Widespread Castleman disease: CT and US findings

The widespread form of Castleman disease is a rare condition that has been recognized only recently as a disease with an aggressive, often malignant course. The authors present computed tomographic (CT) findings in six patients with this condition and ultrasound (US) findings in four of the six. CT demonstrated splenomegaly and retroperitoneal lymphadenopathy in all six patients. In one patient, CT also showed additional widespread mesenteric and peripancreatic lymphadenopathy, a large mesenteric mass adherent to the descending colon in another, and mediastinal lymphadenopathy in a third. Three patients had peripheral axillary or inguinal lymphadenopathy. Enlarged lymph nodes were 1-4 cm in diameter, and none displayed contrast enhancement on CT scans obtained with drip infusion of contrast media. On US scans, the nodes were poorly echogenic in all four cases. In no case was focal liver or splenic infiltration seen on either CT or US scans.     

Multiple myeloma: evaluation by CT

Although patients who have multiple myeloma usually have straightforward clinical symptoms and corroborative radiographs, in some instances, these patients will present atypically, with symptoms suggesting active disease but radiographs that are normal or nonspecific. We reviewed the records of 32 patients who had documented multiple myeloma and had undergone CT examinations, assessing the value of those examinations. Although CT is not indicated in all patients who have multiple myeloma, it is especially useful in patients who have bone pain and normal or nonspecific radiographs. CT provided confirmatory information in all cases in which lesions were seen on radiographs. CT also frequently demonstrated a greater extent of disease than could be appreciated on the radiographs.     

Supraacetabular insufficiency fractures

Insufficiency fractures in the supraacetabular region were identified in five women, aged 55-83 years. Factors contributing to the diminished resistance of their bones included postmenopausal osteoporosis, steroid therapy, radiation therapy, and rheumatoid arthritis. The supraacetabular fractures were seen on routine radiographs as hazy bands of sclerosis located immediately above and parallel to the acetabular roof. All five patients had additional fractures in the spine or pelvis. Supraacetabular insufficiency fractures may be an unsuspected cause of hip pain, especially in older women.     

Pentobarbital and contraction of vascular smooth muscle.

This study, with isolated rat aortic strips and portal veins, was undertaken to : 1) study the effects, if any, of pentobarbital Na (PTB) (5 x 10(-5) to 2 X 10(-3) M) on reactivity to epinephrine, serotonin, and KCl; 2) determine whether certain concentrations of PTB induce direct actions on aortic strips and portal veins; and 3) gain some insight into how these effects are brought about. The results indicate that PTB can: a) inhibit development of spontaneous mechanical activity in these vessels in anesthetic concentrations; b) dose-dependently attenuate contractions induced by epinephrine, serotonin, and KC1; c) cause a noncompetitive type displacement of the dose response curves of these vasoactive agents; d) attenuate Ca2+- induced contractions of potassium-depolarized aortic strips and portal veins concomitant with a dose-dependent displacement of these dose-response curves to the right; and e) rapidly relax drug as well as Ca2+ -induced contractions of aortas and portal veins. In addition, the data indicate that rat portal venous smooth muscle is more sensitive to the inhibitory actions of PTB than rat aortic smooth muscle. Overall, these data suggest that concentrations of PTB used to induce surgical anesthesia can exert profound depressant effects on at least two different types of vascular smooth muscle that may be related to actions on movement and/or translocation of Ca2+.     

Survivin splice variants regulate the balance between proliferation and cell death

Survivin is an inhibitor of apoptosis protein that also plays critical roles in regulating the cell cycle and mitosis. Its prominent expression in essentially all human malignancies, and low or absent expression in most normal tissues, suggests that it would be an ideal target for cancer-directed therapy. Impeding development of safe and effective survivin antagonists for clinical use is a lack of understanding of the molecular mechanisms by which survivin differentially affects apoptosis and cell division, in normal and malignant cells. We show that the diverse functional roles of survivin can be explained, in part, by its heterodimerization with survivin splice variants in tumor cells. Survivin and survivin-DeltaEx3 interact within the mitochondria where they may inhibit mitochondrial-dependent apoptosis. If the expression of all survivin forms is eliminated by siRNA transfections, cells undergo both apoptosis and defective cell division. Overall, we provide new insights suggesting that targeting specific survivin isoforms, rather than survivin alone, may selectively and effectively destroy tumor cells. These findings are likely to have a significant impact in the design of biologic agents for clinical therapy.