Search Results (546)

Oxidative stress is a major constraint limiting animal health and productive performance by disrupting redox homeostasis, mitochondrial function, intestinal integrity, and mineral metabolism. Agronomic biofortification of forage with essential trace minerals represents a promising nutritional strategy; however, its physiological and molecular mechanisms remain poorly understood. This study evaluated the effects of dietary zinc–iron (Zn–Fe) biofortified alfalfa on oxidative stress, antioxidant defense, mineral transport, mitochondrial bioenergetics, intestinal barrier integrity, inflammatory responses, tissue mineral deposition, and growth performance in guinea pigs. Forty-eight male guinea pigs were allocated to six experimental groups according to dietary treatment (control, Zn-biofortified alfalfa, or Zn–Fe biofortified alfalfa) and oxidative stress status. Oxidative biomarkers, antioxidant enzyme activities, inflammatory mediators, mineral concentrations, targeted RT–qPCR, mitochondrial function, intestinal histomorphology, and multivariate physiological analyses were performed. Zn–Fe biofortified alfalfa markedly reduced reactive oxygen species, malondialdehyde, protein carbonyls, 8-hydroxy-2′-deoxyguanosine, advanced oxidation protein products, and the oxidative stress index while significantly increasing superoxide dismutase, catalase, glutathione peroxidase, total antioxidant capacity, and the glutathione redox ratio. Targeted gene-expression analysis demonstrated coordinated upregulation of intestinal mineral transporters (ZIP4, DMT1, and MT1), activation of the Nrf2 antioxidant pathway, increased expression of mitochondrial regulatory genes, and suppression of inflammatory mediators. These molecular responses were accompanied by improved ATP production, mitochondrial membrane potential, respiratory-chain activity, preservation of intestinal villus architecture, enhanced expression of tight-junction proteins, increased tissue Zn and Fe deposition, superior feed efficiency, and greater body weight gain. Integrated physiological analyses consistently identified the Zn–Fe biofortified treatment as the highest-performing physiological phenotype, indicating coordinated adaptation across multiple biological systems. These findings demonstrate that Zn–Fe biofortified alfalfa enhances oxidative stress resilience through simultaneous regulation of mineral transport, antioxidant defense, mitochondrial bioenergetics, intestinal barrier integrity, and systemic physiological performance. Agronomic biofortification of forage therefore represents a promising nutritional strategy for improving animal health, mineral utilization, and productive efficiency under oxidative stress. Full article

Airborne transmission represents a primary route of influenza virus dissemination. In animal infection models, conventional intranasal instillation fails to recapitulate the physiological features of natural respiratory infection. Existing aerosol-based challenge methods—including whole-body inhalation and oronasal exposure—face limitations in precise quantification of the delivered infectious dose. Moreover, oronasal exposure systems require specialized, high-cost instrumentation. This study established an economical and dosing-controlled aerosol challenge method utilizing a lung fluid quantitative nebulizer, which can deliver aerosolized virus directly to the lower respiratory tract via endotracheal intubation. The count median aerodynamic diameter (CMAD) of aerosols generated by the nebulizer was 2.28 μm. We compared pulmonary deposition efficiency and pathogenicity between lung-delivery aerosol inhalation and conventional intranasal instillation of PR8 influenza virus in mice. The pulmonary deposition rate for the aerosol inhalation was 63.1%, with an LD₅₀ of 31.1 EID₅₀; in contrast, intranasal instillation achieved a pulmonary deposition rate of 20.0% and an LD₅₀ of 115.0 EID₅₀. Histopathological analysis revealed significantly more severe lesions in lungs of mice challenged via lung-delivery aerosol inhalation relative to those receiving intranasal instillation. Furthermore, using a guinea pig model and a recombinant PR8 virus expressing Gaussia luciferase (PR8-Gluc), we demonstrated that pulmonary aerosol inhalation resulted in both more homogeneous spatial distribution and higher viral loads across lung tissues. Our results demonstrate that animals are more sensitive to lung-delivery inhaled virus than virus delivered by intranasal instillation. This study provides an optimized, economical, and technically straightforward aerosol challenge method with controlled administered dosing for viral infection models. Full article

Background/Objectives: Metabolic dysfunction-associated steatotic liver disease (MASLD) is closely linked to Western dietary patterns. Yet, preclinical studies rely on continuous high-fat feeding, overlooking the intermittent nature of human eating. Whether dietary periodicity itself influences the gut–liver axis and MASLD pathogenesis remains unknown. We compared continuous and intermittent high-fat, high-cholesterol (HFHC) diets in guinea pigs, a model that mirrors human lipoprotein metabolism, hepatic cholesterol handling, and hindgut fermentation. Methods: Integrated multi-omics analyses (serum metabolomics, fecal 16S rRNA sequencing, and liver transcriptomics) were employed in a guinea pig model, stratified into normal diet (ND), intermittent HFHC diet (IHD), and IHD with flaxseed lignan supplementation, to compare the effects of dietary regimens and the therapeutic efficacy of lignan on hepatic pathology. Results: Both diets induced hallmark hepatic features of MASLD; however, the intermittent regimen provoked significantly more severe hepatic steatosis, inflammation, oxidative stress, and fibrosis. Hepatic transcriptomic analysis identified the PI3K-Akt signaling pathway as the most significantly enriched pathway in the IHD group. Mechanistically, this aggravated liver injury was linked to gut microbiota dysbiosis and a marked depletion of the microbial metabolite enterolactone. Fecal microbiota transplantation confirmed that the dysbiotic microbiota directly transmits the aggravated liver injury phenotype. Supplementation with flaxseed lignan, the dietary precursor of enterolactone, restored enterolactone production, corrected the dysregulated gut microbiota–enterolactone axis, and largely normalized the expression of PI3K-Akt downstream targets, thereby alleviating hepatic pathology. Conclusions: These findings suggest that alterations in the gut microbiota–enterolactone axis may contribute to diet-periodicity-driven liver injury and highlight its potential involvement in disease progression. Modulating this axis through dietary interventions, such as flaxseed lignan supplementation, may represent a promising nutritional strategy for mitigating MASLD associated with cyclical dietary exposure. Full article

Chronic cutaneous ulcers pose a major clinical challenge due to persistent inflammation, impaired angiogenesis, and limited regenerative capacity, underscoring the need to develop bioactive scaffolds that mimic the extracellular matrix (ECM) and promote skin repair. In this study, electrospun Poly(ε-caprolactone) (PCL) scaffolds functionalized with 10% (PCLGLI10) and 20% (PCLGLI20) glycine were fabricated, physicochemically and mechanically characterized, and evaluated in combination with human Wharton’s jelly mesenchymal stromal cells (hWJ-MSCs). Glycine incorporation reduced fiber diameter to the nanoscale range (140–155 nm) and increased scaffold porosity (~71–72%) while preserving mechanical properties compatible with skin. FTIR and X-ray diffraction analyses confirmed glycine incorporation and a polymorphic transition from α- to γ-glycine during electrospinning. Cell viability remained above 95% in all scaffolds; however, PCLGLI10 significantly enhanced cell proliferation, metabolic activity, and the secretion of VEGF and HGF, mediators associated with angiogenesis and tissue repair. Furthermore, in a guinea pig full-thickness wound model, the PCLGLI10+hWJ-MSCs construct promoted a modulated inflammatory response and more organized collagen deposition. These findings support the potential of glycine-functionalized electrospun scaffolds as a promising strategy for chronic cutaneous ulcer regeneration. Full article

Objectives: Antiviral vaccines are usually created by inactivating viruses using physical or chemical methods. Inactivation of poliovirus with β-propiolactone (BPL) has advantages, including the absence of a requirement for long-term incubation with the inactivating agent, which minimizes the risk of negative effects of the potentially dangerous substance on the virus and reduces the duration of the inactivation process. Methods: BPL was applied at 0.2% (w/v) concentration under two conditions: 4 °C for 24 h and 37 °C for 3 h. Inactivation completeness was confirmed on Vero cell culture, while immunogenicity was assessed in guinea pigs via neutralizing antibody test. Conclusions: Two variants of virus inactivation made it possible to obtain inactivated samples that retained their immunogenic properties. BPL-inactivated samples retained sufficient D-antigen levels and elicited neutralizing antibodies comparable to or exceeding those from formaldehyde-inactivated controls. The inactivation method at 37 °C provided faster inactivation, while at 4 °C it provided a smooth decrease in virus titer. These results confirm that β-propiolactone is a viable alternative to formaldehyde for the production of inactivated polio vaccine (IPV), providing rapid inactivation of the virus compared to inactivation with formaldehyde while maintaining immunogenicity, as confirmed by guinea pig control. Full article

African horse sickness (AHS), a noncontagious insect-borne disease affecting equids, is caused by the African horse sickness virus (AHSV) and is associated with extremely high morbidity and mortality. AHSV has nine distinct serotypes (AHSV-1 to AHSV-9). In a previous study, we characterized the genome and in vitro growth properties of AHSV/C, a cell-adapted derivative of an AHSV-1 strain imported into China 60 years ago, and verified its safety in mice. This study preliminarily explored the pathogenicity of AHSV/C in guinea pigs and horses (its natural host). Six groups of guinea pigs were inoculated with three doses of AHSV/C (10^7.5, 10^6.5, and 10^5.5 TCID₅₀ per animal) via both intraperitoneal and subcutaneous routes; two horses were subcutaneously inoculated with 10^5.5 TCID₅₀ of AHSV/C. All animals received a booster inoculation three weeks later. During the entire observation period, we mainly monitored clinical signs, body temperature, viremia, virus shedding and pathological changes (examined only in guinea pigs), and collected serum samples for neutralizing antibody detection. The results showed that no abnormal clinical signs, evident viremia, or virus shedding were observed in either species. Histopathological examinations revealed no evident lesions in guinea pigs. Neutralization tests showed that AHSV/C induced only low neutralizing antibody titers after primary inoculation, with a marked increase after booster administration. Collectively, this study preliminarily characterized the pathogenicity of AHSV/C in guinea pigs and horses, confirming that the strain showed no evident pathogenicity in test animals. These findings suggest that AHSV/C may be an attenuated strain. Further studies with larger sample sizes are required to validate these findings and explore their potential applications. Full article

Background: Rickettsioses are emerging diseases worldwide caused by intracellular bacteria of the genus Rickettsia. In recent years, these diseases have caused deaths in northwestern Mexico, particularly cases of Rocky Mountain spotted fever (RMSF). While ticks are considered the primary vector for RMSF, other possible vectors of rickettsioses, such as fleas, lice, and mosquitoes, coexist with reservoirs, including dogs, cats, and other domestic animals that may interact with humans. This study aimed to detect the presence of Rickettsia spp., including spotted fever group (SFG) Rickettsia, in arthropod vectors not previously reported in northwestern Mexico using real-time polymerase chain reaction (qPCR). Methods: Ticks, fleas, lice, and mosquitoes were collected from dogs, cats, guinea pigs, and humans. qPCR was used to detect Rickettsia spp. and SFG Rickettsia. Results: Rickettsia spp. were detected in dog ticks (Rhipicephalus sanguineus) and cat fleas (Ctenocephalides felis), with pooled positivity rates of 13.5% and 22.2%, respectively. Conclusions: These results suggest that ticks and fleas are the main arthropod vectors involved in transmitting Rickettsia spp. in northwestern Mexico. Full article

Asthma is a chronic airway disease characterized by inflammation, bronchial hyperresponsiveness, and airflow limitation, highlighting the need for novel bronchodilator agents. Cryptotanshinone (CT), a bioactive diterpenoid derived from Salvia miltiorrhiza, exhibits anti-inflammatory and vasodilatory properties; however, its direct effects on airway smooth muscle remain poorly characterized. This study investigated the bronchodilatory activity of CT and its pharmacological mechanisms. Molecular docking was performed to evaluate potential interactions with M₃ muscarinic receptors and L-type calcium channels. Functional experiments were conducted using isolated guinea pig tracheal smooth muscle preparations. The relaxant effects of CT (10⁻⁷–3 × 10⁻⁴ M) were evaluated against carbachol (1 µM)- and high-K⁺ (80 mM)-induced contractions. Docking predicted favorable binding of CT to the M₃ receptor and L-type Ca²⁺ channel, with binding energies of −9.854 and −9.951 kcal/mol, respectively. In vitro, CT produced concentration-dependent relaxation of CCh-induced contractions, reaching a maximal effect of 41.9 ± 2.58% at 3 × 10⁻⁴ M (pEC₅₀ = 4.60). CT produced minimal relaxation in high-K⁺-induced contractions, suggesting receptor-mediated rather than non-selective smooth muscle inhibition. CT also produced a parallel rightward shift of the CCh concentration–response curve at 10⁻⁵ M, whereas a higher concentration (10⁻⁴ M) altered the maximal contractile response, suggesting concentration-dependent pharmacological effects. Pharmacological inhibition studies indicated the involvement of muscarinic receptor-mediated mechanisms, with additional contributions from calcium channel-related mechanisms and partial involvement of the NO/cGMP pathway, while β₂-adrenergic signaling and potassium channels were not significantly involved. These findings suggest that CT exerts bronchodilatory effects through the involvement of multiple pharmacological pathways relevant to airway smooth muscle regulation and provide preliminary mechanistic evidence supporting further investigation. Full article

Bovine viral diarrhea (BVD) is a globally significant disease that adversely affects cattle health and productivity, including in India. It is caused by three bovine pestiviruses: bovine viral diarrhea virus 1 (BVDV-1), BVDV-2, and HoBi-like pestivirus (HoBiPeV), which belong to the Pestivirus genus within the Flaviviridae family. Despite the prevalence of all three pestivirus species in India, no commercial vaccine based on the local circulating strain is currently available. This study evaluates the safety, immunogenicity, and protective efficacy of an inactivated whole-virus BVD vaccine, based on an Indian BVDV-1 strain. The virus was propagated in MDBK cells, inactivated using 3 mM binary ethylenimine (BEI) for 24 h at 37 °C, and formulated with Montanide ISA 61 VG (SEPPIC) in a 50:50 water-in-oil emulsion. Vaccine safety was confirmed in both guinea pigs and bovine calves, with no adverse effects observed. Immunogenicity testing in guinea pigs (n = 6) showed neutralizing antibody titres up to 9 log₂ (1/512). In calves aged 9–12 months (n = 3), the vaccine elicited strong humoral and cell-mediated immune responses, with mean neutralizing antibody titres against the homologous BVDV-1 strain reaching 14 log₂ (1/16,384). Neutralizing antibody levels remained detectable for up to 12 months post vaccination with sustained mean titres of 7 log₂ (1/128). Notably, titres reported to be adequate for fetal protection (≥9 log₂ or ≥1/512 were maintained for five months following vaccination. Challenge studies demonstrated complete protection of vaccinated calves against homologous BVDV-1 acute infection. In addition, the vaccine conferred partial cross-protection against heterologous strains including BVDV-2 and HoBiPeV. In a field trial involving 125 cattle, 74% of animals developed protective neutralizing titres (≥7 log₂ or ≥1/128), while 48% achieved titres reported to be adequate for fetal protection (9 log₂ or 1/512). Furthermore, 92% of vaccinated cattle maintained neutralizing antibody titres of at least 6 log₂ (≥1/64) for up to six months post-booster vaccination. A strong positive correlation was observed between guinea pig and bovine antibody responses (R² = 0.6809; p < 0.0001), indicating the potential of guinea pigs as a predictive model. Vaccine stability was confirmed for up to 8 months when stored at 4 °C, as demonstrated by the immunogenicity in guinea pigs. Collectively, these findings demonstrate that the locally developed inactivated BVDV-1 vaccine is safe, highly immunogenic, and capable of providing protective immunity against BVDV-1 infection, supporting its potential use in BVD control programs in India. Full article

Objectives: Seasonal influenza leads to substantial global morbidity and mortality, especially in adults aged 65 years and older, who present poor immune responses to standard-dose influenza vaccines. This study aimed to systematically evaluate the preclinical safety and immunogenicity of a high-dose quadrivalent seasonal influenza split vaccine (HD-QIV), providing preclinical evidence for its clinical application in the elderly. Methods: Following GLP guidelines, we performed single-dose and repeated-dose toxicity tests in Sprague–Dawley rats, active systemic anaphylaxis assays in guinea pigs, and immunogenicity assessments in young and aged BALB/c mice. Safety indicators included general clinical signs, hematology, blood biochemistry, histopathology and allergic reactions; immunogenicity was evaluated via hemagglutination inhibition (HI) antibody titers and antigen-specific cellular immune responses. Results: HD-QIV only caused mild and reversible local irritation in rats without obvious systemic toxicity, and no dose-related systemic anaphylaxis was observed in guinea pigs. HD-QIV induced robust and dose-dependent humoral immune responses, and showed significantly higher HI antibody titers, earlier seroconversion and longer antibody persistence than standard quadrivalent influenza vaccine in aged mice. Cellular immunity was slightly enhanced but not the dominant protective response. Conclusions: The HD-QIV demonstrates favorable preclinical safety and superior immunogenicity, supporting its further clinical development and use as a priority vaccine for the elderly population. Full article

Beyond gas transport, red blood cells (RBCs) have emerging roles regarding innate immunity, regulating blood flow, and participating in nutrient transport, which can be engineered as drug delivery systems since they contribute to maintaining water homeostasis. Following extensive thermoanalytical studies of human blood plasma, our working group investigated the properties of RBCs, examining their role in healthy and in different disease states by using differential scanning calorimetry (DSC) and the deconvolution of the resulting thermal curve. In the first study, guinea pigs were treated with intraperitoneal chemotherapy. Cyclophosphamide treatment showed a dose-dependent difference between the thermal parameters of control and treated samples, indicating that DSC can be used in this area. Following deconvolution of the DSC studies, the changes can be attributed to the damaged compounds. In the second part of our study, a method for the thermal analysis and deconvolution of RBCs in patients with lower limb ischemia during a three-month cilostazol treatment was developed. The control DSC curve showed 5–6 distinct thermal domains, and in contrast to other drug treatments, this remained stable throughout the entire study period. No effects of stiffness or compact were caused by the anticancer drug cyclophosphamide were observed in the structure of RBCs. These preliminary results highlight the uniqueness of thermodynamic studies of RBCs and provide a fingerprint-like identification of a given individual or disease state. Full article

Temperature abuse during storage represents a critical factor influencing microbial behavior in meat products, particularly in non-conventional matrices such as guinea pig meat. This study aimed to characterize and compare the primary growth kinetics of Aerobic mesophilic bacteria and Staphylococcus aureus (S. aureus) in guinea pig meat burgers under controlled temperature abuse conditions (30, 35, and 40 °C). Microbial growth was monitored over 96 h and described using the modified Gompertz model to estimate key kinetic parameters, including maximum specific growth rate (µ_max) and lag phase duration (λ). Aerobic mesophilic bacteria exhibited increasing µ_max values with temperature, indicating enhanced metabolic activity under elevated thermal conditions. In contrast, S. aureus showed reduced µ_max and prolonged λ at 40 °C, suggesting stress-induced modulation of growth dynamics. These findings demonstrate that temperature increases do not uniformly accelerate microbial proliferation across different populations within the same food matrix. The contrasting kinetic responses indicate that Aerobic mesophilic bacteria and S. aureus respond differently to temperature abuse conditions, highlighting that total aerobic counts alone may not reliably predict pathogen behavior in guinea pig meat burgers. Full article

Foot-and-Mouth Disease (FMD) is caused by the FMD virus. Indirect Sandwich Enzyme-Linked Immunosorbent Assay (IS-ELISA) was standardized to characterize the FMD serotype “O” virus. Total protein content in the guinea pig serum (whole serum), ammonium sulfate precipitated guinea pig serum (ASPGPS) protein and ion-exchange-based purified guinea pig serum (IEGPS) protein was measured as 52 µg/mL, 24 µg/mL and 10 µg/mL respectively. The whole serum of guinea pigs and rabbits showed the 1:32 and 1:64 anti-FMD serotype “O” virus neutralizing antibody titers, while the anti-FMD serotype “O” virus neutralizing antibody titer was 1:128 in the IEGPS proteins. IEGPS protein with 1:128 neutralizing antibody titers were used as capture/trapping antibodies in the standardization of the assay. The IEGPS protein 1:1000 diluted with 10 µg/mL of protein content was found to be optimum for capture/trapping antibodies. To cover residual blank spaces, different available blocking buffers were evaluated and Skimmed Milk Solution 5% in Phosphate-Buffered Saline (PBS5%) proved best amongst blocking buffers. Coating of 1:1000 diluted IEGPS at 37 °C for 1 h followed by storage at 4 °C for overnight was best for incubation time. FMD serotype “O” virus 1:100 diluted was optimum in IS-ELISA. Similarly rabbit anti-FMD serotype “O” virus specific immune serum 1:10,000 diluted and goat anti-rabbit IgG horseradish peroxidase conjugate 1:4000 diluted were found to be optimum during the standardization of the assay. Lastly ELISA plates proved to be best amongst the available plates for assay. In each experiment, the plateau region, test background and plate background were recorded. Lastly it became possible for the establishment of an optimized and potentially cost-effective IS-ELISA requiring further diagnostic validation in research and diagnostic laboratories in the country. Full article

Although renal disease in Syrian hamsters (SHs) has been reported, imaging studies of normal kidneys in this commonly used pet and laboratory species are lacking, despite the key role of imaging in diagnosis. This study aimed to examine kidneys of Syrian hamsters using radiographic and anatomical methods, focusing on kidney location, visibility, size, and its ratio to the second lumbar vertebra, along with the effects of sex, body size, side, and recumbency. Abdominal radiographs were obtained from 29 clinically healthy adult Syrian hamsters of both sexes to assess kidney visibility, position, and size as well as the length of second lumbar vertebral body on lateral and ventrodorsal (VD) views, followed by an in situ anatomical study for comparative analysis. The kidneys were typically located opposite the first to third lumbar vertebrae. On VD views, the left kidney was generally visible, whereas the right was identified in only 28%. The mean values of radiographic RKL, LKL, and 2LVL were 15.2 mm, 12.44 mm, and 14.27 mm, respectively, and the KL/2LVL ratio ranged from 2.66 to 4.00. No significant sex differences were observed in KL or the KL/2LVL ratio in either anatomical or radiographic measurements (p > 0.05). Sex had a significant effect on both radiographic and anatomical 2LVL measurements, with females generally showing higher values than males. Unlike the anatomical measurements, no significant differences between sides were found in radiographic KL and the KL/2LVL ratio. The radiographic RKL, LKL, and 2LVL were significantly larger than those obtained from anatomical measurements. No significant correlation was found between KL, 2LVL, or the KL/2LVL ratio and body length or body weight in either radiographic or anatomical measurements, except for a correlation between body weight and anatomical KL. Right and left kidneys were symmetrically placed, as in rats, but differed from rabbits and guinea pigs. Kidney visibility on VD views was similar to that reported in rabbits. Radiographic RKL, LKL, and 2LVL values differed from those of rodents and rabbits. The radiographic ratio was larger than the values reported in rats, chinchillas, guinea pigs, and rabbits. A single KL-to-2LVL ratio reference range applies to both kidneys and sexes, simplifying clinical assessment. Full article

Background: Lumpy skin disease (LSD) is caused by a Capripoxvirus. Live attenuated vaccines, which are commercially available, could be not safe because of the side effects. The aim of this study was the evaluation of the safety, immunogenicity, and effects on the qualitative and quantitative parameters of milk. The feasibility of identifying vaccinated animals using our inactivated vaccine in dairy cows was analysed. The vaccine was tested in guinea pigs as an immunogenicity predictive model. Methods: LSD virus was propagated on Madin–Darby Bovine Kidney (MDBK) cells, then inactivated and supplemented with keyhole limpet hemocyanin (KLH) protein, obtaining a positive marker vaccine. This was inoculated in guinea pigs and in dairy cows, and animal sera were analysed using enzyme-linked immunosorbent assay (ELISA) and a serum neutralisation (SN) test. Quantitative and qualitative analyses were performed on milk. Results: The vaccine was previously tested for efficacy in vaccinated calves, showing a pronounced reduction in clinical symptoms after challenge. The safety and immunogenicity obtained in calves were also confirmed in dairy cows in this study. In fact, high values of the SN test (1:20 to 1:80) and ELISA (90 and 240 S/P%) were obtained after vaccination. Moreover, high immunogenicity of the vaccine was also assessed in guinea pigs. In addition, the results of the milk analyses did not show any differences between vaccinated and control groups. The KLH was able to elicit an immune response detectable using an ELISA (3.0 and 3.5 optical density values). Finally, our vaccine could be used to reduce LSD symptoms and identify vaccinated animals. Full article