Osteopontin induces increased invasiveness and plasminogen activator expression of human mammary epithelial cells.

Osteopontin (OPN) has been associated with enhanced malignancy in breast cancer, but its functional role in this disease is poorly understood. To study the effect of OPN on cellular invasiveness, basal OPN expression was first assessed in members of a progression series of human mammary epithelial cell lines (21PT: immortalized, non-tumorigenic; 21NT: weakly tumorigenic; 21MT-1: tumorigenic, weakly metastatic; MDA-MB-435 cells: tumorigenic, highly metastatic). The two lines which expressed lowest basal levels of OPN (21PT, 21NT) were then examined for up-regulation of invasive behavior in response to exogenous or transfected (endogenous) OPN. Both 21PT and 21NT showed increased invasiveness through Matrigel when human recombinant (hr)OPN was added to the lower chamber of transwells. Both also showed a cell migration response to hrOPN. Populations of 21PT and 21NT cells stably transfected with an OPN-expression vector showed higher levels of cell invasiness than control vector transfectants. Examination of transfectants for mRNA of a number of secreted proteases showed that only urokinase-type plasminogen activator (uPA) expression was closely associated with OPN expression and cellular invasiveness. Treatment of the parental 21PT and 21NT cells with exogenous hrOPN resulted in increased uPA mRNA expression and increased urokinase activity of the conditioned media. Both increased cell migration and induction of uPA expression are thus potential mechanisms of increased invasiness of breast epithelial cells in response to OPN.

Anomalous quantum criticality in an itinerant ferromagnet.

The dynamics of continuous phase transitions is governed by the dynamic scaling exponent relating the correlation length and correlation time. For transitions at finite temperature, thermodynamic critical properties are independent of the dynamic scaling exponent. In contrast, at quantum phase transitions where the transition temperature becomes zero, static and dynamic properties are inherently entangled by virtue of the uncertainty principle. Consequently, thermodynamic scaling equations explicitly contain the dynamic exponent. Here we report on thermodynamic measurements (as a function of temperature and magnetic field) for the itinerant ferromagnet Sr1-xCaxRuO3 where the transition temperature becomes zero for x=0.7. We find dynamic scaling of the magnetization and specific heat with highly unusual quantum critical dynamics. We observe a small dynamic scaling exponent of 1.76 strongly deviating from current models of ferromagnetic quantum criticality and likely being governed by strong disorder in conjunction with strong electron-electron coupling.

Sequential dose injections. A new technique for technetium-99m colloid gastrointestinal bleeding studies.

For Tc-99m colloid bleeding studies to be positive, the patient must be actively bleeding while the colloid is circulating in the blood pool. A simple technique of sequential dose injections (SDI) is presented where five injections of 2 mCi each are made at 5-minute intervals. Image acquisition is performed after each injection. This technique results in an increase in the effective plasma residence time of the colloidal particles from 10-15 minutes to 35-40 minutes. A case report is presented in which the bleeding site was identified only after the fifth serial injection of a fractionated dose of Tc-99m microaggregated albumin colloid.

Gallium uptake in the thyroid gland in amiodarone-induced hyperthyroidism.

Amiodarone is an iodinated antiarrhythmic agent that is effective in the treatment of atrial and ventricular arrhythmias. A number of side effects are seen, including pulmonary toxicity and thyroid dysfunction. A patient with both amiodarone-induced pneumonitis and hyperthyroidism who exhibited abnormal gallium activity in the lungs, as well as diffuse gallium uptake in the thyroid gland is presented. The latter has not been previously reported and supports the concept of iodide-induced "thyroiditis" with gallium uptake reflecting the inflammatory response.

The significance of platelet counts in coagulation studies.

Traditionally, the platelet count recommended for coagulation studies has been less than 10 x 10(9)/L, but the documentation for this is obscure. In the present study, platelet rich plasma (PRPs) and platelet poor plasmas (PPPs) were prepared from the same blood specimen to determine prothrombin times (PTs), International Normalized Ratios (INRs), partial thromboplastin times (PTTs), and their results compared. The measurements of all three of these parameters are not statistically or clinically significant in 100 paired comparisons. Incremented platelet count studies, selected by the number of platelets in the PRPs, showed that platelet counts of at least 199 x 10(9)/L, or perhaps even higher, did not compromise the results of PTs, INRs or PTTs. Such increased platelet counts, however, cannot be tolerated in the various studies for antiphospholipid antibodies, the Lupus Anticoagulant (LAC), or when monitoring heparin therapy with PTTs. Here, the < 10 x 10(9)/L platelet levels must be respected; otherwise the tests would be compromised by platelet-liberated phospholipid (Triplett, Brand et al., 1983) or by Platelet Factor 4, respectively.