Effects of L-NAME, a non-specific nitric oxide synthase inhibitor, on AlCl3-induced toxicity in the rat forebrain cortex

The present experiments were done to determine the effectiveness of a non-specific nitric oxide synthase inhibitor, N-nitro-L-arginine methyl ester (L-NAME), on oxidative stress parameters induced by aluminium chloride (AlCl₃) intrahippocampal injections in Wistar rats. Animals were sacrificed 3 h and 30 d after treatments, heads were immediately frozen in liquid nitrogen and forebrain cortices were removed. Crude mitochondrial fraction preparations of forebrain cortices were used for the biochemical analyses: nitrite levels, superoxide production, malondialdehyde concentrations, superoxide dismutase (SOD) activities and reduced glutathione contents. AlCl₃ injection resulted in increased nitrite concentrations, superoxide anion production, malondialdehyde concentrations and reduced glutathione contents in the forebrain cortex, suggesting that AlCl₃ exposure promoted oxidative stress in this brain structure. The biochemical changes observed in neuronal tissues showed that aluminium acted as a pro-oxidant. However, the non-specific nitric oxide synthase (NOS) inhibitor, L-NAME, exerted anti-oxidant actions in AlCl₃-treated animals. These results revealed that NO-mediated neurotoxicity due to intrahippocampal AlCl₃ injection spread temporally and spatially to the forebrain cortex, and suggested a potentially neuroprotective effect for L-NAME.     

AMMONIUM AND NITRATE IN SOIL AND RATOON SUGARCANE GROWN IN FUNCTION OF NITROGEN ON OXISOL

After harvest, sugarcane residues left on the soil surface can alter nitrogen (N) dynamics in the plant-soil system. In Oxisols, the nitrogen fertilizer applied had its effects on the levels of ammonium and nitrate in the soil, N concentration in the plant leaves, and on the growth and productivity of second ratoon plants. The N rates tested were of 0, 60, 120, 180, and 240 kg ha^?1. Each treatment was replicated four times. Four months after the experiment was started, ammonium and nitrate concentration in the soil, N levels in plant leaves, and plant growth were evaluated. Productivity was evaluated 11 months after the experiment was set. By increasing the content of mineral N in soil, plant growth variables reflected differences in the production of stems; however, it did not affect foliar N. The use of leaf analysis was not important to assess the nutritional status of nitrogen in the ratoon sugarcane. Nitrogen concentration in soil was affected by nitrogen fertilization, but not the N content in leaves. The rate of 138 kg N ha^?1enabled greater production of sugarcane stalks (140 t ha^?1).     

Simultaneous subchronic exposure to selenium and diazinon as possible risk factor for osteoporosis in adult male rats

Background

Osteoporosis and its main health outcome, fragility fractures, are large and escalating health problems. Skeletal damage may be the critical result of low-level prolonged exposure to several xenobiotics in the general population, but the mechanisms of their adverse effects are not clearly understood. The current study was aimed to investigate the possible ability of simultaneous subchronic peroral administration of selenium (Se) and diazinon (DZN) to induce changes in bone of adult male rats.In our study, twenty 1-month-old male Wistar rats were randomly divided into two experimental groups. In the first group, young males were exposed to 5 mg Na₂SeO₃/L and 40 mg of DZN/L in drinking water, for 90 days. Ten 1-month-old males without Se and DZN intoxication served as a control group. At the end of the experiment, macroscopic and microscopic structures of the femurs were analysed using analytical scales, sliding instrument, and polarized light microscopy.

Results

The body weight, femoral length and cortical bone thickness were significantly decreased in rats simultaneously exposed to Se and DZN (P < 0.05). These rats also displayed different microstructure in the middle part of the compact bone where vascular canals expanded into central area of substantia compacta. The canals occurred only near endosteal surfaces in rats from the control group. Additionally, a smaller number of primary and secondary osteons, as well as a few resorption lacunae were observed near endosteal surfaces in rats simultaneously administered to Se and DZN. The resorption lacunae as typical structures of bone resorption manifestation are connected with an early stage of osteoporosis. Histomorphometric analysis revealed that area, perimeter, maximum and minimum diameters of primary osteons’ vascular canals were significantly increased (P < 0.05) in the Se-DZN-exposed rats. On the other hand, all measured variables of Haversian canals and secondary osteons were considerable reduced (P < 0.05) in these rats.

Conclusions

Simultaneous subchronic peroral exposure to Se and DZN induces changes in macroscopic and microscopic structures of the femurs in adult male rats, and also it can be considered as possible risk factor for osteoporosis. The current study contributes to the knowledge on damaging impact of several xenobiotics on the bone.     

Influence of different factors on the costs and benefits of oral vaccination of foxes against rabies

The oral rabies vaccination (ORV) programme is the most widespread vaccination programme that is implemented in the European Union and targets wildlife diseases. The size of the project requires significant financial resources, so a cost–benefit analysis is necessary to establish the economic value of the project. We summarized all ORV costs during the period 2011–2016 in Croatia, calculated all established benefits and presented the cost–benefit ratio (CBR). Additionally, we analysed all components included in the ORV and rabies control programme (surveillance, preventive human treatment and vaccination of dogs) to find possibilities to increase the benefits. According to our results, in the period 2011–2016, the CBR was only 0.05, and the majority of the cost was derived from the preventive vaccination of dogs (72.3%). With the implementation of 2‐ or 3‐year vaccination intervals, the CBR can be increased to 1.46 or 1.92, respectively, confirming positive economic value. This study shows the importance of analysing all rabies control and eradication components based on the specific characteristics of a particular country to determine the factors that can be modified to potentially improve the benefits of ORV.     

Immune defense of wild‐caught Norway rats is characterized by increased levels of basal activity but reduced capability to respond to further immune stimulation

Studies of wild animals' immunity often use comparison with laboratory‐raised individuals. Using such an approach, various data were obtained concerning wild Norway rat's immunity. Lower or higher potential of immune system cells to respond to activation stimuli were shown, because of analysis of disparate parameters and/ or small number of analyzed individuals. Inconsistent differences between laboratory and wild rats were shown too, owing to great response variability in wild rats. We hypothesized that wild rats will express more intense immune activity compared to their laboratory counterparts which live in a less demanding environment. To test this, we analyzed the circulating levels of inflammatory cytokine interleukin‐6 (IL‐6), a mediator which has a central role in host immune defense. In addition, we examined the activity of the central immune organ, the spleen, including cell proliferation and production of pro‐inflammatory cytokines interferon‐γ (IFN‐γ) and interleukin‐17 (IL‐17), which are major effectors of cellular adaptive immune response. In order to obtain reasonable insight into the immunity of wild Norway rats, analysis was conducted on a much larger number of individuals compared to other studies. Higher levels of plasma IL‐6, higher spleen mass, cellularity and basal IFN‐γ production concomitantly with lower basal production of anti‐inflammatory cytokine interleukin‐10 (IL‐10) revealed more intense immune activity in the wild compared to laboratory rats. However, lower responsiveness of their spleen cells' proinflammatory cytokine production to concanavalin A (ConA) stimulation, along with preserved capacity of IL‐10 response, might be perceived as an indication of wild rats' reduced capability to cope with incoming environmental stimuli, but also as a means to limit tissue damage.     

Effects of fungicide application on physiological and molecular responses of grapevine (Vitis vinifera L.): a comparison between copper and sulfur fungicides applied alone and in combination with novel fungicides

BACKGROUND

Chemical products against fungi and oomycetes pose serious environmental issues. In the last decade, the use of less impacting active ingredients was encouraged to reduce chemical inputs in viticulture. In this study, the effect of different antifungal compounds on grapevine agronomic, physiological, and molecular responses in the vineyard was evaluated in addition to protection against powdery and downy mildews.

RESULTS

In 2 years and in two Vitis vinifera cultivars (Nebbiolo and Arneis), a conventional crop protection approach, based on traditional fungicides (sulfur and copper), was compared to combined strategies. A well-known resistance inducer (potassium phosphonate), Bacillus pumilus strain QST 2808 and calcium oxide, both active ingredients whose biological interaction with grapevine is poorly characterized, were applied in the combined strategies in association with chemical fungicides. Despite a genotype effect occurred, all treatments optimally controlled powdery and downy mildews, with minimal variations in physiological and molecular responses. Gas exchange, chlorophyll content and photosystem II efficiency increased in treated plants at the end of season, along with a slight improvement in the agronomic performances, and an activation of molecular defense processes linked to stilbene and jasmonate pathways.

CONCLUSION

The disease control strategies based on potassium phosphonate, Bacillus pumilus strain QST 2808 or calcium oxide combined with traditional chemical compounds did not cause severe limitations in plant ecophysiology, grape quality, and productive yields. The combination of potassium phosphonate and calcium oxide with traditional fungicides can represent a valuable strategy for reducing copper and sulfur inputs in the vineyards, including those organically managed. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.     

Grapevine rupestris stem pitting virus: a new pathogen of grapevine in Serbia

Journal of Plant Diseases and Protection - Grapevine rupestris stem pitting-associated virus (GRSPaV), a member of the genus Foveavirus, is a commonly detected grapevine virus around the world....     

Diagnosis of canine brucellosis by ELISA using an antigen obtained from wild Brucella canis

An indirect ELISA test was developed for the diagnosis of Brucella canis infection in dogs. A bacterial whole cell extract was used as a solid phase antigen, using B. canis isolated from an infected animal. Sera from culture-positive and healthy negative animals were used as internal reference controls. The cut-off point was determined by a mathematical formula for a statistically valid value, which defined the upper prediction limit, based on the upper tail of the t-distribution of 21 negative control sera readings, for the confidence level of 99.5%. The sensitivity and specificity of the ELISA test were 95% and 91%, respectively. The ELISA test showed a significant concordance index (K=0.84) with the agar gel immunodiffusion test. The reliability of the ELISA for the detection of infected animals was established by a double blind study testing 280 sera provided by serum banks from different diagnostic and research institutions and analyzed by ROC Curve.     

Differences in grain/straw ratio,protein content and yield in landraces and modern varieties of different wheat species under organic farming

Hulled wheat species (einkorn, emmer, spelt) are presumed to be an alternative to bread wheat in organic agriculture since the yield penalty is less pronounced under organic farming and generally higher prices can be achieved for specialty grains. The present study analyzed differences between wheat species with respect to biomass production, harvest index, grain yield and protein content. Spring hulled wheat genetic resources and bread wheat check cultivars were grown in organic field trials in the Czech Republic and Austria between 2010 and 2012. Generally, hulled wheat species were inferior in grain yield and distribution of assimilates to the grain compared to modern bread wheat. Biomass production of some emmer and spelt landraces was similar to bread wheat. A higher protein content (+3–6 %) was observed for spelt, however, considering protein yield the differences between spelt and bread wheat became less pronounced. With respect to the recent high market demand for spelt and the absence of available spring grown varieties some of the landraces were identified as valuable resources for the development of spring spelt varieties suitable for organic farming.     

Comparison of the <Emphasis Type="Italic">Rhodotorula mucilaginosa</Emphasis> Biofilm and Planktonic Culture on Heavy Metal Susceptibility and Removal Potential

This study compares the effect of heavy metals (Hg²⁺, Cu²⁺, and Pb²⁺) on the Rhodotorula mucilaginosa and Saccharomyces boulardii biofilm and planktonic cells. A MBEC^TM-HTP assay was used to test the levels of tolerance to heavy metals. The minimum inhibitory concentration (MICp) and minimum lethal concentration (MLCp) of the R. mucilaginosa and S. boulardii planktonic cells were determined, as well as minimum biofilm eradication concentration (MBEC). Metal removal efficiency was determined by batch biosorption assay. Previous studies had focused on heavy metal tolerance and removal efficiency of planktonic cells from Rhodotorula species only. Hence, our study presents and compares results for metal tolerance and removal efficiency of the R. mucilaginosa planktonic cells and biofilm. Biofilm tolerance was higher than the planktonic cells. The R. mucilaginosa planktonic cells showed the tolerance in the presence of Hg²⁺ (MICp 0.08 mM), Cu²⁺ (MICp 6.40 mM), and Pb²⁺ (MICp 3.51 mM), while the S. boulardii planktonic cells only tolerated Pb²⁺ (MICp 0.43 mM). The R. mucilaginosa biofilm showed the highest tolerance in the presence of Hg²⁺ (MBEC >0.31 mM), Cu²⁺(MBEC >12.81 mM), Pb²⁺ (MBEC >7.12 mM), and obtained results were confirmed by fluorescence microscopy. S. boulardii did not show potential in biofilm formation. The R. mucilaginosa biofilm exhibited better efficiency in removal of all tested metals than the planktonic cells. Metal removal efficiency was in the range from 4.79–10.25% for planktonic cells and 91.71–95.39% for biofilm.