Isolation and identification of an antifungal compound from endophytic Streptomyces sp. CEN26 active against Alternaria brassicicola.

UNLABELLED: 2,5-Bis(hydroxymethyl)furan monoacetate (BHMF-OAc) compound was isolated from the culture filtrate secreted by Streptomyces sp. CEN26, an endophytic actinomycete found in the root nodes of Centella asiatica (L.) Urban. The compound was purified using various chromatographic techniques and bioassay-guided fractionation. The compound was then identified through a structural characterization using (1) H, (13) C-NMR and MS analysis. After the purification and identification process, a series of experiments were conducted in order to test whether the compound affected conidial germination of Alternaria brassicicola. Findings show that the compound inhibited and deformed the conidial germination of A. brassicicola. Its minimal inhibitory concentrations of MIC90 and MIC50 were found to be 100 and 25 ppm respectively. Further experimentation show that the aforementioned concentrations of MIC90 and MIC50 completely suppressed the appressorium formation of the fungal pathogen. Therefore, the BHMF-OAc compound does have antifungal properties that help protect plants from infection by A. brassicicola. SIGNIFICANCE AND IMPACT OF THE STUDY: Endophytic Streptomyces sp. CEN26 produces 2,5-bis(hydroxymethyl)furan monoacetate (BHMF-OAc), which is a compound that inhibits the infection process of Alternaria brassicicola in cabbage. Such an antifungal property would allow for the use of the BHMF-OAc as an alternative to chemical fungicides.

Prolonged postprocedural outbreak of Mycobacterium massiliense infections associated with ultrasound transmission gel.

Postprocedural infections by Mycobacterium abscessus complex are increasing worldwide, and the source and route of transmission are infrequently identified. Here the extension of a previous clustering of paediatric patients with surgical site infections due to a single strain of the subspecies M. massiliense is reported. The investigation was conducted at a 2200-bed teaching hospital in Taiwan and included microbial surveillance of the environment (water, air, equipment and supplies) and a case-control study. We performed molecular identification and typing of the isolates by a trilocus sequencing scheme, confirmed by multilocus sequencing typing and pulsed-field gel electrophoresis. We investigated 40 patients who developed postprocedure soft tissue or bloodstream infections by M. massiliense (TPE101) during a 3-year period. Thirty-eight patients were identified at hospital A, and one newborn and her mother were identified at hospital B (185 km from hospital A). A case-control study identified the association of invasive procedures (adjusted odds ratio, 9.13) and ultrasonography (adjusted odds ratio, 2.97) (both p <0.05) with acquiring the outbreak strain. Isolates from the cases and unopened bottles of ultrasound transmission gel were all of strain ST48 and indistinguishable or closely related by pulsed-field gel electrophoresis. After replacement of contaminated gel, no new cases were detected during 18 months' follow-up. This investigation identified the use of contaminated gel as the common source causing an outbreak on a larger scale than had been recognized. Our findings halted production by the manufacturer and prompted revision of hospital guidelines.

Development of a selective and differential medium for capsulated Lactococcus garvieae.

A selective and differential medium termed 'LG agar' was developed for the isolation and presumptive identification of Lactococcus garvieae that results in black colonies with red halos. In this study, all 14 strains of L. garvieae and only 9 of the 148 strains representing 38 other species were able to grow on the LG agar. The nine viable strains on LG agar plates (including Enterococcus faecalis, Enterococcus faecium, Lactococcus lactis, Vibrio fluvialis, Vibrio furnissii, Vibrio mimicus and Vibrio salmonicida) were further differentiated from L. garvieae by various colours or colony features. Colonies isolated from the mixing culture and the infected giant sea perch using LG agar plates were all positively identified as L. garvieae by conventional tests and 16S rDNA sequencing. Furthermore, LG agar discriminated capsulated strains of L. garvieae, which were believed to be correlated with pathogens of fish and shellfish, from non-capsulated ones by colony appearances. The specificity and differentiating ability of LG agar suggest that this medium displays considerable potential for primary isolation and presumptive identification of L. garvieae from pathological and environmental samples.

MicroRNA-17-5p post-transcriptionally regulates p21 expression in irradiated betel quid chewing-related oral squamous cell carcinoma cells.

BACKGROUND AND PURPOSE: Betel nut chewing is associated with oral cavity cancer in Taiwan. OC3 is an oral carcinoma cell line that was established from cells collected from a long-term betel nut chewer who does not smoke. After we found that microRNA-17-5p (miR-17-5p) is induced in OC3 cells, we used this cell line to examine the biological role(s) of this microRNA in response to exposure to ionizing radiation. MATERIALS AND METHODS: A combined SYBR green-based real-time PCR and oligonucleotide ligation assay was used to examine the expression of the miR-17 polycistron in irradiated OC3 cells. The roles of miR-17-5p and p21 were evaluated with specific antisense oligonucleotides (ODN) that were designed and used to inhibit their expression. Expression of the p21 protein was evaluated by Western blotting. The clonogenic assay and annexin V staining were used to evaluate cell survival and apoptosis, respectively. Cells in which miR-17-5p was stably knocked down were used to create ectopic xenografts to evaluate in vivo the role of miR-17-5p. RESULTS: A radiation dose of 5 Gy significantly increased miR-17-5p expression in irradiated OC3 cells. Inhibition of miR-17-5p expression enhanced the radiosensitivity of the OC3 cells. We found that miR-17-5p downregulates radiation-induced p21 expression in OC3 cells and, by using a tumor xenograft model, it was found that p21 plays a critical role in increasing the radiosensitivity of OC3 cells in vitro and in vivo. CONCLUSION: miR-17-5p is induced in irradiated OC3 cells and it downregulates p21 protein expression, contributing to the radioresistance of OC3 cells.

Ventricular assist device application as a bridge to pediatric heart transplantation: a single center's experience.

OBJECTIVES: There are limited options for mechanical circulatory support to treat end-stage heart failure in pediatric patients. Although extracorporeal membrane oxygenation is commonly used in infants and children, ventricular assist devices (VAD) provide a longer duration of support with fewer complications before recovery or as a bridge to heart transplantation (HTx), as described herein. METHODS: This retrospective chart review of eight patients transplanted from April 2008 to December 2011, after left ventricular assist device (LVAD) implantation due to end-stage heart failure. Their mean age was 12 years (9-15 y) and mean body weight, 48 kg (20-78). All were New York Heart Association functional class IV with mean left ventricular ejection fractions less than 15%. RESULTS: The six patients (75%) received HTx after a mean LVAD support duration of 43.2 days; 2 (25%) died before a suitable heart became available. Their mean duration of LVAD support was 30 days. There were 4 (50%) who experienced clinically evident thromboembolic events: 3 (37.5%) cerebrovascular with 1 mortality and 1 (12.5%) as acute limb ischemia. Transient hemodialysis was performed in 4 (50%). Bloodstream infection identified in 6 (75%) was controlled with intravenous antibiotics. Driveline infection identified in 4 (50%) was treated successfully with local wound dressing changes and intravenous antibiotics. One 9-year-old boy died of rejection at 16 months after transplantation. CONCLUSIONS: Because of the organ shortage, pediatric patients have a low chance to undergo HTx. VAD provides long-term support for children with end-stage heart failure before a suitable heart becomes available. A thromboembolic event remains a major complication influencing their survival.

Novel measurements of mammary stem cells in human umbilical cord blood as prospective predictors of breast cancer susceptibility in later life.

BACKGROUND: The size of the breast stem-cell pool could underlie the intrauterine roots of breast cancer. We studied whether breast stem cells exist in umbilical cord blood and if they correlate with hematopoietic stem-cell measurements that have been positively associated with perinatal risk factors for breast cancer. SUBJECTS AND METHODS: We isolated mononuclear cells from umbilical cord blood of 170 singleton full-term pregnancies and determined, by reverse transcription polymerase chain reaction, the presence of genes of putative breast epithelial stem-cell/progenitor markers [including epithelial cell adhesion molecule (EpCAM), CD49f (α6-integrin), CD117 (c-kit receptor), CD24, and CD29 (ß1-integrin)]. By immunocytochemistry, we colocalized protein expressions of EpCAM+CD49f+, CD49f+CD24+, and CD24+CD29+. We correlated concentrations of putative breast stem-cell/progenitor subpopulations, quantified by flow cytometry, with concentrations of hematopoietic stem cells. RESULTS: Mammary stem-cell phenotypes were identified in umbilical cord blood. The measured EpCAM+ subpopulation was positively correlated with concentrations of CD34+ and CD34+CD38- hematopoietic stem cells (both P=0.006). Additionally, EpCAM+CD49f+ and CD49f+CD24+ subpopulations were positively correlated to the CD34+ cells (P=0.03 and 0.008, respectively). CONCLUSION: The positive association between measurable breast and hematopoietic stem cells in human umbilical cord blood suggests plausible mechanisms for a prenatal influence on breast cancer risk.

The effect of soy isoflavone on bone mineral density in postmenopausal Taiwanese women with bone loss: a 2-year randomized double-blind placebo-controlled study.

UNLABELLED: The treatment of 300-mg/day isoflavones (aglycone equivalents) (172.5 mg genistein + 127.5 mg daidzein) for 2 years failed to prevent lumbar spine and total proximal femur bone mineral density (BMD) from declining as compared with the placebo group in a randomized, double-blind, two-arm designed study enrolling 431 postmenopausal women 45-65 years old. INTRODUCTION: This study evaluated the effects of soy isoflavones on bone metabolism in postmenopausal women. METHODS: Four hundred and thirty-one women, aged 45-65 years, orally consumed 300-mg/day isoflavones (aglycone equivalents) or a placebo for 2 years in a parallel group, randomized, double-blind, two-arm study. Each participant also ingested 600 mg of calcium and 125 IU of vitamin D(3) per day. The BMD of the lumbar spine and total proximal femur were measured using dual-energy X-ray absorptiometry at baseline and every half-year thereafter. Serum bone-specific alkaline phosphatase, urinary N-telopeptide of type 1 collagen/creatinine, and other safety assessments were examined regularly. RESULTS: Two hundred out of 217 subjects in the isoflavone group and 199 out of 214 cases in placebo group completed the treatment. Serum concentrations of isoflavone metabolites, genistein and daidzein, of the intervention group were remarkably elevated following intake of isoflavones (p < 0.001). However, differences in the mean percentage changes of BMD throughout the treatment period were not statistically significant (lumbar spine, p = 0.42; total femur, p = 0.39) between the isoflavone and placebo groups, according to the generalized estimating equation (GEE) method. A significant time trend of bone loss was observed at both sites as assessed by the GEE method following repeated measurement of BMD (p < 0.001). Differences in bone marker levels were not significant between the two treatment groups. CONCLUSION: Treatment with 300-mg/day isoflavones (aglycone equivalents) failed to prevent a decline in BMD in the lumbar spine or total femur compared with the placebo group.

A selective and differential medium for Vibrio alginolyticus.

In this paper, we present a selective and differential medium, termed Vibrio alginolyticus (VAL) agar, developed for the isolation and identification of V. alginolyticus. The presence of bile salts, high salinity and high incubation temperature allows the selective growth of moderately halophilic Vibrio species. Differentiation of bacteria is achieved by identifying species capable of sucrose fermentation, made visible by the pH indicator bromocresol purple. In this study, all of the 26 strains of V. alginolyticus and only three of the 99 strains representing 30 species (including 19 Vibrio species) other than V. alginolyticus were able to grow in the VAL medium. The remaining three strains could be further differentiated from V. alginolyticus according to colour or the diameter of colonies produced on VAL agar plates. Colonies isolated from shellfish rearing water and infected shrimp through the use of VAL agar plates were all positively identified as V. alginolyticus by conventional tests and 16S rDNA sequencing. The testing of specificity and differentiation capability of VAL shows the potential of the agar as a medium for the primary isolation of V. alginolyticus from pathological and environmental samples.

Inhibition of cyclin-dependent kinases by olomoucine and roscovitine reduces lipopolysaccharide-induced inflammatory responses via down-regulation of nuclear factor kappaB.

OBJECTIVES: Initiation and maintenance of pro-inflammatory reactions elicited by bacterial lipopolysaccharide and/or cytokines in the macrophage lineage have been reported to play a crucial role in acute and chronic pathogenic effects. Whether pro-inflammatory responses triggered by lipopolysaccharide in growth arrested cells differ from those in proliferating cells remains unanswered. MATERIALS AND METHODS: Olomoucine and roscovitine are cyclin-dependent kinase (CDK) inhibitors that prevent progression through the cell cycle. After treatment with CDK inhibitors, expression of pro-inflammatory genes was analysed by reverse transcriptase-polymerase chain reaction. Protein levels of inducible nitric oxide synthase (iNOS) and nuclear factor kappaB (NF-kappaB) were determined by Western blotting. Promoter activity of iNOS was measured by the luciferase activity assay. RESULTS: In this study we have demonstrated that both olomoucine and roscovitine inhibit cell proliferation and diminish nitric oxide production and cytokine gene expression, in lipopolysaccharide-stimulated murine RAW264.7 macrophages. In addition, olomoucine reduces iNOS promoter activity and alleviates NF-kappaB transcription activation. After co-transfection with E2F1 interference RNA, suppression of lipopolysaccharide-mediated iNOS promoter activity and NF-kappaB activation was observed. Furthermore, we demonstrated that olomoucine-induced growth arrested cells reduce expression of the p65 subunit of NF-kappaB. CONCLUSIONS: The findings of this study suggest that inhibition of cell-cycle progression is capable of reducing pro-inflammatory responses via down-regulation of NF-kappaB.

An unusual cause of chylothorax after Norwood stage one reconstruction.

We report an unusual cause of prolonged chylothorax drainage after Norwood stage one reconstruction. This 1-month-old girl's chylous drainage was refractory to medical treatment. Echocardiography revealed thrombosis of the superior vena cava. Upon sternotomy to remove the thrombus, we were surprised to find the ePTFE (expanded polytetrafluoroethylene) tube previously used for selective cerebral perfusion compressing the innominate vein and the pericardium-based aortic arch. We performed a superior vena cava thrombectomy and shortened the ePTFE tube. Her chylothorax subsided gradually. We suggest that external compression of the venous drainage system should be considered in patients with prolonged chylothorax drainage. Once medical treatment fails, early surgical exploration may be helpful to stop the chylothorax.

Cardiac arrest after methylprednisolone pulse therapy rescued using extracorporeal membrane oxygenation in patients with acute cardiac rejection: two case reports.

Patients receive methylprednisolone pulse therapy (MPT) when acute cardiac rejection occurs. Although the regimen is generally safe and effective, severe complications occasionally develop. From 1997 to 2007, there were 210 cardiac transplantation procedures performed at our hospital. Among these patients, there were 23 episodes of acute rejection treated with MPT, 10 mg/kg/d. Two patients in our series had cardiac arrest within 36 hours after initiating the therapy. Endomyocardial biopsy specimens showed International Society for Heart Transplantation grade 1B allograft rejection in both cases. Emergent intubation and cardiopulmonary resuscitation were performed. Venoarterial extracorporeal membrane oxygenation (ECMO) was used to rescue the patients. The cardiac function in both patients recovered gradually. Left ventricular ejection fraction increased from 16.2% to 47% in one patient and from 27% to 30% in the other patient. One patient was successfully weaned from ECMO after 2 days of support. The other patient was discharged against medical advice because of hypoxia-related brain death after 3 days. Both patients had a history of tachyarrhythmias before initiation of MPT. Although the relationship between mechanisms of cardiac arrest and MPT is uncertain, the risk of cardiac arrest cannot be overlooked when initiating MPT, especially in patients with a history of tachyarrhythmia. Meanwhile, ECMO can serve as a rescue method if cardiac arrest occurs.

Evolving strategies and improving outcomes of Norwood stage one reconstruction: a decade experience of a single institution in Taiwan.

AIM: The aim of this study was to define the improvement in short-term outcome and risk factors of Norwood stage one reconstruction for hypoplastic left heart syndrome (HLHS) in Taiwan, after implementing new perioperative management strategies. METHODS: Data were retrieved from a retrospective chart review of patients with HLHS treated between July 1997 and July 2007. Since we implemented new perioperative strategies in 2004, we divided our patients into two groups, early era (1997-2003) and late era (2004-2007), and compared the outcome. RESULTS: We enrolled 48 patients. In the early era group (n=28), the diagnosis was confirmed by cardiac catheterization and controlled ventilation was used to manipulate the balance between systemic and pulmonary blood flow. The survival rate was only 17.9% (5/28). Surgery was performed at 15.2+/-10.7 days, which was significantly later than in the late era group (4.6+/-4.0 days, n=20). A lower preoperative shock and more prenatal diagnoses were recorded for the late era group. RV-PA conduit was used in 17 patients in the late era group of which 12 (70.6%) survived to be discharged from hospital. The risk factor was significant TR (tricuspid regurgitation). CONCLUSIONS: With our contemporary perioperative management and change in surgical strategy, survival after first-stage palliation has improved. We believe that our HLHS experience is valuable for low volume centers and also for Asian cohorts.

Two new naphthoquinones from the stem of Diospyros maritima.

Two new naphthoquinones, 2-ethoxy-8'-hydroxyisodiospyrin (1) and 3-ethoxy-8'-hydroxyisodiospyrin (2), together with two known naphthoquinones, 6-hydroxy-5-methoxy-2-methyl-1,4-naphthoquinone and bisisodiospyrin were isolated from the stems of Diospyros maritima. The structures of 1 and 2 were established on the basis of spectroscopic data.

The peptidoglycan recognition proteins LCa and LCx.

Infection of bacteria triggers innate immune defense reactions in Drosophila. So far, the only bacterial component known to be recognized by the insect innate immune system is peptidoglycan, one of the most abundant constituents of the bacterial cell wall. Insects use peptidoglycan recognition proteins to detect peptidoglycan and to activate innate immune responses. Such specialized peptidoglycan receptors appear to have evolved from phage enzymes that hydrolyze bacterial cell walls. They are able to bind specific peptidoglycan molecules with distinct chemical moieties and activate innate immune pathways by interacting with other signaling proteins. Recent X-ray crystallographic studies of the peptidoglycan recognition proteins LCa, and LCx bound to peptidoglycan have provided structural insights into recognition of peptidoglycan and activation of innate immunity in insects.

Oleanane-type triterpenes from Ludwigia octovalvis.

Two new oleanane-type triterpenes, (23Z)-feruloylhederagenin (1) and (23E)-feruloylhederagenin (2), together with two known oleanane-type triterpenes, beta-amyrin acetate and beta-amyrin palmitate, have been isolated from the whole plant of Ludwigia octovalvis. The structures of 1 and 2 were characterised on the basis of spectral evidence.

Single-center experience of pediatric heart transplantation in taiwan.

Heart transplantation (HTx) is a treatment for end-stage heart failure or a complex or inoperable congenital defect. The long-term survival and the adequate donor to recipient body weight (D/R BW) ratio remain to be determined. From March 1995 to May 2004, 14 children (6 months-16 years of age) underwent HTx due to underlying diseases of idiopathic dilated cardiomyopathy (n = 10; 71.4%), congenital heart disease (n = 3; 21.4%), and Kawasaki disease (n = 1; 7.1%). Donor-recipient body weight ratio ranged from 0.89 to 3.9. Big heart syndrome was present in one patient when D/R BW ratio was more than 3. Actuarial survival was 92.9% at 5 years after transplantation. Only the one patient who had Kawasaki disease died due to early primary graft failure. HTx is a feasible method with good long-term survival rates for end-stage heart failure or for complex or inoperable congenital defects. After careful pretransplant evaluation, a high D/R BW ratio (more than 3) is acceptable.

3D ROC Analysis for Medical Imaging Diagnosis.

Receiver operating characteristics (ROC) has been widely used as a performance evaluation tool to measure effectiveness of medical modalities. It is derived from a standard detection theory with false alarm and detection power interpreted as false positive (FP) and true positive (TP) respectively in terms of medical diagnosis. The ROC curve is plotted based on TP versus FP via hard decisions. This paper presents a three dimensional (3D) ROC analysis which extends the traditional two-dimensional (2D) ROC analysis by including a threshold parameter in a third dimension resulting from soft decisions, (SD). As a result, a 3D ROC curve can be plotted based on three parameters, TP, FP and SD. By virtue of such a 3D ROC curve three two-dimensional (2D) ROC curves can be derived, one of which is the traditional 2D ROC curve of TP versus FP with SD reduced to hard decision. In order to illustrate its utility in medical diagnosis, its application to magnetic resonance (MR) image classification is demonstrated.

A comparative study and analysis on techniques for diffusion-weighted magnetic resonance imaging.

Neural scientists have long been eager to find the subcortical pathways between different parts of cortex in human brain. By far, Diffusion Weighted-Magnetic Resonance Imaging (DW-MRI) is the only noninvasive technique to achieve this task in vivo. It applies a bipolar gradient to reveal diffusion of water molecules. With the assumption that the directions of neural fibers parallel to the directions in which water molecules diffuse, we can use the DW-MRI to track the neural fibers. Various signal processing techniques have been developed in extracting the directional information via DW-MRI. In this study, four techniques that are currently being used but have not been rigorously compared for performance are evaluated via custom-designed synthetic data and phantoms. By combining different techniques in accordance with their specialties, a better approach to track finer subcortical pathways in vivo can be derived and used to verify theories in human brain mapping.