917 research outputs found
Th1 Cytokine-Secreting Recombinant Mycobacterium bovis Bacillus Calmette-Guérin and Prospective Use in Immunotherapy of Bladder Cancer
Intravesical instillation of Mycobacterium bovis bacillus Calmette-Guérin (BCG) has been used for treating bladder cancer for 3 decades. However, BCG therapy is ineffective in approximately 30–40% of cases. Since evidence supports the T helper type 1 (Th1) response to be essential in BCG-induced tumor destruction, studies have focused on enhancing BCG induction of Th1 immune responses. Although BCG in combination with Th1 cytokines (e.g., interferon-α) has demonstrated improved efficacy, combination therapy requires multiple applications and a large quantity of cytokines. On the other hand, genetic manipulation of BCG to secrete Th1 cytokines continues to be pursued with considerable interest. To date, a number of recombinant BCG (rBCG) strains capable of secreting functional Th1 cytokines have been developed and demonstrated to be superior to BCG. This paper discusses current rBCG research, concerns, and future directions with an intention to inspire the development of this very promising immunotherapeutic modality for bladder cancer
Review of Topical Treatment of Upper Tract Urothelial Carcinoma
A select group of patients with upper tract urothelial carcinoma may be appropriate candidates for minimally invasive management. Organ-preserving endoscopic procedures may be appropriate for patients with an inability to tolerate major surgery, solitary kidney, bilateral disease, poor renal function, small tumor burden, low-grade disease, or carcinoma in situ. We review the published literature on the use of topical treatment for upper tract urothelial carcinoma and provide our approach to treatment in the office setting
Bis(2-acetylpyridine-κ2 N,O)silver(I) tetrafluoridoborate: a complex with silver in a seesaw coordination geometry
The reaction of 2-acetylpyridine with silver(I) tetrafluoridoborate leads to the discrete title complex, [Ag(C7H7NO)2]BF4, in the cation of which the Ag atom is coordinated by two 2-acetylpyridine ligands, each of which is N,O-bidentate, albeit with stronger bonding to the N atoms [Ag—N = 2.2018 (15) and 2.2088 (14) Å; Ag—O = 2.5380 (13) and 2.5454 (13) Å]. The four-coordinate Ag atom has a seesaw coordination geometry with a τ4 index of 0.51. The tetrafluoridoborate anion is disordered over two orientations with 0.568 (10):0.432 (10) occupancies
Rubin H. Flocks and Colloidal Gold Treatments for Prostate Cancer
In the early 1950s, Rubin H. Flocks of the University of Iowa began to treat prostate cancer patients with colloidal gold (Au198) therapy, evolving his technique over nearly 25 years in 1515 patients. We reviewed the long-term outcomes of Flocks' prostate cancer patients as compared to those patients treated by other methods at the University of Iowa before Flocks' chairmanship. We reviewed archived patient records, Flocks' published data, and long-term survival data from the Iowa Tumor Registry to determine short- and long-term outcomes of Flocks' work with colloidal gold. We also reviewed the literature of Flocks’ time to compare his outcomes against those of his contemporaries. The use of colloidal gold, either as primary or adjunctive therapy, provided short- and long-term survival benefit for the majority of Flocks' patients as compared to historical treatment options (p < 0.001). Flocks' use of colloidal gold for the treatment of locally advanced prostate cancer offered short- and long-term survival benefits compared to other contemporary treatments
Murine Cytomegalovirus Is Regulated by a Discrete Subset of Natural Killer Cells Reactive with Monoclonal Antibody to Ly49h
Antiviral roles of natural killer (NK) cell subsets were examined in C57BL/6 mice infected with murine cytomegalovirus (MCMV) and other viruses, including lymphocytic choriomeningitis virus (LCMV), vaccinia virus (VV), and mouse hepatitis virus (MHV). Each virus vigorously induced an NK cell infiltrate into the peritoneal cavity and liver, causing some redistributions of NK cell subsets defined by monoclonal antibody (mAb) directed against Ly49A, C/I, D, and G2. Striking results were seen with a mAb (1F8) reactive with the positively signaling molecule Ly49H, present in MCMV-resistant C57BL/6 mice. mAb 1F8 also stains Ly49 C and I, but exclusion of those reactivities with mAb 5E6, which recognizes Ly49 C and I, indicated that Ly49H+ cells infiltrated the peritoneal cavity and liver and were particularly effective at synthesizing interferon γ. Depletion of 1F8+ but not 5E6+ cells in vivo by mAb injections enhanced MCMV titers by 20-1,000-fold in the spleen and approximately fivefold in the liver. Titers of LCMV or VV were not enhanced. These anti-MCMV effects were attributed to prototypical NK1.1+CD3− NK cells and not to NK1.1+CD3+ “NK/T” cells. This is the first evidence that control of a virus infection in vivo is mediated by a distinct NK cell subset
Intramembrane proteolysis mediates shedding of a key adhesin during erythrocyte invasion by the malaria parasite.
Apicomplexan pathogens are obligate intracellular parasites. To enter cells, they must bind with high affinity to host cell receptors and then uncouple these interactions to complete invasion. Merozoites of Plasmodium falciparum, the parasite responsible for the most dangerous form of malaria, invade erythrocytes using a family of adhesins called Duffy binding ligand-erythrocyte binding proteins (DBL-EBPs). The best-characterized P. falciparum DBL-EBP is erythrocyte binding antigen 175 (EBA-175), which binds erythrocyte surface glycophorin A. We report that EBA-175 is shed from the merozoite at around the point of invasion. Shedding occurs by proteolytic cleavage within the transmembrane domain (TMD) at a site that is conserved across the DBL-EBP family. We show that EBA-175 is cleaved by PfROM4, a rhomboid protease that localizes to the merozoite plasma membrane, but not by other rhomboids tested. Mutations within the EBA-175 TMD that abolish cleavage by PfROM4 prevent parasite growth. Our results identify a crucial role for intramembrane proteolysis in the life cycle of this pathogen
Molecular Identification of a Malaria Merozoite Surface Sheddase
Proteolytic shedding of surface proteins during invasion by apicomplexan parasites is a widespread phenomenon, thought to represent a mechanism by which the parasites disengage adhesin-receptor complexes in order to gain entry into their host cell. Erythrocyte invasion by merozoites of the malaria parasite Plasmodium falciparum requires the shedding of ectodomain components of two essential surface proteins, called MSP1 and AMA1. Both are released by the same merozoite surface “sheddase,” but the molecular identity and mode of action of this protease is unknown. Here we identify it as PfSUB2, an integral membrane subtilisin-like protease (subtilase). We show that PfSUB2 is stored in apical secretory organelles called micronemes. Upon merozoite release it is secreted onto the parasite surface and translocates to its posterior pole in an actin-dependent manner, a trafficking pattern predicted of the sheddase. Subtilase propeptides are usually selective inhibitors of their cognate protease, and the PfSUB2 propeptide is no exception; we show that recombinant PfSUB2 propeptide binds specifically to mature parasite-derived PfSUB2 and is a potent, selective inhibitor of MSP1 and AMA1 shedding, directly establishing PfSUB2 as the sheddase. PfSUB2 is a new potential target for drugs designed to prevent erythrocyte invasion by the malaria parasite
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