The investigation of 32P wire for catheter-based endovascular irradiation

The dose distribution from a 32P source has been measured and calculated in order to evaluate its application in endovascular irradiation. The source dimension was 27 mm in length and 0.3 mm in diameter and was embedded in the end of a Ni-Ti wire. Dose measurements were performed using radiochromic film in several specially designed tissue equivalent phantoms. Loevinger's point dose kernel was used for the calculation. The approximate dose rate at a radial distance of 1.5 mm from the center of the source was found to be 6.75 cGy/s per GBq (0.25 cGy/s per mCi), which allows the delivery of a therapeutic dose in a short time interval with a satisfactory homogeneity without stepping the source. However, the dose rate falls off almost exponentially along the radial distance. Therefore it may not be suitable for treating large diameter vessel from a centrally located source. The effect of a curved 32P wire source on the radial dose distribution was also investigated. The results showed that for a maximum bend of 180 degrees the dose rate was increased by as much as 20% along the inner radial distance but decreased by as much as 20% along the outer radial distance compared to the dose along a straight wire. However, for curvatures normally encountered in a clinical situation, the dose rate was changed less than 5%.     

Mammographic findings of recurrent breast cancer after lumpectomy and radiation therapy: comparison with the primary tumor

PURPOSE: To compare the mammographic findings of recurrent breast cancer with those of the primary tumor in patients who underwent lumpectomy and radiation therapy. MATERIALS AND METHODS: Mammograms were reviewed of primary and recurrent tumors in 25 patients (26 lesions). Mammographic appearance, location, and histopathologic characteristics were retrospectively compared between primary and recurrent tumors. RESULTS: Primary and recurrent tumors were mammographically similar in 21 (81%) of the 26 lesions. Of 14 primary tumors with calcifications, 12 (86%) recurred with calcifications, and of the 12 masses, nine (75%) recurred as masses. Recurrent tumors that occurred in the lumpectomy quadrant were more often similar in mammographic appearance to the primary tumor (20 of 22 tumors) than those in other quadrants (one of four tumors) (P < .02). CONCLUSION: After conservative treatment of breast cancer, the majority of recurrent tumors appear to be mammographically similar to primary tumors. It is prudent to review preoperative mammograms during follow-up of patients after lumpectomy and radiation therapy.     

Evaluation of a dual-color flow cytometry immunophenotyping panel in a multicenter quality assurance program

A basic immunophenotyping panel that employed dual-color combinations of fluorescein isothiocyanate (FITC) and phycoerythrin (PE) conjugated monoclonal antibodies (mAb; FITC-CD45/PE-CD14, FITC-IgG1/PE-IgG2, FITC-CD3/PE-CD8, FITC-CD3/PE-CD4, FITC-CD3/PE-CD16 + PE-CD56, and PE-CD19) was utilized in a quality assurance program to determine whether the 4 laboratories participating in a multicenter AIDS study obtained similar lymphocyte subset percentage values for T cells, B cells, NK cells, and CD4+ and CD8+ T cells. Over a 1 1/2 year period, 78 shared peripheral blood specimens were prepared and analyzed in each laboratory. The CD45bright CD14- percentage for each specimen was used to correct that individual's lymphocyte subset values. Interlaboratory coefficients of variation (CV) for the human immunodeficiency virus type I (HIV) seronegative (n = 38) and HIV-seropositive (n = 40) specimens using this panel were < 3% for total T cells; < 5% for CD4+ T cells and CD8+ T cells; < or = 17% for B and NK cells; and < 8% for CD4T/CD8T ratios. The 6-tube basic immunophenotyping panel has several notable features: a) for clinical studies, it permits comprehensive evaluation of an individual's major lymphocyte subsets, i.e., T, B, NK, and CD4+ and CD8+ T cells; b) for interlaboratory proficiency testing programs, it allows the detection of differences among laboratories in measurements of several functionally distinct cell populations; and c) for within-sample quality assurance, it provides several quality control checks, including the lymphosum, i.e., the sum of an individual's corrected T+B+NK values, a sum that was generally 100 +/- 5% on the HIV-seronegative specimens analyzed in this study.     

Primary intrathoracic lymphangioma masquerading as teratoma

Two cases of cystic hygroma arising as a primary lesion in the chest are presented. Because of calcifications discovered on CT and because of the anterior location of the mass in both cases, teratoma was the first diagnostic consideration. However, after surgical removal, histologic study determined that both lesions were cystic hygromas with areas of scattered calcification probably secondary to hemorrhage. These cases are presented because of the remarkable similarity of their imaging features to those of teratoma.     

Segmental reflex sympathetic dystrophy: clinical and scintigraphic criteria

Clinical and scintigraphic criteria are proposed for the diagnosis of segmental reflex sympathetic dystrophy. Eight patients met previously described clinical criteria for reflex sympathetic dystrophy with involvement limited to only a portion of the hand. The delayed phase of the three-phase radionuclide bone scan was found to be highly sensitive (100%) for this small group of patients. Consecutive bone scans (n = 127) performed during a 6-month period for a variety of upper extremity problems were reviewed, and a segmentally diffuse pattern of tracer uptake was found to be highly specific (98%) for segmental reflex sympathetic dystrophy. Recognition and documentation of a more localized form of reflex sympathetic dystrophy will allow earlier recognition and treatment, which is an important factor in a successful outcome for managing pain dysfunction disorders.     

Global folds of highly deuterated, methyl-protonated proteins by multidimensional NMR

The development of 15N, 13C, 2H multidimensional NMR spectroscopy has facilitated the assignment of backbone and side chain resonances of proteins and protein complexes with molecular masses of over 30 kDa. The success of these methods has been achieved through the production of highly deuterated proteins; replacing carbon-bound protons with deuterons significantly improves the sensitivity of many of the experiments used in chemical shift assignment. Unfortunately, uniform deuteration also radically depletes the number of interproton distance restraints available for structure determination, degrading the quality of the resulting structures. Here we describe an approach for improving the precision and accuracy of global folds determined from highly deuterated proteins through the use of deuterated, selectively methyl-protonated samples. This labeling profile maintains the efficiency of triple-resonance NMR experiments while retaining a sufficient number of protons at locations where they can be used to establish NOE-based contacts between different elements of secondary structure. We evaluate how this deuteration scheme affects the sensitivity and resolution of experiments used to assign 15N, 13C, and 1H chemical shifts and interproton NOEs. This approach is tested experimentally on a 14 kDa SH2/phosphopeptide complex, and a global protein fold is obtained from a set of methyl-methyl, methyl-NH, and NH-NH distance restraints. We demonstrate that the inclusion of methyl-NH and methyl-methyl distance restraints greatly improves the precision and accuracy of structures relative to those generated with only NH-NH distance restraints. Finally, we examine the general applicability of this approach by determining the structures of several proteins with molecular masses of up to 40 kDa from simulated distance and dihedral angle restraint tables.