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1.
Proc Natl Acad Sci U S A ; 121(15): e2314763121, 2024 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-38557194

RESUMO

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.


Assuntos
Perda Auditiva Provocada por Ruído , Perda Auditiva Neurossensorial , Cobaias , Animais , Audição , Cóclea , Ruído/efeitos adversos , Células Ciliadas Auditivas Externas/fisiologia , Limiar Auditivo
2.
BMC Ophthalmol ; 24(1): 161, 2024 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-38605375

RESUMO

BACKGROUND: Myopia is becoming a huge burden on the world's public health systems. The purpose of this study was to explore the effect of brimonidine in the treatment of form-deprivation myopia (FDM) and the relationship between intraocular pressure (IOP) and myopia development. METHODS: Monocular form deprivation myopia (FDM) was induced in three-week-old pigmented male guinea pigs. They were treated with 3 different methods of brimonidine administration (eye drops, and subconjunctival or intravitreal injections). Four different concentrations of brimonidine were tested for each method (2µg/µL, 4µg/µL, 20µg/µL, and 40µg/µL). All treatments continued for a period of 21 days. Tonometry, retinoscopy, and A-scan ultrasonography were used to monitor intraocular pressure, refractive error and axial length (AL), respectively. RESULTS: Treatment with subconjunctival brimonidine at 40µg/µL, and intravitreal brimonidine at 2µg/µL and 4µg/µL, inhibited the development of FDM. The myopic refraction, excessive axial length, and elevation of IOP were significantly decreased. Brimonidine in eye drops was ineffective. CONCLUSION: Brimonidine at appropriate doses significantly reduced the development of FD myopia in guinea pigs. The IOP may change with FD myopia.


Assuntos
Miopia , Erros de Refração , Masculino , Animais , Cobaias , Tartarato de Brimonidina/uso terapêutico , Miopia/tratamento farmacológico , Refração Ocular , Soluções Oftálmicas , Privação Sensorial , Modelos Animais de Doenças
3.
J Physiol Sci ; 74(1): 24, 2024 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-38600445

RESUMO

Actin linked regulatory mechanisms are known to contribute contraction/relaxation in smooth muscle. In order to clarify whether modulation of polymerization/depolymerization of actin filaments affects relaxation process, we examined the effects of cytochalasin D on relaxation process by Ca2+ removal after Ca2+-induced contraction of ß-escin skinned (cell membrane permeabilized) taenia cecum and carotid artery preparations from guinea pigs. Cytochalasin D, an inhibitor of actin polymerization, significantly suppressed the force during relaxation both in skinned taenia cecum and carotid artery. The data fitting analysis of the relaxation processes indicates that cytochalasin D accelerates slow (latch-like) bridge dissociation. Cytochalasin D seems to directly disrupts actin filament organization or its length, resulting in modulation of actin filament structure that prevents myosin binding.


Assuntos
Actinas , Contração Muscular , Cobaias , Animais , Contração Muscular/fisiologia , Actinas/metabolismo , Citocalasina D/farmacologia , Citocalasina D/metabolismo , Ceco/metabolismo , Artérias Carótidas/metabolismo , Cálcio/metabolismo
4.
mBio ; 15(4): e0345023, 2024 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-38445878

RESUMO

We compared the growth characteristics of a virulent Rickettsia rickettsii strain (Sheila Smith) to an attenuated R. rickettsii stain (Iowa) and a non-pathogenic species (R. montanensis) in primary human dermal microvascular endothelial cells (HDMEC). All replicated in Vero cells, however, only the Sheila Smith strain productively replicated in HDMECs. The Iowa strain showed minimal replication over a 24-h period, while R. montanensis lost viability and induced lysis of the HDMECs via a rapid programmed cell death response. Both the virulent and attenuated R. rickettsii strains, but not R. montanensis, induced an interferon-1 response, although the response was of lesser magnitude and delayed in the Sheila Smith strain. IFN-ß secretion correlated with increased host cell lysis, and treatment with anti-IFNAR2 antibody decreased lysis from Iowa-infected but not Sheila Smith-infected cells. Both Sheila Smith- and Iowa-infected cells eventually lysed, although the response from Sheila Smith was delayed and showed characteristics of apoptosis. We, therefore, examined whether reconstitution of the Iowa strain with two recently described putative virulence determinants might enhance survival of Iowa within HDMECs. Reconstitution with RARP2, which is inhibitory to anterograde trafficking through the Golgi apparatus, reduced IFN-ß secretion but had no effect on cell lysis. RapL, which proteolytically processes surface exposed autotransporters and enhances replication of Iowa in Guinea pigs, suppressed both IFN-ß production and host cell lysis. These findings suggest distinct mechanisms by which virulent spotted fever group rickettsiae may enhance intracellular survival and replication.IMPORTANCEWe examined a naturally occurring non-pathogenic rickettsial species, R. montanensis, a laboratory-attenuated R. rickettsii strain (Iowa), and a fully virulent R. rickettsii strain (Sheila Smith) for growth in human dermal microvascular endothelial cells. The two avirulent strains replicated poorly or not at all. Only the virulent Sheila Smith strain replicated. IFN-ß production correlated with the inhibition of R. rickettsii Iowa. Reconstitution of Iowa with either of two recently described putative virulence determinants altered the IFN-ß response. A rickettsial ankyrin repeat protein, RARP2, disrupts the trans-Golgi network and inhibits IFN-ß secretion. An autotransporter peptidase, RapL, restores proteolytic maturation of outer membrane autotransporters and diminishes the IFN-ß response to enhance cell survival and permit replication of the recombinant strain. These studies point the way toward discovery of mechanisms for innate immune response avoidance by virulent rickettsia.


Assuntos
Rickettsia , Febre Maculosa das Montanhas Rochosas , Animais , Cobaias , Humanos , Chlorocebus aethiops , Células Endoteliais/patologia , Rickettsia rickettsii/metabolismo , Febre Maculosa das Montanhas Rochosas/microbiologia , Sistemas de Secreção Tipo V/metabolismo , Células Vero , Virulência , Fatores de Virulência/metabolismo , Interferon beta
5.
Skinmed ; 22(1): 67-68, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38494619

RESUMO

A healthy 32-year-old woman presented to clinic with tender pruritic lesions of 2-month duration at the vulva and lesions for weeks on the shins. She was treated with topical corticosteroids and intravenous vancomycin without significant improvement. On examination, dozens of follicular hemorrhagic papulopustules were detected at the suprapubic area and vulva (Figure 1). Similar but less prominent lesions were observed on the shins as well. Biopsies of the vulva and shin revealed a follicular inflammatory infiltrate of neutrophils, histiocytes, and lymphocytes as well as fungal hyphae within the follicular infundibulum and hair shafts, consistent with Majocchi's granuloma (MG). Gram and Fite-Faraco staining, direct immunofluorescence, and bacterial culture were negative. Tissue culture grew Trichophyton mentagrophytes, which was identified using sequence analysis of the D1/D2 region of the 28s rDNA. Minimum inhibitory concentrations for terbinafine, ketoconazole, and itraconazole were determined, with terbinafine having the lowest concentration. Additional history revealed that shortly prior to commencement of her clinical manifestations, the patient had acquired a pet guinea pig with eruptions and hair loss (Figure 2). The patient was prescribed ketoconazole cream and terbinafine, 250 mg daily, with almost immediate improvement. Based on clinical response, the patient remained on terbinafine and ketoconazole cream for 6 months. Her skin remained clear 4 months after discontinuing all antifungals. Based on the results of patient's culture, a veterinarian treated her guinea pig successfully with systemic terbinafine and miconazole lotion.


Assuntos
Cetoconazol , Tinha , Trichophyton , Feminino , Humanos , Animais , Cobaias , Adulto , Terbinafina/uso terapêutico , Cetoconazol/uso terapêutico , Antifúngicos/uso terapêutico , Vulva
6.
J Pharmacol Sci ; 154(4): 256-263, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38485343

RESUMO

Platelet-activating factor (PAF) is expected to increase esophageal motility. However, to the best of our knowledge, this has not been examined. Thus, we investigated the contractile effects of PAF on guinea pig (GP) esophageal muscularis mucosae (EMM) and the extracellular Ca2+ influx pathways responsible. PAF (10-9-10-6 M) contracted EMM in a concentration-dependent manner. PAF (10-6 M)-induced contractions were almost completely suppressed by apafant (a PAF receptor antagonist, 3 × 10-5 M). In EMM strips, PAF receptor and PAF-synthesizing/degrading enzyme mRNAs were detected. PAF (10-6 M)-induced contractions were abolished by extracellular Ca2+ removal but were not affected by diltiazem [a voltage-dependent Ca2+ channel (VDCC) inhibitor, 10-5 M]. PAF (10-6 M)-induced contractions in the presence of diltiazem were significantly suppressed by LOE-908 [a receptor-operated Ca2+ channel (ROCC) inhibitor, 3 × 10-5 M], SKF-96365 [an ROCC and store-operated Ca2+ channel (SOCC) inhibitor, 3 × 10-5 M], and LOE-908 plus SKF-96365. Among the tested ROCC/SOCC-related mRNAs, Trpc3, Trpc6, and Trpv4/Orai1, Orai3, and Stim2 were abundantly expressed in EMM strips. These results indicate that PAF potently induces GP EMM contractions that are dependent on extracellular Ca2+ influx through ROCCs/SOCCs, and VDCCs are unlikely to be involved.


Assuntos
Diltiazem , Isoquinolinas , Fator de Ativação de Plaquetas , Cobaias , Animais , Diltiazem/farmacologia , Fator de Ativação de Plaquetas/farmacologia , Acetamidas , Canais de Cálcio/metabolismo , Mucosa/metabolismo , Cálcio/metabolismo
7.
Biol Pharm Bull ; 47(3): 660-668, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38508741

RESUMO

Flopropione (Flo) has been used for gallstone and urolithiasis as a spasmolytic agent almost exclusively in Japan. According to the package insert, its main mechanism is catechol-O-methyltransferase (COMT) inhibition and anti-serotonergic effect. This is obviously contrary to pharmacological common sense, but it is described that way in pharmacology textbooks and occurs in questions in the National Examination for Pharmacists in Japan. As this is a serious problem in education, we re-examined the action of Flo. The guinea pig ureter was hardly contracted by serotonin, but noradrenaline (NA) elicited repetitive twitch contraction, which was inhibited by Flo. The sphincter of Oddi (SO) exhibited a spontaneous repetitive twitch contraction, which was inhibited by NA and Flo. The inhibitory effect of NA was reversed by α- and ß-blockers, whereas that of Flo was not. Entacapone, a representative COMT inhibitor, did not affect the movement of the ureter and the SO. Nifedipine suppressed carbachol-induced contraction of the taenia coli, spontaneous movement of the SO, and NA-induced contraction of the ureter to almost the same extent, whereas Flo did not inhibit the taenia coli, but inhibited the contraction of the SO and the ureter. The inhibitory pattern of Flo resembled that of the ryanodine receptor agonist 4-chloro-m-cresol and the inositol 1,4,5-trisphosphate (IP3) receptor antagonist 2-aminoethoxydiphenyl borate. It is concluded that COMT inhibition or serotonin inhibition is not involved in the spasmolytic action of Flo. Flo might act on ryanodine receptors and/or IP3 receptors, which are responsible for periodic Ca release from Ca stores, to disrupt coordinated Ca dynamics.


Assuntos
Contração Muscular , Parassimpatolíticos , Propiofenonas , Animais , Cobaias , Parassimpatolíticos/farmacologia , Catecol O-Metiltransferase/farmacologia , Serotonina/farmacologia , Catecóis/farmacologia , Cálcio/farmacologia
8.
Exp Eye Res ; 241: 109849, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38430983

RESUMO

Currently, researchers have mainly focused on the role of the tissues of the posterior segment of the eyes in the development of myopia. However, the ciliary body, an anterior ocular tissue that contracts to initiate the process of accommodation, may also play an important role in the progression of myopia due to the increased demand for near work. In the present study, we established a lens-induced myopia (LIM) animal model in guinea pigs and investigated the molecular changes in the ciliary body associated with the development of myopia based on RNA sequencing. As a result, 871 differentially expressed (DE) mRNAs and 19 DE lncRNAs were identified in the ciliary body between the LIM group and the normal control group. In addition, the lncRNA-mRNA co-expression analysis was performed to explore the target genes of lncRNAs, which were mainly enriched in the Rap1 signaling pathway, cytokine-cytokine receptor interaction, and complement and coagulation cascades pathways based on the functional enrichment analysis. Among the target genes of lncRNAs, three hub genes, including Ctnnb1, Pik3r1, and Itgb1, were found to be involved in the Rap1 signaling pathway. Interestingly, two crucial genes, Grk1 and Pde6a, which are mainly expressed in retinal photoreceptors, were enriched in visual perception in the ciliary body in functional analysis and were verified to be expressed in the ciliary body. These findings indicate the molecular pathogenetic role of the ciliary body in myopia and provide new insights into the underlying mechanism of myopia development. Further studies are needed to explore the specific contributions of these identified lncRNAs and mRNAs to the development of myopia.


Assuntos
Miopia , RNA Longo não Codificante , Animais , Cobaias , Corpo Ciliar/metabolismo , RNA Longo não Codificante/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Visão Ocular
9.
Exp Eye Res ; 241: 109853, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38453038

RESUMO

High myopia is a risk factor for primary open angle glaucoma (POAG). The pathological mechanism of high myopia induced POAG occurrence is not fully understood. In this study, we successfully established the guinea pig model of ocular hypertension with high myopia, and demonstrated the susceptibility of high myopia for the occurrence of microbead-induced glaucoma compared with non-myopia group and the effect of YAP/TGF-ß signaling pathway in TM pathogenesis induced by high myopia. Moreover, we performed stretching treatment on primary trabecular meshwork (TM) cells to simulate the mechanical environment of high myopia. It was found that stretching treatment disrupted the cytoskeleton, decreased phagocytic function, enhanced ECM remodeling, and promoted cell apoptosis. The experiments of mechanics-induced human TM cell lines appeared the similar trend. Mechanically, the differential expressed genes of TM cells caused by stretch treatment enriched YAP/TGF-ß signaling pathway. To inhibit YAP/TGF-ß signaling pathway effectively reversed mechanics-induced TM damage. Together, this study enriches mechanistic insights of high myopia induced POAG susceptibility and provides a potential target for the prevention of POAG with high myopia.


Assuntos
Glaucoma de Ângulo Aberto , Hipertensão Ocular , Humanos , Animais , Cobaias , Fator de Crescimento Transformador beta/metabolismo , Malha Trabecular/metabolismo , Glaucoma de Ângulo Aberto/prevenção & controle , Glaucoma de Ângulo Aberto/genética , Hipertensão Ocular/metabolismo , Fatores de Risco , Células Cultivadas
10.
BMC Pulm Med ; 24(1): 140, 2024 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-38504249

RESUMO

BACKGROUND: In the early literature, unintentional vitamin C deficiency in humans was associated with heart failure. Experimental vitamin C deficiency in guinea pigs caused enlargement of the heart. The purpose of this study was to collect and analyze case reports on vitamin C and pulmonary hypertension. METHODS: We searched Pubmed and Scopus for case studies in which vitamin C deficiency was considered to be the cause of pulmonary hypertension. We selected reports in which pulmonary hypertension was diagnosed by echocardiography or catheterization, for any age, sex, or dosage of vitamin C. We extracted quantitative data for our analysis. We used the mean pulmonary artery pressure (mPAP) as the outcome of primary interest. RESULTS: We identified 32 case reports, 21 of which were published in the last 5 years. Dyspnea was reported in 69%, edema in 53% and fatigue in 28% of the patients. Vitamin C plasma levels, measured in 27 cases, were undetectable in 24 and very low in 3 cases. Diet was poor in 30 cases and 17 cases had neuropsychiatric disorders. Right ventricular enlargement was reported in 24 cases. During periods of vitamin C deficiency, the median mPAP was 48 mmHg (range 29-77 mmHg; N = 28). After the start of vitamin C administration, the median mPAP was 20 mmHg (range 12-33 mmHg; N = 18). For the latter 18 cases, mPAP was 2.4-fold (median) higher during vitamin C deficiency. Pulmonary vascular resistance (PVR) during vitamin C deficiency was reported for 9 cases, ranging from 4.1 to 41 Wood units. PVR was 9-fold (median; N = 5) higher during vitamin C deficiency than during vitamin C administration. In 8 cases, there was direct evidence that the cases were pulmonary artery hypertension (PAH). Probably the majority of the remaining cases were also PAH. CONCLUSIONS: The cases analyzed in our study indicate that pulmonary hypertension can be one explanation for the reported heart failure of scurvy patients in the early literature. It would seem sensible to measure plasma vitamin C levels of patients with PH and examine the effects of vitamin C administration.


Assuntos
Deficiência de Ácido Ascórbico , Insuficiência Cardíaca , Hipertensão Pulmonar , Hipertensão Arterial Pulmonar , Escorbuto , Humanos , Animais , Cobaias , Hipertensão Pulmonar/tratamento farmacológico , Hipertensão Pulmonar/etiologia , Hipertensão Pulmonar/diagnóstico , Escorbuto/complicações , Hipertensão Arterial Pulmonar/complicações , Resistência Vascular , Deficiência de Ácido Ascórbico/complicações , Ácido Ascórbico/uso terapêutico
11.
J Virol ; 98(4): e0011224, 2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38506509

RESUMO

Live-attenuated virus vaccines provide long-lived protection against viral disease but carry inherent risks of residual pathogenicity and genetic reversion. The live-attenuated Candid#1 vaccine was developed to protect Argentines against lethal infection by the Argentine hemorrhagic fever arenavirus, Junín virus. Despite its safety and efficacy in Phase III clinical study, the vaccine is not licensed in the US, in part due to concerns regarding the genetic stability of attenuation. Previous studies had identified a single F427I mutation in the transmembrane domain of the Candid#1 envelope glycoprotein GPC as the key determinant of attenuation, as well as the propensity of this mutation to revert upon passage in cell culture and neonatal mice. To ascertain the consequences of this reversion event, we introduced the I427F mutation into recombinant Candid#1 (I427F rCan) and investigated the effects in two validated small-animal models: in mice expressing the essential virus receptor (human transferrin receptor 1; huTfR1) and in the conventional guinea pig model. We report that I427F rCan displays only modest virulence in huTfR1 mice and appears attenuated in guinea pigs. Reversion at another attenuating locus in Candid#1 GPC (T168A) was also examined, and a similar pattern was observed. By contrast, virus bearing both revertant mutations (A168T+I427F rCan) approached the lethal virulence of the pathogenic Romero strain in huTfR1 mice. Virulence was less extreme in guinea pigs. Our findings suggest that genetic stabilization at both positions is required to minimize the likelihood of reversion to virulence in a second-generation Candid#1 vaccine.IMPORTANCELive-attenuated virus vaccines, such as measles/mumps/rubella and oral poliovirus, provide robust protection against disease but carry with them the risk of genetic reversion to the virulent form. Here, we analyze the genetics of reversion in the live-attenuated Candid#1 vaccine that is used to protect against Argentine hemorrhagic fever, an often-lethal disease caused by the Junín arenavirus. In two validated small-animal models, we find that restoration of virulence in recombinant Candid#1 viruses requires back-mutation at two positions specific to the Candid#1 envelope glycoprotein GPC, at positions 168 and 427. Viruses bearing only a single change showed only modest virulence. We discuss strategies to genetically harden Candid#1 GPC against these two reversion events in order to develop a safer second-generation Candid#1 vaccine virus.


Assuntos
Febre Hemorrágica Americana , Vírus Junin , População da América do Sul , Vacinas Virais , Humanos , Animais , Cobaias , Camundongos , Virulência , Febre Hemorrágica Americana/prevenção & controle , Vacinas Atenuadas/genética , Glicoproteínas/genética , Vacinas Virais/genética
12.
Hear Res ; 445: 108989, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38518394

RESUMO

Age-related hearing loss affects a large and growing segment of the population, with profound impacts on quality of life. Age-related pathology of the cochlea-the mammalian hearing organ-underlies age-related hearing loss. Because investigating age-related changes in the cochlea in humans is challenging and often impossible, animal models are indispensable to investigate these mechanisms as well as the complex consequences of age-related hearing loss on the brain and behavior. In this review, we advocate for a comparative and interdisciplinary approach while also addressing the challenges of comparing age-related hearing loss across species with varying lifespans. We describe the experimental advantages and limitations as well as areas for future research in well-established models of age-related hearing loss, including mice, rats, gerbils, chinchillas, and birds. We also indicate the need to expand characterization of age-related hearing loss in other established animal models, especially guinea pigs, cats, and non-human primates, in which auditory function is well characterized but age-related cochlear pathology is understudied. Finally, we highlight the potential of emerging animal models for advancing our understanding of age-related hearing loss, including deer mice, with their notably extended lifespans and preserved hearing, naked mole rats, with their exceptional longevity and extensive vocal communications, as well as zebrafish, which offer genetic tractability and suitability for drug screening. Ultimately, a comparative and interdisciplinary approach in auditory research, combining insights from various animal models with human studies, is key to robust and reliable research outcomes that better advance our understanding and treatment of age-related hearing loss.


Assuntos
Surdez , Presbiacusia , Animais , Cobaias , Envelhecimento/genética , Cóclea , Potenciais Evocados Auditivos do Tronco Encefálico , Mamíferos , Modelos Animais , Qualidade de Vida , Peixe-Zebra , Gatos
13.
Colloids Surf B Biointerfaces ; 237: 113855, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38513298

RESUMO

Local drug delivery has been exploited recently to treat hearing loss, as this method can both bypass the blood-labyrinth barrier and provide sustained drug release. Combined drug microcrystals (MCs) offer additional advantages for sensorineural hearing loss treatment via intratympanic (IT) injection due to their shape effect and combination strategy. In this study, to endow viscous effects of hydrogels, nonspherical dexamethasone (DEX) and lipoic acid (LA) MCs were incorporated into silk fibroin (SF) hydrogels, which were subsequently administered to the tympanic cavity to investigate their pharmaceutical properties. First, we prepared DEX and LA MCs by a traditional precipitation technique followed by SF hydrogel incorporation (SF+DEX+LA). After characterization of the physicochemical features, including morphology, rheology, and dissolution, both a suspension of combined DEX and LA MCs (DEX+LA) and SF+DEX+LA were administered to guinea pigs by IT injection, after which the pharmacokinetics, biodegradation and biocompatibility were evaluated. To our surprise, compared to the DEX+LA group, the pharmacokinetics of the SF+DEX+LA hydrogel group did not improve significantly, which may be ascribed to their nonspherical shape and deposition effects of the drugs MCs. The cochlear tissue in each group displayed good morphology, with no obvious inflammatory reactions. This combined MC suspension has the clear advantages of no vehicle, easy scale-up preparation, and good biocompatibility and outcomes, which paves the way for practical treatment of hearing loss via local drug delivery.


Assuntos
Orelha Interna , Fibroínas , Perda Auditiva , Ácido Tióctico , Animais , Cobaias , Hidrogéis/química , Ácido Tióctico/farmacologia , Dexametasona , Seda/metabolismo , Orelha Interna/metabolismo , Perda Auditiva/tratamento farmacológico , Perda Auditiva/metabolismo , Fibroínas/farmacologia
14.
Dev Neurobiol ; 84(2): 93-110, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38526217

RESUMO

Children born preterm have an increased likelihood of developing neurobehavioral disorders such as attention-deficit hyperactivity disorder (ADHD) and anxiety. These disorders have a sex bias, with males having a higher incidence of ADHD, whereas anxiety disorder tends to be more prevalent in females. Both disorders are underpinned by imbalances to key neurotransmitter systems, with dopamine and noradrenaline in particular having major roles in attention regulation and stress modulation. Preterm birth disturbances to neurodevelopment may affect this neurotransmission in a sexually dimorphic manner. Time-mated guinea pig dams were allocated to deliver by preterm induction of labor (gestational age 62 [GA62]) or spontaneously at term (GA69). The resultant offspring were randomized to endpoints as neonates (24 h after term-equivalence age) or juveniles (corrected postnatal day 40, childhood equivalence). Relative mRNA expressions of key dopamine and noradrenaline pathway genes were examined in the frontal cortex and hippocampus and quantified with real-time PCR. Myelin basic protein and neuronal nuclei immunostaining were performed to characterize the impact of preterm birth. Within the frontal cortex, there were persisting reductions in the expression of dopaminergic pathway components that occurred in preterm males only. Conversely, preterm-born females had increased expression of key noradrenergic receptors and a reduction of the noradrenergic transporter within the hippocampus. This study demonstrated that preterm birth results in major changes in dopaminergic and noradrenergic receptor, transporter, and synthesis enzyme gene expression in a sex- and region-based manner that may contribute to the sex differences in susceptibility to neurobehavioral disorders. These findings highlight the need for the development of sex-based treatments for improving these conditions.


Assuntos
Nascimento Prematuro , Recém-Nascido , Criança , Animais , Humanos , Masculino , Cobaias , Feminino , Pessoa de Meia-Idade , Nascimento Prematuro/genética , Nascimento Prematuro/metabolismo , Dopamina/metabolismo , Lobo Frontal , Hipocampo/metabolismo , Norepinefrina/metabolismo
15.
ACS Appl Mater Interfaces ; 16(13): 15893-15906, 2024 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-38512725

RESUMO

Polymer-mediated cell surface engineering can be a powerful tool to modify the cell's biological behavior, but a simple ligation strategy must be identified. This manuscript assessed the use of transglutamination as a versatile and adaptable approach for cell surface engineering in various cellular models relevant to biomedical applications. This enzymatic approach was evaluated for its feasibility and potential for conjugating polymers to diverse cell surfaces and its biological effects. Transglutaminase-mediated ligation was successfully performed at temperatures ranging from 4 to 37 °C in as quickly as 30 min, while maintaining biocompatibility and preserving cell viability. This approach was successfully applied to nine different cell surfaces (including adherent cells and suspension cells) by optimizing the enzyme source (guinea pig liver vs microbial), buffer compositions, and incubation conditions. Finally, polymer-mediated cell surface engineering using transglutaminase exhibited immunocamouflage abilities for endothelial cells, T cells, and red blood cells by preventing the recognition of cell surface proteins by antibodies. Employing transglutaminase in polymer-mediated cell surface engineering is a promising approach to maximize its application in cell therapy and other biomedical applications.


Assuntos
Polímeros , Transglutaminases , Animais , Cobaias , Polímeros/metabolismo , Transglutaminases/metabolismo , Células Endoteliais/metabolismo , Membrana Celular/metabolismo , Engenharia Celular
16.
Open Vet J ; 14(2): 716-729, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38549567

RESUMO

Background: Presently, there exists a growing interest in mitigating the utilization of antibiotics in response to the challenges emanating from their usage in livestock. A viable alternative strategy encompasses the introduction of live microorganisms recognized as probiotics, exerting advantageous impacts on the immune system and nutritional aspects of the host animals. Native lactic acid bacteria, inherently possessing specific properties and adaptive capabilities tailored to each animal, are deemed optimal contenders for probiotic advancement. Aim: In the current investigation, microorganisms exhibiting probiotic potential were isolated, characterized, and identified from the fecal samples of guinea pigs (Cavia porcellus) belonging to the Peruvian breed. Methods: The lactic acid bacteria isolated on Man, Rogosa, and Sharpe agar underwent Gram staining, catalase testing, proteolytic, amylolytic, and cellulolytic activity assays, low pH tolerance assessment, hemolytic evaluation, antagonism against Salmonella sp., determination of autoaggregation and coaggregation capacity, and genotypic characterization through sequencing of the 16S rRNA gene. Results: A total of 33 lactic acid bacteria were isolated from the feces of 30 guinea pigs, also 10 isolates were selected based on Gram staining and catalase testing. All strains exhibited proteolytic activity, while only one demonstrated amylolytic capability, and none displayed cellulase activity. These bacteria showed higher tolerance to pH 5.0 and, to a lesser extent, to pH 4.0. Furthermore, they exhibited antagonistic activity against Salmonella sp. Only two bacteria demonstrated hemolytic activity, and were subsequently excluded from further evaluations. Subsequent assessments revealed autoaggregation capacities ranging from 4.55% to 23.19%, with a lesser degree of coaggregation with Salmonella sp. ranging from 3.53% to 8.94% for the remaining eight bacterial isolates. Based on these comprehensive tests, five bacteria with notable probiotic potential were identified by molecular assays as Leuconostoc citreum, Enterococcus gallinarum, Exiguobacterium sp., and Lactococcus lactis. Conclusion: The identified bacteria stand out as promising probiotic candidates, deserving further assessment in Peruvian breed guinea pigs. This exploration aims to enhance production outcomes while mitigating the adverse effects induced by pathogenic microorganisms.


Assuntos
Lactobacillales , Probióticos , Humanos , Cobaias , Animais , Lactobacillales/genética , RNA Ribossômico 16S/genética , Catalase/farmacologia , Fezes , Genômica , Probióticos/farmacologia
17.
Scand J Immunol ; 99(3): e13342, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38441294

RESUMO

In contrast to delayed-type hypersensitivity (DTH) and other hallmark reactions of cell-mediated immunity that correlate with vaccine-mediated protection against Mycobacterium tuberculosis, the contribution of vaccine dose on responses that emerge early after infection in the skin with Bacille Calmette-Guérin (BCG) is not well understood. We used a mouse model of BCG skin infection to study the effect of BCG dose on the relocation of skin Dendritic cells (DCs) to draining lymph node (DLN). Mycobacterium antigen 85B-specific CD4+ P25 T cell-receptor transgenic (P25 TCRTg) cells were used to probe priming to BCG in DLN. DC migration and T cell priming were studied across BCG inocula that varied up to 100-fold (104 to 106 Colony-forming units-CFUs). In line with earlier results in guinea pigs, DTH reaction in our model correlated with BCG dose. Importantly, priming of P25 TCRTg cells in DLN also escalated in a dose-dependent manner, peaking at day 6 after infection. Similar dose-escalation effects were seen for DC migration from infected skin and the accompanying transport of BCG to the DLN. BCG-triggered upregulation of co-stimulatory molecules on migratory DCs was restricted to the first 24 hour after infection and was independent of BCG dose over a 10-fold range (105 to 106 CFUs). The dose seemed to be a determinant of the number of total skin DCs that move to the DLN. In summary, our results support the use of higher BCG doses to detect robust DC migration and T cell priming.


Assuntos
Vacina BCG , Linfócitos T , Camundongos , Animais , Cobaias , Imunidade Celular , Células de Langerhans , Linfonodos
18.
Pharmeur Bio Sci Notes ; 2024: 12-26, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38533690

RESUMO

For more than 50 years, in vivo assays have been used for testing pharmaceutical product safety due to their assumed ability to broadly detect potential unidentified contaminants. As part of these in vivo tests, the animal tests for depressor substances and histamine have been described in the European Pharmacopoeia since its first edition in 1977. Both tests measure the effect of histamine and histamine-like substances, using guinea-pigs and cats respectively. In 2024, the Histamine (2.6.10) general chapter is referenced in the Production section of four monographs and 10 monographs have variations of a sentence on designing the manufacturing process to eliminate or minimise substances lowering blood pressure in this same section, without referencing the chapter. The Depressor substances (2.6.11) chapter is referenced only in the Histamine (2.6.10) chapter as a next step if the histamine test is invalid. A historical search was performed and it has shown that the tests for histamine and for depressor substances were introduced by different groups of experts in an inconsistent way at different times, and for different reasons, leading to non-harmonised approaches across monographs. The control of histamine and other depressor substances has been the subject of numerous debates where their use was questioned. During these discussions, reports on positive cases or batches failing the test for histamine or depressor substances were anecdotal. In addition, in vivo tests can be considered non-specific, very variable, time-consuming, costly and ethically doubtful. More importantly, the majority of in vivo methods originate from a time when good manufacturing practice was not widely used and formal method validation requirements were not yet established. In view of the above, the removal of all references to animal tests for histamine or depressor substances from all texts still referring to them is proposed. Since the sentences in the Production section referring to the control of "substances lowering blood pressure", "vasoactive substances" or "hypotensive substances" appeared as remainders of the animal test without further guarantee of safety, it will also be proposed to remove all these sentences from the concerned monographs. Ultimately, the suppression of general chapters 2.6.10 and 2.6.11 from the Ph. Eur. is envisaged. Independently from the above, it is also envisaged to elaborate a new general chapter Histamine in active substances (2.5.47) to include physicochemical or immunochemical methods enabling the detection of histamine. This new text would aim at supporting manufacturers in their histamine control strategy following the inclusion of precaution statements in the general monograph on Products of fermentation (1468); these statements had been added in Ph. Eur. Supplements 9.6 and 10.4, following adverse events related to a GMP issue with gentamicin sulfate. This strategy has been endorsed by the European Pharmacopoeia Commission at its 177th Session in November 2023. The concerned monographs would be a subject of public consultation in Pharmeuropa 36.2 (April 2024).


Assuntos
Alternativas aos Testes com Animais , Histamina , Animais , Cobaias , Histamina/análise , Gatos
19.
Viruses ; 16(3)2024 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-38543722

RESUMO

The H6 subtype of avian influenza viruses (AIVs) has emerged as one of the predominant subtypes in both wild and domestic avian species. Currently, H6 AIVs have acquired the ability to infect a wide range of mammals, though the related molecular mechanisms have yet to be fully investigated. In this study, a wild bird-origin H6N2 AIV was isolated from the East Asian-Australasian migratory flyway region located in Liaoning Province. This H6N2 virus initially expressed limited replication in mice. However, after one passage in mice, the virus acquired two mutations, PB2 E627K and HA A110V. The mutant displayed enhanced replication both in vitro and in vivo, proving lethal to mice. But the mutant retained the α-2, 3-linked sialic acid binding property and failed to transmit in guinea pigs. We explored the molecular mechanisms underlying the pathogenicity difference between the wild type and the mutant. Our findings revealed that PB2 E627K dramatically enhanced the polymerase activity of the H6N2 virus, while the HA A110V mutation decreased the pH of HA activation. This study demonstrated that the H6N2 subtype wild bird-origin AIV easily acquired the mammalian adaptation. The monitoring and evaluation of H6 wild bird-origin AIV should be strengthened.


Assuntos
Vírus da Influenza A , Influenza Aviária , Animais , Cobaias , Camundongos , Aves , Vírus da Influenza A/genética , Mamíferos , Filogenia , Virulência
20.
Sci Rep ; 14(1): 5764, 2024 03 08.
Artigo em Inglês | MEDLINE | ID: mdl-38459219

RESUMO

The metabolic syndrome, often accompanied by hepatic manifestations, is a high-risk factor for developing cardiovascular disease. Patients with metabolic dysfunction associated with steatohepatic disease (MASDL) are at significant risk of developing coronary artery disease. Atherosclerosis is a systemic inflammatory disorder in which several factors, including dietary or infectious factors, can cause an inflammatory response. Helicobacter pylori (HP) bacteria have been implicated in the progression of proatherogenic vascular endothelial lesions, moreover, our previous study in an experimental in vivo model of Cavia porcellus showed that HP components and high-fat substances acted synergistically in promoting vascular endothelial inflammation, leading to an early onset of a proatherogenic environment. In the present study, our goal was to determine the contribution of HP components to the development of hepatic manifestations of metabolic syndrome in an experimental model. Our results showed that HP infection in animals exposed to a high-fat diet increased oxidative stress and lipid peroxidation, followed by endothelial lipid deposition, impaired endothelial apoptosis, cell lysis, and increased vascular stiffness. Finally, histopathological analysis of liver tissue showed signs of MASLD development in HP-infected animals fed a high-fat diet.


Assuntos
Infecções por Helicobacter , Helicobacter pylori , Síndrome Metabólica , Humanos , Animais , Cobaias , Síndrome Metabólica/complicações , Dieta Hiperlipídica/efeitos adversos , Fígado , Fatores de Risco , Infecções por Helicobacter/microbiologia
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