In vitro ability of Staphylococcus aureus isolates from bacteraemic patients with and without metastatic complications to invade vascular endothelial cells

Invasion of vascular endothelial cells is thought to be a critical step in the development of metastatic infections in patients with Staphylococcus aureus bacteraemia. This study was designed to evaluate the association between the ability to invade endothelial cells and metastatic infection by S. aureus. Patients with metastatic infection were identified among those with community-acquired S. aureus bacteraemia in a tertiary referral hospital. Patients with simple bacteraemia caused by S. aureus over the same period served as the control group. The ability of each clinical isolate to invade endothelial cells was evaluated by counting the number of intracellular organisms 1 h after inoculation onto human umbilical vein endothelial cells in vitro. The cytotoxic activity of intracellular S. aureus was determined 24 h after internalization, and expressed as the percentage of cells killed. The clinical isolates varied in invasiveness and cytotoxicity. The median invasiveness, relative to S. aureus reference strain ATCC 29213, was 145 % in the cases (n=10) [interquartile range (IQR) 103-160] and 153 % (IQR 111-173) in the controls (n=11; P=0.44). The median cytotoxicity was 59.4 % (IQR 47-68) in the cases and 65.2 % (IQR 50-74) in the controls (P=0.44). Differences in the ability of S. aureus to invade and destroy vascular endothelial cells in vitro were not associated with the development of metastatic complications in patients with S. aureus bacteraemia. This implies that the invasiveness and toxicity of S. aureus for endothelial cells may not be major determinants of metastatic infection.The work was supported by grant no. 02-05-026 from the research fund of Seoul National University Bundang Hospital

Community-Acquired versus Nosocomial Klebsiella pneumoniae Bacteremia: Clinical Features, Treatment Outcomes, and Clinical Implication of Antimicrobial Resistance

We conducted this study to compare clinical features, outcomes, and clinical implication of antimicrobial resistance in Klebsiella pneumoniae bacteremia acquired as community vs. nosocomial infection. A total of 377 patients with K. pneumoniae bacteremia (191 community-acquired and 186 nosocomial) were retrospectively analyzed. Neoplastic diseases (hematologic malignancy and solid tumor, 56%) were the most commonly associated conditions in patients with nosocomial bacteremia, whereas chronic liver disease (35%) and diabetes mellitus (20%) were the most commonly associated conditions in patients with community-acquired bacteremia. Bacteremic liver abscess occurred almost exclusively in patients with community-acquired infection. The overall 30-day mortality was 24% (91/377), and the mortality of nosocomial bacteremia was significantly higher than that of community-acquired bacteremia (32% vs. 16%, p<0.001). Of all community-acquired and nosocomial isolates, 4% and 33%, respectively, were extended-spectrum cephalosporin (ESC)-resistant, and 4% and 21%, respectively, were ciprofloxacin (CIP)-resistant. In nosocomial infections, prior uses of ESC and CIP were found to be independent risk factors for ESC and CIP resistance, respectively. Significant differences were identified between community-acquired and nosocomial K. pneumoniae bacteremia, and the mortality of nosocomial infections was more than twice than that of community-acquired infections. Antimicrobial resistance was a widespread nosocomial problem and also identified in community-acquired infections

Preparation of Mullite-Silica Composites Using Silica-Rich Monophasic Precursor Obtained as a Byproduct of Mineral Carbonation of Blast-Furnace Slag

Previously, mineral carbonation of blast-furnace slag was carried out to sequestrate CO2 and attain pure CaCO3 crystals. In this process, amorphous silica-alumina nanoparticles were obtained as a byproduct. In this study, the crystallization of these nanoparticles on calcination at various temperatures in air was examined using TGA-DTA, XRD, MAS-NMR spectroscopy, and FT-IR spectroscopy. The precursor nanoparticles (Si:Al = 78:22 mol %) were prepared using the solution extracted from blast-furnace slag (BFS) with acetic acid at room temperature. The XRD analysis showed that the initial amorphous state was retained up to 800 &deg;C, and decomposition to amorphous silica and mullite started after calcination at 950 &deg;C. At temperatures between 1150 &deg;C and 1250 &deg;C, amorphous silica crystalized to cristobalite, which eventually melted to glassy silica at 1500 &deg;C. The mullite crystals initially adopted a metastable tetragonal phase and transformed to a stable, needle-like orthorhombic phase at higher temperatures. 27Al MAS-NMR spectroscopy revealed that octahedrally coordinated Al was favored up to a temperature of 800 &deg;C as a result of the dehydration process and transformed into tetrahedrally coordinated Al at higher temperatures. A microstructural examination revealed that the initially randomly-oriented mullite developed into stable, needle-like grains owing to anisotropic grain growth in the presence of a glass phase at high temperatures. This study suggests that the recycling of BFS can be exploited for the procurement of a mullite-type ceramic material

Preparation of Silica-Alumina Nanoparticles via Blast-Furnace Slag Dissolution in Low-Concentration Acetic Acid for Carbonation

Blast-furnace slag (BFS) has been used as a feedstock for CO2 sequestration by indirect mineral carbonation to produce calcium carbonate precipitates and solid residues. The most-abundant elements in these residues, Si and Al, are usually considered to be impurities that need to be removed in acid-dissolution processes involving BFS. The co-production of value-added materials from these residues is an attractive option for strengthening the economic competitiveness of mineral carbonation methods. In view of this, we separated the Si and Al, as their hydrated forms, during the dissolution of BFS in acetic acid prior to carbonation. During the sol-gel processing of Si-Al nanoparticles, a catalyst is usually required during the hydrolysis and subsequent condensation processes. In this study, only condensation occurs because the low-concentrations of acetic acid used facilitate in-situ hydrolysis during the dissolution process. Aging was carried out not only to structurally arrange the Si and Al but also to oxidize the marginal Fe(II) to reddish Fe(III). Silica-alumina nanoparticles (78% Si and 22% Al) were prepared by a simple sol-gel route at ambient pressure. These nanoparticles were amorphous and below 20 nm in size. Fourier-transform infrared (FT-IR) studies reveal that the nanoparticles consist of Si–O–Si and Si–O–Al bonds. 27Al nuclear magnetic resonance (NMR) spectroscopy reveals a significant resonance corresponding to tetra-coordinated Al inside the particle framework

Paclitaxel/platinum-based perioperative chemotherapy and surgery in stage IIIA non-small cell lung cancer

Objective: The objectives of the present study were to assess the efficacy and tolerability of perioiperative paclitaxel/platinum-based chemotherapy and surgery in patients with stage IIIA clinical N2 (cN2) non-small cell lung cancer (NSCLC). Methods: Clinical N2 was defined as either > 15 mm or > 10 mm and multiple nodes on computed tomography (CT) scan. Thirty-four chemotherapy-naive patients with stage IIIA cN2 received preoperative paclitaxel/cisplatin for two cycles and then underwent surgery. The treatment with paclitaxel/carboplatin was repeated for three cycles after the operation. Results: Of the 34 patients, none achieved a complete response (CR) and 22 achieved a partial response (PR), resulting in a response rate of 65%. Among 29 patients (85%) who had received thoracotomy, 25 (74%) underwent complete resection. Two pathological CRs were observed and mediastinal nodes were free of tumor in 21 %. Grade 3-4 toxicity was uncommon and treatment-related mortality was not observed. The median time to progression (TTP) was 12.1 months [95% confidence interval (CI) 8.3-15.9 months] and median overall survival (OS) was 23.6 months (95% CI 17.7-30.2 months). Conclusions: Paclitaxel/platinum-based perioperative chemotherapy and surgery for patients with stage IIIA cN2 NSCLC is effective and well tolerated.

Triple negativity and young age as prognostic factors in lymph node-negative invasive ductal carcinoma of 1 cm or less

Background: Whether a systemic adjuvant treatment is needed is an area of controversy in patients with node-negative early breast cancer with tumor size of <= 1 cm, including T1mic. Methods: We performed a retrospective analysis of clinical and pathology data of all consecutive patients with node-negative T1mic, T1a, and T1b invasive ductal carcinoma who received surgery between Jan 2000 and Dec 2006. The recurrence free survival (RFS) and risk factors for recurrence were identified. Results: Out of 3889 patients diagnosed with breast cancer, 375 patients were enrolled (T1mic:120, T1a:93, T1b:162). Median age at diagnosis was 49. After a median follow up of 60.8 months, 12 patients developed recurrences (T1mic:4 (3.3%), T1a:2 (2.2%), T1b:6 (3.7%)), with a five-year cumulative RFS rate of 97.2%. Distant recurrence was identified in three patients. Age younger than 35 years (HR 4.91; 95% CI 1.014-23.763, p = 0.048) and triple negative disease (HR 4.93; 95% CI 1.312-18.519, p = 0.018) were significantly associated with a higher rate of recurrence. HER2 overexpression, Ki-67, and p53 status did not affect RFS. Conclusions: Prognosis of node-negative breast cancer with T1mic, T1a and T1b is excellent, but patients under 35 years of age or with triple negative disease have a relatively high risk of recurrence.Jung SY, 2009, ANN SURG ONCOL, V16, P1112, DOI 10.1245/s10434-009-0334-7Hugh J, 2009, J CLIN ONCOL, V27, P1168, DOI 10.1200/JCO.2008.18.1024Tovey SM, 2009, BRIT J CANCER, V100, P680, DOI 10.1038/sj.bjc.6604940Menard S, 2008, ANN ONCOL, V19, P1706, DOI 10.1093/annonc/mdn369Baak JPA, 2008, ANN ONCOL, V19, P649, DOI 10.1093/annonc/mdm535Soerjomataram I, 2008, BREAST CANCER RES TR, V107, P309, DOI 10.1007/s10549-007-9556-1RAKKHIT RBK, 2008, 31 CTRC AACR SAN ANTHanrahan EO, 2007, J CLIN ONCOL, V25, P4952, DOI 10.1200/JCO.2006.08.0499Duijm LEM, 2007, BREAST CANCER RES TR, V106, P113, DOI 10.1007/s10549-006-9468-5Torrisi R, 2007, EUR J CANCER, V43, P2339, DOI 10.1016/j.ejca.2007.07.033Ahn SH, 2007, J CLIN ONCOL, V25, P2360, DOI 10.1200/JCO.2006.10.3754Agarwal G, 2007, WORLD J SURG, V31, P1031, DOI 10.1007/s00268-005-0585-9Railo M, 2007, TUMOR BIOL, V28, P45, DOI 10.1159/000097702Ponzone R, 2006, ANN ONCOL, V17, P1631, DOI 10.1093/annonc/mdl296Colleoni M, 2006, ANN ONCOL, V17, DOI 10.1093/annonc/mdj087Louwman WJ, 2006, INT J CANCER, V118, P2310, DOI 10.1002/ijc.21623Son BH, 2006, ARCH SURG-CHICAGO, V141, P155Cavaliere A, 2006, PATHOL RES PRACT, V202, P131, DOI 10.1016/j.prp.2006.01.001Berry DA, 2005, NEW ENGL J MED, V353, P1784, DOI 10.1056/NEJMoa050518Trudeau ME, 2005, BREAST CANCER RES TR, V89, P35Colleoni M, 2004, ANN ONCOL, V15, P1633, DOI 10.1093/annonc/mdh434Chia SK, 2004, J CLIN ONCOL, V22, P1630, DOI 10.1200/JCO.2004.09.070Ahn SH, 2004, ARCH SURG-CHICAGO, V139, P27Choi DH, 2003, CANCER, V98, P1587, DOI 10.1002/cncr.11703Otto SJ, 2003, LANCET, V361, P1411Joensuu H, 2003, CLIN CANCER RES, V9, P923*CANC AJCO, 2002, AJCC CANC STAG MAN, P6Fisher B, 2001, J NATL CANCER I, V93, P112Joensuu H, 1999, CANCER, V85, P2183Parker SL, 1997, CA-CANCER J CLIN, V47, P5LEITNER SP, 1995, CANCER, V76, P2266QUIET CA, 1995, J CLIN ONCOL, V13, P1144STIERER M, 1992, SURG GYNECOL OBSTET, V175, P151PARK SY, CLIN CANC RES, V16, P876