Enterohemorrhagic Escherichia coli O157:H7 Shiga toxins inhibit gamma interferon-mediated cellular activation

Enterohemorrhagic Escherichia coli (EHEC) serotype O157:H7 is a food-borne pathogen that causes significant morbidity and mortality in developing and industrialized nations. EHEC infection of host epithelial cells is capable of inhibiting the gamma interferon (IFN-γ) proinflammatory pathway through the inhibition of Stat-1 phosphorylation, which is important for host defense against microbial pathogens. The aim of this study was to determine the bacterial factors involved in the inhibition of Stat-1 tyrosine phosphorylation. Human HEp-2 and Caco-2 epithelial cells were challenged directly with either EHEC or bacterial culture supernatants and stimulated with IFN-γ, and then the protein extracts were analyzed by immunoblotting. The data showed that IFN-γ-mediated Stat-1 tyrosine phosphorylation was inhibited by EHEC secreted proteins. Using two-dimensional difference gel electrophoresis, EHEC Shiga toxins were identified as candidate inhibitory factors. EHEC Shiga toxin mutants were then generated and complemented in trans, and mutant culture supernatant was supplemented with purified Stx to confirm their ability to subvert IFN-γ-mediated cell activation. We conclude that while other factors are likely involved in the suppression of IFN-γ-mediated Stat-1 tyrosine phosphorylation, E. coli-derived Shiga toxins represent a novel mechanism by which EHEC evades the host immune system.     

Thickness and tension of the gluteal aponeurosis and the implications for subfascial gluteal augmentation

The aim of this study is to elucidate the thickness and tension of the gluteal aponeurosis (GA) as related to subfascial gluteal augmentation. Twenty buttocks from 10 Korean fresh cadavers (age range: 69-92 years, five men and five women) were dissected. Five radial lines were made from the greater trochanter (GT) to the highest point of origin of the gluteus maximus muscle (GM), the posterior inferior iliac spine (PSIS), the piriformis line (P), the coccyx (Co) and the ischial tuberosity (IT). The upper four lines were intersected by three curvilinear lines that divided them by a quarter, half and three-quarters ratios, and the lowest line was divided by a third ratio and a two-thirds ratio. At the 14 intersecting points, the force needed to break the 6 mm width of the GA was measured. The thickness of the GA was also measured with a digital caliper. The GA was widest at the GT-Co line (161.7±15.8 mm), and it was narrowest at the GT-IT line (106.5±21.2 mm). At most of the points (12 among the 14 points), the breaking strength of the GA was greater than 20 Newtons (N). The breaking strength of the GA did not vary significantly according to the locations (P=0.568, anova). The breaking strength of the males (22.8±6.6 N) was significantly greater than that of the females (20.3±7.5 N, P=0.003, t-test). The thickness of the GA varied according to the locations (0.4±0.2 mm to 0.7±0.3 mm). The thickness of the GA of the upper part (GT-GM line: 0.64±0.24 mm; GT-PSIS line: 0.66±0.23 mm; GT-P line: 0.66±0.24 mm) was significantly greater (P=0.040, 0.017, 0.018, respectively) than that of the lower part (GT-IT line: 0.49±0.18 mm). The GA of the males (0.70±0.23 mm) was significantly thicker than that of the females (0.53±0.21 mm, P<0.001, t-test). We conclude that the GA is capable of holding gluteal implants in the proper position, as the average force to break up the 6 mm width of the GA in females was greater than 20 N.     

Pathway analysis of genome-wide association studies on uric acid concentrations

Objective

The aims of this study were to identify the candidate causal single nucleotide polymorphisms (SNPs) and candidate causal mechanisms influencing uric acid level and to generate hypotheses for the SNP to gene to pathways that influence uric acid concentrations.

Methods

Meta-analysis data of 954 SNPs with genome-wide significance in 14 genome-wide association studies (GWASs) comprising 28,141 individuals of European ancestry was subjected to ICSNPathway (Identify candidate Causal SNPs and Pathways) analysis to establish associations between pathways and uric acid concentrations.

Results

ICSNPathway analysis identified 14 candidate causal SNPs, five genes, and two candidate causal pathways, which provided two hypothetical biologic mechanisms: (1) rs2728121 (regulatory region) to polycystic kidney disease 2 (PKD2) to ion transmembrane transporter activity; (2) rs942377, rs3799346, rs3799344, rs2762353, rs13197601, rs3757131, rs1165215, rs1165196 to SLC17A1 to ion transmembrane transporter activity and secondary active transmembrane transporter activity. SLC17A1, SLC17A3, SLC17A4, SLC22A11, and SLC2A9 were involved in both pathways, and PKD2 and SLC16A9 in one pathway.

Conclusion

By applying ICSNPathway analysis to GWAS data on uric acid levels, 14 SNPs, five genes, and two pathways involving the PKD2, SLC17A1, SLC17A3, SLC17A4, and SLC2A9 genes were identified that might contribute to the condition in Europeans.     

Involvement of endoplasmic reticulum stress in myofibroblastic differentiation of lung fibroblasts

Stress that impairs endoplasmic reticulum (ER) function leads to an accumulation of unfolded or misfolded proteins in the ER (ER stress) and triggers the unfolded protein response (UPR). Recent studies suggest that ER stress is involved in idiopathic pulmonary fibrosis (IPF). The present study was undertaken to determine the role of ER stress on myofibroblastic differentiation of fibroblasts. Fibroblasts in fibroblastic foci of IPF showed immunoreactivity for GRP78. To determine the role of ER stress on α-smooth muscle actin (α-SMA) and collagen type I expression in fibroblasts, mouse and human lung fibroblasts were treated with TGF-β1, and expression of ER stress-related proteins, α-SMA, and collagen type I was analyzed by Western blotting. TGF-β1 significantly increased expression of GRP78, XBP-1, and ATF6α, which was accompanied by increases in α-SMA and collagen type I expression in mouse and human fibroblasts. A chemical chaperone, 4-PBA, suppressed TGF-β1-induced UPR and α-SMA and collagen type I induction. We also showed that TGF-β1-induced UPR was mediated through the reactive oxygen species generation. Our study provides the first evidence implicating the UPR in myofibroblastic differentiation during fibrosis. These findings of the role of ER stress and chemical chaperones in pulmonary fibrosis may improve our understanding of the pathogenesis of IPF.     

Outpatient-basis chemotherapy of oxaliplatin, 5-fluorouracil, and leucovorin as first-line treatment for patients with metastatic or recurrent colorectal cancer

The objectives of the present study were to evaluate the efficacy and safety of an outpatient-basis chemotherapy of oxaliplatin, 5-fluorouracil, and leucovorin as the first-line treatment for patients with advanced colorectal cancer. Forty-three histologically confirmed patients with metastatic or recurrent colorectal cancer were enrolled. The chemotherapy consisted of oxaliplatin 85 mg/m(2) as a 2-hr infusion on day 1, plus leucovorin 30 mg/m(2) over 10 min, followed by bolus 5-fluorouracil 400 mg/m(2) and an 8-hr infusion of 5-fluorouracil 600 mg/m(2) on days 1 and 2 (modified FOLFOX4), all of which were administered on an outpatient basis every 2 weeks. The median age was 58 yr (range 33-72 yr), and 25 (58.1%) patients had metastatic diseases. Eventually, 39 patients were assessable for efficacy and all assessable for toxicity. Four (9.3%) complete responses and 11 (25.6%) partial responses were confirmed, giving an overall response rate of 34.9% (95% CI; 20.0-49.7%). The median time to progression and median overall survival for all patients was 6.1 months and 17.4 months, respectively. Grade 3/4 neutropenia occurred in 2 patients (4.7%) and febrile neutropenia was observed in 1 patient (2.3%). Modified FOLFOX4, an outpatient-basis regimen, was found to be well-tolerated and effective as the first-line chemotherapy in patients with advanced colorectal cancer.     

Discovery of a novel Mycobacterium tuberculosis lineage that is a major cause of tuberculosis in Rio de Janeiro, Brazil

The current study evaluated Mycobacterium tuberculosis isolates from Rio de Janeiro, Brazil, for genomic deletions. One locus in our panel of PCR targets failed to amplify in approximately 30% of strains. A single novel long sequence polymorphism (>26.3 kb) was characterized and designated RD(Rio). Homologous recombination between two similar protein-coding genes is proposed as the mechanism for deleting or modifying 10 genes, including two potentially immunogenic PPE proteins. The flanking regions of the RD(Rio) locus were identical in all strains bearing the deletion. Genetic testing by principal genetic group, spoligotyping, variable-number tandem repeats of mycobacterial interspersed repetitive units (MIRU-VNTR), and IS6110-based restriction fragment length polymorphism analysis cumulatively support the idea that RD(Rio) strains are derived from a common ancestor belonging solely to the Latin American-Mediterranean spoligotype family. The RD(Rio) lineage is therefore the predominant clade causing tuberculosis (TB) in Rio de Janeiro and, as indicated by genotypic clustering in MIRU-VNTR analysis, the most significant source of recent transmission. Limited retrospective reviews of bacteriological and patient records showed a lack of association with multidrug resistance or specific risk factors for TB. However, trends in the data did suggest that RD(Rio) strains may cause a form of TB with a distinct clinical presentation. Overall, the high prevalence of this genotype may be related to enhanced virulence, transmissibility, and/or specific adaptation to a Euro-Latin American host population. The identification of RD(Rio) strains outside of Brazil points to the ongoing intercontinental dissemination of this important genotype. Further studies are needed to determine the differential strain-specific features, pathobiology, and worldwide prevalence of RD(Rio) M. tuberculosis.     

Thermal therapy for breast tumors by using a cylindrical ultrasound phased array with multifocus pattern scanning: a preliminary numerical study

The purpose of this study is to investigate the feasibility of using a 1 MHz cylindrical ultrasound phased array with multifocus pattern scanning to produce uniform heating for breast tumor thermal therapy. The breast was submerged in water and surrounded by the cylindrical ultrasound phased array. A multifocus pattern was generated and electrically scanned by the phased array to enlarge the treatment lesion in single heating. To prevent overheating normal tissues, a large planning target volume (PTV) would be divided into several planes with several subunits on each plane and sequentially treated with a cooling phase between two successive heatings of the subunit. Heating results for different target temperatures (T(tgt)), blood perfusion rates and sizes of the PTV have been studied. Furthermore, a superficial breast tumor with different water temperatures was also studied. Results indicated that a higher target temperature would produce a slightly larger thermal lesion, and a higher blood perfusion rate would not affect the heating lesion size but increase the heating time significantly. The acoustic power deposition and temperature elevations in ribs can be minimized by orienting the acoustic beam from the ultrasound phased array approximately parallel to the ribs. In addition, a large acoustic window on the convex-shaped breast surface for the proposed ultrasound phased array and the cooling effect of water would prevent the skin overheating for the production of a lesion at any desired location. This study demonstrated that the proposed cylindrical ultrasound phased array can provide effective heating for breast tumor thermal therapy without overheating the skin and ribs within a reasonable treatment time.     

Human placenta-derived feeders support prolonged undifferentiated propagation of a human embryonic stem cell line, SNUhES3: comparison with human bone marrow-derived feeders

Co-culture of human embryonic stem (ES) cells on mouse fibroblast feeders is the commonly used method for in vitro expansion of human ES cells in an undifferentiated state. However, it has potential risks of pathogen transmission from animals; thus, human cell-derived feeders have been employed to minimize this problem. In this study, we compared human placenta-derived feeders with bone marrow to demonstrate its effectiveness as feeders for in vitro long-term culture of human ES cells. We cultured a human ES cell line, SNUhES3, on human placenta-derived mesenchymal stem cell feeders and compared their culture efficiency with human bone marrow-derived feeders and control group (mouse fibroblast feeders, STO). The mean number of human ES cell colonies was 166 +/- 35 in the placenta feeders; this was significantly higher than bone marrow-derived feeders (87 +/- 16, p < 0.05). We could propagate the culture of SNUhES3 on the placenta feeders past the 50th week similar to control group. During the culture, the maintenance of undifferentiated state of SNUhES3 was demonstrated by the expression of SSEA-4, TRA-1-81, TRA-1-60, and Oct-4. However, we failed to propagate the culture of human ES cells on the human bone marrow-derived feeders past the 5th week. The efficiency of embryoid body formation was similar between placenta and control group, indicating the preservation of differentiation ability. Thus, placenta-derived feeders are more efficient for the long-term in vitro culture of human ES cells than bone marrow-derived feeders suggesting the possible role of placenta as a source for human cell-derived feeders.     

Polymerase chain reaction identification of three members of the Anopheles sundaicus (Diptera: Culicidae) complex, malaria vectors in Southeast Asia

Anopheles sundaicus s.l., a major malaria vector taxon, occurs primarily along coastal areas and on islands in Southeast Asia. Our previous studies using cytochrome oxidase I, cytochrome-b, and internal transcribed spacer 2 markers discriminated three allopatric species: An. sundaicus s.s. in northern Borneo, An. epiroticus in Southeast Asia, and An. sundaicus E on Sumatra and Java, Indonesia. Morphological comparisons of three developmental stages did not reveal unique diagnostic characters that could reliably distinguish the three species. Therefore, we developed a multiplex polymerase chain reaction (PCR) assay based on two mitochondrial DNA markers to unambiguously identify them. This PCR was tested on 374 specimens from 24 different geographical populations, expanding our knowledge of the distribution of these species.     

Persistent monocytosis after intravenous immunoglobulin therapy correlated with the development of coronary artery lesions in patients with Kawasaki disease.

BACKGROUND AND PURPOSE: This study was conducted to investigate whether changes in the complete blood count (CBC)/differential count (DC) and C-reactive protein (CRP) were correlated to Kawasaki disease (KD) with coronary artery lesions (CALs). METHODS: A retrospective analysis was performed of all children with KD at Chang Gung Memorial Hospital at Kaohsiung from 2001 to 2006. KD patients were divided into those with and without CALs for testing of correlations with changes in CBC/DC and CRP levels. RESULTS: A total of 147 patients were enrolled for this analysis. Serial CBC/DC and CRP measurements and echocardiographic data for determination of CAL formation were obtained before and after intravenous immunoglobulin (IVIG) treatment. There were 44 (29%) KD patients having CAL formation (>3 mm in diameter of internal lumen). There was no significant difference in terms of age distribution and major diagnostic criteria between KD patients with and without CALs. Male KD patients, however, had a significantly higher rate of CAL formation (p=0.009). In multivariate logistical regression analysis, persistent monocytosis after IVIG treatment was the only factor significantly correlated to CAL formation (p=0.003). CONCLUSIONS: Of the febrile routine measurements of CBC/DC and CRP in KD, persistent monocytosis after IVIG treatment was correlated to CAL formation. Further studies to clarify the mechanism of monocytosis may help prevent the CALs of KD.