Impact of arterial input function selection on the accuracy of dynamic contrast-enhanced MRI quantitative analysis for the diagnosis of clinically significant prostate cancer.

PURPOSE: Using a limited temporal resolution dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) dataset to assess the impact of the arterial input function (AIF) choice on the transfer constant (K(trans) ) to distinguish prostate carcinoma (PCa) from benign tissue. MATERIALS AND METHODS: Thirty-eight patients with clinically important peripheral PCa (≥0.5 cc) were retrospectively studied. These patients underwent 1.5T multiparametric prostate MR with PCa and benign regions of interest (ROIs) selected using a visual registration with morphometric reconstruction obtained from radical prostatectomy. Using three pharmacokinetic (PK) analysis software programs, the mean K(trans) of ROIs was computed using three AIFs: an individual AIF (Ind-AIF) and two literature population average AIFs of Weinmann (W-AIF) and of Fritz-Hansen (FH-AIF). A pairwise comparison of the area under the receiver operating characteristic curves (AUROCC) obtained with different AIFs was performed. RESULTS: AUROCCs obtained with W-AIF (ranging from 0.801 to 0.843) were significantly higher than FH-AIF (ranging from 0.698 to 0.780, 0.002 ≤ P ≤ 0.045) and similar to or higher than Ind-AIF (ranging from 0.591 to 0.839, 0.014 ≤ P ≤ 0.9). Ind-AIF and FH-AIF provided similar AUROCC (0.34 ≤ P ≤ 0.81). The pairwise correlation of K(trans) values was moderate to very strong when comparing W-AIF with FH-AIF (the Spearman's correlation coefficients [SCCs] ranged from 0.55 to 0.93) and very weak to moderate when comparing W-AIF with Ind-AIF (the SCCs ranged from 0.018 to 0.59) or FH-AIF with Ind-AIF (the SCCs ranged from 0.30 to 0.51). CONCLUSION: W-AIF yielded a higher performance than FH-AIF and a similar or higher performance than Ind-AIF in distinguishing PCa from benign tissue.

Ability of lymphokine-activated killer cells to lyse mycobacteria-infected cells.

Lymphokine-activated killer (LAK) cells were generated by interleukin-2 activation of peripheral blood lymphocytes obtained from lepromatous leprosy (LL) patients and healthy individuals. The ability of LAK cells to lyse targets (macrophages and T-24, a bladder carcinoma cell line) infected with mycobacteria (Mycobacterium leprae and mycobacterial strain ICRC) was assessed in a 51 chromium-release assay. It was observed that LAK cells generated from LL patients and healthy individuals could preferentially lyse M. leprae or ICRC-pulsed macrophages and T-24 cells, compared to non-pulsed targets. The ability of LAK cells to kill intracellular mycobacteria was demonstrated in colony forming assays. These results indicate a promising role for LAK cells in immunotherapy of leprosy.

Immunolocalization of cell-wall-deficient forms of Mycobacterium tuberculosis complex in sarcoidosis and in sinus histiocytosis of lymph nodes draining carcinoma.

In sarcoidosis, pleomorphic chromogens (PCs) occur as multivariate pigmented elements within sinusoids of lymph nodes (sinusoidal phase) and as tiny "round bodies" detectable in granulomas (generalized phase). The sinusoidal phase occurs in other conditions as well and characteristically contains yeastlike bodies also known as H-W bodies. To elucidate the antigenic profile of all variant forms, 28 cases of sarcoidosis (series A) and 14 cases of malignancy associated sinus histiocytosis (series B) were studied immunohistochemically with panels of various antibodies, including antimycobacterial MAbs specific for M tuberculosis complex (TB68, TB71), for M. leprae (MMP-I-3C3) and for cross-reactive mycobacterial antigens (F24-2-3 and F116-5, the latter recognizing superoxide dismutase). Results for series A indicate that: 1) PCs are cell-wall-deficient (CWD) mycobacterial forms belonging to M. tuberculosis complex (over 95%); 2) both phases are antigenically identical parts of the L-cycle; 3) "round bodies" of the "infective" phase have an endolysosomal evolution; 4)uncommon vacuolated forms represent a labile spheroplast stage; 5) the yeastlike bodies are specialized sinusoidal large bodies of unknown function. Results for series B show that in roughly two thirds of cases the pigmented forms are also CWD mycobacteria, have the same immunophenotype as sarcoid PCs in 35.7% of cases, have a much higher incidence of labile vacuolated forms and, finally, that malignancy associated "pseudosarcoid" granulomas do not differ antigenically from genuine sarcoid granulomas. Unlike conventional mycobacteria, PCs do not express cytoskeletal proteins consistently. Their general reactivity for HBcAg raises the possibility of phage interactions being responsible for the L-cycle since it may reflect shared epitopes between unrelated virus entities.

[Cutaneous neoplasms during leprosy: 2 case reports]. / Néoplasie cutanée au cours de la lèpre: a propos de deux cas.

The authors report on two cases of dermal neoplasia in foot trophic disorders observed in leprous subjects. The report includes the description of the clinic and histologic data as well as the surgical technique used; finally, it underlines the importance of a precocious diagnostic so as to obtain a good therapeutic result.

Differentiation of pancreatic acinar carcinoma cells cultured on rat testicular seminiferous tubular basement membranes.

The use of rat testicular seminiferous tubular basement membrane (STBM) segments as a model substratum for the in vitro maintenance of tumor cells dissociated from a transplantable pancreatic acinar rat carcinoma (J. K. Reddy and M. S. Rao, Science (Wash. DC), 198: 78-80, 1977) is described. Ultrastructurally pure, hollow tubular segments of STBM were prepared by mechanical disaggregation, DNase digestion, and deoxycholate treatment. Dissociated pancreatic acinar carcinoma cells adhered readily to STBM segments within 1 to 6 hr, and these STBM-tumor cell aggregates were maintained for up to 7 days in serum-free chemically defined medium supplemented with hydrocortisone, insulin, vitamin C, and soybean trypsin inhibitor. The tumor cells formed acinar-like clusters and displayed intercellular junctions and polarization of secretory granules toward the center of these clusters. By 4 days, virtually all cells of this acinar carcinoma maintained on STBM in supplemented chemically defined medium contained numerous secretory granules. Cell replication, as determined by [3H]thymidine autoradiography, ceased within 18 hr of attachment of neoplastic cells to STBM; however, all cells incorporated [3H]leucine as evidenced by light and electron microscopic autoradiography. In addition, two-dimensional analysis and fluorography of newly synthesized secretory proteins discharged by these cells in response to carbamylcholine revealed the presence of Mr 24,000 protein and 19 other secretory proteins characteristic of this tumor (L. J. Hansen, M. K. Reddy, and J. K. Reddy, Proc. Natl. Acad. Sci. USA, 80: 4379-4383, 1983). The culture system utilizing STBM and supplemented chemically defined medium should allow investigation of the effects of a variety of factors on morphogenesis, cytodifferentiation, and gene expression in pancreatic acinar tumors.