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To compare the vibrational patterns of human and guinea pig cochleae accurately, we developed and validated a novel finite element model of the guinea pig, leveraging it to analyze vibrational patterns in the cochlea. This approach is mirrored in our examination of the human cochlear model, providing granular insights into the nuances of human bone conduction hearing. The comparative analysis reveals that the guinea pig cochlea mirrors human cochlear vibrational patterns, thus serving as an efficient proxy for exploring human cochlear function. The human mastoid and the upper region of the guinea pig's skull are recommended as the convenient and comparable sites for bone conduction stimulation. The cochlear vibration pattern encompasses a mix of rigid, rotational, and compressive motion. Significantly, the guinea pig model demonstrates robust agreement with existing experimental data and other studies, these findings are confirming the validity of the model. Our study delineates the distinct roles of the three vibration types across various frequency spectrums. At lower frequencies, rigid motion is the dominant mechanism, supplemented by rotational motion. However, at higher frequencies, the influence of rigid motion wanes, ceding prominence to rotational and compressive motions. This trend is consistently observed in both human and guinea pig models. [ABSTRACT FROM AUTHOR]

Human cytomegalovirus (HCMV) is a ubiquitous herpesvirus and the leading cause of infectious disease related birth defects worldwide. How the immune response modulates the risk of intrauterine transmission of HCMV after maternal infection remains poorly understood. Maternal T cells likely play a critical role in preventing infection at the maternal-fetal interface and limiting spread across the placenta, but concerns exist that immune responses to infection may also cause placental dysfunction and adverse pregnancy outcomes. This study investigated the role of CD4+ and CD8+ T cells in a guinea pig model of primary cytomegalovirus infection. Monoclonal antibodies specific to guinea pig CD4 and CD8 were used to deplete T cells in non-pregnant and in pregnant guinea pigs after mid-gestation. CD4+ T cell depletion increased the severity of illness, caused significantly elevated viral loads, and increased the rate of congenital guinea pig cytomegalovirus (GPCMV) infection relative to animals treated with control antibody. CD8+ T cell depletion was comparably well tolerated and did not significantly affect the weight of infected guinea pigs or viral loads in their blood or tissue. However, significantly more viral genomes and transcripts were detected in the placenta and decidua of CD8+ T cell depleted dams post-infection. This study corroborates earlier findings made in nonhuman primates that maternal CD4+ T cells play a critical role in limiting the severity of primary CMV infection during pregnancy while also revealing that other innate and adaptive immune responses can compensate for an absent CD8+ T cell response in α-CD8-treated guinea pigs. Author summary: Congenital cytomegalovirus infection is a leading cause of adverse pregnancy outcomes and preventable disability in children. Using guinea pigs, a well-established small animal model of congenital infection and intrauterine development, this study tested how depleting T cells affects the course of primary cytomegalovirus infections. Severe illness and high rates of congenital infection were observed when helper CD4+ T cells were depleted. The depletion of killer CD8+ T cells did not affect the severity of disease or the rate of congenital infection but did increase the amount of virus that was detected in the placenta. A greater understanding how an immune response can prevent the infection of the placenta and developing offspring is needed to inform vaccine and therapeutic development. This study not only describes a new reagent that can be used to study the guinea pig immune system but also sheds new light in how adaptive immunity regulates congenital viral infection. [ABSTRACT FROM AUTHOR]

Lowering the levels of the cellular prion protein (PrPC) is widely considered a promising strategy for the treatment of prion diseases. Building on work that established immediate spatial proximity of PrPC and Na+, K+-ATPases (NKAs) in the brain, we recently showed that PrPC levels can be reduced by targeting NKAs with their natural cardiac glycoside (CG) inhibitors. We then introduced C4'-dehydro-oleandrin as a CG with improved pharmacological properties for this indication, showing that it reduced PrPC levels by 84% in immortalized human cells that had been differentiated to acquire neural or astrocytic characteristics. Here we report that our lead compound caused cell surface PrPC levels to drop also in other human cell models, even when the analyses of whole cell lysates suggested otherwise. Because mice are refractory to CGs, we explored guinea pigs as an alternative rodent model for the preclinical evaluation of C4'-dehydro-oleandrin. We found that guinea pig cell lines, primary cells, and brain slices were responsive to our lead compound, albeit it at 30-fold higher concentrations than human cells. Of potential significance for other PrPC lowering approaches, we observed that cells attempted to compensate for the loss of cell surface PrPC levels by increasing the expression of the prion gene, requiring daily administration of C4'-dehydro-oleandrin for a sustained PrPC lowering effect. Regrettably, when administered systemically in vivo, the levels of C4'-dehydro-oleandrin that reached the guinea pig brain remained insufficient for the PrPC lowering effect to manifest. A more suitable preclinical model is still needed to determine if C4'-dehydro-oleandrin can offer a cost-effective complementary strategy for pushing PrPC levels below a threshold required for long-term prion disease survival. [ABSTRACT FROM AUTHOR]

Trixacarus caviae is a sarcoptic mange mite infesting guinea pigs. Infestation in immunosuppressed animals produces severe dermatological problems, including alopecia, intense pruritus, hyperkeratosis and non‐dermatological issues (e.g., seizures). Treatment options are limited and include topical application of macrocyclic lactones or amitraz or injectable administration of ivermectin or doramectin. Considering the severity of the disease and the challenging treatment, the present paper aimed to determine the efficacy of oral afoxolaner in a severe case of infestation with T. caviae in a pet guinea pig. One female guinea pig was referred to the New Companion Animal Clinic due to severe dermatological problems. A clinical evaluation was done, and skin scrapings were collected and examined under the microscope. Small mites were detected and morphologically identified as T. caviae. The animal was treated with a single oral dose of 2.50 mg/kg afoxolaner, and the lesions, presence/absence of mites and intensity of pruritus were evaluated periodically until 2 months post‐treatment. A week after the medication, the lesions were milder, but pruritus was still present and was attributed to the healing process. Further examinations showed significant improvement with the complete remission of clinical signs and no mites at the microscopic examination after 4 weeks. Afoxolaner was safe and effective in this guinea pig for the treatment of T. caviae mange with no repetition needed. [ABSTRACT FROM AUTHOR]

To understand the large inter-species variations in drug effects on repolarization, the properties of the rapid (IKr) and the slow (IKs) components of the delayed rectifier potassium currents were compared in myocytes isolated from undiseased human donor (HM), dog (DM), rabbit (RM) and guinea pig (GM) ventricles by applying the patch clamp and conventional microelectrode techniques at 37 °C. The amplitude of the E-4031-sensitive IKr tail current measured at −40 mV after a 1 s long test pulse of 20 mV, which was very similar in HM and DM but significant larger in RM and GM. The L-735,821-sensitive IKs tail current was considerably larger in GM than in RM. In HM, the IKs tail was even smaller than in DM. At 30 mV, the IKr component was activated extremely rapidly and monoexponentially in each studied species. The deactivation of the IKr component in HM, DM, and RM measured at −40 mV. After a 30 mV pulse, it was slow and biexponential, while in GM, the IKr tail current was best fitted triexponentially. At 30 mV, the IKs component activated slowly and had an apparent monoxponential time course in HM, DM, and RM. In contrast, in GM, the activation was clearly biexponential. In HM, DM, and RM, IKs component deactivation measured at −40 mV was fast and monoexponential, while in GM, in addition to the fast component, another slower component was also revealed. These results suggest that the IK in HM resembles that measured in DM and RM and considerably differs from that observed in GM. These findings suggest that the dog and rabbit are more appropriate species than the guinea pig for preclinical evaluation of new potential drugs expected to affect cardiac repolarization. [ABSTRACT FROM AUTHOR]

Development and characterization of guinea pig anti-insulin polyclonal antibody against a target-specific insulin antigen. In India, an insulin immunogenicity kit for detecting insulin antibodies (neutralizing Nab) is an unmet medical need for diabetic patient's routine diagnosis. Type 1 diabetics rely on insulin injections daily basis for survival; if the body develops anti-insulin antibodies and neutralizes the exogenous recombinant insulin, glucose control is lost, and the patient eventually dies. Antibodies are excellent diagnostic reagents due to the specificity and sensitivity they provide in recognizing specific and unique target antigens. The paper describes the use of insulin as a target antigen and the development of target (insulin) specific antibodies in guinea pigs for use as a positive control for immunogenicity kit validation. Anti-insulin polyclonal antibody was raised against insulin in the Dunkin Hartley guinea pigs host. Anti-insulin antibody titer of all bleeds from four animals was tested using an indirect ELISA assay format. All four animals responded to the target-specific antigen but only one animal (#4) responded with a high-affinity antibody titer. The hyperimmune sera were purified using a protein A column. The purified anti-insulin antibody was characterized through SDS Page and western blot. The specificity, reactivity, and antibody binding efficiency were confirmed through immunoassays. Guinea pig anti-insulin polyclonal antibody developed in this study showed good specificity, reactivity, and efficiency in the immunoassays. This paper describes the development and characterization of anti-insulin antibodies for use as a control in developing a user-friendly insulin immunogenicity kit. [ABSTRACT FROM AUTHOR]

Obesity is a major risk factor for the development of life-threatening malignant ventricular tachyarrhythmias (VT) and sudden cardiac death (SCD). Risks may be highest for patients with high levels of the proinflammatory cytokine interleukin (IL)-6. We used our guinea pig model of high-fat diet (HFD)-induced arrhythmias that exhibit a heightened proinflammatory-like pathology, which is also observed in human obesity arrhythmias, as well as immunofluorescence and confocal microscopy approaches to evaluate the pathological IL-6 trans-signaling function and explore the underlying mechanisms. Using blind-stick and electrocardiogram (ECG) techniques, we tested the hypothesis that heightened IL-6 trans-signaling would exhibit increased ventricular arrhythmia/SCD incidence and underlying arrhythmia substrates. Remarkably, compared to low-fat diet (LFD)-fed controls, HFD promoted phosphorylation of the IL-6 signal transducer and activator of transcription 4 (STAT4), leading to its activation and enhanced nuclear translocation of pSTAT4/STAT4 compared to LFD controls and pSTAT3/STAT3 nuclear expression. Overactivation of IL-6 trans-signaling in guinea pigs prolonged the QT interval, which resulted in greater susceptibility to arrhythmias/SCD with isoproterenol challenge, as also observed with the downstream Janus kinase (JAK) 2 activator. These findings may have potentially profound implications for more effective arrhythmia therapy in the vulnerable obese patient population. [ABSTRACT FROM AUTHOR]

Background: Segmental aplasia of the caudal vena cava (CVC) with azygos continuation is a congenital malformation macroscopically described in mammals including humans, dogs, and rodents. It is usually detected as an incidental finding and the final diagnosis is reached by computed tomography (CT), fluoroscopy, or post-mortem dissection. Case Description: A 3-year-old guinea pig (Cavia porcellus) presented with subacute dyspnea. A computed tomographic examination was performed for the evaluation of subtle pulmonary changes previously suspected on conventional radiography, and a segmental aplasia of the CVC with azygos continuation was identified as an incidental finding. Conclusion: According to database negative results, this is the first report describing a segmental aplasia of the CVC and azygos continuation in a guinea pig by CT. [ABSTRACT FROM AUTHOR]

Copyright of Berkala Ilmiah Biologi is the property of Universitas Gadjah Mada, Fakultas Biologi and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Experimental evidence suggests that chronic intermittent hypoxia (CIH), a major hallmark of obstructive sleep apnea (OSA), boosts carotid body (CB) responsiveness, thereby causing increased sympathetic activity, arterial and pulmonary hypertension, and cardiovascular disease. An enhanced circulatory chemoreflex, oxidative stress, and NO signaling appear to play important roles in these responses to CIH in rodents. Since the guinea pig has a hypofunctional CB (i.e., it is a natural CB knockout), in this study we used it as a model to investigate the CB dependence of the effects of CIH on pulmonary vascular responses, including those mediated by NO, by comparing them with those previously described in the rat. We have analyzed pulmonary artery pressure (PAP), the hypoxic pulmonary vasoconstriction (HPV) response, endothelial function both in vivo and in vitro, and vascular remodeling (intima–media thickness, collagen fiber content, and vessel lumen area). We demonstrate that 30 days of the exposure of guinea pigs to CIH (FiO2, 5% for 40 s, 30 cycles/h) induces pulmonary artery remodeling but does not alter endothelial function or the contractile response to phenylephrine (PE) in these arteries. In contrast, CIH exposure increased the systemic arterial pressure and enhanced the contractile response to PE while decreasing endothelium-dependent vasorelaxation to carbachol in the aorta without causing its remodeling. We conclude that since all of these effects are independent of CB sensitization, there must be other oxygen sensors, beyond the CB, with the capacity to alter the autonomic control of the heart and vascular function and structure in CIH. [ABSTRACT FROM AUTHOR]

An approximately 3‐year‐old, male, neutered, black Dutch guinea pig (Cavia porcellus) was presented for routine health check shortly following adoption. Physical examination revealed an incidental non‐painful, firm, highly mobile, ovoid mass ventrally in the mid‐abdomen. The remaining examination was otherwise normal, and investigation was declined due to lack of clinical signs. The guinea pig was re‐presented 2 months later, as it appeared less interactive. The mass was unchanged, but mild abdominal pain was present on palpation. Ultrasound examination revealed a 60 × 40 mm discoid, hyperechoic mass with multiple hypoechoic, well‐demarcated cavitary areas. Exploratory laparotomy was performed and a free‐floating, dark tan, smooth, firm, biconvex mass was removed without further dissection or ligation. Clinical signs resolved in the first week, and the animal remained clinically normal 3 months postoperatively. A necrotic lipoma was confirmed on histology, and should therefore be a differential for an abdominal mass in this species. [ABSTRACT FROM AUTHOR]

A 4‐year‐old, male, entire guinea pig (Cavia porcellus) was presented in stuporous state with hypoglycaemia, hypothermia and hypotension. After stabilising the animal, a complete blood cell count, biochemistry, survey radiographs and an abdominal ultrasound were performed. The abdominal ultrasound revealed a 3.2 × 5.4 cm soft tissue mass occupying the caudal half from lateral to medial part of the right kidney. To investigate further, a computed tomography scan with intravenous contrast was performed and confirmed the invasion of the mass into the caudal vena cava. A right nephrectomy was performed and submitted for histopathology, and a diagnosis of renal liposarcoma was made. The animal, although stable during surgery, died after recovery from anaesthesia. Spontaneous renal liposarcoma is rarely reported in human and veterinary medicine. This case report describes the clinical signs, diagnostic evaluation, surgical procedure, and gross and histological features of renal liposarcoma in a guinea pig. [ABSTRACT FROM AUTHOR]

Objective: To explore a method for establishing a model of ocular accommodative spasm in guinea pigs by using different concentrations of carbachol eye drops and different frequency of administration. Methods: Eighteen healthy guinea pigs were selected to establish models for both eyes. Guinea pigs were randomly divided into two groups. Group A was modeled with carbachol eye drops at a concentration of 2 ml:0.1 mg, and group B was modeled with carbachol eye drops at a concentration of 4 ml:0.1 mg. The two groups were further randomly divided into three groups according to the random number table method. Three groups of guinea pigs were established: In the A1, B1 group, the drug was administered one time/day; in the A2, B2 group, the drug was administered two times/day; and in the A3, B3 group, the drug was administered three times/day. Before modeling, retinoscopy optometry was performed on the guinea pigs without mydriasis and mydriasis, and a refractive state was recorded. On subsequent days, modeling was performed again, and carbachol eye drops were administered using the same administration times. Retinoscopy was performed in a dark room without mydriasis on days 1, 3, 7, 14 and 21, and the data were recorded. After optimizing the modeling method, the ciliary muscle tissue of the model guinea pig and normal guinea pig were obtained for hematoxylin and eosin (H&E) staining of paraffin sections to compare the morphological differences under a light microscope. Results: (1) There was no statistical significance in the interaction of time*0 d and time*drug frequency between group A and group B (P > 0.05). However, the main effect of different dose times varied between group A and group B (P < 0.05), and the modeling effect of three drops was better. (2) The overall modeling methods of groups A and B were not affected by the time factor, but three doses of carbachol eye drops achieved the best modeling effect on the 7th day, and the diopter of guinea pigs stabilized on the 14th and 21st days. (3) To further optimize the medication, the A and B groups were given three drops. On the 7th day, the refractive data of guinea pigs were compared between the groups, and the refractive status of the two groups of guinea pigs before modeling was compared within the groups. There was no statistical difference between the groups (P > 0.05), and there was a statistical difference within the groups (P < 0.05). (4) In the H&E staining of paraffin sections, the color of the ciliary muscle of the guinea pig with spasm of accommodation was darker than that of the normal guinea pig, and the myofilaments were more closely arranged. Conclusion: (1) Carbachol has the effect of contracting the ciliary muscle; (2) Three drops of 2 ml:0.1 mg or 4 ml:0.1 mg of carbachol eye drops can be selected for seven days for modeling. [ABSTRACT FROM AUTHOR]

Remdesivir (RDV) is the first drug approved by the FDA for clinical treatment of hospitalized patients infected with COVID-19 because it has been shown to have good antiviral activity against a variety of viruses, including Arenaviridae and Coronaviridae viral families. However, it has been reported that its clinical treatment leads to the symptoms of sick sinus syndrome such as sinus bradycardia, conduction block, and sinus arrest, but the electrophysiological mechanism of its specific cardiac adverse events is still unclear. We report complementary, experimental, studies of its electrophysiological effects. In wireless cardiac telemetry experiments in vivo and electrocardiographic studies in ex vivo cardiac preparations, RDV significantly caused sinus bradycardia, sinus atrial block, and prolongation of the QT interval in guinea pigs. Dose-dependent effects of RDV on the electrical activities of sinoatrial node (SA node) preparations of guinea pigs were characterised by multielectrode, optical RH237 voltage mapping. These revealed reversibly reduced sinoatrial conduction time (SACT), increased AP durations (APDs), and decreased the pacemaking rate of the SA node. Patch-clamp experiments showed that RDV significantly inhibited the If current of HCN4 channels, resulting in a significant decrease in the spontaneous firing rate of SA node cells, which may underlie the development of sick sinus node syndrome. In addition, RDV significantly inhibits IKr currents in hERG channels, leading to prolongation of the QT interval and playing a role in bradycardia. Therefore, these findings provide insights into the understanding the bradycardia effect of RDV, which may be used as basic theoretical guidance for the intervention of its adverse events, and prompt safety investigations of RDV's cardiac safety in the future. [ABSTRACT FROM AUTHOR]

Aims Electroanatomical adaptations during the neonatal to adult phase have not been comprehensively studied in preclinical animal models. To explore the impact of age as a biological variable on cardiac electrophysiology, we employed neonatal and adult guinea pigs, which are a recognized animal model for developmental research. Methods and results Electrocardiogram recordings were collected in vivo from anaesthetized animals. A Langendorff-perfusion system was employed for the optical assessment of action potentials and calcium transients. Optical data sets were analysed using Kairosight 3.0 software. The allometric relationship between heart weight and body weight diminishes with age, it is strongest at the neonatal stage (R 2 = 0.84) and abolished in older adults (R 2 = 1E−06). Neonatal hearts exhibit circular activation, while adults show prototypical elliptical shapes. Neonatal conduction velocity (40.6 ± 4.0 cm/s) is slower than adults (younger: 61.6 ± 9.3 cm/s; older: 53.6 ± 9.2 cm/s). Neonatal hearts have a longer action potential duration (APD) and exhibit regional heterogeneity (left apex; APD30: 68.6 ± 5.6 ms, left basal; APD30: 62.8 ± 3.6), which was absent in adults. With dynamic pacing, neonatal hearts exhibit a flatter APD restitution slope (APD70: 0.29 ± 0.04) compared with older adults (0.49 ± 0.04). Similar restitution characteristics are observed with extrasystolic pacing, with a flatter slope in neonates (APD70: 0.54 ± 0.1) compared with adults (younger: 0.85 ± 0.4; older: 0.95 ± 0.7). Neonatal hearts display unidirectional excitation–contraction coupling, while adults exhibit bidirectionality. Conclusion Postnatal development is characterized by transient changes in electroanatomical properties. Age-specific patterns can influence cardiac physiology, pathology, and therapies for cardiovascular diseases. Understanding heart development is crucial to evaluating therapeutic eligibility, safety, and efficacy. [ABSTRACT FROM AUTHOR]

Favipiravir is a ribonucleoside analogue that has been explored as a therapeutic for the treatment of Ebola Virus Disease (EVD). Promising data from rodent models has informed nonhuman primate trials, as well as evaluation in patients during the 2013–2016 West African EVD outbreak of favipiravir treatment. However, mixed results from these studies hindered regulatory approval of favipiravir for the indication of EVD. This study examined the influence of route of administration, duration of treatment, and treatment schedule of favipiravir in immune competent mouse and guinea pig models using rodent-adapted Zaire ebolavirus (EBOV). A dose of 300 mg/kg/day of favipiravir with an 8-day treatment was found to be fully effective at preventing lethal EVD-like disease in BALB/c mice regardless of route of administration (oral, intraperitoneal, or subcutaneous) or whether it was provided as a once-daily dose or a twice-daily split dose. Preclinical data generated in guinea pigs demonstrates that an 8-day treatment of 300 mg/kg/day of favipiravir reduces mortality following EBOV challenge regardless of route of treatment or duration of treatments for 8, 11, or 15 days. This work supports the future translational development of favipiravir as an EVD therapeutic. [ABSTRACT FROM AUTHOR]

Copyright of Animal Health, Production & Hygiene is the property of Animal Health, Production & Hygiene and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This study applied plithogenic statistics to evaluate how different doses of guinea pig manure affect the cultivation of Opuntia ficus-indica (commonly known as prickly pear) and soil quality. It was determined that 7.5 tons/ha, referred to as treatment T3, is the optimal dose, as it maximizes the growth and production of the plant, improves plant height, and increases the production of buttons and berries. T3 also optimized organic matter and adjusted the pH to ideal levels, maintaining a nutritional balance that ensures the availability of nitrogen, phosphorus, and potassium. This balance enhances agricultural production without sacrificing soil sustainability. In conclusion, the research showed that T3 provides the best performance, improving soil quality without the risks associated with higher doses. This underscores the need to carefully calibrate organic fertilizers to maximize efficiency and minimize negative environmental impacts. [ABSTRACT FROM AUTHOR]

Introduction: The herbal preparation STW 5 ameliorates functional dyspepsia partly by relaxing smooth muscle of the proximal stomach, thus improving gastric accommodation. We explored the unknown pathways responsible for this effect by testing targets known to modulate gastric smooth muscle relaxation. Methods: STW 5‐induced relaxation of smooth muscle strips from guinea pig gastric corpus before and after pharmacological interventions were recorded with force transducers in an organ bath. ORAI1 mRNA expression was tested in the proximal stomach. Key Results: Blockade of Ca2+‐activated K+ and Cl− channels, voltage‐gated L‐ or T‐type Ca2+ channels, TRPA1‐, TRPV1‐, adenosine or 5‐HT4 receptors, antagonizing ryanodine receptors, inhibiting cyclooxygenase or sarcoplasmic reticulum calcium ATPase did not affect STW 5‐evoked relaxation. Likewise, protein‐kinase A or G were not involved. However, the relaxation evoked by STW 5 was significantly reduced by phorbol‐12‐myristat‐13‐acetat, an activator of protein‐kinase C, by 2‐ aminoethyldiphenylborinate, an inhibitor of the IP3 receptor‐mediated Ca2+ release from the sarcoplasmic reticulum or by SKF‐96365, a nonselective store‐operated calcium entry (SOCE) blocker. Furthermore, the mixed TRPC3/SOCE inhibitor Pyr3, but not the selective TRPC3 blocker Pyr10, reduced the effect of STW 5. Finally, BTP2, a potent blocker of ORAI‐coupled SOCE, almost abolished STW 5‐evoked relaxation. Expression of ORAI1 could be demonstrated in the corpus/fundus. Conclusions & Inferences: STW 5 inhibited SOCE, most likely ORAI channels, which are modulated by IP3‐ and PKC‐dependent mechanisms. Our findings impact on the design of drugs to induce muscle relaxation and help identify phytochemicals with similar modes of actions to treat gastrointestinal disturbances. [ABSTRACT FROM AUTHOR]

A survey was carried out on 356 breeders in the Department of the Menoua Region of West Cameroon to characterize guinea pig breeding systems, using descriptive analysis, factorial analysis of multiple correspondences (AFCM), and upward hierarchical classification (CAH). Three types of guinea pig breeders have been identified, discriminated according to the size of the herd and the professional character of the breeding. Most of the housing systems were of the traditional type, free-ranging on the ground. Feed generally was based on fodders and food residues, and hygiene conditions were considered as good. The main difficulties faced by the farmers were mortalities resulting from diseases and predation. Guinea pig breeding was considered a source of income for households. Sales were year-round, at age-related prices. Development of guinea pig breeding in Cameroon would require better-addressing breeding techniques and the creation of economic interest groups to strengthen food security allowed by this activity. [ABSTRACT FROM AUTHOR]

Late sodium current (INa,late) is an important inward current contributing to the plateau phase of the action potential (AP) in the mammalian heart. Although INa,late is considered as a possible target for antiarrhythmic agents, several aspects of this current remained hidden. In this work, the profile of INa,late, together with the respective conductance changes (GNa,late), were studied and compared in rabbit, canine, and guinea pig ventricular myocytes using the action potential voltage clamp (APVC) technique. In canine and rabbit myocytes, the density of INa,late was relatively stable during the plateau and decreased only along terminal repolarization of the AP, while GNa,late decreased monotonically. In contrast, INa,late increased monotonically, while GNa,late remained largely unchanged during the AP in guinea pig. The estimated slow inactivation of Na+ channels was much slower in guinea pig than in canine or rabbit myocytes. The characteristics of canine INa,late and GNa,late were not altered by using command APs recorded from rabbit or guinea pig myocytes, indicating that the different shapes of the current profiles are related to genuine interspecies differences in the gating of INa,late. Both INa,late and GNa,late decreased in canine myocytes when the intracellular Ca2+ concentration was reduced either by the extracellular application of 1 µM nisoldipine or by the intracellular application of BAPTA. Finally, a comparison of the INa,late and GNa,late profiles induced by the toxin of Anemonia sulcata (ATX-II) in canine and guinea pig myocytes revealed profound differences between the two species: in dog, the ATX-II induced INa,late and GNa,late showed kinetics similar to those observed with the native current, while in guinea pig, the ATX-II induced GNa,late increased during the AP. Our results show that there are notable interspecies differences in the gating kinetics of INa,late that cannot be explained by differences in AP morphology. These differences must be considered when interpreting the INa,late results obtained in guinea pig. [ABSTRACT FROM AUTHOR]

Guinea pigs have historically been used as a food source and are also an important model for studying the human intestines. Fasting is the act of temporarily stopping the intake of food. This process can alter the microbiota of various animals. This study is the first to investigate the impact of fasting on the cecum microbiome of three guinea pig breeds. We investigated the impact of fasting on the microbiome population structure in the cecum of three guinea pig breeds. This was done by sequencing and analyzing the V4 hypervariable region of the 16S rRNA gene in bacterial communities found in cecum mucosa samples. To achieve this, we established two treatment groups (fasting and fed), for each of the three guinea pig breeds: Andina, Inti, and Peru. The study involved twenty-eight guinea pigs, which were divided into the following groups: Andina-fed (five), Andina-fasting (five), Inti-fed (four), Inti-fasting (five), Peru-fed (five), and Peru-fasting (four). The results indicated a significant difference in beta diversity between the treatment groups for the Peru breed (P-value = 0.049), but not for the treatment groups of the Andina and Inti breeds. The dominant phyla across all groups were Firmicutes and Bacteroidetes. We observed variations in the abundance of different taxa in the cecum microbiota when comparing the treatment groups for each breed. Additionally, there was a higher number of unique taxa observed in the fasting groups compared to the fed groups. We discovered that the genus Victivallis was the only one present in all fasting groups across all breeds. Despite the findings, the resilience of the gutmicrobiome was not challenged in all three breeds, which can lead to disruptive changes that may affect the overall maintenance of the cecum microbiome. Based on the observed differences in the treatment groups of the Peru breed, it can be suggested that fasting has a greater impact on this particular breed. [ABSTRACT FROM AUTHOR]

Copyright of Kocatepe Veterinary Journal / Kocatepe Veteriner Dergisi is the property of Afyon Kocatepe University, Faculty of Veterinary Medicine and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this study, six animals of each rabbit, guinea pig and mongoose were used to compare the morphological features of the humerus. The biometrical parameters of the humerus, viz., mean length, width and circumference at the proximal extremity, distal extremity, and shaft were studied. In proximal extremity, anteriorly, the head of the rabbit humerus was comparatively thicker as compared to guinea pig and mongoose. The lateral tuberosity was large and less clearly divided in mongooses and the division was not visible in guinea pigs and rabbits. The lateral surface of the lateral tuberosity was found with a notch that was deep in mongooses and shallow in rabbit and guinea pig. The bicipital groove was very deep in guinea pig, less deep in rabbit and shallow in mongooses. The lateral surface of the shaft was spiral, smooth, and with musculo-spiral groove which was deep in mongooses, shallow in rabbit, and the groove was not visible in the guinea pig. On the lateral surface of the mongoose's proximal extremity of the humerus, the deltoid tuberosity was found sharp but in rabbit and guinea pig, it was blunt. The coronoid and olecranon fossa were deep in all the three species studied, but was found to be prominent in rabbit and guinea pig when compared to mongoose. Mongoose humerus was observed with an additional supracondylar foramen in the medial surface of distal one fourth of the shaft above the supratrochlear foramen. [ABSTRACT FROM AUTHOR]

The study emphasizes the need of implementing several ways to promote guinea pig farming in small family units. It highlights the relevance of enhanced nutrition, effective health management, genetic enhancement, and acceptable habitat conditions as essential factors for enhancing productivity and profitability. Suggestions encompass the adoption of advanced breeding methods, offering training and technical support, and expanding the range of goods and markets to ensure the long-term economic viability of guinea pig farming. The utilization of neutrosophic sets provided a strong framework for assessing these techniques, enabling a thorough study that considers the inherent uncertainties in decision-making processes. To enhance future study, it is recommended to improve and broaden neutrosophic approaches to comprehend the intricacies of guinea pig farming systems more effectively. It will be beneficial to create more advanced models that include a broader set of factors and extensive data, as well as to undertake longitudinal studies to evaluate the long-term effects. It is essential to work together with local communities to customize tactics that are suitable for specific geographical conditions and socioeconomic contexts. This is necessary to ensure that these interventions are practical and successful. [ABSTRACT FROM AUTHOR]

NaV1.7 plays a crucial role in inducing and conducting action potentials in pain‐transducing sensory nociceptor fibres, suggesting that NaV1.7 blockers could be effective non‐opioid analgesics. While SCN9A is expressed in both sensory and autonomic neurons, its functional role in the autonomic system remains less established. Our single neuron rt‐PCR analysis revealed that 82% of sympathetic neurons isolated from guinea‐pig stellate ganglia expressed NaV1.7 mRNA, with NaV1.3 being the only other tetrodotoxin‐sensitive channel expressed in approximately 50% of neurons. We investigated the role of NaV1.7 in conducting action potentials in postganglionic sympathetic nerves and in the sympathetic adrenergic contractions of blood vessels using selective NaV1.7 inhibitors. Two highly selective NaV1.7 blockers, GNE8493 and PF 05089771, significantly inhibited postganglionic compound action potentials by approximately 70% (P < 0.01), with residual activity being blocked by the NaV1.3 inhibitor, ICA 121431. Electrical field stimulation (EFS) induced rapid contractions in guinea‐pig isolated aorta, pulmonary arteries, and human isolated pulmonary arteries via stimulation of intrinsic nerves, which were inhibited by prazosin or the NaV1 blocker tetrodotoxin. Our results demonstrated that blocking NaV1.7 with GNE8493, PF 05089771, or ST2262 abolished or strongly inhibited sympathetic adrenergic responses in guinea‐pigs and human vascular smooth muscle. These findings support the hypothesis that pharmacologically inhibiting NaV1.7 could potentially reduce sympathetic and parasympathetic function in specific vascular beds and airways. Key points: 82% of sympathetic neurons isolated from the stellate ganglion predominantly express NaV1.7 mRNA.NaV1.7 blockers inhibit action potential conduction in postganglionic sympathetic nerves.NaV1.7 blockade substantially inhibits sympathetic nerve‐mediated adrenergic contractions in human and guinea‐pig blood vessels.Pharmacologically blocking NaV1.7 profoundly affects sympathetic and parasympathetic responses in addition to sensory fibres, prompting exploration into the broader physiological consequences of NaV1.7 mutations on autonomic nerve activity. [ABSTRACT FROM AUTHOR]

Background: Furry animals are an important source of indoor allergens. Diagnosis of allergy to small pets such as guinea‐pigs still relies on animal dander extracts which do not allow to define the primary sensitization source. Objective: To identify major guinea‐pig allergens and to evaluate their potential as marker allergens for in vitro IgE‐diagnosis in comparison with dander extracts. Methods: A group of patients allergic to guinea‐pig (n = 29) and a group of patients allergic to cat and dog (n = 30) were recruited for the study. A panel of four guinea‐pig lipocalin allergens was expressed as recombinant proteins in E. coli. Specific IgE were quantified by ImmunoCAP and ELISA. Results: The combination of 4 guinea‐pig lipocalin allergens, including 2 new lipocalins, Cav p 1.0201 and Cav p 6.0101, and the previously characterized lipocalins Cav p 2 and Cav p 3, enabled the identification of 90% of all patients allergic to guinea‐pig. The vast majority had specific IgE to Cav p 1 (83%). Cav p 6 shares 54% sequence identity with Fel d 4 and Can f 6 and was found to be IgE‐cross‐reactive with these allergens. In the group of cat‐ and dog‐allergic patients, 73% had also specific IgE to guinea‐pig dander. However, only 27% of the cat /dog‐allergic patients had specific IgE to any of the non‐cross‐reactive guinea‐pig allergens Cav p 1, Cav p 2 or Cav p 3. The high prevalence of IgE to guinea‐pig dander could be explained by IgE‐cross‐reactivity among serum albumins and certain lipocalins. Conclusions and clinical relevance: The availability of specific allergen markers is essential for the assessment of primary sensitization, especially in polysensitized patients. The proposed panel of guinea‐pig allergens Cav p 1, Cav p 2 and Cav p 3 is a first step to component‐resolved IgE‐diagnosis of allergy to small furry pets. [ABSTRACT FROM AUTHOR]

Background: To investigate whether the sclera of guinea pig contains stem cells with multiple differentiation potentials. Methods: Scleral tissue from guinea pig was separated from the retina and choroid and digested to release single cells. The cells cultured was identified as stem cells by flow cytometric analysis, semiquantitative RT-PCR. Abilities for multipotent differentiation were analyzed by histochemical staining technique (oil-red-O staining, alcian blue staining and alizarin red staining). Scleral fibroblast cell was treated as control group. Results: The cultured scleral stem cells were positive for CD44 and CD105 (mesenchymal stem cell surface markers) by flow cytometry. The cells cultured expressed stem cell markers ABCG2, Notch1, Six2, and Pax6, and the most important component of sclera type I collagen. The positive staining informed that the cells cultured were able to differentiate to adipogenic, chondrogenic, and osteogenic lineages. Scleral fibroblast cell was stained negative by oil-red-O staining and alizarin red staining. Expression of Sox9 in the cells cultured after chondrogenic differentiation significantly increased compared with scleral fibroblast cell. Conclusion: The guinea pig sclera contained stem cells with multiple differentiation potentials. The cells were also related to scleral collagen and cartilage related proteins. The finding may provide a new tool to help clarify mechanisms of sclera related disease in further studies. [ABSTRACT FROM AUTHOR]

Primary cell culture is a technique that is widely used in neuroscience research to investigate mechanisms that underlie pathologies at a cellular level. Typically, mouse or rat tissue is used for this process; however, altricial rodent species have markedly different neurodevelopmental trajectories comparatively to humans. The use of guinea pig brain tissue presents a novel aspect to this routinely used cell culture method whilst also allowing for dual isolation of two major cell types from a physiologically relevant animal model for studying perinatal neurodevelopment. Primary neuronal and oligodendrocyte cell cultures were derived from fetal guinea pig's frontal cortex brain tissue collected at a gestational age of 62 days (GA62), which is a key time in the neuronal and oligodendrocyte development. The major advantage of this protocol is the ability to acquire both neuronal and oligodendrocyte cellular cultures from the frontal cortex of one fetal brain. Briefly, neuronal cells were grown in 12-well plates initially in a 24-h serum-rich medium to enhance neuronal survival before switching to a serum-free media formulation. Oligodendrocytes were first grown in cell culture flasks using a serum-rich medium that enabled the growth of oligodendrocyte progenitor cells (OPCs) on an astrocyte bed. Following confluency, the shake method of differential adhesion and separation was utilized via horizontally shaking the OPCs off the astrocyte bed overnight. Therefore, OPCs were plated in 12-well plates and were initially expanded in media supplemented with growth hormones, before switching to maturation media to progress the lineage to a mature phenotype. Reverse transcription-polymerase chain reaction (RT-PCR) was performed on both cell culture types to analyze key population markers, and the results were further validated using immunocytochemistry. Primary neurons displayed the mRNA expression of multiple neuronal markers, including those specific to GABAergic populations. These cells also positively stained for microtubule-associated protein 2 (MAP2; a dendritic marker specific to neurons) and NeuN (a marker of neuronal cell bodies). Primary oligodendrocytes expressed all investigated markers of the oligodendrocyte lineage, with a majority of the cells displaying an immature oligodendrocyte phenotype. This finding was further confirmed with positive oligodendrocyte transcription factor (OLIG2) staining, which serves as a marker for the overall oligodendrocyte population. This study demonstrates a novel method for isolating both neurons and oligodendrocytes from the guinea pig brain tissue. These isolated cells display key markers and gene expression that will allow for functional experiments to occur and may be particularly useful in studying neurodevelopmental conditions with perinatal origins. [ABSTRACT FROM AUTHOR]

Simple Summary: Every year, the consumption of beef cattle increases, as does slaughter waste, including rumen content, blood, and other waste such as ears and cheeks. These can be converted into meals through heat treatment, so it is important to know their nutritional value. In this study, tests were carried out that allowed us to determine the chemical composition, the contribution of available nutrients, and the energy content of this slaughter waste to prepare rations for guinea pigs. After the study, it was verified that flours made from ruminal content, blood, ears, and cheeks are good sources of protein and energy for guinea pigs and are consumed without problems when included as one-fifth of a barley-based diet. This circular economy approach allows this type of waste to be recovered and valued, with the advantage of reducing its polluting power due to inadequate disposal or its disposal into rivers. Biowaste from slaughterhouses can be recovered to benefit food security and reduce contamination potential. More than 3 billion heads of livestock are consumed worldwide, which will increase by 17% by 2028, generating more biowaste, increasing infectious agents, and causing economic losses due to circular economy principles not being applied. This work evaluated the nutritional quality of four types of biowaste from bovine slaughter which were transformed into a meal for guinea pigs (rumen content (RCM), ears (EaM), blood (BM), and cheeks (CM)) according to their chemical composition, digestible components, energy contribution, and voluntary consumption. For the animal model, adult male guinea pigs were arranged in metabolic cages for feces collection without urinary contamination. Nine guinea pigs were used in each digestibility test. First, a direct digestibility test was conducted using a meal of barley as a reference diet (RD), the indigestibility coefficient of which allowed for the estimation of the digestibility of biowaste meals through indirect calculations; for this, diets composed of 80% of the RD and 20% of the corresponding biowaste meals were evaluated. The difference method was suitable for determining the digestibility of beef biowaste using the indigestibility coefficients of the reference diet to calculate the digestibility of ingredients which could not be offered as 100% of the meal but were incorporated as 20%. The digestible protein and metabolizable energy contents of RCM, EaM, BM, and CM were 10.2% and 2853 kcal/kg, 44.5% and 3325 kcal/kg, 70.7% and 2583 kcal/kg, and 80.8% and 3386 kcal/kg, respectively. The CM and BM feeds had the highest contributions of digestible protein due to their higher nitrogen content, and the CM and EaM feeds had the highest ME contents due to their higher fat contents. The biowaste meal consumption in descending order was CM > RCM > EaM > BM, which were consumed without problems. These results are indicative that these components can be part of guinea pigs' diets, and it is recommended to continue studies into guinea pig growth and fattening diets with different levels of these biowaste meals. [ABSTRACT FROM AUTHOR]

Osteoarthritis (OA) is the most common degenerative joint disease. Currently, no satisfactory pharmacological treatment exists for OA. The potential anti-inflammatory properties of Dihydrotanshinone I (DHT) have been reported, but its effects on OA are unclear. In this study, we assess the impact of DHT on the viability of human chondrocytes in vitro. We then use a guinea pig model to investigate the effects of DHT on knee osteoarthritis progression. Twelve-week-old Dunkin Hartley guinea pigs spontaneously developing OA were intraperitoneally injected with different doses of DHT for eight weeks. Micro-CT analysis was performed on the subchondral bone in the knee, and histological assessment of the knee joint was done using stained sections, the ratio of hyaline to calcified cartilage, and Mankin scores. DHT successfully restored IL-1β-induced decreases in cell viability in human primary chondrocytes. In the guinea pig model, intraperitoneal injections of DHT ameliorated age-induced OA, effectively reduced the expression level of two cartilage metabolism-related genes (ADAMTS4 and MMP13) and decreased the inflammatory biomarker IL-6 in the serum of guinea pigs developing spontaneous osteoarthritis. These findings demonstrate DHT's protective effects on chondrocytes and suggest that it alleviates cartilage degradation and proteoglycan loss in OA. [ABSTRACT FROM AUTHOR]

Background: Coping with the ingested food, the gastric regions of fundus, corpus, and antrum display different motility patterns. Intrinsic components of such patterns involving mechanosensitive enteric neurons (MEN) have been described in the guinea pig gastric corpus but are poorly understood in the fundus and antrum. Methods: To elucidate mechanosensitive properties of myenteric neurons in the gastric fundus and antrum, membrane potential imaging using Di‐8‐ANEPPS was applied. A small‐volume injection led to neuronal compression. We analyzed the number of MEN and their firing frequency in addition to the involvement of selected mechanoreceptors. To characterize the neurochemical phenotype of MEN, we performed immunohistochemistry. Key Results: In the gastric fundus, 16% of the neurons reproducibly responded to mechanical stimulation and thus were MEN. Of those, 83% were cholinergic and 19% nitrergic. In the antrum, 6% of the neurons responded to the compression stimulus, equally distributed among cholinergic and nitrergic MEN. Defunctionalizing the sensory extrinsic afferents led to a significant drop in the number of MEN in both regions. Conclusion: We provided evidence for MEN in the gastric fundus and antrum and further investigated mechanoreceptors. However, the proportions of the chemical phenotypes of the MEN differed significantly between both regions. Further investigations of synaptic connections of MEN are crucial to understand the hardwired neuronal circuits in the stomach. [ABSTRACT FROM AUTHOR]

Background: Serving as a reservoir, the gastric fundus can expand significantly, with an initial receptive and a following adaptive relaxation, controlled by extrinsic and intrinsic reflex circuits, respectively. We hypothesize that mechanosensitive enteric neurons (MEN) are involved in the adaptive relaxation, which is initiated when a particular gastric volume and a certain stretch of the stomach wall is reached. To investigate whether the responsiveness of MEN in the gastric fundus is dependent on tissue stretch, we performed mechanical stimulations in stretched versus ganglia "at rest". Methods: Responses of myenteric neurons in the guinea pig gastric fundus were recorded with membrane potential imaging using Di‐8‐ANEPPS. MEN were identified by small‐volume intraganglionic injection in ganglia stretched to different degrees using a self‐constructed stretching tool. Immunohistochemical staining identified the neurochemical phenotype of MEN. Hexamethonium and capsaicin were added to test their effect on recruited MEN. Key Results: In stretched compared to "at rest" ganglia, significantly more MEN were activated. The change in the ganglionic area correlated significantly with the number of additional recruited MEN. The additional recruitment of MEN was independent from nicotinic transmission and the ratio of active MEN in stretched ganglia shifted towards a nitrergic phenotype. Conclusion and Inferences: The higher number of active MEN with increasing stretch of the ganglia and their greater share of nitrergic phenotype might indicate their contribution to the adaptive relaxation. Further experiments are necessary to address the receptors involved in mechanotransduction. [ABSTRACT FROM AUTHOR]

The effects of enhanced late INa, a persistent component of the Na+ channel current, on the intracellular ion dynamics and the automaticity of the pulmonary vein cardiomyocytes were studied with fluorescent microscopy. Anemonia viridis toxin II (ATX- II), an enhancer of late INa, caused increases in the basal Na+ and Ca2+ concentrations, increases in the number of Ca2+ sparks and Ca2+ waves, and the generation of repetitive Ca2+ transients. These phenomena were inhibited by eleclazine, a blocker of the late INa; SEA0400, an inhibitor of the Na+/Ca2+ exchanger (NCX); H89, a protein kinase A (PKA) inhibitor; and KN-93, a Ca2+/calmodulin-dependent protein kinase II (CaMKII) inhibitor. These results suggest that enhancement of late INa in the pulmonary vein cardiomyocytes causes disturbance of the intracellular ion environment through activation of the NCX and Ca2+-dependent enzymes. Such mechanisms are probably involved in the ectopic electrical activity of the pulmonary vein myocardium. [ABSTRACT FROM AUTHOR]

Aim: Alzheimer's disease (AD) is the most common form of dementia. However, while 150+ animal models of AD exist, drug translation from preclinical models to humans for treatment usually fails. One factor contributing to low translation is likely the absence of neurodegenerative models that also encompass the multi‐morbidities of human aging. We previously demonstrated that, in comparison to the PigmEnTed (PET) guinea pig strain which models "typical" brain aging, the Hartley strain develops hallmarks of AD like aging humans. Hartleys also exhibit age‐related impairments in cartilage and skeletal muscle. Impaired mitochondrial respiration is one driver of both cellular aging and AD. In humans with cognitive decline, diminished skeletal muscle and brain respiratory control occurs in parallel. We previously reported age‐related declines in skeletal muscle mitochondrial respiration in Hartleys. It is unknown if there is concomitant mitochondrial dysfunction in the brain. Methods: Therefore, we assessed hippocampal mitochondrial respiration in 5‐ and 12‐month Hartley and PET guinea pigs using high‐resolution respirometry. Results: At 12 months, PETs had higher complex I supported mitochondrial respiration paralleling their increase in body mass compared to 5 months PETs. Hartleys were also heavier at 12 months compared to 5 months but did not have higher complex I respiration. Compared to 5 months Hartleys, 12 months Hartleys had lower complex I mitochondrial efficiency and compensatory increases in mitochondrial proteins collectively suggesting mitochondrial dysfunction with age. Conclusions: Therefore, Hartleys might be a relevant model to test promising therapies targeting mitochondria to slow brain aging and AD progression. [ABSTRACT FROM AUTHOR]

Airway smooth muscle (ASM) contraction is determined by the increase in intracellular Ca2+ concentration ([Ca2+]i) caused by its release from the sarcoplasmic reticulum (SR) or by extracellular Ca2+ influx. Major channels involved in Ca2+ influx in ASM cells are L-type voltage-dependent Ca2+ channels (L-VDCCs) and nonselective cation channels (NSCCs). Transient receptor potential vanilloid 4 (TRPV4) is an NSCC recently studied in ASM. Mechanical stimuli, such as contraction, can activate TRPV4. We investigated the possible activation of TRPV4 by histamine (His)- or carbachol (CCh)-induced contraction in guinea pig ASM. In single myocytes, the TRPV4 agonist (GSK101) evoked an increase in [Ca2+]i, characterized by a slow onset and a plateau phase. The TRPV4 antagonist (GSK219) decreased channel activity by 94%, whereas the Ca2+-free medium abolished the Ca2+ response induced by GSK101. Moreover, GSK101 caused Na+ influx in tracheal myocytes. GSK219 reduced the Ca2+ peak and the Ca2+ plateau triggered by His or CCh. TRPV4 blockade shifted the concentration–response curve relating to His and CCh to the right in tracheal rings and reduced the maximal contraction. Finally, the activation of TRPV4 in single myocytes increased the Ca2+ refilling of the SR. We conclude that contraction of ASM cells after stimulation with His or CCh promotes TRPV4 activation, the subsequent influx of Ca2+ and Na+, and the opening of L-VDCCs. The entry of Ca2+ into ASM cells via TRPV4 and L-VDCCs contributes to optimal smooth muscle contraction. [ABSTRACT FROM AUTHOR]

Simple Summary: Is our ability to discriminate speech in noise an innate and fixed ability, or can it be increased by a perceptual learning task? And if this is the case, can we find neural correlates of this improved perceptual ability? To address this question, we trained adult mice to discriminate between acoustically similar calls from guinea pigs, first in quiet, then in two types of masking noise at three different signal-to-noise ratios. The mice performance was excellent in quiet and decreased when the signal-to-noise became negative. After three months of training, we recorded the auditory responses in auditory brainstem neurons (inferior colliculus) and found that their responses tended to be stronger and more discriminative than those of passively exposed mice and, more surprisingly, sometimes stronger and more discriminative than those of guinea pigs. These results exemplify the fact that extensive practice in a perceptual learning task can improve the way auditory neurons process speech-like sounds in noise. Humans and animals maintain accurate discrimination between communication sounds in the presence of loud sources of background noise. In previous studies performed in anesthetized guinea pigs, we showed that, in the auditory pathway, the highest discriminative abilities between conspecific vocalizations were found in the inferior colliculus. Here, we trained CBA/J mice in a Go/No-Go task to discriminate between two similar guinea pig whistles, first in quiet conditions, then in two types of noise, a stationary noise and a chorus noise at three SNRs. Control mice were passively exposed to the same number of whistles as trained mice. After three months of extensive training, inferior colliculus (IC) neurons were recorded under anesthesia and the responses were quantified as in our previous studies. In quiet, the mean values of the firing rate, the temporal reliability and mutual information obtained from trained mice were higher than from the exposed mice and the guinea pigs. In stationary and chorus noise, there were only a few differences between the trained mice and the guinea pigs; and the lowest mean values of the parameters were found in the exposed mice. These results suggest that behavioral training can trigger plasticity in IC that allows mice neurons to reach guinea pig-like discrimination abilities. [ABSTRACT FROM AUTHOR]

Objective: This study aimed to comparatively evaluate the antifungal effects of 405-nm and 635-nm dual-band diode lasers using an in vivo guinea pig model of dermatophytosis. Materials and Methods: A guinea pig model was developed by the repetitive application of fungal spore preparations to the back skin of guinea pigs. Dual-diode laser treatment was delivered to the guinea pig skin at a power of 24 mW at a wavelength of 405 nm and 18 mW at 635 nm for 12 min. The treatments were administered three times weekly for 2 weeks, and a mycological study was performed. Results: Mycological studies using scraped samples obtained from treatment groups A (N = 8) and B (N = 8) after dual-diode laser treatment revealed that seven of eight (87.5%) samples in each group had negative results for direct potassium hydroxide microscopy and fungal culture studies. Skin specimens from each infected laser-untreated guinea pig exhibited spongiotic psoriasiform epidermis with parakeratosis. Meanwhile, skin specimens from infected laser-treated guinea pigs in groups A and B demonstrated thinner epidermal thickness than those from infected untreated controls but thicker than those from uninfected treated controls without noticeable inflammatory cell infiltration in the dermis. Conclusion: The guinea pig dermatophytosis model can be used to comparatively evaluate the efficacy and safety of various treatment modalities, including dual-diode lasers, for superficial fungal skin infection. [ABSTRACT FROM AUTHOR]

Asthma is a disease characterized by chronic inflammation and hyper responsiveness of airways. We aimed to assess the relaxant potential of phosphodiesterase-4 (PDE4) inhibitors N-sulfonilhidrazonic derivatives on non-asthmatic and asthmatic guinea pig trachea. Firstly, guinea pigs were sensitized and challenged with ovalbumin, and then morphological, and contractile changes were evaluated resulting from asthma, followed by evaluation of relaxant effect of derivatives on guinea pig trachea and the cAMP levels measurement by ELISA. It has been evidenced hypertrophy of airway smooth muscle, inflammatory infiltrate, and vascular abnormalities. Moreover, only sensitized tracheal rings were responsive to OVA. Contractile response to histamine, but not to carbachol, was greater in sensitized animals, however the relaxant response to aminophylline and isoprenaline were the same in non-asthmatics and asthmatics. N-sulfonilhidrazonic derivatives presented equipotent relaxant action independent of epithelium, with exception of LASSBio-1850 that presented a low efficacy (< 50%) and LASSBio-1847 with a 4-fold higher potency on asthmatics. LASSBio-1847 relaxant curve was impaired in the presence of propranolol and potentiated by isoprenaline in both groups. Furthermore, relaxation was potentiated 54- and 4-fold by forskolin in non-asthmatics and asthmatics, respectively. Likewise, LASSBio-1847 potentiated relaxant curve of aminophylline 147- and 4-fold in both groups. The PKA inhibitor H-89 impaired the relaxant potency of the derivative. Finally, LASSBio-1847 increased tracheal intracellular cAMP levels similarly to rolipram, selective PDE4 inhibitor, in both animals. LASSBio-1847 showed to be promising to relax guinea pig trachea from non-sensitized and sensitized guinea pigs by activation of β2-adrenergic receptors/AC/cAMP pathway. [ABSTRACT FROM AUTHOR]

Although sudden sensorineural hearing loss (SSNHL) is a serious condition, there are currently no approved drugs for its treatment. Nevertheless, there is a growing understanding that the cochlear pathologies that underlie SSNHL include apoptotic death of sensory outer hair cells (OHCs) as well as loss of ribbon synapses connecting sensory inner hair cells (IHCs) and neurites of the auditory nerve, designated synaptopathy. Noise-induced hearing loss (NIHL) is a common subtype of SSNHL and is widely used to model hearing loss preclinically. Here, we demonstrate that a single interventive application of a small pyridoindole molecule (AC102) into the middle ear restored auditory function almost to prenoise levels in a guinea pig model of NIHL. AC102 prevented noise-triggered loss of OHCs and reduced IHC synaptopathy suggesting a role of AC102 in reconnecting auditory neurons to their sensory target cells. Notably, AC102 exerted its therapeutic properties over a wide frequency range. Such strong improvements in hearing have not previously been demonstrated for other therapeutic agents. In vitro experiments of a neuronal damage model revealed that AC102 protected cells from apoptosis and promoted neurite growth. These effects may be explained by increased production of adenosine triphosphate, indicating improved mitochondrial function, and reduced levels of reactive-oxygen species which prevents the apoptotic processes responsible for OHC death. This action profile of AC102 might be causal for the observed hearing recovery in in vivo models. [ABSTRACT FROM AUTHOR]

Guinea Pig Herpes-Like Virus (GPHLV) is a virus isolated from leukemic guinea pigs with herpes virus-like morphology described by Hsiung and Kaplow in 1969. GPHLV transformed embryonic cells from Syrian hamsters or rats, which were tumorigenic in adult animals. Herein, we present the genomic sequence of GPHLV strain LK40 as a reference for future molecular analysis. GPHLV has a broad host tropism and replicates efficiently in Guinea pig, Cat, and Green African Monkey-derived cell lines. GPHLV has a GC content of 35.45%. The genome is predicted to encode at least 75 open-reading frames (ORFs) with 84% (63 ORFs) sharing homology to human Kaposi Sarcoma Associated Herpes Virus (KSHV). Importantly, GPHLV encodes homologues of the KSHV oncogenes, vBCL2 (ORF16), vPK (ORF36), viral cyclin (v-cyclin, ORF72), the latency associated nuclear antigen (LANA, ORF73), and vGPCR (ORF74). GPHLV is a Rhadinovirus of Cavia porcellus, and we propose the formal name of Caviid gamma herpesvirus 1 (CaGHV-1). GPHLV can be a novel small animal model of Rhadinovirus pathogenesis with broad host tropism. [ABSTRACT FROM AUTHOR]

Background: Intrauterine growth restriction (IUGR) is an obstetrical condition where a fetus has not achieved its genetic potential. A consequence of IUGR is a decrease in brain myelin content. Myelin water imaging (MWI) has been used to assess fetal myelin water fraction (MWF) and might potentially assess myelination changes associated with IUGR. Purpose: To quantify and compare the MWF of non‐IUGR and IUGR fetal guinea pigs (GPs) in late gestation. Study Type: Prospective animal model. Animal Model: Dunkin‐Hartley GP model of spontaneous IUGR (mean ± SD: 60 ± 1.2 days gestation; 19 IUGR, 52 control). Field Strength/Sequence: Eight spoiled gradient‐recalled (SPGR) gradient echo volumes (flip angles [α]: 2°–16°), and two sets of eight balanced steady‐state free precession (bSSFP) gradient echo volumes (α: 8° – 64°), at 0° and 180° phase increments, at 3.0 T. Assessment: MWF maps were generated for each fetal GP brain using multicomponent driven equilibrium single pulse observation of T1/T2 (mcDESPOT). MWF was quantified in the fetal corpus callosum (CC), fornix (FOR), parasagittal white matter (PSW), and whole fetal brain. Statistical Tests: Linear regression was performed between five fetal IUGR markers (body volume, body‐to‐pregnancy volume ratio, brain‐to‐liver volume ratio, brain‐to‐placenta volume ratio, and brain‐to‐body volume ratio) and MWF (coefficient of determination, R2). A t‐test with a linear mixed model compared the MWF of non‐IUGR and IUGR fetal GPs (significance was determined at α < 0.05). Results: The MWF of the control fetuses are (mean ± SD): 0.23 ± 0.02 (CC), 0.31 ± 0.02 (FOR), 0.28 ± 0.02 (PSW), and 0.20 ± 0.01 (whole brain). The MWF of the IUGR fetuses are (mean ± SD): 0.19 ± 0.02 (CC), 0.27 ± 0.01 (FOR), 0.24 ± 0.03 (PSW), and 0.16 ± 0.01 (whole brain). Significant differences in MWF were found between the non‐IUGR and IUGR fetuses in every comparison. Data Conclusion: The mean MWF of IUGR fetal GPs is significantly lower than non‐IUGR fetal GPs. Evidence Level: 2 Technical Efficacy: Stage 1 [ABSTRACT FROM AUTHOR]