Nutritional utilization by the rat of diets based on lentil (Lens culinaris) seed meal or its fractions

The nutritional effects in the rat of raw lentil meal or its fractions have been evaluated in three feeding trials. Growth, gain/feed ratio, apparent N digestibility, and N retention were significantly (p < 0.05) reduced by the inclusion of whole lentil meal, dehulled lentil meal, or ethanol-extracted lentil meal as the sole source of protein in the diet. Pure lentil lectin and lectin-depleted albumin proteins had no significant negative effect on nutritional performance. In contrast, growth, gain/feed ratio, protein conversion efficiency, N digestibility, and N retention were significantly (p < 0.05) reduced by diets containing lentil globulins or lentil hulls. The poor nutritional quality of raw lentil meal for rats is therefore likely to be primarily due to the combined effects of these two components.     

Physicochemical and Antimicrobial Properties of Thermosensitive Chitosan Hydrogel Loaded with Fosfomycin

Thermosensitive chitosan hydrogels—renewable, biocompatible materials—have many applications as injectable biomaterials for localized drug delivery in the treatment of a variety of diseases. To combat infections such as Staphylococcus aureus osteomyelitis, localized antibiotic delivery would allow for higher doses at the site of infection without the risks associated with traditional antibiotic regimens. Fosfomycin, a small antibiotic in its own class, was loaded into a chitosan hydrogel system with varied beta-glycerol phosphate (β-GP) and fosfomycin (FOS) concentrations. The purpose of this study was to elucidate the interactions between FOS and chitosan hydrogel. The Kirby Bauer assay revealed an unexpected concentration-dependent inhibition of S. aureus, with reduced efficacy at the high FOS concentration but only at the low β-GP concentration. No effect of FOS concentration was observed for the planktonic assay. Rheological testing revealed that increasing β-GP concentration increased the storage modulus while decreasing gelation temperature. NMR showed that FOS was removed from the liquid portion of the hydrogel by reaction over 12 h. SEM and FTIR confirmed gels degraded and released organophosphates over 5 days. This work provides insight into the physicochemical interactions between fosfomycin and chitosan hydrogel systems and informs selection of biomaterial components for improving infection treatment.     

Non-traditional vectors for paralytic shellfish poisoning

Paralytic shellfish poisoning (PSP), due to saxitoxin and related compounds, typically results from the consumption of filter-feeding molluscan shellfish that concentrate toxins from marine dinoflagellates. In addition to these microalgal sources, saxitoxin and related compounds, referred to in this review as STXs, are also produced in freshwater cyanobacteria and have been associated with calcareous red macroalgae. STXs are transferred and bioaccumulate throughout aquatic food webs, and can be vectored to terrestrial biota, including humans. Fisheries closures and human intoxications due to STXs have been documented in several non-traditional (i.e. non-filter-feeding) vectors. These include, but are not limited to, marine gastropods, both carnivorous and grazing, crustacea, and fish that acquire STXs through toxin transfer. Often due to spatial, temporal, or a species disconnection from the primary source of STXs (bloom forming dinoflagellates), monitoring and management of such non-traditional PSP vectors has been challenging. A brief literature review is provided for filter feeding (traditional) and non-filter feeding (non-traditional) vectors of STXs with specific reference to human effects. We include several case studies pertaining to management actions to prevent PSP, as well as food poisoning incidents from STX(s) accumulation in non-traditional PSP vectors.     

A new model for the soil-water retention curve that solves the problem of residual water contents

We present a new model for the soil‐water retention curve, θ(h_m), which, in contrast to earlier models, anchors the curve at zero water content and does away with the unspecified residual water content. The proposed equation covers the complete retention curve, with the pressure head, h_m, stretching over approximately seven orders of magnitude. We review the concept of pF from its origin in the papers of Schofield and discuss what Schofield meant by the ‘free energy, F ’. We deal with (historical) criticisms regarding the use of the log scale of the pressure head, which, unfortunately, led to the apparent demise of the pF. We espouse the advantages of using the log scale in a model for which the pF is the independent variable, and we present a method to deal with the problem of the saturated water content on the semi‐log graph being located at a pF of minus infinity. Where a smaller range of the water retention is being considered, the model also gives an excellent fit on a linear scale using the pressure head, h_m, itself as the independent variable. We applied the model to pF curves found in the literature for a great variety of soil textures ranging from dune‐sand to river‐basin clay. We found the equation for the model to be capable of fitting the pF curves with remarkable success over the complete range from saturation to oven dryness. However, because interest generally lies in the plant‐available water range (i.e. saturation, θ_s, to wilting point, θ_wp), the following relation, which can be plotted on a linear scale, is sufficient for most purposes: , where k₀, k₁ and n are adjustable fitting parameters.     

Standardized exercise test and daily heart rate responses of thoroughbreds undergoing conventional race training and detraining

Ten healthy sedentary male Thoroughbreds with previous race training experience were studied for 14 weeks. Horses were trained for 9 weeks, using a program designed after those used commonly in the United States. Horses were trained conventionally by slow trotting (250 m/min) for 2 weeks and galloping (390 to 450 m/min) for 4 weeks, followed by 3 weeks of galloping (440 to 480 m/min) and intermittent sprinting exercises (breezes) at distances between 600 and 1,000 m (900 to 950 m/min). The horses were then pasture rested for 5 weeks. A standardized exercise test (SET) involving an 800-m gallop at 800 m/min was administered before and after the 9-week training period and after the 5-week detraining period. Heart rate (HR) was monitored during exercise and at standardized intervals after exercise for 60 minutes. Venous blood for determination of plasma lactate concentration was obtained at 5 minutes after exercise. Heart rate was monitored daily at rest, during exercise, and through the first 60 minutes of recovery. Venous plasma samples (for lactate determination) were obtained 5 minutes after the sprinting exercises. Horses were observed daily before exercise for signs of lameness and were not allowed to train if lame. Differences after 9 weeks' training were seen in the SET recovery HR at 0.5 through 5 minutes after exercise (P less than 0.05 to P less than 0.01). Differences after detraining were seen in the SET recovery HR at 40 and 60 minutes after exercise (P less than 0.05 to P less than 0.01). Neither training nor detraining resulted in differences in plasma lactate concentration after the SET gallop.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effect of dietary vitamin E supplementation and feeding period on pork quality

Feeding increased levels of dietary vitamin E can inhibit lipid oxidation. The aim of this study was to investigate the effect of levels of dietary alpha-tocopherol acetate (VE) and feeding duration on meat quality and lipid oxidation. Eighty-one pigs were allocated to 1 of 3 diets containing 40, 200, or 400 IU of VE/kg of feed, and each diet group was divided into 3 feeding periods (3, 6, or 9 wk). Carcass characteristics and meat quality were evaluated. Oxidative stability of fresh and cooked pork patties and pork chops was determined after chilled or frozen storage. Increasing dietary concentrations of VE did not affect any growth performance parameter. Drip loss, however, decreased (P < 0.05) with increased dietary VE levels. Moreover, an increased duration of VE feeding improved (P < 0.05) pH and drip loss. Less lipid oxidation (P < 0.05) was detected in fresh ground pork from pigs fed greater concentrations of VE after 4 d of storage. A greater (P < 0.05) resistance to oxidation in cooked ground pork was observed in pigs fed 200 or 400 IU of VE/kg at 2 and 6 d of storage. Fresh and cooked pork patty oxidation decreased (P < 0.05) linearly as feeding duration increased from 3 to 9 wk. After 6 mo of freezer storage, lipid oxidation of pork chops from pigs fed 200 or 400 IU of VE/kg was lower (P < 0.05) than for pigs fed 40 IU of VE/kg. Likewise, lipid oxidation of pork chops of pigs fed VE for an extended period of time (6 wk) was lower (P < 0.05) after 9 mo of storage. Fatty acid profiles of neutral lipid fraction of the LM became more unsaturated (P < 0.05) with added VE to the feed. These results indicate an increased intake of dietary VE concentration, and prolonged feeding of VE can improve drip loss and reduce lipid oxidation in ground pork and pork chops. This study suggests that supplementation with 200 IU of VE/kg of feed for 6 wk before market is beneficial in improving lipid stability and pork quality.     

Metabolism of isometamidium in hepatocytes isolated from control and inducer-treated rats

Little is known about the metabolism and mechanism of action of the trypanocide, isometamidium (ISM), the major drug used for prophylaxis of trypanosomiasis. We have investigated its metabolism and distribution in isolated rat hepatocytes using liquid chromatography-mass spectrometry and confocal laser scanning microscopy (CLSM). Two putative metabolites were formed, which were proposed to be a mono-acetyl derivative and an oxidized metabolite (SII). This is the first demonstration of the hepatic metabolism of ISM, as previous in vivo studies were hampered by dose-limiting toxicity and insensitive analytical methods. The intrinsic fluorescence of the drug enabled its intracellular uptake to be followed by CLSM. It is taken up rapidly into the nucleolus, nuclear membrane and endoplasmic reticulum within 5 min, and retained in the nucleus for at least 24 h. Persistent binding of ISM to cellular macromolecules may contribute to its prophylactic effect in vivo. Pretreatment of rats with 3-methylcholanthrene, phenobarbitone (PB) or the widely used pyrethroid pesticide, deltamethrin, resulted in an increase in metabolism of ISM to the proposed SII after 1 h incubation with hepatocytes. 3-methylcholanthrene was the most potent inducer, causing a maximal 19.5-fold induction of SII formation after exposure of hepatocytes to ISM for 1 h compared with formation by control hepatocytes. In comparison, at the 1 h timepoint deltamethrin pre-treatment caused a 10.2-fold induction, and PB only 8.2 fold.     

Evidence for vertical transmission of Mycoplasma haemocanis,but not Ehrlichia ewingii,in a dog

A 2‐year‐old female intact pregnant Beagle was evaluated after the owner surrendered her to a shelter. Prepartum and 2 months postpartum at the time of routine spay, the dam was whole‐blood polymerase chain reaction (PCR) positive for Ehrlichia ewingii. She was also whole‐blood PCR positive for Mycoplasma haemocanis prepartum and continuously for 5 months thereafter. The dam delivered 5 healthy puppies, 1 of which was whole‐blood PCR positive for M. haemocanis. All 5 puppies had antibodies against Ehrlichia spp. at 1 month of age but not thereafter, and all puppies were Ehrlichia spp. PCR negative for 5 months of follow‐up. Therefore, this study supports a potential role for vertical transmission in the maintenance of M. haemocanis in dogs as reservoir hosts. In contrast, in this case there was no evidence that E. ewingii was transmitted transplacentally or during the perinatal period.