is detected via the in-plane conductivity of a two-dimensional electron system at unity Landau level filling factor in the regime of the quantum Hall effect in narrow and wide quantum wells. The NMR is spatially selective to nuclei with a coupling to electrons in the current carrying edge states at the perimeter of the 2DES. Interpretation of the electron-nuclear double resonance signals is facilitated by numerical simulations. A new RF swept method for conductivity-detected NMR is introduced which offers more efficient signal averaging. The method is applied to the study of electric quadrupole interactions, weakly allowed overtone transitions, and evaluation of the extent of electron wave function delocalization in the wide quantum well.

The analysis of methyl salicylate and salicylic acid from Chinese herbal medicine ingestion.

This paper presents a multi-drug fatality in which methyl salicylate was ingested. It is presented to inform the toxicological community that a particularly expeditious method of detection for methyl salicylate exists. Previously published methods for the analysis of methyl salicylate include a gas chromatographic-mass spectrometric method and an alkaline/acidic extraction followed by high-performance liquid chromatographic (HPLC) analysis. This article describes a method for analyzing methyl salicylate using HPLC, in which a simple, rapid extraction procedure is used. Using a previously published HPLC method, methyl salicylate and salicylic acid were easily identified in biological specimens. Methyl salicylate and salicylic acid were detected using an extraction solution of acetonitrile coupled with internal standard and then analyzed by HPLC-diode-array detection. Because of its concentrated liquid form, methyl salicylate ingestion can cause rapid onset salicylate toxicity. As the potentially fatal methyl salicylate forms are readily available and easily found on drugstore shelves, the need to rapidly detect and quantitate salicylic acid concentrations that are due to methyl salicylate ingestion may arise. In the case presented, the peripheral blood concentration of salicylic acid from methyl salicylate ingestion was 320 mg/L, and the concentration in gastric contents was 820 mg. It alone was not the cause of death, however. The discovery of the ability to detect and quantitate methyl salicylate was due to its suspected ingestion.

Presleep attributions about arousal during sleep: nocturnal panic.

This study examined the role of presleep attributions about physiological events during sleep in nocturnal panic attacks. Patients who regularly experienced nocturnal panic were physiologically monitored as audio signals were presented during sleep. They were randomly assigned to 1 of 3 conditions: expected, in which signals of intense physiological changes were expected; unexpected, in which signals of intense physiological changes were not expected; or control, involving distinctly different signals unrelated to physiological responses. The unexpected condition led to substantially more self-reported distress and panic attacks. The experimental conditions did not elicit different autonomic reactions, but those who panicked showed stronger physiological responses than those who did not panic. The findings are consistent with a cognitive model of nocturnal panic attacks.