Value of ultrafast and standard dynamic contrast-enhanced magnetic resonance imaging in the evaluation of the presence and extension of residual disease after neoadjuvant chemotherapy in breast cancer.

PURPOSE: To evaluate the diagnostic performance of ultrafast and standard dynamic contrast-enhanced (DCE)-MRI in evaluating the residual disease after neoadjuvant chemotherapy (NAC) for breast cancer. MATERIALS AND METHODS: Sixty-seven consecutive patients underwent MRI after NAC. Visual analysis of enhancement was performed on ultrafast and standard DCE-MRI, and compared between no residual disease and residual disease groups. The lesion diameters measured on the last phase of ultrafast DCE-MRI and early and delayed phases of standard DCE-MRI were compared with pathological diameter of entire residual cancer and residual invasive ductal carcinoma (IDC). RESULTS: The visual analysis in the delayed phase of standard DCE-MRI exhibited the highest sensitivity (90%), whereas ultrafast DCE-MRI revealed the highest positive predictive value (92%). There were no significant differences between the diameters in the delayed phase of the standard DCE-MRI and the pathological entire residual cancer (p = 0.97), and the diameters in ultrafast DCE-MRI and the pathological residual IDC (p = 0.97). CONCLUSION: The delayed phase of standard DCE-MRI may be effective for detecting the residual disease and evaluating the extension of entire residual cancer. Enhancement in ultrafast DCE-MRI may be strongly suggestive of the presence of residual disease, and effective for evaluating the extension of residual IDC.

Seven-Step Synthesis of All-Nitrogenated Sugar Derivatives Using Sequential Overman Rearrangements.

All-nitrogenated sugars (ANSs), in which all hydroxy groups in a carbohydrate are replaced with amino groups, are anticipated to be privileged structures with useful biological activities. However, ANS synthesis has been challenging due to the difficulty in the installation of multi-amino groups. We report herein the development of a concise synthetic route to peracetylated ANSs in seven steps from commercially available monosaccharides. The key to success is the use of the sequential Overman rearrangement, which enables formal simultaneous substitution of four or five hydroxy groups in monosaccharides with amino groups. A variety of ANSs are available through the same reaction sequence starting from different initial monosaccharides by chirality transfer of secondary alcohols. Transformations of the resulting peracetylated ANSs such as glycosylation and deacetylation are also demonstrated. Biological studies reveal that ANS-modified cholesterol show cytotoxicity against human cancer cell lines, whereas each ANS and cholesterol have no cytotoxicity.

Effects of Cytokines and TLR Ligands on the Production of PlGF and sVEGFR1 in Primary Trophoblasts.

AIM: Cytokines such as tumor necrosis factor-alpha (TNF-α) and interferon-gamma (IFN-γ) play an important role in maintaining pregnancy. Toll-like receptors (TLRs) have also been associated with innate immune responses during pregnancy. Placenta growth factor (PlGF) is one of the angiogenic factors and soluble vascular endothelial growth factor receptor 1 (sVEGFR1) is one of the antiangiogenic factors that regulate PlGF function. To elucidate the effects of cytokines and TLR ligands on the production of angiogenic and antiangiogenic factors in trophoblasts, we examined the production of PlGF and sVEGFR1 from trophoblasts following stimulation with cytokines and TLR ligands. METHODS: Villous tissues were obtained from healthy pregnant women who had had an artificial abortion. The trophoblasts were isolated from villous tissues. Subsequently, trophoblasts were treated with TNF-α, IFN-γ and TLR ligands. The levels of PlGF and sVEGFR1 were measured by enzyme-linked immunosorbent assay. The expression of those mRNA was analyzed using quantitative reverse transcription PCR. RESULTS: The production of PlGF in trophoblasts increased by the addition of TNF-α or IFN-γ and decreased by TLR4 ligand. sVEGFR1 levels also increased by following the stimulation with IFN-γ or TLR ligand. CONCLUSIONS: Cytokines such as TNF-α and IFN-γ and TLR ligands may contribute to the production of angiogenic and antiangiogenic factors and may affect the placental formation.

Expression of placenta growth factor, soluble fms-like tyrosine kinase-1, metal-responsive transcription factor-1, heme oxygenase 1 and hypoxia inducible factor-1α mRNAs in pre-eclampsia placenta and the effect of pre-eclampsia sera on their expression of choriocarcinoma cells.

AIM: We studied the effect of pre-eclampsia sera on the expression of placenta growth factor (PlGF), soluble fms-like tyrosine kinase-1 (sFlt-1), metal-responsive transcription factor-1 (MTF-1), heme oxygenase 1 (HO-1) and hypoxia inducible factor-1α (HIF-1α) mRNAs in JEG-3 cells (trophoblast-derived cells) and placenta from pre-eclampsia patients to investigate pre-eclampsia pathophysiology. MATERIAL AND METHODS: Placenta and serum samples were taken from pre-eclampsia and normal pregnancy patients. JEG-3 cells were cultured with pre-eclampsia and normal pregnant sera in 24-well tissue culture plates. RNA was purified from placental trophoblast cells and JEG-3 cells 24 h after incubation. The expression of mRNA was measured using real-time polymerase chain reaction. RESULTS: The expression of sFlt-1 mRNA increased, and that of PlGF and HO-1 mRNA decreased in JEG-3 cells after incubation with pre-eclampsia sera. The expression of PlGF mRNA decreased, and that of sFlt-1mRNA increased in pre-eclampsia placenta. The expression of MTF-1 and HO-1 mRNA decreased. A correlation was found between PlGF mRNA expression and the expression of MTF-1 and HIF-1α mRNA. A correlation between sFlt-1 and HIF-1α mRNA expression was also found. CONCLUSION: Changes in PlGF mRNA expression in pre-eclampsia placenta may relate to serum factors and the expression of MTF-1 and HIF-α mRNA. Changes in sFlt-1mRNA expression may relate to serum factors and the expression of HIF-α mRNA. We suggest that serum factors play a role in PlGF and sFlt-1 expression in pre-eclampsia placenta.

Effects of Hsp90 inhibitors, geldanamycin and its analog, on ceramide metabolism and cytotoxicity in PC12 cells.

The inhibitors of heat shock protein-90 (Hsp90), geldanamycin (GA) and 17-(allylamino)-17-desmethoxygeldanamycin, show various cellular effects including destabilization of Hsp90 clients and expression of other chaperones, etc. and modulate cytotoxicity depending on cell types and stimuli. In this study, we investigated the effects of Hsp90 inhibitors on survival of PC12 cells with and without cytotoxic stimuli including orthovanadate, Na(3)VO(4). Treatment with Hsp90 inhibitors at 2 µM for 16 hr did not cause cell detachment and leakage of lactate dehydrogenase, and at concentrations greater than 5 µM resulted in cytotoxicity. The inhibitors at 2 µM enhanced the cytotoxicity of 1 mM Na(3)VO(4), and did not protect PC12 cells at any concentrations against Na(3)VO(4). Next, the effects of Hsp90 inhibitors on the intracellular metabolism of ceramide and arachidonic acid (AA) were examined, since these processes also regulate cytotoxicity. In cells treated with 4-nitrobenzo-2-oxa-1,3-diazole (NBD)-labeled C6-ceramide, Hsp90 inhibitors reduced the formation of NBD-glucosylceramide and Na(3)VO(4)-induced formation of NBD-caproic acid, a counterpart of sphingosine, without affecting other metabolites including NBD-sphingomyelin. GA treatment did not change the amounts of AA released in PC12 cells with and without Na(3)VO(4). In HeLa cells, however, GA treatment decreased the release of AA via cytosolic phospholipase A(2)α's activation probably because of dysfunctional Hsp90 clients. Our results suggest the possible involvement of ceramide metabolism, not AA release, in GA-induced cytotoxicity in PC12 cells.

Dysfunction of neurogenic VIP-mediated relaxation in mouse distal colon with dextran sulfate sodium-induced colitis.

Vasoactive intestinal peptide (VIP) regulates various functions including motility and immune homeostasis in colon. The VIP system including its receptors has been established to control the development of ulcerative colitis, but the functional changes of the system-regulated motility in colon with ulcerative colitis are not well understood. In this study, we investigated VIP-related contractile responses in distal colon from mice with dextran sulfate sodium (DSS)-induced acute colitis. Electrical stimulation (ES) under our conditions caused relaxation during ES and contraction after withdrawal of ES in a tetrodotoxin-sensitive manner. Pharmacological analyses showed two phases of ES-induced relaxation: a transient neuronal nitric oxide (NO) synthase-dependent phase (I), and a continued VIP receptor-mediated phase (II). Inhibition of VIP receptors and protein kinase A decreased both phases. In colon from DSS-treated mice, ES-induced phase II (also phase I) and VIP-induced, but not cyclic AMP analog-induced, relaxation were decreased. Stimulation with VIP significantly increased cyclic AMP formation in colon preparations from control but not DSS-treated mice. In colon from DSS-treated mice, the basal cyclic AMP level was markedly greater without changes in the level of VIP receptor VPAC(2). Isoprenaline- and forskolin-induced relaxation and cyclic AMP formation were not changed by DSS treatment. These findings suggest that dysfunction of VIP receptors in muscles, in addition to loss of the neuronal VIP and NO pathways, are involved in abnormal motility in mouse colon with DSS-induced colitis.

Decrease of guanylyl cyclase ß1 subunit and nitric oxide (NO)-induced relaxation in mouse rectum with colitis and its reproduction on long-term NO treatment.

Nitric oxide (NO) influences motility in the colon in patients with ulcerative colitis, but the exact mechanism involved remains unknown. Colitis was induced in mice by the oral administration of 2.5% dextran sodium sulfate (DSS), and the motility in longitudinal preparations from rectum and distal colon and expression of ß1 subunit of soluble guanylyl cyclase (sGCß1) were analyzed. Electrical stimulation (ES) caused a transient relaxation via the NO pathway in both rectum and colon from control mice. Stimulation with sodium nitroprusside (SNP) caused relaxation in the two regions, and the half-time (T (1/2)) of the maximal relaxation induced by 100 µM SNP was 8.1 ± 1.0 s in rectum. DSS treatment (1) abolished the ES-induced relaxation, but not dibutyryl cyclic GMP-induced response, in both regions, (2) decreased the maximal response to SNP accompanied by a loss of immunoreactive sGCß1 protein in rectum, but did not affect the amplitude of the relaxant response or the protein in distal colon, and (3) caused an increase in the T (1/2) value in response to SNP in both regions. Pretreatment of both preparations from control mice with 600 µM SNP for 30 min decreased both ES- and SNP-induced relaxation, SNP-induced cyclic GMP formation, and immunoreactive sGCß1 levels. NO-mediated relaxation was impaired by a dysfunctional sGC with and without a loss of immunoreactivity to sGCß1 in rectum and colon from DSS-treated mice, respectively. Long-term exposure of the tissues with an excess amount of NO changes the sGC-mediated relaxation.

Neurogenic contraction of mouse rectum via the cyclooxygenase pathway: Changes of PGE2-induced contraction with dextran sulfate sodium-induced colitis.

Recent reports suggest that cyclooxygenases (COXs) including COX-2 are constitutively expressed, and prostaglandins (PGs) regulate motility and/or contraction in the colon and rectum. This study examines the role of COXs in the regulation of neuromuscular function in longitudinal preparations of isolated rectum and distal colon (Side A, close to the transverse colon; and Side B, close to the rectum) in normal mice and after the induction of colitis by dextran sulfate sodium (DSS). In control rectum, electrical stimulation (ES)-induced contractions were inhibited by atropine and by COX inhibitors, in an independent manner. PGE(2) at 3microM caused a marked contraction, but the secondary response at 20min after the first application was 60% desensitized. In rectum from DSS-treated mice, spontaneous and ES-induced contractions were significantly less intense than in the control preparations, and the response to PGE(2) was abolished but that to 3microM acetylcholine was not. In control distal colon, the responses to PGE(2) in neither side were desensitized by the repeated application. In DSS-treated distal colon, PGE(2) response was impaired in the two regions, and was desensitized on Side B more than Side A. DSS treatment impaired contractions by 40mM KCl in rectum and on Side B but not Side A. DSS treatment increased COX-2 expression in rectum, but not in distal colon. These findings suggest that the induction of colitis by DSS affects ES- and PGE(2)-regulated motility in the order rectum>distal colon close to the rectum>distal colon in mice.