Acute inflammation is a complex biological response triggered by various invading agents provoking distinct immune pathways. As inter-strain variability in guinea pigs can influence inflammatory responses, ultimately affecting disease progression, understanding these strain-specific differences can improve the reliability and translational relevance of guinea pig models for studying acute inflammation. In this study, two guinea pig strains, Trik coloured and Dunkin-Hartley albino, were subjected to bacterial endotoxin lipopolysaccharide (LPS) to induce acute systemic inflammation. Specific metabolite alterations in the blood plasma and bronchoalveolar lavage fluid (BALF) were identified using hydrogen-1 nuclear magnetic resonance (¹H NMR) spectroscopy. Distinct differences in the metabolomic profiles in the blood plasma indicated significant inter-strain variability in circulating metabolites during LPS-induced acute inflammation, including those involved in amino acid transamination, ammonia transfer, and immune responses. Metabolomic analysis of BALF from guinea pigs with LPS-induced inflammation revealed decreased levels of specific metabolites. Moreover, changes in blood and BALF white blood cell counts and body weight were evaluated after LPS exposure. In BALF, LPS caused a slight, non-significant increase in total cell count and a significant neutrophil increase in the Dunkin-Hartley strain. In blood, Trik strain showed a significant increase in total count of cells and a significant neutrophil decrease. LPS induced weight loss in both strains, more pronounced in Trik. The study points out strain-specific metabolomic changes in guinea pig LPS model, highlighting the importance of strain selection in inflammation research. While descriptive, these preliminary findings provide a basis for future work to explore inflammatory mechanisms of LPS and improve translation to human disease.

BMP2 inhibits myopia progression by upregulating PPARγ in guinea pigs.

Xiaoyan Lidan formula ameliorates cholecystitis by regulating cholesterol transportation and water permeability of the gall bladder through the activation of LXRβ.

Combination of oximes as experimental therapeutic approach to organophosphates poisonings: a critical review.

Investigation of the role of ILC2 in middle ear mucosa using a novel model of eosinophilic otitis media.

Acetazolamide alleviates motion sickness by inhibiting inner ear carbonic anhydrase 2 and reducing endolymph volume.

An In Silico-Designed Chimeric Antigen Confers Broad Protection Against Major Diarrheal Pathogens (Shigella, ETEC, and EHEC) in Preclinical Models.

The ability to continuously monitor key biomarkers is crucial for advancing personalized medicine and enabling early disease intervention. Potassium ions (K+) play a vital role in neural signaling, cardiac function, and sensory processing, particularly in the cochlea, where potassium imbalances are linked to disorders such as Ménière's disease. However, existing diagnostic methods cannot monitor K+ in the inner ear in real time, limiting insight into the ionic mechanisms that underlie auditory function and related disorders. This study presents a miniaturized potassium-selective biosensor, incorporating a stable reference electrode, for continuous and real-time monitoring of K+ dynamics in the inner ear. The sensor underwent extensive benchtop validation, demonstrating high sensitivity (⁓52.8 mV/dec), a broad linear range (10-5-10-1mol/L), a limit of detection of 10-5·16mol/L, strong selectivity coefficients (-2.62 for Na+, -4.10 for Mg2+, and -3.85 for Ca2+), and excellent stability over two months. In-vivo experiments in a guinea pig model confirmed the biosensor's capability to track dynamic potassium fluctuations under physiological conditions, such as responses to controlled potassium administration. These findings establish the feasibility of real-time K+ monitoring in the cochlea, providing a valuable tool for studying auditory physiology, understanding potassium regulation in the inner ear, and advancing targeted diagnostics and treatments for inner ear disorders.

To investigate the extracellular matrix (ECM) change in choroid and explore the key regulator of choroidal vascular scaffold in axial myopia. Myopia was induced in pigmented rabbits and guinea pigs using the form-deprivation approach. Quantitative label-free proteomics were performed using the samples of rabbits to investigate the differentially expressed proteins (DEPs) in myopic choroid. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment was conducted to explore the potential biomarkers and signal pathways that form the scaffold and regulate the choroid morphology in myopia. Immunoblotting and immunofluorescence were applied to determine the expression and distribution of DEPs in choroid. Adeno-associated virus was used to knock down the expression of COL4A2 to verify its biological function in refraction development and choroid morphology. Long-term form deprivation significantly induced myopia shifts and decreased the choroidal thickness in pigmented rabbits. Proteomic analysis revealed that COL4A2 negatively regulates vasculature development. Masson's trichome staining and immunofluorescence showed decreased choroidal thickness and lumen scaffold deformation with decreased collagen IV in form-deprivation myopia (FDM) choroid. Immunoblotting revealed that COL4A2 rather than COL4A1 contributes to the downregulation of collagen IV in FDM choroid. Dysfunction of COL4A2 hindered choroidal vascular scaffold formation, decreased guinea pig choroidal thickness, and promoted myopia shifts with refraction change and axial elongation. Type IV collagen is a key ECM in construction of the choroidal vascular lumen. COL4A2 is downregulated in FDM choroid, and suppression of COL4A2 impairs the choroid vascular scaffold and promotes myopia shift with decreased choroidal thickness.

The most investigated form of autoimmune-long-QT-syndrome (LQTS) is caused by circulating anti-Ro/SSA(Sjögren's syndrome-related antigen-A)-52kD antibodies, which cross-react with a specific sequence of the human ether-à-go-go-related(hERG) potassium channel's pore region, reducing the rapid inward-rectifying potassium current(IKr) density. We designed the scaffolded monobody decoy peptide-4, MDP4, comprised of a segment of the hERG extracellular pore region fused to a carrier monobody, aiming to neutralize the circulating anti-Ro/SSA-52kD antibodies cross-reacting with hERG. MDP4 was designed using 3D-structure-based protein engineering and optimized via conformational search and energy minimization. QT-interval prolongation was induced in an established guinea pig model of autoimmune-associated LQTS via injection of Ro/SSA-52kD antigen over 15 days. Upon confirmation of QT-interval prolongation, MDP4 was administered, and electrocardiogram parameters were monitored for 30 days. IKr and action potentials were measured using the patch-clamp technique in guinea pig ventricular cardiomyocytes treated with IgG isolated from the sera of an anti-Ro/SSA-52kD antibody-positive patient with LQTS and TorsadesdePointes. Guinea pigs immunized with Ro/SSA-52kD antigen exhibit QTc prolongation and hERG-cross-reactive anti-Ro/SSA-52kD serum antibodies. In vivo treatment with MDP4 reverses QTc prolongation. MDP4 in vitro treatment of guinea pig ventricular myocytes also reverses IKr inhibition and action potential duration prolongation by anti-Ro/SSA-52kD antibodies from patients with LQTS and TorsadesdePointes. Treatment with MDP4 results in recovery of both the QT-interval prolongation in vivo and IKr inhibition in vitro. MDP4 and other conceptually similar molecules may represent an innovative therapeutic approach for autoimmune LQTS in humans, and, prospectively, for other forms of arrhythmogenic autoimmune cardiac channelopathies.

The guinea pig with guinea pig cytomegalovirus (GPCMV) is the only small-animal model for congenital cytomegalovirus, a leading cause of cognitive impairment and hearing loss in newborns. GPCMV encodes human cytomegalovirus (HCMV) homologues of viral entry glycoprotein complexes, which are neutralizing-antibody vaccine targets. As with HCMV, GPCMV has two pathways of cell entry (direct and endocytic). Specific viral gH/gL-based complexes are necessary for receptor interaction and cell entry: gH/gL/gO trimer (direct) and pentamer complex (PC) (endocytic). Both pathways also require gB as the fusogenic protein. Direct GPCMV cell entry requires platelet-derived growth factor receptor alpha (PDGFRA), but an endocytic PC receptor remains unknown. We hypothesized that cellular knockout of direct and endocytic receptors would completely block infection, which cannot be achieved by gB-based antibodies. Candidate receptors including neuropilin proteins (NRP1, NRP2) and CD147 present on all established guinea pig cell lines were selected based on importance as common virus receptors or in fetal development. Results demonstrated that NRP2 interacted with PC, unlike NRP1 or CD147, in immunoprecipitation assays and eliminated NRP1/NRP2 heterodimer receptor interaction. The viral trimer only interacted with PDGFRA. Double knockout of PDGFRA/NRP2 completely blocked GPCMV infection. In contrast, the CD147/PDGFRA double knockout had limited GPCMV inhibition, and the single knockout of CD147 had no impact. Knockout of the various receptors had no effect on control HSV-1 infection. Ectopic expression of guinea pig cell receptors restored GPCMV infection but not human NRP2/PDGFRA, indicating a basis for the species-specific barrier for GPCMV and HCMV infection. Overall, results increase the translational relevance of GPCMV for the development of CMV intervention strategies.

A multi-target combinatorial therapy of MDBA alleviates atopic dermatitis via synchronized immunosuppression and barrier repair.

Bovine purified protein derivative (PPD-B), a crude protein extract from Mycobacterium bovis cultures, has been the standard reagent for delayed-type hypersensitivity (DTH) testing in cattle, but its undefined composition and variability compromise reproducibility and specificity. To address these limitations, we developed and evaluated RRbTB-E, a recombinant fusion protein comprising ESAT-6, as a defined alternative for skin testing. RRbTB-E was produced in Escherichia coli, purified by affinity chromatography, and characterized by SDS-PAGE and Western blot. In M. bovis-sensitized guinea pigs, RRbTB-E induced robust DTH reactions comparable to PPD-B, with consistent performance across six independent experiments and long-term stability after storage at 4-8 °C for more than 900 days. Furthermore, RRbTB-E did not induce significant reactions in non-sensitized or Mycobacterium avium-sensitized animals, confirming antigenic specificity. RRbTB-E also elicited DTH responses in Mycobacterium tuberculosis-sensitized guinea pigs. In naturally infected cattle, it triggered responses similar in magnitude to PPD-B, while remaining negative in non-infected animals. These findings support RRbTB-E as a stable, reproducible, and specific candidate for standardized intradermal testing in bovine tuberculosis diagnosis.

To evaluate the use and adverse effects of parenterally administered penicillin G procaine/benzathine and ceftiofur crystalline free acid (CFA) in guinea pig and chinchilla patients. Retrospectively, the medical records of a university veterinary teaching hospital were searched for guinea pigs and chinchillas evaluated between 2001 and 2023 that were prescribed penicillin G procaine/benzathine or ceftiofur parenterally. Information on signalment, indication for treatment, drug dose, and administration frequency and duration, as well as potential adverse effects, was extracted. Penicillin G was administered to 15 guinea pigs and 43 chinchillas. Ceftiofur was administered to 42 guinea pigs and 24 chinchillas. The drugs were administered SC in all cases. The median doses for both species were 50,000 IU of penicillin G/kg and 40 mg of ceftiofur/kg. Adverse effects were suspected in 1 of 15 guinea pigs and 2 of 43 chinchillas following parenteral penicillin administration. No gastrointestinal clinical signs, such as diarrhea, were reported as adverse effects. No adverse effects were reported in any animals after ceftiofur injection. Parenteral ceftiofur CFA appears to be safe in guinea pigs and chinchillas. While parenteral penicillin procaine/benzathine may result in adverse effects, which are challenging to distinguish from the consequences of underlying disease processes, gastrointestinal signs secondary to dysbiosis are not to be expected. Parenteral ceftiofur CFA administration can be considered safe in guinea pigs and chinchillas, but its clinical efficacy for the treatment of bacterial infections is unknown because of a lack of species-specific pharmacokinetic data.

Otitis is a major disease impacting both pet guinea pigs and laboratory guinea pigs that are used as models in human otological studies. Medical records from two veterinary clinics were retrospectively reviewed to identify guinea pigs diagnosed with computed tomography (CT)-confirmed otitis between 2014 and 2023. The clinical signs, treatment and bacteria isolatedin these cases were noted, and predisposing factors were identified. Thirty-six guinea pigs out of the 1477 seen at the clinics during the study period had otitis, giving a prevalence of 2.4%. The majority (61%) of guinea pigs had non-specific clinical signs, with 12 (33%) having respiratory signs and nine (25%) having dental disease. Only 14 animals (39%) had vestibular signs. Females were less likely to have otitis than males (odds ratio: 0.2). No age predilection was identified (age range 5-60 months). Animals with vestibular signs or respiratory signs had 21.8 and 9.5 times higher odds of having otitis, respectively. Treatment was divided into medical management or surgery and antibiotic therapy. No difference in survival times was observed regarding treatment received. Limitations of the study include the small number of animals and lack of repeat CT. Veterinarians should remember that otitis is a common disease in guinea pigs of all ages, with males being slightly more predisposed than females. Affected animals can have non-specific clinical signs, such as respiratory or dental disease. Head tilt is the most common vestibular sign.

Purpose To investigate changes in signal transducer and activator of transcription 3 (STAT3) activation in posterior segment ocular tissues, scleral matrix metalloproteinase-2/tissue inhibitor of metalloproteinases-2 (MMP-2/TIMP-2) balance, and their potential mechanisms during lens-induced myopia (LIM) development. Methods Sixty 2-week-old pigmented guinea pigs were divided into four groups: normal control (NC, no intervention), lens-induced myopia (LIM, right eye fitted with a −6.00D lens), LIM + AG490 (following LIM induction, intravitreal injection of 5 μL AG490 solution every 2 days), and LIM + injection control (LIM + InjCon, following LIM induction, intravitreal injection of 5 μL physiological saline every 2 days). At 2 and 4 weeks, refraction, axial length, retinal/choroidal thickness, posterior segment microstructure, and levels of STAT3/phosphorylated (p)-STAT3 (retina, choroid, sclera) and scleral MMP-2/TIMP-2 were measured. Results Compared with the NC group, the LIM group showed a significant myopic refractive shift, axial elongation, enhanced STAT3 activation in the retina, choroid, and sclera, upregulated scleral MMP-2, downregulated scleral TIMP-2, along with thinning and loosening of posterior pole tissues (including the sclera) at 2 and 4 weeks. In contrast to the LIM group, the LIM + AG490 group exhibited attenuated myopia progression, reduced STAT3 activation, downregulated scleral MMP-2, upregulated scleral TIMP-2, and alleviated thinning of posterior pole tissues. The results of the LIM + InjCon group were similar to those of the LIM group. Conclusions During LIM development, STAT3 activation is enhanced in the retina, choroid, and sclera, with disrupted scleral MMP-2/TIMP-2 balance. These changes may correlate with myopia-related phenotypes (e.g. axial elongation, scleral remodeling), though their specific mechanism(s) remain to be elucidated.

Unveiling the impact of electroacupuncture on retinal cells in myopic guinea pigs via single-cell sequencing.

Chitosan nanoparticle based ΔgE IBRV Vaccine: A Novel DIVA compatible strategy for enhanced immunity in guinea pigs.

Preliminary safety evaluation of a diphtheria, tetanus, acellular component pertussis, Sabin inactivated poliovirus and Haemophilus influenzae type b combination vaccine (DTacP-sIPV/Hib).

Ultra-rapid freezing yields a higher cryoresistance than the conventional slow freezing of epididymal guinea pig (Cavia porcellus) spermatozoa.