Relationship between Productive HIV-1 Infection of Macrophages and CCR5 Utilization

AbstractHIV-1 isolates exhibit specificity for infection of immortalized T-cell lines and macrophages. The distinct cellular tropisms have been attributed to expression of coreceptors CXCR4 or CCR5, respectively. However, it is unclear whether or not other tissue-specific determinants regulate entry. The current study uses a panel of viruses to analyze the relationship between CCR5 utilization and macrophage infection. Only chimeric viruses with the entire V3 loop from macrophage-tropic isolates, ADA or SF162, were able to infect macrophages. In contrast, chimeric viruses with smaller portions of the ADA V3 loop or the V3 loop of SF2, sufficient to allow CCR5 use, were insufficient for macrophage infection. PCR analysis showed that the defect in macrophage infection of the latter viruses was due to a defect in entry. Moreover, strains capable of infecting macrophages showed relative resistance to neutralization by anti-CCR5 antibody, 2D7, compared to strains which utilize CCR5 but are incapable of macrophage infection

Streptozocin-Induced Diabetic Mouse Model of Urinary Tract Infection▿

Diabetics have a higher incidence of urinary tract infection (UTI), are infected with a broader range of uropathogens, and more commonly develop serious UTI sequelae than nondiabetics. To better study UTI in the diabetic host, we created and characterized a murine model of diabetic UTI using the pancreatic islet β-cell toxin streptozocin in C3H/HeN, C3H/HeJ, and C57BL/6 mouse backgrounds. Intraperitoneal injections of streptozocin were used to initiate diabetes in healthy mouse backgrounds, as defined by consecutive blood glucose levels of >250 mg/dl. UTIs caused by uropathogenic Escherichia coli (UTI89), Klebsiella pneumoniae (TOP52 1721), and Enterococcus faecalis (0852) were studied, and diabetic mice were found to be considerably more susceptible to infection. All three uropathogens produced significantly higher bladder and kidney titers than buffer-treated controls. Uropathogens did not have as large an advantage in the Toll-like receptor 4-defective C3H/HeJ diabetic mouse, arguing that the dramatic increase in colonization seen in C3H/HeN diabetic mice may partially be due to diabetic-induced defects in innate immunity. Competition experiments demonstrated that E. coli had a significant advantage over K. pneumoniae in the bladders of healthy mice and less of an advantage in diabetic bladders. In the kidneys, K. pneumoniae outcompeted E. coli in healthy mice but in diabetic mice E. coli outcompeted K. pneumoniae and caused severe pyelonephritis. Diabetic kidneys contained renal tubules laden with communities of E. coli UTI89 bacteria within an extracellular-matrix material. Diabetic mice also had glucosuria, which may enhance bacterial replication in the urinary tract. These data support that this murine diabetic UTI model is consistent with known characteristics of human diabetic UTI and can provide a powerful tool for dissecting this infection in the multifactorial setting of diabetes

Endovascular intervention in Taiwanese patients with critical limb ischemia: Patient outcomes in 333 consecutive limb procedures with a 3-year follow-up

Midterm outcomes of endovascular intervention (EVI) for critical limb ischemia (CLI) have not been previously reported in Taiwan. This study assessed the safety, feasibility, and patient-oriented outcomes for CLI patients after EVI. Methods: From June 2005 to December 2011, 270 patients underwent EVI for CLI of 333 limbs. Primary patency (PP), assisted primary patency (AP), limb salvage, sustained clinical success (SCS), secondary SCS (SSCS), and survival were assessed using Kaplan-Meier analysis. Results: The procedural success rate was 89%, and the periprocedural mortality and major complication rates within 30 days were 0.6% and 6.9%, respectively. During the mean follow-up time of 27 ± 20 months (1–77), 64 patients died and 25 legs required major amputation. Eighty-one percent of the patients with tissue loss had wound healing at 6 months and 75% of the patients were ambulatory, with or without assisting devices, at 1 year. The overall survival and limb salvage rates at 3 years were 70% and 90%, respectively. The PP and AP at 1 and 3 years were 58% and 37% and 79% and 61%, respectively. The SCS and SSCS were 65% and 46% and 80% and 64% at 1 and 3 years, respectively. Conclusion: In Taiwan, EVI was a safe and feasible procedure for CLI patients, with a high procedural success rate and lower complication rate. Sustained limb salvage and clinical success can be afforded with an active surveillance program and prompt intervention during midterm follow-up

Iridescent biofilms of Cellulophaga lytica are tunable platforms for scalable, ordered materials

Abstract Nature offers many examples of materials which exhibit exceptional properties due to hierarchical assembly of their constituents. In well-studied multi-cellular systems, such as the morpho butterfly, a visible indication of having ordered submicron features is given by the display of structural color. Detailed investigations of nature’s designs have yielded mechanistic insights and led to the development of biomimetic materials at laboratory scales. However, the manufacturing of hierarchical assemblies at industrial scales remains difficult. Biomanufacturing aims to leverage the autonomy of biological systems to produce materials at lower cost and with fewer carbon emissions. Earlier reports documented that some bacteria, particularly those with gliding motility, self-assemble into biofilms with polycrystalline structures and exhibit glittery, iridescent colors. The current study demonstrates the potential of using one of these bacteria, Cellulophaga lytica, as a platform for the large scale biomanufacturing of ordered materials. Specific approaches for controlling C. lytica biofilm optical, spatial and temporal properties are reported. Complementary microscopy-based studies reveal that biofilm color variations are attributed to changes in morphology induced by cellular responses to the local environment. Incorporation of C. lytica biofilms into materials is also demonstrated, thereby facilitating their handling and downstream processing, as would be needed during manufacturing processes. Finally, the utility of C. lytica as a self-printing, photonic ink is established by this study. In summary, autonomous surface assembly of C. lytica under ambient conditions and across multiple length scales circumvent challenges that currently hinder production of ordered materials in industrial settings