Immunocytochemical localisation of para-coumaric acid and feruloyl-arabinose in the cell walls of maize stem

Two phenolic compounds, p-coumaric acid and feruloyl-arabinose, were localised by immunocytochemistry in the cell walls of the apical internode of two lines of maize (Co125 and W401) of different digestibility. The compounds were detected at two stages of cell maturity in the lignified tissues (sclerenchyma, fibres and xylem) and in the medullary parenchyma, which, in the samples studied, was not lignified. p-Coumaric acid is a phenolic acid associated with lignins, which confer resistance on plant cell walls to microbial degradation in the rumen. Feruloyl-arabinose is a compound associated with xylans, the principal hemicelluloses in Gramineae, which are potentially degradable. Labelling of p-coumaric acid decreased in both maize lines with cell age and as the cell walls became lignified. The mass of lignin deposited in the cell walls masked p-coumaric acid, thereby making it less accessible to the antibodies. There was an inverse relationship in the labelling of p-coumaric acid and feruloyl-arabinose. Feruloyl-arabinose was more heavily labelled as the plant cell walls matured in all the lignified tissues of both maize lines and in the parenchyma of the less digestible line. All tissues except the parenchyma were more heavily labelled with both sera in Co125, the more digestible line. © 1998 Society of Chemical Industry.     

A coagulase-negative variant of Staphylococcus aureus from bovine mastitis milk

Bacteriological analysis of milk samples from quarters of a dairy cow suffering from subclinical mastitis yielded two isolates of Staphylococcus aureus which gave a negative reaction in the standard coagulase test. Both isolates were also clumping factor and thermonuclease negative, and gave a negative reaction in the Staphaurex? test. The isolates were identified by using commercial biochemical systems, and by PCR analysis of different staphylococcal cell surface protein and exoprotein genes. Further molecular identification of the isolates, which included sequencing of the 16S rRNA gene and RT-PCR of coagulase (coa), clumping-factor (clfA) and thermonuclease (nuc) genes, was consistent with the diagnosis phenotypically 'coagulase-negative variant of Staph. aureus'. The fact that coagulase-negative Staph. aureus variants can occur in the context of intramammary infections in cattle may result in the incorrect diagnosis 'coagulase-negative staphylococci (CNS)' in routine mastitis diagnostic, at least in rare cases. To fully ensure correct species diagnosis, sequencing of the 16S rRNA gene and amplification of specific genes such as coa is necessary in these cases.     

Removal of oxide nanoparticles in a model wastewater treatment plant: influence of agglomeration and surfactants on clearing efficiency

The rapidly increasing production of engineered nanoparticles has created a demand for particle removal from industrial and communal wastewater streams. Efficient removal is particularly important in view of increasing long-term persistence and evidence for considerable ecotoxicity of specific nanoparticles. The present work investigates the use of a model wastewater treatment plant for removal of oxide nanoparticles. While a majority of the nanoparticles could be captured through adhesion to clearing sludge, a significant fraction of the engineered nanoparticles escaped the wastewater plant's clearing system, and up to 6 wt % of the model compound cerium oxide was found in the exit stream of the model plant. Our study demonstrates a significant influence of surface charge and the addition of dispersion stabilizing surfactants as routinely used in the preparation of nanoparticle derived products. A detailed investigation on the agglomeration of oxide nanoparticles in wastewater streams revealed a high stabilization of the particles against clearance (adsorption on the bacteria from the sludge). This unexpected finding suggests a need to investigate nanoparticle clearance in more detail and demonstrates the complex interactions between dissolved species and the nanoparticles within the continuously changing environment of the clearing sludge.     

Response of pocket gophers (Thomomys talpoides) to an operational application of synthetic semiochemicals of stoat (Mustela erminea)

This paper reports on laboratory bioassays and a large-scale field trial of synthetic mustelid anal-gland compounds in controlled-release devices designed for operational application to burrow systems of northern pocket gophers (Thomomys talpoides). The field study was conducted in an apple orchard in the Okanagan Valley of British Columbia. In laboratory bioassays, a 1∶1 mixture of 2-propylthietane and 3-propyl-1,2-dithiolane from the stoat (Mustela erminea) and 3,3-dimethyl-1,2-dithiolane from the ferret (M. putorius), dispensed in clay pellets (activated alumina), produced a significant avoidance response by gophers. All resident gophers were permanently removed from 4-ha control and treatment blocks prior to placement of stoat odor in burrows. As indexed by soil mounds, significantly fewer gophers colonized the treatment (40) than the control (68) removal area during a 5.5-month overwinter experiment. There was also a significant difference when comparing the number of mounds between pre-(79) and posttreatment (40) censuses. In addition, most gopher activity tended to occur on the perimeter of the treatment block. Abundance of gophers showed little difference between additional 4-ha control and treatment blocks where gophers had not been removed. The results of this study provide an alternative technique to toxicants for pocket gopher control on forest and agricultural land.     

Synthese du furyl-2 oxiranne en milieu hétérogène solide-liquide faiblement hydrate: Determination du régime de production,expression de la loi cinétique

Optimum conditions for scaling up the synthesis of furyl-2 oxyrane from furfural have been determined. A continuous stirred tank reactor proved the most efficient configuration for the production of the oxirane. The kinetic model makes it possible to predict the yields of epoxide per unit volume and unit time.     

A far infra-red study of conformational disorder in PTFE

The examination of the 250–350 cm^?1 region of the infra-red spectrum of polytetrafluoroethylene (PTFE) has been extended by studies of thermally degraded and sintered material. We conclude that a band at 277 cm^?1 does not arise from a true mode of the crystal but has its origin in regions where the chain has a bent conformation. Our previous speculation that bands at 292 cm^?1 and 312¹ cm^?1 (Raman active only, for the isolated chain) acquire their weak activity in the infra-red through conformational disorder is confirmed. It is likely that the conformational disorder in question arises from chain folding in the polymer crystal.     

The Human Host Defense Ribonucleases 1, 3 and 7 Are Elevated in Patients with Sepsis after Major Surgery—A Pilot Study

Sepsis is the most common cause of death in intensive care units and associated with widespread activation of host innate immunity responses. Ribonucleases (RNases) are important components of the innate immune system, however the role of RNases in sepsis has not been investigated. We evaluated serum levels of RNase 1, 3 and 7 in 20 surgical sepsis patients (Sepsis), nine surgical patients (Surgery) and 10 healthy controls (Healthy). RNase 1 and 3 were elevated in Sepsis compared to Surgery (2.2- and 3.1-fold, respectively; both p < 0.0001) or compared to Healthy (3.0- and 15.5-fold, respectively; both p < 0.0001). RNase 1 showed a high predictive value for the development of more than two organ failures (AUC 0.82, p = 0.01). Patients with renal dysfunction revealed higher RNase 1 levels than without renal dysfunction (p = 0.03). RNase 1 and 3 were higher in respiratory failure than without respiratory failure (p < 0.0001 and p = 0.02, respectively). RNase 7 was not detected in Healthy patients and only in two patients of Surgery, however RNase 7 was detected in 10 of 20 Sepsis patients. RNase 7 was higher in renal or metabolic failure than without failure (p = 0.04 and p = 0.02, respectively). In conclusion, RNase 1, 3 and 7 are secreted into serum under conditions with tissue injury, such as major surgery or sepsis. Thus, RNases might serve as laboratory parameters to diagnose and monitor organ failure in sepsis.     

Melanocytes Affect Nodal Expression and Signaling in Melanoma Cells: A Lesson from Pediatric Large Congenital Melanocytic Nevi

Expression of Nodal, a Transforming Growth Factor-beta (TGF-β) related growth factor, is associated with aggressive melanoma. Nodal expression in adult dysplastic nevi may predict the development of aggressive melanoma in some patients. A subset of pediatric patients diagnosed with giant or large congenital melanocytic nevi (LCMN) has shown increased risk for development of melanoma. Here, we investigate whether Nodal expression can help identify the rare cases of LCMN that develop melanoma and shed light on why the majority of these patients do not. Immunohistochemistry (IHC) staining results show varying degree of Nodal expression in pediatric dysplastic nevi and LCMN. Moreover, median scores from Nodal IHC expression analysis were not significantly different between these two groups. Additionally, none of the LCMN patients in this study developed melanoma, regardless of Nodal IHC levels. Co-culture experiments revealed reduced tumor growth and lower levels of Nodal and its signaling molecules P-SMAD2 and P-ERK1/2 when melanoma cells were grown in vivo or in vitro with normal melanocytes. The same was observed in melanoma cells cultured with melanocyte conditioned media containing pigmented melanocyte derived melanosomes (MDM). Since MDM contain molecules capable of inactivating radical oxygen species, to investigate potential anti-oxidant effect of MDM on Nodal expression and signaling in melanoma, melanoma cells were treated with either N-acetyl-l-cysteine (NAC), a component of the anti-oxidant glutathione or synthetic melanin, which in addition to providing pigmentation can also exert free radical scavenging activity. Melanoma cells treated with NAC or synthetic melanin showed reduced levels of Nodal, P-SMAD2 and P-ERK1/2 compared to untreated melanoma cells. Thus, the potential role for Nodal in melanoma development in LCMN is less evident than in adult dysplastic nevi possibly due to melanocyte cross-talk in LCMN capable of offsetting or delaying the pro-melanoma effects of Nodal via anti-oxidant effects of MDM.