Antifungal drugs affecting the chemotaxis of polymorphonuclear neutrophils

Investigations on the chemotaxis of polymorphonuclear neutrophils (PMNs) towards a cytoplasmic extract of Trichophyton rubrum in the presence and absence of antifungal drugs are described. It is shown that with griseofulvin, clotrimazole, econazole, ketoconazole, miconazole and natamycin at 1 mg l(-1), the number of PMNs migrating was significantly reduced. After 3 h of exposure to 10 mg l(-1), not one of the drugs tested had any discernable effect on the viability of the PMNs, or the complement. The anti-inflammatory activity of the drugs is discussed and whilst the chemosuppression of PMN chemotaxis may be an undesirable feature in a drug used to treat systemic mycoses, it is unlikely to have any adverse effect in the therapy of the dermatophytoses.     

CD64 and Group II Secretory Phospholipase A2 (sPLA2-IIA) as Biomarkers for Distinguishing Adult Sepsis and Bacterial Infections in the Emergency Department

Introduction

Early diagnosis of sepsis and bacterial infection is imperative as treatment relies on early antibiotic administration. There is a need to develop new biomarkers to detect patients with sepsis and bacterial infection as early as possible, thereby enabling prompt antibiotic treatment and improving the survival rate.

Methods

Fifty-one adult patients with suspected bacterial sepsis on admission to the Emergency Department (ED) of a teaching hospital were included into the study. All relevant cultures and serology tests were performed. Serum levels for Group II Secretory Phospholipase A2 (sPLA2-IIA) and CD64 were subsequently analyzed.

Results and Discussion

Sepsis was confirmed in 42 patients from a total of 51 recruited subjects. Twenty-one patients had culture-confirmed bacterial infections. Both biomarkers were shown to be good in distinguishing sepsis from non-sepsis groups. CD64 and sPLA2-IIA also demonstrated a strong correlation with early sepsis diagnosis in adults. The area under the curve (AUC) of both Receiver Operating Characteristic curves showed that sPLA2-IIA was better than CD64 (AUC = 0.93, 95% confidence interval (CI) = 0.83–0.97 and AUC = 0.88, 95% CI = 0.82–0.99, respectively). The optimum cutoff value was 2.13μg/l for sPLA2-IIA (sensitivity = 91%, specificity = 78%) and 45 antigen bound cell (abc) for CD64 (sensitivity = 81%, specificity = 89%). In diagnosing bacterial infections, sPLA2-IIA showed superiority over CD64 (AUC = 0.97, 95% CI = 0.85–0.96, and AUC = 0.95, 95% CI = 0.93–1.00, respectively). The optimum cutoff value for bacterial infection was 5.63μg/l for sPLA2-IIA (sensitivity = 94%, specificity = 94%) and 46abc for CD64 (sensitivity = 94%, specificity = 83%).

Conclusions

sPLA2-IIA showed superior performance in sepsis and bacterial infection diagnosis compared to CD64. sPLA2-IIA appears to be an excellent biomarker for sepsis screening and for diagnosing bacterial infections, whereas CD64 could be used for screening bacterial infections. Both biomarkers either alone or in combination with other markers may assist in decision making for early antimicrobial administration. We recommend incorporating sPLA2-IIA and CD64 into the diagnostic algorithm of sepsis in ED.     

Alstiphyllanines I-O, ajmaline type alkaloids from Alstonia macrophylla showing vasorelaxant activity

Seven new ajmaline type alkaloids, alstiphyllanines I-O (1-7) were isolated from the leaves of Alstonia macrophylla together with six related alkaloids (8-13). Structures and stereochemistry of 1-7 were fully elucidated and characterized by 2D NMR analysis. A series of alstiphyllanines I-O (1-7) as well as the known ajmaline type alkaloids (8-13) showed that they relaxed phenylephrine (PE)-induced contractions against rat aortic ring. Among them, vincamedine (10) showed potent vasorelaxant activity, which may be mediated through inhibition of Ca(2+) influx through voltage-dependent Ca(2+) channels (VDCs) and/or receptor-operated Ca(2+) channels (ROCs) as well as partially mediated the NO release from endothelial cells. The presence of substituents at both N-1 and C-17 may be important to show vasorelaxation activity.     

Multiple endocrine neoplasia type 1 (MEN1) in two Asian families

Multiple endocrine neoplasia type 1 (MEN1), an autosomal dominant disease characterized by neoplasia of the parathyroid glands, anterior pituitary and endocrine pancreas, is rarely reported in Asian populations. The MEN1 gene, mapped to chromosome 11q13 but yet to be cloned, has been found to be homogeneous in Caucasian populations through linkage analysis. Here, two previously unreported Asian kindreds with MEN1 are described; link-age analysis using microsatellite polymorphic markers in the MEN1 region was carried out. The first kindred, of Mongolian-Chinese origin, is a multigeneration family with over 150 living members, eight of whom are affected toB. T. Teh and S. I. Hii are to be considered as joint first authors     

Antibiofilm properties of chemically synthesized silver nanoparticles found against Pseudomonas aeruginosa

Nanomedicine is now being introduced as a recent trend in the field of medicine. It has been documented that metal nanoparticles have antimicrobial effects for bacteria, fungi and viruses. Recent advances in technology has revived the use of silver nanoparticles in the medical field; treatment, diagnosis, monitoring and control of disease. It has been used since ancient times for treating wide range of illnesses. Bacterial cells adheres to surfaces and develop structures known as biofilms. These structures are natural survival strategy of the bacteria to invade the host. They are more tolerant to commonly used antimicrobial agents, thus being more difficult to be controlled. This leads to increase in severity of infection. In this study, we have investigated the effect of silver nanoparticles in the formation of biofilm in multidrug resistant strains of Pseudomonas aeruginosa. Observation showed that biofilm formation occurred at bacterial concentration of 10⁶ cfu/ml for the sensitive strain of P. aeruginosa while in the resistant strain, the biofilm was evident at bacterial concentration of about 10³ cfu/ml. The biofilm were then tested against various concentrations of silver nanoparticles to determine the inhibitory effect of the silver nanoparticles. In the sensitive strain, 20 μg/ml of silver nanoparticles inhibited the growth optimally at bacterial concentration of 10⁴ cfu/ml with an inhibition rate of 67%. Similarly, silver nanoparticles inhibited the formation of biofilm in the resistant strain at an optimal bacterial concentration of 10⁵ cfu/ml with an inhibition rate of 56%. Thus, silver nanoparticles could be used as a potential alternative therapy to reduce severity of disease due to P. aeruginosa infections.     

Probing the cruzain S2 recognition subsite: a kinetic and binding energy calculation study

Cysteine proteases are relevant to several aspects of the parasite life cycle and the parasite-host relationship. Moreover, they appear as promising targets for antiparasite chemotherapy. Here, a quantitative investigation on the catalytic properties of cruzain, the papain-like cysteine protease from epimastigotes of Trypanosoma cruzi, is reported. The results indicate that kinetics for the cruzain catalyzed hydrolysis of N-alpha-benzyloxycarbonyl-l-arginyl-l-alanine-(7-amino-4-methylcoumarin), N-alpha-benzyloxycarbonyl-l-phenylalanyl-l-alanine-(7-amino-4-methylcoumarin), and N-alpha-benzyloxycarbonyl-l-tyrosyl-l-alanine-(7-amino-4-methylcoumarin) can be consistently fitted to the minimum three-step mechanism of cysteine proteases involving the acyl.enzyme intermediate E.P; the deacylation step is rate-limiting in enzyme catalysis. Remarkably, these substrates show identical catalytic parameters. This reflects the ability of the cruzain Glu205 residue, located at the bottom of the S(2) subsite, to neutralize the substrate/inhibitor polar P(2) residues (e.g., Arg or Tyr) and to be solvent-exposed when substrate/inhibitor nonpolar P(2) residues (e.g., Phe) fit the S(2) subsite. More complex catalytic mechanisms are also discussed. Binding free-energy calculation provides a quantitative framework for the interpretation of these results; in particular, direct evidence for the compensatory effect between Coulomb interaction(s) and solvation effect(s) is reported. These results appear of general significance for a deeper understanding of (macro)molecular recognition and for the rational design of novel inhibitors of parasitic cysteine proteases.     

Characterization of the hemodynamic wall shear stresses in human umbilical vessels from normal and intrauterine growth restricted pregnancies

Significant reductions in blood flow and umbilical diameters were reported in pregnancies affected by intrauterine growth restriction (IUGR) from placental insufficiency. However, it is not known if IUGR umbilical blood vessels experience different hemodynamic wall shear stresses (WSS) compared to normal umbilical vessels. As WSS is known to influence vasoactivity and vascular growth and remodeling, which can regulate flow rates, it is important to study this parameter. In this study, we aim to characterize umbilical vascular WSS environment in normal and IUGR pregnancies, and evaluate correlation between WSS and vascular diameter, and gestational age. Twenty-two normal and 21 IUGR pregnancies were assessed via ultrasound between the 27th and 39th gestational week. IUGR was defined as estimated fetal weight and/or abdominal circumference below the 10th centile, with no improvement during the remainder of the pregnancy. Vascular diameter was determined by 3D ultrasound scans and image segmentation. Umbilical artery (UA) WSS was computed via computational flow simulations, while umbilical vein (UV) WSS was computed via the Poiseuille equation. Univariate multiple regression analysis was used to test for the differences between normal and IUGR cohort. UV volumetric flow rate, UA and UV diameters were significantly lower in IUGR fetuses, but flow velocities and WSS trends in UA and UV were very similar between normal and IUGR groups. In both groups, UV WSS showed a significant negative correlation with diameter, but UA WSS had no correlation with diameter, suggesting a constancy of WSS environment and the existence of WSS homeostasis in UA, but not in UV. Despite having reduced flow rate and vascular sizes, IUGR UAs had hemodynamic mechanical stress environments and trends that were similar to those in normal pregnancies. This suggested that endothelial dysfunction or abnormal mechanosensing was unlikely to be the cause of small vessels in IUGR umbilical cords.     

A p300 and SIRT1 Regulated Acetylation Switch of C/EBPα Controls Mitochondrial Function

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Alstiphyllanines E–H,picraline and ajmaline-type alkaloids from Alstonia macrophylla inhibiting sodium glucose cotransporter

Three new picraline-type alkaloids, alstiphyllanines E–G (1–3) and a new ajmaline-type alkaloid, alstiphyllanine H (4) were isolated from the leaves of Alstonia macrophylla together with 16 related alkaloids (5–20). Structures and stereochemistry of 1–4 were fully elucidated and characterized by 2D NMR analysis. Alstiphyllanines E and F (1 and 2) showed moderate Na⁺-glucose cotransporter (SGLT1 and SGLT2) inhibitory activity. A series of a hydroxy substituted derivatives 21–28 at C-17 of the picraline-type alkaloids have been derived as having potent SGLT inhibitory activity. 10-Methoxy-N(1)-methylburnamine-17-O-veratrate (6) exhibited potent inhibitory activity, suggesting that the presence of an ester side chain at C-17 may be important to show SGLT inhibitory activity. Structure activity relationship of alstiphyllanines on inhibitory activity of SGLT was discussed.     

Molecular characterization of relatedness among colour variants of Asian Arowana (Scleropages formosus)

Morphological identification of fish taxa can sometimes prove difficult because phenotypic variation is either being affected by environmental factors, phenotypic characters are highly conserved or marker selection has been inappropriate. DNA based markers especially neutral mitochondrial DNA (mtDNA) have been used widely in recent times to provide better resolution of systematic relationships among vertebrate taxa. The Asian Arowana (Scleropages formosus) is a high value ornamental fish belonging to the family Osteoglossidae with a number of different colour variants distributed geographically across different locations around Southeast Asia. Systematic relationships among colour variants still remain unresolved. Partial sequences of the Cytochrome B (Cyt B) and DNA barcoding gene, Cytochrome C Oxidase I (COI) were used here to assess genetic relationships among colour variants and as a tool for molecular identification for differentiating among colour variants in this species. Results of the study show that in general, colour pattern shows no relationship with extent of COI or Cyt B mtDNA differentiation and so cannot be used to identify taxa. Partial sequences of the mtDNA genes were sufficient however, to identify S. formosus from a closely related species within the order Osteoglossidae.