RESUMEN
To describe the diagnosis and successful treatment of systemic francisellosis in a dog. An 11-year-old female spayed Labrador retriever presented for progressive lethargy, hyporexia, and cough. The dog was febrile with a neutrophilia, nonregenerative anemia, thrombocytopenia, and had increased activity in serum of liver-derived enzymes. Francisella philomiragia was isolated from aerobic blood culture. The dog was treated for 6 weeks with enrofloxacin orally. Repeated aerobic blood cultures after 2 and 6 weeks of antibiotic therapy were negative. The dog was clinically normal 7 months after diagnosis with no evidence of relapse.
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Antibacterianos , Bacteriemia , Enfermedades de los Perros , Enrofloxacina , Francisella , Infecciones por Bacterias Gramnegativas , Animales , Perros , Femenino , Enfermedades de los Perros/tratamiento farmacológico , Enfermedades de los Perros/microbiología , Enrofloxacina/uso terapéutico , Antibacterianos/uso terapéutico , Bacteriemia/veterinaria , Bacteriemia/tratamiento farmacológico , Bacteriemia/microbiología , Infecciones por Bacterias Gramnegativas/veterinaria , Infecciones por Bacterias Gramnegativas/tratamiento farmacológico , Infecciones por Bacterias Gramnegativas/microbiologíaRESUMEN
Cinacalcet is an oral calcimimetic that has potential to non-invasively treat primary hyperparathyroidism in dogs (Canis lupis familiaris). There is minimal data assessing its efficacy in dogs. This study aimed to determine whether a single dose of cinacalcet decreases serum ionized calcium (iCa), total calcium (tCa), and parathyroid hormone (PTH) concentrations. Twelve dogs received a median dose of 0.49 mg/kg (range 0.30-0.69 mg/kg) cinacalcet per os. Venous blood samples were collected at time 0 (before cinacalcet administration), 3, 8, and 24 h following cinacalcet administration. PTH, iCa, and tCa concentrations were measured at each time point and compared to 0 hour concentrations. A significant (50%) decrease in serum PTH occurred at 3 h with a median PTH of 4.6 pmol/L (range 2.7-10.8) at baseline and 1.65 pmol/L (range 0.5-14.7) at 3 h; p = .005. A significant, but not clinically relevant, decrease in serum iCa from a median baseline of 1.340 mmol/L (range 1.32-1.41) to a 3 h median of 1.325 mmol/L (range 1.26-1.39), p = .043, was also observed. tCa concentrations were not different. This study showed that a single dose of cinacalcet leads to transient decreases in iCa and PTH concentrations in healthy dogs.
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Calcio , Cinacalcet , Hormona Paratiroidea , Animales , Perros/sangre , Hormona Paratiroidea/sangre , Cinacalcet/administración & dosificación , Cinacalcet/farmacología , Calcio/sangre , Masculino , Femenino , Administración Oral , Calcimiméticos/administración & dosificación , Calcimiméticos/farmacologíaRESUMEN
OBJECTIVE: To describe the prevalence of postoperative bacteriuria, clinical course of subclinical bacteriuria in the absence of antimicrobial intervention, clinical signs of bacteriuria that trigger antimicrobial treatment, and outcomes for dogs with subclinical bacteriuria following surgical decompression of acute intervertebral disc herniation (IVDH) Hansen type I. ANIMALS: Twenty client-owned dogs undergoing hemilaminectomy for acute (≤ 6 days) IVDH Hansen type I affecting the thoracolumbar spinal cord segments between August 2018 and January 2019. PROCEDURES: In this prospective study, dogs were serially evaluated at presentation, hospital discharge, 2 weeks postoperatively, and between 4 and 6 weeks postoperatively. Dogs were monitored for clinical signs of bacteriuria, underwent laboratory monitoring (CBC, biochemical analyses, urinalysis, urine bacterial culture), and were scored for neurologic and urinary status. In the absence of clinical signs, bacteriuria was not treated with antimicrobials. RESULTS: Four of the 18 dogs developed bacteriuria without clinical signs 4 days to 4 to 6 weeks after surgery. In all 4 dogs, bacteriuria resulted in lower urinary tract signs 13 to 26 weeks postoperatively. No dogs had evidence of systemic illness despite delaying antimicrobial treatment until clinical signs developed. New-onset incontinence was the only clinical sign in 3 dogs. All bacterial isolates had wide antimicrobial susceptibility. Bacteriuria and clinical signs resolved with beta-lactam antimicrobial treatment. CLINICAL RELEVANCE: Postoperative bacteriuria occurs in some dogs with IVDH Hansen type I and, when present, may lead to clinical signs over time. Clinical signs of bacteriuria may be limited to new-onset urinary incontinence, inappropriate urination, or both. Delaying antimicrobial treatment until clinical signs of bacteriuria developed did not result in adverse consequences or systemic illness.
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Antiinfecciosos , Bacteriuria , Enfermedades de los Perros , Desplazamiento del Disco Intervertebral , Animales , Perros , Desplazamiento del Disco Intervertebral/cirugía , Desplazamiento del Disco Intervertebral/veterinaria , Estudios Prospectivos , Bacteriuria/tratamiento farmacológico , Bacteriuria/veterinaria , Bacteriuria/epidemiología , Descompresión Quirúrgica/efectos adversos , Descompresión Quirúrgica/veterinaria , Antiinfecciosos/uso terapéutico , Enfermedades de los Perros/tratamiento farmacológico , Enfermedades de los Perros/cirugía , Enfermedades de los Perros/epidemiologíaRESUMEN
Allogeneic islet transplantation is a promising experimental therapy for poorly controlled diabetes. Despite pharmacological immunosuppression, long-term islet engraftment remains elusive. Here, we designed a synthetic fusion transgene coupling PD-L1 and indoleamine dioxygenase [hereafter PIDO] whose constitutive expression prevents immune destruction of genetically engineered islet allograft transplanted in immunocompetent mice. PIDO expressing murine islets maintain robust dynamic insulin secretion in vitro and when transplanted in allogeneic hyperglycemic murine recipients reverse pre-existing streptozotocin-induced and autoimmune diabetes in the absence of pharmacological immunosuppression for more than 50 and 8 weeks, respectively, and is dependent on host CD4 competence. Additionally, PIDO expression in allografts preserves endocrine functional viability of islets and promotes a localized tolerogenic milieu characterized by the suppression of host CD8 T cell and phagocyte recruitment and accumulation of FOXP3+ Tregs. Furthermore, in the canine model of xenogeneic islet transplantation, muscle implanted PIDO-expressing porcine islets displayed physiological glucose-responsive insulin secretion competency in euglycemic recipient for up to 20 weeks. In conclusion, the PIDO transgenic technology enables host CD4+ T cell-modulated immune evasiveness and long-term functional viability of islet allo- and xenografts in immune-competent recipients without the need for pharmacological immune suppression and would allow for improved outcomes for tissue transplantation.
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Diabetes Mellitus Tipo 1 , Trasplante de Islotes Pancreáticos , Islotes Pancreáticos , Animales , Perros , Humanos , Ratones , Aloinjertos , Antígeno B7-H1/metabolismo , Rechazo de Injerto/prevención & control , Supervivencia de Injerto , Terapia de Inmunosupresión , Islotes Pancreáticos/metabolismo , Ratones Endogámicos C57BL , Porcinos , Indolamina-Pirrol 2,3,-DioxigenasaRESUMEN
OBJECTIVE: To compare urine concentrations of fibrinogen (uFIB) and interleukin-6 (uIL-6) between dogs with risk factors for enterococcal bacteriuria and healthy dogs. SAMPLE: Banked urine samples with negative aerobic culture results from 8 dogs with urolithiasis, 9 dogs with anatomic abnormalities of the lower portion of the urinary tract (LUT), 10 dogs with LUT neoplasia, and 21 healthy control dogs. PROCEDURES: Urine creatinine concentration (uCrea) was determined by an automated biochemical analyzer, and uFIB and uIL-6 were determined by dog-specific ELISAs. The uFIB:uCrea and uIL-6:uCrea ratios were calculated for each sample to normalize intersample differences in urine concentration and were compared among the 4 experimental groups. RESULTS: Median uFIB:uCrea ratios for dogs with urolithiasis (0.72; interquartile [25th to 75 percentile] range [IQR], 0.46 to 3.48) and LUT neoplasia (6.16; IQR, 3.89 to 12.75), but not for dogs with LUT anatomic abnormalities (0.48; IQR, 0.27 to 0.69), were significantly greater than that for control dogs (0.17; IQR, 0.07 to 0.39). Median uIL-6: uCrea ratios for dogs with urolithiasis (0.48; IQR, 0.18 to 1.61), LUT anatomic abnormalities (0.25; IQR, 0.17 to 0.33), and LUT neoplasia (0.25; IQR, 0.12 to 1.01) were significantly greater than that for control dogs (0.08; IQR, 0.06 to 0.11). CONCLUSIONS AND CLINICAL RELEVANCE: The uFIB and uIL-6 in dogs with risk factors for enterococcal bacteriuria were generally greater than corresponding values in control dogs. Further investigation is necessary to determine the role of fibrinogen in enterococcal colonization of the urinary tract of dogs.
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Bacteriuria , Enfermedades de los Perros , Infecciones Urinarias , Animales , Bacteriuria/epidemiología , Bacteriuria/veterinaria , Enfermedades de los Perros/epidemiología , Perros , Fibrinógeno , Interleucina-6 , Factores de Riesgo , Urinálisis/veterinaria , Infecciones Urinarias/veterinariaRESUMEN
CASE DESCRIPTION: A 3-year-old 17.5-kg (38.5-lb) mixed-breed dog was referred for evaluation because of nasal discharge, sneezing, and signs of nasal congestion of approximately 9 months' duration. A diagnosis of nasopharyngeal stenosis (NPS) was made prior to referral. CLINICAL FINDINGS: Sneezing, bilateral mucopurulent nasal discharge, reduced nasal airflow, stertor, and increased inspiratory effort were noted on physical examination. Results of serum biochemical analysis were within respective reference ranges. Review of CT images of the skull revealed findings consistent with severe bilateral partial osseous choanal atresia and NPS. Retrograde rhinoscopy confirmed membranous NPS. TREATMENT AND OUTCOME: A ventral rhinotomy was performed; communication between the pharynx and nasal passageway was reestablished by surgical debridement of the caudal border of the palatine bone and vomerine crest and groove, followed by dissection of the membranous NPS and reconstruction of the caudal part of the nasopharynx. A covered nasopharyngeal stent was placed in the newly established nasopharynx. The dog recovered uneventfully but was presented 3 weeks later with recurrent signs; diagnostic findings were consistent with stenosis rostral to the stent. The stenosis was treated with balloon dilation, and a second covered stent was placed rostral to and overlapping the first stent, spanning the stenotic region. Eleven months after this procedure, the dog was doing well. CLINICAL RELEVANCE: Results for this patient suggested that ventral rhinotomy and covered nasopharyngeal stent placement can be used successfully for the management of osseous choanal atresia in dogs; however, careful attention to preoperative planning and potential complications is necessary.
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Atresia de las Coanas , Enfermedades de los Perros , Enfermedades Nasofaríngeas , Animales , Atresia de las Coanas/cirugía , Atresia de las Coanas/veterinaria , Constricción Patológica/cirugía , Constricción Patológica/veterinaria , Enfermedades de los Perros/cirugía , Perros , Endoscopía/veterinaria , Enfermedades Nasofaríngeas/cirugía , Enfermedades Nasofaríngeas/veterinaria , StentsRESUMEN
BACKGROUND: In humans, Enterococcus spp. urinary tract infections (UTI) are commonly associated with urinary catheter-induced urothelial inflammation but this is not the case in dogs. HYPOTHESIS/OBJECTIVES: To identify risk factors predisposing dogs to enterococcal bacteriuria. ANIMALS: Seventy dogs with Enterococcus spp. bacteriuria (case) and 70 dogs with Enterococcus coli bacteriuria (control). METHODS: A single center retrospective case-control study with subjects and controls identified by a medical records search for Enterococcus spp. (subject) or E coli (control) bacteriuria from January 1, 2014 to December 31, 2017. Cases and controls were balanced with respect to average age and weight. Binary logistic regression was used to estimate and test whether the odds of having Enterococcus spp. bacteriuria (instead of E coli) were associated with the presence of any given characteristic. RESULTS: A history of recurrent bacteriuria was significantly more common in Enterococcus spp. cases than in E coli controls (odds ratio [OR]: 2.07; 95% confidence interval [CI]: 1.04-4.16, P = .04). Comorbidities associated with the presence of Enterococcus spp. bacteriuria included lower urinary tract (LUT) anatomic abnormalities (OR: 2.94; 95% CI: 1.17-8.10, P = .02), urolithiasis (P = .01), and the presence of LUT neoplasia (P = .04). Small frequencies (n = 12 and n = 6, respectively) compromise our ability to precisely estimate the genuine OR for the latter 2 characteristics. CONCLUSIONS AND CLINICAL IMPORTANCE: If the identified risk factors promote Enterococcus spp. colonization in dogs via induced LUT inflammation similar to people then Enterococcus spp. bacteriuria could be a sentinel for underlying LUT inflammation.
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Bacteriuria , Enfermedades de los Perros , Infecciones Urinarias , Animales , Bacteriuria/epidemiología , Bacteriuria/veterinaria , Estudios de Casos y Controles , Enfermedades de los Perros/epidemiología , Perros , Enterococcus , Escherichia coli , Estudios Retrospectivos , Factores de Riesgo , Infecciones Urinarias/epidemiología , Infecciones Urinarias/veterinariaRESUMEN
BACKGROUND: The identity and spatial distribution of prostatic cell types has been determined in humans but not in dogs, even though aging- and prostate-related voiding disorders are common in both species and mechanistic factors, such as prostatic collagen accumulation, appear to be shared between species. In this publication we characterize the regional distribution of prostatic cell types in the young intact dog to enable comparisons with human and mice and we examine how the cellular source of procollagen 1A1 changes with age in intact male dogs. METHODS: A multichotomous decision tree involving sequential immunohistochemical stains was validated for use in dog and used to identify specific prostatic cell types and determine their distribution in the capsule, peripheral, periurethral and urethral regions of the young intact canine prostate. Prostatic cells identified using this technique include perivascular smooth muscle cells, pericytes, endothelial cells, luminal, intermediate, and basal epithelial cells, neuroendocrine cells, myofibroblasts, fibroblasts, fibrocytes, and other hematolymphoid cells. To enhance rigor and transparency, all high resolution images (representative images shown in the figures and biological replicates) are available through the GUDMAP database at https://doi.org/10.25548/16-WMM4. RESULTS: The prostatic peripheral region harbors the largest proportion of epithelial cells. Aging does not change the density of hematolymphoid cells, fibroblasts, and myofibroblasts in the peripheral region or in the fibromuscular capsule, regions where we previously observed aging- and androgen-mediated increases in prostatic collagen abundance Instead, we observed aging-related changes the procollagen 1A1 positive prostatic cell identity from a myofibroblast to a fibroblast. CONCLUSIONS: Hematolymphoid cells and myofibroblasts are often identified as sources of collagen in tissues prone to aging-related fibrosis. We show that these are not the likely sources of pathological collagen synthesis in older intact male dogs. Instead, we identify an aging-related shift in the prostatic cell type producing procollagen 1A1 that will help direct development of cell type and prostate appropriate therapeutics for collagen accumulation.
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Envejecimiento/fisiología , Fibroblastos/metabolismo , Miofibroblastos/metabolismo , Procolágeno/biosíntesis , Próstata/citología , Vejiga Urinaria/fisiopatología , Envejecimiento/metabolismo , Envejecimiento/patología , Animales , Susceptibilidad a Enfermedades , Perros , Inmunohistoquímica , Masculino , Próstata/metabolismo , Próstata/patologíaRESUMEN
High quantities of quality RNA are necessary for many veterinary laboratory tests. Several commercial kits are available for RNA isolation from human whole blood; their resultant RNA yield and purity have not been reported for canine whole blood, to our knowledge. We assessed the performance of 4 RNA extraction kits (RiboPure, TRIzol, RNeasy Protect animal blood, and QIAamp RNA blood mini). Whole blood from a healthy dog was stored in the manufacturer-recommended RNA stabilizing buffer as directed. RNA isolation, including DNase treatment, was performed using each kit's manufacturer's protocol. Resultant RNA yield and purity were evaluated using spectrophotometric absorbance, capillary electrophoresis and electropherogram analysis, and a reverse-transcription real-time PCR (RT-rtPCR) assay. The RNeasy Protect animal blood kit extracted the highest, and RiboPure the lowest, concentration of nucleic acid. RNA integrity numbers classified extracted RNA as good quality or better for all kits except RNeasy Protect. All kits had evidence of genomic DNA contamination as assessed by RT-rtPCR. Overall, QIAamp RNA blood mini kit and TRIzol optimized both RNA yield and purity from canine whole blood. These kits extracted high quantities of good quality RNA as evidenced by high RNA integrity numbers and minimal contamination with proteins and solvents.
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Análisis Químico de la Sangre/veterinaria , Perros/sangre , Técnicas Genéticas/veterinaria , ARN/aislamiento & purificación , Animales , Análisis Químico de la Sangre/instrumentación , Técnicas Genéticas/instrumentación , ARN/análisis , Juego de Reactivos para Diagnóstico/veterinariaRESUMEN
Alzheimer's disease (AD), the leading cause of dementia, is a chronic neurodegenerative disease. Apolipoprotein E (apoE), which carries lipids in the brain in the form of lipoproteins, plays an undisputed role in AD pathophysiology. A high-throughput phenotypic screen was conducted using a CCF-STTG1 human astrocytoma cell line to identify small molecules that could upregulate apoE secretion. AZ7235, a previously discovered Axl kinase inhibitor, was identified to have robust apoE activity in brain microglia, astrocytes and pericytes. AZ7235 also increased expression of ATP-binding cassette protein A1 (ABCA1), which is involved in the lipidation and secretion of apoE. Moreover, AZ7235 did not exhibit Liver-X-Receptor (LXR) activity and stimulated apoE and ABCA1 expression in the absence of LXR. Target validation studies using AXL-/- CCF-STTG1 cells showed that Axl is required to mediate AZ7235 upregulation of apoE and ABCA1. Intriguingly, apoE expression and secretion was significantly attenuated in AXL-deficient CCF-STTG1 cells and reconstitution of Axl or kinase-dead Axl significantly restored apoE baseline levels, demonstrating that Axl also plays a role in maintaining apoE homeostasis in astrocytes independent of its kinase activity. Lastly, these effects may require human apoE regulatory sequences, as AZ7235 exhibited little stimulatory activity toward apoE and ABCA1 in primary murine glia derived from neonatal human APOE3 targeted-replacement mice. Collectively, we identified a small molecule that exhibits robust apoE and ABCA1 activity independent of the LXR pathway in human cells and elucidated a novel relationship between Axl and apoE homeostasis in human astrocytes.
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Enfermedad de Alzheimer/metabolismo , Apolipoproteínas E/metabolismo , Astrocitos/efectos de los fármacos , Astrocitoma/metabolismo , Proteínas Proto-Oncogénicas/metabolismo , Proteínas Tirosina Quinasas Receptoras/metabolismo , Transportador 1 de Casete de Unión a ATP/metabolismo , Animales , Apolipoproteínas E/genética , Astrocitoma/genética , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Supervivencia Celular/genética , Técnicas de Silenciamiento del Gen , Ensayos Analíticos de Alto Rendimiento , Humanos , Ratones , Microglía/efectos de los fármacos , Microglía/metabolismo , Proteínas Proto-Oncogénicas/genética , Proteínas Tirosina Quinasas Receptoras/genética , Tirosina Quinasa del Receptor AxlRESUMEN
OBJECTIVE: To quantify the magnitude and duration of changes in urine chondroitin sulfate concentration (uCS) as a result of oral administration of a chondroitin sulfate-containing supplement in dogs. ANIMALS: 8 healthy privately owned dogs. PROCEDURES: A urine sample was collected from each dog via cystocentesis on day 1; free-catch midstream urine samples were collected once daily on days 2 through 5. Pretreatment uCS was established from those samples. Each dog then received a chondroitin sulfate-containing supplement (20 to 30 mg/kg, PO, q 12 h) for 8 days (on days 7 through 14). Urine samples were collected on days 8 through 12 and day 15. For each sample, uCS was quantified by liquid chromatography-tandem mass spectrometry. Variable urine concentration was accounted for by dividing the uCS by urine creatinine concentration (uCrea) to determine the uCS:uCrea ratio. Pretreatment uCS:uCrea ratios were compared with treatment uCS:uCrea ratios to calculate the fold change in uCS after supplement administration. RESULTS: Among the study dogs, oral administration of the chondroitin sulfate-containing supplement resulted in a 1.9-fold increase in the median uCS:uCrea ratio. Data obtained on days 8 through 12 and day 15 indicated that the daily increase in uCS remained consistent and was not additive. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that oral administration of supplemental chondroitin sulfate to dogs modestly increased uCS within 24 hours; however, subsequent supplement administration did not have an additive effect. A potential therapeutic benefit of persistently increased uCS in preventing recurrent urinary tract infections in dogs warrants investigation.
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Sulfatos de Condroitina/administración & dosificación , Sulfatos de Condroitina/orina , Perros/orina , Administración Oral , Animales , Cromatografía Liquida/veterinaria , Suplementos Dietéticos , Esquema de Medicación , Femenino , Masculino , Estudios Prospectivos , Espectrometría de Masas en Tándem/veterinaria , Urinálisis/veterinariaRESUMEN
This letter describes progress towards an M4 PAM preclinical candidate inspired by an unexpected aldehyde oxidase (AO) metabolite of a novel, CNS penetrant thieno[2,3-c]pyridine core to an equipotent, non-CNS penetrant thieno[2,3-c]pyrdin-7(6H)-one core. Medicinal chemistry design efforts yielded two novel tricyclic cores that enhanced M4 PAM potency, regained CNS penetration, displayed favorable DMPK properties and afforded robust in vivo efficacy in reversing amphetamine-induced hyperlocomotion in rats.
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Aldehído Oxidasa/metabolismo , Miotonía Congénita/metabolismo , Receptor Muscarínico M4/metabolismo , Animales , Descubrimiento de Drogas , Humanos , Ratas , Relación Estructura-ActividadRESUMEN
This letter describes progress towards an M4 PAM preclinical candidate that resulted in the discovery of VU6005806/AZN-00016130. While the thieno[2,3-c]pyridazine core has been a consistent feature of key M4 PAMs, no work had previously been reported with respect to alternate functionality at the C3 position of the pyridazine ring. Here, we detail new chemistry and analogs that explored this region, and quickly led to VU6005806/AZN-00016130, which was profiled as a putative candidate. While, the ß-amino carboxamide moiety engendered solubility limited absorption in higher species precluding advancement (or requiring extensive pharmaceutical sciences formulation), VU6005806/AZN-00016130 represents a new, high quality preclinical in vivo probe.
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Regulación Alostérica/inmunología , Receptor Muscarínico M4/inmunología , Estructura Molecular , Relación Estructura-ActividadRESUMEN
BACKGROUND: Prostate stiffness and increased collagen content both associate with the presence of urinary symptoms in men but mechanisms responsible, including impact of age and androgens, are unknown. Dogs develop prostate-related urinary dysfunction similar to humans, but mechanisms are also unknown. Mice have been used to examine how prostatic collagen accumulation affects voiding but whether mouse prostatic collagen organization resembles human or dog has not been evaluated. Here, we have constructed the first comprehensive, comparative maps of collagen architecture in canine, human, and mouse prostate and test whether canine prostatic collagen content is increased by aging and reduced by castration. METHODS: Complete transverse prostate sections were stained with picrosirius red and imaged with confocal microscopy to reveal and compare collagen architecture across species. Canine prostatic collagen fiber length, diameter, and density in prostatic urethral, periurethral, peripheral, and capsular regions were quantified and compared among four experimental groups: young intact, young neutered, old intact, and old neutered dogs. RESULTS: Surprisingly, the majority of collagen was localized to the prostatic urethra in canine, human, and mouse. In canine and human, capsular regions also featured a dense collagen network but it appeared less dense than around prostatic urethra. Older, intact male canines exhibited overall denser prostate collagen fibers and had thicker capsular fibers than young, intact males. Prostatic glandular regions undergo dramatic atrophy and regression following castration, and our finding of neutered animals having increased collagen fiber density in both periurethral and peripheral regions is consistent with glandular contraction and increased proportion of stroma. CONCLUSIONS: Collagen architecture in dog appears similar to that in humans when cross sections are compared side-by-side. Canine collagen organization is affected by both age and androgen status, suggesting these factors may contribute to collagen accumulation in some males.
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Colágeno/metabolismo , Próstata/citología , Próstata/metabolismo , Animales , Castración , Perros , Humanos , Masculino , Ratones , Ratones Endogámicos C57BLRESUMEN
A series of isoquinuclidine benzamides as glycine uptake inhibitors for the treatment of schizophrenia are described. Potency, lipophilicity, and intrinsic human microsomal clearance were parameters for optimization. Potency correlated with the nature of the ortho substituents of the benzamide ring, and reductions in lipophilicity could be achieved through heteroatom incorporation in the benzamide and pendant phenyl moieties. Improvements in human CLint were achieved through changes in ring size and the N-alkyl group of the isoquinuclidine itself, with des-alkyl derivatives (40-41, 44) demonstrating the most robust microsomal stability. Dimethylbenzamide 9 was tested in a mouse MK801 LMA assay and had a statistically significant attenuation of locomotor activity at 3 and 10⯵mol/kg compared to control.
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Benzamidas/farmacología , Compuestos Bicíclicos con Puentes/farmacología , Proteínas de Transporte de Glicina en la Membrana Plasmática/antagonistas & inhibidores , Administración Oral , Animales , Benzamidas/administración & dosificación , Benzamidas/química , Compuestos Bicíclicos con Puentes/administración & dosificación , Compuestos Bicíclicos con Puentes/química , Relación Dosis-Respuesta a Droga , Humanos , Inyecciones Intravenosas , Locomoción/efectos de los fármacos , Masculino , Ratones , Estructura Molecular , Ratas , Ratas Sprague-Dawley , Relación Estructura-ActividadRESUMEN
apoE is the primary lipid carrier within the CNS and the strongest genetic risk factor for late onset Alzheimer's disease (AD). apoE is primarily lipidated via ABCA1, and both are under transcriptional regulation by the nuclear liver X receptor (LXR). Considerable evidence from genetic (using ABCA1 overexpression) and pharmacological (using synthetic LXR agonists) studies in AD mouse models suggests that increased levels of lipidated apoE can improve cognitive performance and, in some strains, can reduce amyloid burden. However, direct synthetic LXR ligands have hepatotoxic side effects that limit their clinical use. Here, we describe a set of small molecules, previously annotated as antagonists of the purinergic receptor, P2X7, which enhance ABCA1 expression and activity as well as apoE secretion, and are not direct LXR ligands. Furthermore, P2X7 is not required for these molecules to induce ABCA1 upregulation and apoE secretion, demonstrating that the ABCA1 and apoE effects are mechanistically independent of P2X7 inhibition. Hence, we have identified novel dual activity compounds that upregulate ABCA1 across multiple CNS cell types, including human astrocytes, pericytes, and microglia, through an indirect LXR mechanism and that also independently inhibit P2X7 receptor activity.
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Transportador 1 de Casete de Unión a ATP/agonistas , Apolipoproteínas E/agonistas , Antagonistas del Receptor Purinérgico P2X/farmacología , Receptores Purinérgicos P2X7/metabolismo , Bibliotecas de Moléculas Pequeñas/farmacología , Transportador 1 de Casete de Unión a ATP/metabolismo , Adamantano/análogos & derivados , Adamantano/química , Adamantano/farmacología , Animales , Apolipoproteínas E/metabolismo , Aziridinas/química , Aziridinas/farmacología , Benzamidas/química , Benzamidas/farmacología , Células Cultivadas , Humanos , Ratones , Ratones Noqueados , Estructura Molecular , Naftoquinonas/química , Naftoquinonas/farmacología , Antagonistas del Receptor Purinérgico P2X/química , Receptores Purinérgicos P2X7/deficiencia , Bibliotecas de Moléculas Pequeñas/química , Sulfonamidas/química , Sulfonamidas/farmacología , Regulación hacia Arriba/efectos de los fármacosRESUMEN
Although selective activation of the M1 muscarinic acetylcholine receptor (mAChR) subtype has been shown to improve cognitive function in animal models of neuropsychiatric disorders, recent evidence suggests that enhancing M4 mAChR function can also improve memory performance. Positive allosteric modulators (PAMs) targeting the M4 mAChR subtype have shown therapeutic potential for the treatment of multiple symptoms observed in schizophrenia, including positive and cognitive symptoms when assessed in acute preclinical dosing paradigms. Since the cholinergic system has been implicated in multiple stages of learning and memory, we evaluated the effects of repeated dosing with the highly selective M4 PAM VU0467154 on either acquisition and/or consolidation of learning and memory when dosed alone or after pharmacologic challenge with the N-methyl-d-aspartate subtype of glutamate receptors (NMDAR) antagonist MK-801. MK-801 challenge represents a well-documented preclinical model of NMDAR hypofunction that is thought to underlie some of the positive and cognitive symptoms observed in schizophrenia. In wildtype mice, 10-day, once-daily dosing of VU0467154 either prior to, or immediately after daily testing enhanced the rate of learning in a touchscreen visual pairwise discrimination task; these effects were absent in M4 mAChR knockout mice. Following a similar 10-day, once-daily dosing regimen of VU0467154, we also observed 1) improved acquisition of memory in a cue-mediated conditioned freezing paradigm, 2) attenuation of MK-801-induced disruptions in the acquisition of memory in a context-mediated conditioned freezing paradigm and 3) reversal of MK-801-induced hyperlocomotion. Comparable efficacy and plasma and brain concentrations of VU0467154 were observed after repeated dosing as those previously reported with an acute, single dose administration of this M4 PAM. Together, these studies are the first to demonstrate that cognitive enhancing and antipsychotic-like activity are not subject to the development of tolerance following repeated dosing with a selective M4 PAM in mice and further suggest that activation of M4 mAChRs may modulate both acquisition and consolidation of memory functions.
Asunto(s)
Antipsicóticos/uso terapéutico , Trastornos del Conocimiento/tratamiento farmacológico , Piridazinas/uso terapéutico , Receptor Muscarínico M4/genética , Tiofenos/uso terapéutico , Regulación Alostérica/efectos de los fármacos , Animales , Antipsicóticos/metabolismo , Encéfalo/efectos de los fármacos , Trastornos del Conocimiento/etiología , Discriminación en Psicología/efectos de los fármacos , Modelos Animales de Enfermedad , Maleato de Dizocilpina/toxicidad , Relación Dosis-Respuesta a Droga , Hipercinesia/inducido químicamente , Hipercinesia/tratamiento farmacológico , Masculino , Trastornos de la Memoria/inducido químicamente , Trastornos de la Memoria/tratamiento farmacológico , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Piridazinas/metabolismo , Esquizofrenia/complicaciones , Esquizofrenia/tratamiento farmacológico , Esquizofrenia/genética , Tiofenos/metabolismoRESUMEN
Herein we describe the continued optimization of M4 positive allosteric modulators (PAMs) within the 5-amino-thieno[2,3-c]pyridazine series of compounds. In this letter, we disclose our studies on tertiary amides derived from substituted azetidines. This series provided excellent CNS penetration, which had been challenging to consistently achieve in other amide series. Efforts to mitigate high clearance, aided by metabolic softspot analysis, were unsuccessful and precluded this series from further consideration as a preclinical candidate. In the course of this study, we found that potassium tetrafluoroborate salts could be engaged in a tosyl hydrazone reductive cross coupling reaction, a previously unreported transformation, which expands the synthetic utility of the methodology.