Safer, more expensive iodinated contrast agents: how do we decide?

The advantages of the new, safer, but more expensive iodinated contrast agents are discussed, and opinions on which patient groups should receive the agents are presented.     

Tumor antigen phenotype, biologic staging, and prognosis in head and neck squamous carcinoma.

Prior studies of alterations in tumor expression of normal blood group antigens and A9/alpha 6 beta 4 integrin, an extracellular matrix receptor, have suggested that these immunohistologic markers reflect the biologic aggressiveness of head and neck squamous carcinomas. To confirm these preliminary observations, prospective long-term follow-up of 82 previously untreated head and neck squamous carcinoma patients was performed. All patients were treated with conventional therapy. Median follow-up was 57 months. Tumor immunohistology for ABH blood group and A9/alpha 6 beta 4 integrin expression was performed and correlated with measures of host cellular immunity, disease-free survival, and overall survival. Loss of blood group expression and high A9/alpha 6 beta 4 integrin expression were each directly related to an increased frequency of early tumor recurrence. The combination of both variables was significantly associated with both disease-free (P = .029) and overall survival (P = .05). Increased expression of A9/alpha 6 beta 4 was associated with impaired T-lymphocyte function (P = .005), and loss of blood group expression was associated with decreased peripheral blood levels of CD8+ T-lymphocytes (P = .013). The findings suggest that these phenotypic characteristics of antigen expression in head and neck squamous carcinomas are important markers of biologically aggressive cancers and impaired host immune response. The clinical use of these biologic staging parameters in the initial assessment of patients should allow selection of more aggressive primary treatment strategies for individual patients.     

Initial experience with dynamic MR imaging in evaluation of normal bone marrow versus malignant bone marrow infiltrations in humans

The purpose of this study was (a) evaluation of dynamic contrast-enhanced MR imaging of normal bone marrow versus malignant bone marrow infiltrations in patients with proven B-cell-type chronic lymphocytic leukemia (B-CLL) and (b) correlation with the clinical stage according to Binet (stages A, B, C) and response to therapy. Bone marrow imaging of the lumbar spine, pelvis, and proximal femurs was performed at 1.5 T in 45 patients without known malignancy and in 30 patients with B-CLL. The differences between opposed-phase and in-phase dynamic gradient-echo sequences before and up to 10 minutes after intravenous application of .1 mmol/kg body weight of gadolinium-diethylenetriamine penta-acetic acid (Gd-DTPA) were evaluated in normal bone marrow. The contrast-enhancement patterns of normal and malignant bone marrow were compared using the opposed-phase dynamic gradient-echo sequence. Ten of the patients with bone marrow infiltrations (Binet stage C) additionally underwent MR imaging follow-up during therapy. Opposed-phase gradient echo sequences demonstrated a signal decrease of normal bone marrow, and in-phase gradient echo sequences demonstrated a signal increase of normal bone marrow after administration of Gd-DTPA. The dynamic signal intensity time courses differed significantly (P < .05) between Binet stages B and C and controls as well as among the three Binet stages of B-CLL. In the 10 patients followed during therapy, MR imaging sensitively demonstrated response (n = 6), nonresponse (n = 2), or relapse after initial response (n = 2). In out-of-phase imaging, both normal bone marrow and initial bone marrow infiltration in CLL stage Binet A show signal decrease after administration of contrast agent, whereas there is increase in signal intensity in higher-grade bone marrow infiltration in Binet stage B or C disease. The signal loss of normal bone marrow in out-of-phase imaging is a phase effect rather than a T2* effect. The differentiation of initial from higher-grade bone marrow infiltration on out-of-phase images relies solely on a shift in the fat/water ratio.     

Complications of intravesical bacillus Calmette-Guerin: a case report.

Bacillus Calmette-Guerin (BCG) is the most effective agent currently available to treat superficial bladder cancer. However, this form of therapy is not without potential serious or fatal complications. In addition to the potentially toxic systemic side effects attributed to hematogenous absorption of the bacillus, direct upper tract seeding may occur in patients with vesicoureteral reflux. We report on a patient treated with intravesical BCG for bladder cancer in whom unilateral necrotizing granulomatous pyelonephritis developed. Although severe, this complication is rare and we conclude that reflux is not a contraindication for intravesical BCG therapy.     

Comparative PET studies of the kinetics and distribution of cocaine and cocaethylene in baboon brain.

Recent studies have suggested that cocaethylene, an active metabolite of cocaine found in blood and postmortem brain of individuals self-administering cocaine and alcohol, may play a role in the increased toxicity seen when coadministering these 2 drugs. We have used positron emission tomography (PET) and carbon-11 (t1/2:20.4 min) labeled cocaine and cocaethylene to compare the short-term kinetics of cocaine and cocaethylene in baboon brain. The regional uptake of [11C]cocaine cocaethylene in baboon brain. The regional uptake of [11C]cocaine ([11C]COC) and [11C]cocaethylene ([11C]CE), 5-8 mCi and 4-6 micrograms, in baboon brain (n = 7) were similar but clearance from whole brain (global, GL) and from striatum (SR), thalamus (TH), and cerebellum (CB) was slower for cocaethylene. Steady-state distribution volumes (DV) were not significantly different in the striatum but were greater for cocaethylene in the thalamus, cerebellum, and whole brain. Debenzoylation of cocaethylene proceeded at about one-third the rate of cocaine, as determined by in vitro incubation of labeled cocaethylene and labeled cocaine with baboon plasma and with purified horse butyryl-cholinesterase (EC 3.1.1.8). Even though the slower clearance of cocaethylene could lead to longer tissue exposures and potentially accentuated or different physiological effects relative to cocaine, the difference between the 2 drugs is not large. Thus it is more likely that the direct actions of cocaine and alcohol on some organs, rather than cocaethylene, account for this enhanced toxicity.     

Impact of HIV antibody testing on changes in sexual behavior among homosexual men in The Netherlands.

Between October 1984 and May 1986, 746 homosexual men, living in and around Amsterdam, The Netherlands, were surveyed at three consecutive six months periods regarding their sexual behavior. At the start of the study all subjects, of whom 234 (31 per cent) were HIV-Ab seropositive, were informed about their HIV antibody status. Seropositives initially reported more sexual partners than seronegatives; they also showed a greater reduction in the number of sexual partners and the number of partners with whom all forms of sexual practices were performed than did seronegatives. In both groups subjects were more likely to terminate orogenital intercourse than anogenital intercourse and masturbation.     

Longitudinal in vivo effects of growth hormone overexpression on bone in transgenic mice.

In this study we examined the effect of systemic overexpression of GH on bone in transgenic mice longitudinally in vivo over a period of 9 months. We observed substantially increased BMC in GH transgenic mice and a significant reduction in serum osteocalcin. GH effects on bone were strongly dependent on gender and developmental stage. INTRODUCTION: State-of-the-art bone marker and microimaging technology was applied in this longitudinal study to examine bone metabolism, BMC, bone density, and cortical bone structure over the life span of growth hormone (GH) transgenic (tg) mice. MATERIALS AND METHODS: Thirty-eight mice from four genetic groups (male, female, tg, and controls) were examined with DXA, and their femur and tibia were examined with peripheral QCT (pQCT). Osteocalcin (formation) and collagen cross-links (resorption) from serum and urine were also measured at postnatal weeks 3, 6, 9, 12, 18, 26, and 38. RESULTS: GH tg mice displayed a significant increase in body weight (up to 50%) and BMC (up to 90%), but serum osteocalcin was significantly reduced compared with controls. GH tg females (but not males) displayed increased trabecular density over controls up to week 12. In contrast, male (but not female) GH tg mice displayed a higher cortical cross-sectional area than controls. Cortical density was significantly lower in both male and female GH tg mice compared with control mice. CONCLUSIONS: The increase in BMC in GH tg mice is associated with reduced serum osteocalcin levels, indicating that bone turnover may be lower than in the control mice. On a structural level, bone responds to GH excess in a gender-specific manner, with alterations varying substantially between different developmental stages.