Nonspontaneous internal jugular vein thrombosis (IJVT) is an uncommon condition historically associated with deep neck infections during the pre-antibiotic era. Today, trauma to the internal jugular vein from catheterization and repeated intravenous injections by drug users are the leading causes of thrombosis, with direct extension of tumor being a rare cause. Spontaneous IJVT occurs when there are no apparent predisposing causes, although many of these patients may harbor an occult malignant neoplasm. Therefore, careful investigation and follow-up are imperative in these patients. The diagnosis of IJVT is readily confirmed by contrast-enhanced computed tomography or magnetic resonance imaging. Management of IJVT involves anticoagulation, antibiotics, and with few indications for surgical intervention.

Aged↗

PubMedDate not supplied

Mass spectral characterization of three anthracycline antibiotics: a comparison of thermospray mass spectrometry to particle beam mass spectrometry.

Mass spectral results for three anthracyclines, doxorubicin, daunorubicin, and carminomycin are compared by using thermospray (TS) or particle beam (PB) [electron ionization (EI) and chemical ionization (CI)] instruments. Typically, positive ion TS mass spectrometry (MS) provided intense [MH]+ ions and some fragment ions, while PBMS in the EI mode provided only fragment ions. Significant [MH]+ ions were observed for carminomycin and daunorubicin when analyzed using PBMS in the positive ion CI mode. Under negative ion detection, TSMS yielded intense [M-H]- ions for these compounds while PBCIMS resulted in significant M- ions. Fragment ions observed in all three anthracyclines under positive and negative ion detection by TSMS and PBCIMS are due mainly to the cleavage of glycosidic bond, loss of H2O, and the loss of the side chain (COCH2R2) from the aglycone.

Carubicin↗

PubMedDate not supplied

Effects of clasp flexure on a 4-META adhered light-polymerized composite resin.

Three specimen sets of removable partial denture claps were veneered using a composite resin with 4-META onto a 50-microns aluminum oxide air-abraded surface and flexed 0.01, 0.02, and 0.03 inches for 1,500 cycles. No veneers survived intact following 0.03-inch flexures; 58% survived 0.01-inch flexures and 44% survived 0.02-inch flexures intact. There was a significant increase in the number of veneer cracks in 0.02-inch flexed clasps compared to those flexed 0.01 inch.

Acrylic Resins↗