Evaluation of glucose metabolism in three horses with lower motor neuron degeneration

OBJECTIVES: To determine whether increased glucose metabolism is the potential cause of the decreased plasma glucose curve determined after oral glucose tolerance testing in horses with lower motor neuron degeneration. ANIMALS: 3 horses with signs suggestive of lower motor neuron degeneration, 1 horse with malignant melanoma with multiple metastases, and an obese but otherwise healthy horse. Procedures-Glucose metabolism was assessed by use of the hyperglycemic clamp and euglycemic hyperinsulinemic clamp techniques. RESULTS: Mean rate of glucose metabolism of horses with lower motor neuron degeneration was significantly greater (mean, 3.7 times greater than control horses; range, 2.1 to 4.8 times greater) than that reported in 5 healthy control horses (41 +/- 13 micromol/kg/min vs 11 +/- 4.5 micromol/kg/min, respectively). In addition, one of the affected horses, an 8-year-old warmblood gelding, had a 5.6-times increased sensitivity to exogenously administered insulin, compared with that reported in 5 healthy control horses. Pancreatic insulin secretion was not insufficient in horses with lower motor neuron degeneration. Findings in the 2 diseased control horses were unremarkable. CONCLUSIONS AND CLINICAL RELEVANCE: Increased glucose metabolism in horses with lower motor neuron degeneration may be the cause of the decreased plasma glucose curve detected after oral glucose tolerance testing. This finding could aid in developing supportive treatments with respect to adequate glucose and vitamin E supplementation.     

A simple random amplified polymorphic DNA genotyping method for field isolates of Dermatophilus congolensis

Dermatophilus congolensis is the pathogenic actinomycete that causes dermatophilosis in cattle, lumpy wool in sheep and rain scald in horses. Phenotypic variation between isolates has previously been described, but its genetic basis, extent and importance have not been investigated. Standard DNA extraction methods are not always successful for D. congolensis due to its complex life cycle, one stage of which is encapsulated. Here we describe the development of rapid and reliable DNA extraction and random amplified polymorphic DNA (RAPD) methods that can be used for genotyping D. congolensis field isolates. Our results suggest that genotypic variation between isolates correlates with host species. Several DNA extraction methods and RAPD protocols were compared. An extraction method based on incubation of the bacterium in lysozyme, sodium dodecyl sulphate (SDS) and proteinase K treatments and phenolic extraction yielded high-quality DNA, which was used to optimize RAPD-polymerase chain reaction (PCR) protocols for two random primers. An alternative rapid, non-phenolic extraction method based on proteinase K treatment and thermal shock was selected for routine RAPD typing of isolates. DNA extracted from reference strains from cattle, sheep and horse using either method gave reproducible banding patterns with different DNA batches and different thermal cyclers. The rapid DNA extraction method and RAPD-PCR were applied to 38 D. congolensis field isolates. The band patterns of the field and type isolates correlated with host species but not with geographical location.     

Bioactivities of Lipid Extracts and Complex Lipids from Seaweeds: Current Knowledge and Future Prospects

While complex lipids of seaweeds are known to display important phytochemical properties, their full potential is yet to be explored. This review summarizes the findings of a systematic survey of scientific publications spanning over the years 2000 to January 2021 retrieved from Web of Science (WoS) and Scopus databases to map the state of the art and identify knowledge gaps on the relationship between the complex lipids of seaweeds and their reported bioactivities. Eligible publications (270 in total) were classified in five categories according to the type of studies using seaweeds as raw biomass (category 1); studies using organic extracts (category 2); studies using organic extracts with identified complex lipids (category 3); studies of extracts enriched in isolated groups or classes of complex lipids (category 4); and studies of isolated complex lipids molecular species (category 5), organized by seaweed phyla and reported bioactivities. Studies that identified the molecular composition of these bioactive compounds in detail (29 in total) were selected and described according to their bioactivities (antitumor, anti-inflammatory, antimicrobial, and others). Overall, to date, the value for seaweeds in terms of health and wellness effects were found to be mostly based on empirical knowledge. Although lipids from seaweeds are little explored, the published work showed the potential of lipid extracts, fractions, and complex lipids from seaweeds as functional ingredients for the food and feed, cosmeceutical, and pharmaceutical industries. This knowledge will boost the use of the chemical diversity of seaweeds for innovative value-added products and new biotechnological applications.     

Small-scale variation of vegetation in a mixed forest understorey is partly controlled by the effect of overstory composition on litter accumulation

We investigated how richness and composition of vascular plant species in the understory of a mixed hardwood forest stand varied with respect to the abundance and composition of the overstory. The stand is in central Spain and represents the southernmost range of distribution of several tree and herbaceous species in Europe. Understory species were identified in 46 quadrats (0.25 m²) where variables litter depth and light availability were measured. In addition, we estimated tree density, basal area, and percent basal area by tree species within 6-m-radius areas around each plot. Species richness and composition were studied using path analysis and scale-dependent geostatistical methods, respectively. We found that the relative abundance of certain trees species in the overstory was more important than total overstory abundance in explaining understory species richness. Richness decreased as soil litter depth increased, and soil litter increased as the relative proportion of Fagus sylvatica in the overstory increased, which accounted for a negative, indirect effect of Fagus sylvatica on richness. Regarding understory species composition, we found that some species distributed preferentially below certain tree species. For example, Melica uniflora was most frequent below Fagus sylvatica and Quercus petraea while the increasing proportion of Q. pyrenaica in the overstory favored the presence of Cruciata glabra, Arenaria montana, Prunus avium, Conopodium bourgaei, Holcus mollis, Stellaria media and Galium aparine in the understory. Overall, these results emphasize the importance of individual tree species in controlling the assemblage and richness of understory species in mixed stands. We conclude that soil litter accumulation is one way through which overstory composition shapes the understory community.     

Functional genomic approach to the study of biodiversitywithin Trichoderma

Trichoderma is a fungal genus of great and demonstrable biotechnological value, but its genome is poorly surveyed compared with other model microorganisms. Due to their ubiquity and rapid substrate colonization, Trichoderma species have been widely used as biocontrol organisms for agriculture, and their enzyme systems are widely used in industry. Therefore, there is a clear interest to explore beyond the phenotype to exploit the underlying genetic systems using functional genomics tools. Th…     

Structure of the prefusion form of the vesicular stomatitis virus glycoprotein G

Glycoprotein G of the vesicular stomatitis virus triggers membrane fusion via a low pH-induced structural rearrangement. Despite the equilibrium between the pre- and postfusion states, the structure of the prefusion form, determined to 3.0 angstrom resolution, shows that the fusogenic transition entails an extensive structural reorganization of G. Comparison with the structure of the postfusion form suggests a pathway for the conformational change. In the prefusion form, G has the shape of a tripod with the fusion loops exposed, which point toward the viral membrane, and with the antigenic sites located at the distal end of the molecule. A large number of G glycoproteins, perhaps organized as in the crystals, act cooperatively to induce membrane merging.     

Distribution of 5-hydroxytryptamine and related compounds in various brain regions of rainbow trout (Oncorhynchus mykiss)

The levels of tryptophan (Try), 5-hydroxytryptamine (serotonin, 5-HT) and 5-hydroxyindoleacetic acid (5-HIAA) were determined in the brain regions of rainbow trout (Oncorhynchus mykiss) by high performance liquid chromatography with electrochemical detection (HPLC-EC). Brain tryptophan concentrations varied from 3.972 ± 357 ng/g cerebellum) to 8.841 ± 772 ng/g (hypothalamus). The 5-HT concentrations varied from 69 ± 7 ng/g (optic tectum) to 573 ± 34 ng/g (hypothalamus). The concentrations of 5-HIAA varied from 29 ± 3 ng/g (medulla oblongata) to 68 ± 7 ng/g (hypothalamus). Total and free serum tryptophan levels were also determined; in adult rainbow trout 92% of the serum tryptophan was observed to be free i.e., not protein-bound.     

Avian regulation of crop and forest pests,a meta-analysis

BACKGROUND

Birds have been shown to reduce pest effects on various ecosystem types. This study aimed to synthesize the effect of birds on pest abundance, product damage and yield in agricultural and forest systems in different environments. Our hypothesis is that birds are effective pest regulators that contribute to a reduction in pest abundance, enhancement of yield quality and quantity and economic profit, and that pest regulation may depend on moderators such as the type of ecosystem, climate, pest, and indicator (ecological or economic).

RESULTS

We performed a systematic literature review of experimental and observational studies related to biological control in the presence and absence of regulatory birds. We retained 449 observations from 104 primary studies that were evaluated through qualitative and quantitative analyses. Of the 79 studies with known effects of birds on pest regulation, nearly half of the 334 observations showed positive effects (49%), 46% showed neutral effects, and very few (5%) showed negative effects. Overall effect sizes were positive (mean Hedges’ d = 0.38 ± 0.06). A multiple model selection retained only ecosystem and indicator types as significant moderators.

CONCLUSION

Our results support our hypothesis that there is a positive effect of avian control of pests for each analyzed moderator and this effect was significant for both ecological and economic indicators. Avian regulation of pests is a potential effective approach for environmentally friendly pest management that can reduce pesticide use regardless of the context of implementation. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.     

Involvement of PAPP‐A and IGFR1 in Cystic Ovarian Disease in Cattle

Cystic ovarian disease (COD) is one of the main causes of infertility in dairy cattle. It has been shown that intra‐ovarian factors, such as members of the insulin‐like growth factor (IGF) system, may contribute to follicular persistence. The bioavailability of IGF to initiate its response by binding to specific receptors (IGFRs) depends on interactions with related compounds, such as pregnancy‐associated plasma protein A (PAPP‐A). The aim of this study was to determine IGFR1 and PAPP‐A expression both in follicles at different stages of development and in cysts, to evaluate the roles in the etiopathogenesis of COD in cattle. The mRNA expression of PAPP‐A was higher in granulosa cells of large tertiary follicles than in cysts, whereas the protein PAPP‐A present in the follicular fluid from these follicles showed no differences. Although no PAPP‐A mRNA expression was detected in smaller tertiary follicles, in their follicular fluid, this protease was detected in lesser concentration than in cysts. The mRNA expression of IGFR1 was lower in granulosa cells from cystic follicles than in those from tertiary ones. However, the protein expression of this receptor presented the highest levels in cystic structures, probably to increase the possibility of IGF response. The data obtained would indicate that animals with COD have an altered regulation of the IGF system in the ovary, which could be involved in the pathogenesis of this disease in cattle.