RESUMEN
Pancreatic ductal adenocarcinoma (PDAC) is a poor prognosis cancer with an .aggressive growth profile that is often diagnosed at late stage and that has few curative or therapeutic options. PDAC growth has been linked to alterations in the pancreas microbiome, which could include the presence of the fungus Malassezia. We used RNA-sequencing to compare 14 paired tumor and normal (tumor adjacent) pancreatic cancer samples and found Malassezia RNA in both the PDAC and normal tissues. Although the presence of Malassezia was not correlated with tumor growth, a set of immune- and inflammatory-related genes were up-regulated in the PDAC compared to the normal samples, suggesting that they are involved in tumor progression. Gene set enrichment analysis suggests that activation of the complement cascade pathway and inflammation could be involved in pro PDAC growth.
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This case report describes an outbreak and novel findings associated with a beta coronavirus (BCoV) infection that occurred on an American Miniature Horse (AMH) breeding farm in upstate New York, in January and February of 2013. Twenty-nine AMH and one donkey were present on the farm when the outbreak occurred. One 10-year-old Quarter Horse mare, stabled at a separate location and owned by an employee of the farm, also tested positive. A polymerase chain reaction (PCR) assay for the detection of BCoV was performed at the Animal Health Diagnostic Center (AHDC) at Cornell on all faecal samples. The PCR assay used detects multiple beta coronaviruses, including, but not limited to, equine enteric coronavirus (ECoV). Novel findings regarding this BCoV infection in horses were recognised in this outbreak study. To the authors' knowledge, this is the largest outbreak of BCoV described thus far in a closed herd on a single premise. The case fatality rate was 0% unlike that described in a previous outbreak of ECoV involving miniature horses and a miniature donkey (Fielding et al. 2015). The morbidity rate was lower in this outbreak than in previously described studies (Oue et al. 2013; Pusterla et al. 2013). This outbreak also demonstrated the potential for BCoV transmission via farm personnel. The duration of shedding of virus in the faeces among some asymptomatic horses in this outbreak was longer than previously described clinical cases of ECoV (Pusterla et al. 2013; Nemoto et al. 2014). This study suggests that asymptomatic animals may play a role in the maintenance of BCoV during an outbreak; therefore, the need for diagnostic testing of both clinically affected and apparently clinically normal horses on a premises followed by appropriate biosecurity and control measures.
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There are reports of horses with acute onset acquired cervical scoliosis and cutaneous analgesia. The underlying dorsal gray column myelitis that produces these neurologic signs has been only presumptively attributed to migration of Parelaphostrongylus tenuis within the spinal cord. Despite previous confirmation brain by polymerase chain reaction testing, of P. tenuis within the brain of horses by polymerase chain reaction testing, genetic testing has failed to definitively identify the presence of this parasite in cases of equine myelitis. This case report provides molecular confirmation via polymerase chain reaction of P. tenuis within the cervical spinal cord of a horse with scoliosis and cutaneous analgesia.
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Infecciones del Sistema Nervioso Central/veterinaria , Enfermedades de los Caballos/parasitología , Meningitis/veterinaria , Metastrongyloidea , Mielitis/veterinaria , Escoliosis/veterinaria , Infecciones por Strongylida/veterinaria , Animales , Infecciones del Sistema Nervioso Central/complicaciones , Infecciones del Sistema Nervioso Central/diagnóstico , Infecciones del Sistema Nervioso Central/parasitología , Femenino , Enfermedades de los Caballos/diagnóstico , Caballos , Meningitis/diagnóstico , Meningitis/parasitología , Mielitis/diagnóstico , Mielitis/parasitología , Reacción en Cadena de la Polimerasa/veterinaria , Escoliosis/etiología , Escoliosis/parasitología , Infecciones por Strongylida/complicaciones , Infecciones por Strongylida/parasitologíaAsunto(s)
Linaje de la Célula , Resistencia a Antineoplásicos/genética , N-Metiltransferasa de Histona-Lisina/genética , Proteínas de Homeodominio/genética , Proteína de la Leucemia Mieloide-Linfoide/genética , Recurrencia Local de Neoplasia/genética , Leucemia-Linfoma Linfoblástico de Células T Precursoras/genética , Adolescente , Adulto , Niño , Preescolar , Supervivencia sin Enfermedad , Femenino , Reordenamiento Génico , Humanos , Masculino , Recurrencia Local de Neoplasia/mortalidad , Leucemia-Linfoma Linfoblástico de Células T Precursoras/mortalidad , Pronóstico , Estudios RetrospectivosRESUMEN
Donkeys (Equus asinus) are used as both companion and working animals throughout the world and in some countries, their meat and milk are used for human consumption. Here we report the first serological survey of Toxoplasma gondii in donkeys in the United States. Serum samples from 373 donkeys from eight farms in five states were tested for T. gondii antibodies by the modified agglutination test (MAT). Twenty-four of 373 (6.4%) of donkeys were seropositive, with MAT titers ranging from 25 to ≥ 200. All seropositive donkeys were Miniature breed. Seropositivity prevalence was 7.0% in female donkeys (20/282) and 4.1% in male donkeys (4/91). No donkeys less than 24 months of age (129) were seropositive, suggesting postnatal transmission of infection. Domestic cats were present on six of the eight farms. Three cats from one farm had MAT titers of 200. Viable T. gondii was isolated from the hearts of two cats, but not from brain tissues. Genotyping of isolate DNA extracted from culture-derived tachyzoites using 10 PCR-restriction fragment length polymorphism (RFLP) markers (SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, PK1, L358 and Apico loci) revealed that both isolates were clonal Type II (ToxoDB PCR-RFLP genotype #1). This is the first serological survey for T. gondii in donkeys in the United States, and suggests that donkey milk and meat should be considered as a potential source for human infection. The role of barn cats in the transmission of T. gondii to donkeys on farms warrents further investigation.
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Animales Domésticos/parasitología , Anticuerpos Antiprotozoarios/sangre , Toxoplasma/fisiología , Toxoplasmosis Animal/epidemiología , Pruebas de Aglutinación/veterinaria , Animales , Enfermedades de los Gatos/parasitología , Gatos , Equidae , Femenino , Genes Protozoarios/genética , Genotipo , Corazón/parasitología , Masculino , Ratones , Polimorfismo de Longitud del Fragmento de Restricción , Estudios Seroepidemiológicos , Toxoplasma/genética , Toxoplasma/aislamiento & purificación , Toxoplasmosis Animal/transmisión , Estados Unidos/epidemiologíaAsunto(s)
Absceso/veterinaria , Diverticulitis/veterinaria , Enfermedades de los Caballos/patología , Absceso Hepático/veterinaria , Absceso Pulmonar/veterinaria , Absceso/diagnóstico por imagen , Absceso/microbiología , Absceso/patología , Animales , Diverticulitis/diagnóstico por imagen , Diverticulitis/microbiología , Diverticulitis/patología , Resultado Fatal , Femenino , Histocitoquímica/veterinaria , Enfermedades de los Caballos/diagnóstico por imagen , Enfermedades de los Caballos/microbiología , Caballos , Absceso Hepático/diagnóstico por imagen , Absceso Hepático/inmunología , Absceso Hepático/patología , Absceso Pulmonar/diagnóstico por imagen , Absceso Pulmonar/microbiología , Absceso Pulmonar/patología , RadiografíaAsunto(s)
Encefalopatía Hepática/veterinaria , Enfermedades de los Caballos/patología , Hiperamonemia/veterinaria , Vena Porta/patología , Trombosis de la Vena/veterinaria , Animales , Resultado Fatal , Femenino , Encefalopatía Hepática/patología , Encefalopatía Hepática/terapia , Enfermedades de los Caballos/terapia , Caballos , Hiperamonemia/patología , Hiperamonemia/terapia , Trombosis de la Vena/patología , Trombosis de la Vena/terapiaRESUMEN
Gamma secretase inhibitors (GSIs) comprise a growing class of compounds that interfere with the membrane-bound Notch signaling protein and its downstream intra-nuclear transcriptional targets. As GSI-I (Z-LLNle-CHO) is also a derivative of a widely used proteosome inhibitor MG-132, we hypothesized that this compound might be active in precursor-B acute lymphoblastic leukemia (ALL) cell lines and patient samples. We found that GSI-I treatment of precursor-B ALL blasts induced apoptotic cell death within 18-24 h. With confirmation using RNA and protein analyses, GSI-I blocked nuclear accumulation of cleaved Notch1 and Notch2, and inhibited Notch targets Hey2 and Myc. Microarray analyses of 207 children with high-risk precursor-B ALL demonstrate that Notch pathway expression is a common feature of these neoplasms. However, microarray studies also implicated additional transcriptional targets in GSI-I-dependent cell death, including genes in the unfolded protein response, nuclear factor-κB and p53 pathways. Z-LLNle-CHO blocks both γ-secretase and proteosome activity, inducing more robust cell death in precursor-B ALL cells than either proteosome-selective or γ-secretase-selective inhibitors alone. Using Z-LLNle-CHO in a nonobese diabetes/severe combined immunodeficiency (NOD/SCID) precursor-B ALL xenograft model, we found that GSI-I alone delayed or prevented engraftment of B-lymphoblasts in 50% of the animals comprising the experimental group, suggesting that this compound is worthy of additional testing.
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Secretasas de la Proteína Precursora del Amiloide/antagonistas & inhibidores , Antineoplásicos/farmacología , Apoptosis/efectos de los fármacos , Proteínas de Neoplasias/antagonistas & inhibidores , Oligopéptidos/farmacología , Leucemia-Linfoma Linfoblástico de Células Precursoras B/enzimología , Inhibidores de Proteasas/farmacología , Inhibidores de Proteasoma , Receptores Notch/fisiología , Secretasas de la Proteína Precursora del Amiloide/metabolismo , Animales , Antineoplásicos/uso terapéutico , Linfocitos B/efectos de los fármacos , Linfocitos B/enzimología , Línea Celular Tumoral/efectos de los fármacos , Línea Celular Tumoral/enzimología , Niño , Estudios de Cohortes , Regulación Leucémica de la Expresión Génica/efectos de los fármacos , Humanos , Ratones , Ratones Endogámicos NOD , Ratones SCID , Proteínas de Neoplasias/efectos de los fármacos , Proteínas de Neoplasias/metabolismo , Oligopéptidos/uso terapéutico , Leucemia-Linfoma Linfoblástico de Células Precursoras B/tratamiento farmacológico , Leucemia-Linfoma Linfoblástico de Células Precursoras B/patología , Inhibidores de Proteasas/uso terapéutico , Complejo de la Endopetidasa Proteasomal/efectos de los fármacos , ARN Mensajero/metabolismo , ARN Neoplásico/metabolismo , Receptores Notch/genética , Riesgo , Organismos Libres de Patógenos Específicos , Transcripción Genética/efectos de los fármacos , Ensayos Antitumor por Modelo de Xenoinjerto , Adulto JovenRESUMEN
PURPOSE: To report 1-year visual and anatomic outcomes of a prospective, double-masked randomised clinical trial comparing bevacizumab with ranibizumab for the treatment of age-related macular degeneration (AMD). METHODS: Patients who met inclusion criteria were randomised 2 : 1 to bevacizumab or ranibizumab. All subjects and investigators (except for the pharmacist responsible for study assignments) were masked to treatment arms. Visual acuity was taken on Early Treatment Diabetic Retinopathy Study chart. Patients were given either bevacizumab or ranibizumab every month for the first 3 months, followed by an optical coherence tomography-guided, variable-dosing treatment schedule. Main outcomes measured included visual acuity, foveal thickness, and total number of injections over the 1-year treatment period. RESULTS: In total, 15 patients received bevacizumab and 7 patients received ranibizumab. The average pre-operative visual acuity was 34.9 letters in the bevacizumab group, and 32.7 letters in the ranibizumab group. At 1-year follow-up, mean vision was 42.5 letters in the bevacizumab group, and 39.0 letters in the ranibizumab group. Two-tailed t-test failed to showed statistical significance between the two groups (P=0.5). Patients in the bevacizumab group underwent an average of eight injections, whereas patients in the ranibizumab group underwent a mean of four injections (P=0.001). CONCLUSION: The 1-year outcomes of a prospective, double-masked, randomised clinical trial comparing bevacizumab with ranibizumab failed to show a difference in visual and anatomic outcomes between the two treatments for choroidal neovascularisation in AMD. Total injections given over the treatment period were significantly different between the two groups. Further studies with larger sample sizes are warranted.
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Inhibidores de la Angiogénesis/uso terapéutico , Anticuerpos Monoclonales/uso terapéutico , Degeneración Macular/tratamiento farmacológico , Anciano , Anciano de 80 o más Años , Anticuerpos Monoclonales Humanizados , Bevacizumab , Método Doble Ciego , Femenino , Fóvea Central/patología , Humanos , Inyecciones Intravítreas , Degeneración Macular/fisiopatología , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Ranibizumab , Agudeza Visual/fisiologíaRESUMEN
OBJECTIVE: To evaluate the efficacy and safety of adjunctive topiramate (sprinkle capsules or oral liquid) in reducing daily rates of partial-onset seizures (POS) in infants with refractory POS. METHODS: In this double-blind, placebo-controlled, parallel-group, international study, infants (n = 149) with clinical or EEG evidence of refractory POS were randomly allocated (1:1:1:1) to receive adjunctive topiramate 5, 15, or 25 mg/kg/d or placebo for 20 days. The primary variable was the median percentage reductions in daily POS rate from baseline to final assessment as recorded on a 48-hour video-EEG. RESULTS: Of the 149 infants (mean age 12 months) included in the intent-to-treat analysis set, 130 completed the study. Median percentage reduction from baseline in daily POS rate was not significantly different (p = 0.97) between topiramate 25 mg/kg (20.4%) and placebo (13.1%). Lower doses were not formally tested, but nominal p values for comparisons with placebo were not significant (15-mg/kg/d dose: p = 0.97; 5-mg/kg/d dose: p = 0.91). Treatment-emergent fever, diarrhea, vomiting, anorexia, weight decrease, somnolence, and viral infection occurred more frequently (> or = 10% difference) with topiramate than with placebo. CONCLUSION: In infants aged 1-24 months, topiramate 5, 15, or 25 mg/kg/d was not effective as adjunctive treatment for refractory partial-onset seizures. No new safety concerns associated with topiramate use were noted. CLASSIFICATION OF EVIDENCE: This interventional study provides Class I evidence that topiramate 5, 15, or 25 mg/kg/d compared with placebo does not significantly reduce seizure rates in infants aged 1 month to 2 years with refractory partial-onset seizures.
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Anticonvulsivantes/uso terapéutico , Epilepsias Parciales/tratamiento farmacológico , Fructosa/análogos & derivados , Convulsiones/tratamiento farmacológico , Anticonvulsivantes/administración & dosificación , Anticonvulsivantes/efectos adversos , Encéfalo/efectos de los fármacos , Encéfalo/fisiopatología , Quimioterapia Adyuvante , Método Doble Ciego , Electroencefalografía , Epilepsias Parciales/fisiopatología , Femenino , Fructosa/administración & dosificación , Fructosa/efectos adversos , Fructosa/uso terapéutico , Humanos , Lactante , Masculino , Convulsiones/fisiopatología , Topiramato , Resultado del Tratamiento , Grabación en VideoRESUMEN
OBJECTIVE: To assess the feasibility and diagnostic accuracy of real-time myocardial contrast echocardiography (MCE)-derived absolute myocardial blood flow for detection of myocardial perfusion abnormalities compared with simultaneous technetium 99 m sestamibi single-photon emission computed tomography (SPECT). DESIGN: Prospective study. SETTING: Tertiary-care medical institution. PATIENTS: 79 patients with known or suspected coronary artery disease. INTERVENTIONS: Simultaneous SPECT and real-time MCE during adenosine stress. MAIN OUTCOME MEASURES: Absolute myocardial blood flow (MBF, ml/min/g), microbubble velocity (beta, min(-1)), and reserve values. Endpoints included sensitivity, specificity, positive likelihood ratio (LR+) or negative likelihood ratio (LR-) and area under the curve (AUC) of the receiver operating characteristic curve. RESULTS: Reserve measurements were feasible in 975 of 1343 segments (73%); of these, 130 segments (13%) were abnormal by SPECT. MCE perfusion parameters clearly distinguished abnormal from normal segments for beta reserve (1.13 (0.99) vs 2.22 (1.36), p<0.001) and MBF reserve (1.80 (2.29) vs 3.69 (2.79), p<0.001). The beta reserve cut-off of 1.60 provided the following: AUC, 0.787; sensitivity, 82%; specificity, 66%; LR+, 2.40; and LR-, 0.28. The MBF reserve cut-off of 1.90 provided the following: AUC, 0.779; sensitivity, 73%; specificity, 72%; LR+, 2.69; and LR-, 0.37. MBF reserve had an AUC of 0.773 for the left anterior descending coronary artery, 0.885 for the left circumflex coronary artery and 0.739 for the right coronary artery. CONCLUSIONS: Real-time MCE-derived absolute MBF, beta, and reserve values are feasible and accurate for detecting myocardial perfusion abnormalities as defined by SPECT.
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Enfermedad de la Arteria Coronaria/fisiopatología , Circulación Coronaria/fisiología , Adenosina , Adulto , Anciano , Anciano de 80 o más Años , Velocidad del Flujo Sanguíneo/fisiología , Enfermedad de la Arteria Coronaria/diagnóstico por imagen , Ecocardiografía/métodos , Ecocardiografía de Estrés/métodos , Estudios de Factibilidad , Femenino , Humanos , Masculino , Persona de Mediana Edad , Variaciones Dependientes del Observador , Estudios Prospectivos , Radiofármacos , Tecnecio Tc 99m Sestamibi , Tomografía Computarizada de Emisión de Fotón Único , VasodilatadoresRESUMEN
The v-Myb oncoprotein encoded by Avian Myeloblastosis Virus is highly oncogenic, induces leukemias in chickens and mice and transforms immature hematopoietic cells in vitro. The v-Myb protein is a mutated and truncated version of c-Myb, a DNA-binding transcription factor expressed in many cell types that is essential for normal hematopoiesis. Previous studies suggested that two types of differences, DNA binding domain mutations and the deletion of a C-terminal negative regulatory domain were important for increasing the transforming activity of v-Myb. Here, we combined structure-function studies of the v-Myb and c-Myb proteins with unbiased microarray-based transcription assays to compare the transcriptional specificities of the two proteins. In human cells, the v-Myb and c-Myb proteins displayed strikingly different activities and regulated overlapping, but largely distinct sets of target genes. Each type of mutation that distinguished v-Myb from c-Myb, including the N- and C-terminal deletions, DNA binding domain changes and mutations in the transcriptional activation domain, affected different sets of target genes and contributed to the different activities of c-Myb and v-Myb. The results suggest that v-Myb is not just a de-repressed version of c-Myb. Instead, it is a distinct transcriptional regulator with a unique set of activities.
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Mutación , Oncogenes , Proteínas Proto-Oncogénicas c-myb/fisiología , Transcripción Genética/genética , Animales , Secuencia de Bases , Línea Celular Tumoral , Cartilla de ADN , Humanos , Análisis de Secuencia por Matrices de OligonucleótidosAsunto(s)
Pérdida Auditiva Sensorineural , Judíos/genética , Retinitis Pigmentosa , Enfermedades Vestibulares , Adulto , Anciano , Europa Oriental/etnología , Femenino , Genotipo , Pérdida Auditiva Sensorineural/diagnóstico , Pérdida Auditiva Sensorineural/etnología , Pérdida Auditiva Sensorineural/genética , Homocigoto , Humanos , Masculino , Proteínas de la Membrana/genética , Persona de Mediana Edad , Mutación , Linaje , Fenotipo , Retinitis Pigmentosa/diagnóstico , Retinitis Pigmentosa/etnología , Retinitis Pigmentosa/genética , Síndrome , Enfermedades Vestibulares/diagnóstico , Enfermedades Vestibulares/etnología , Enfermedades Vestibulares/genéticaRESUMEN
SUMMARY: One of the more common uses of the program FingerPrint Contigs (FPC) is to assemble random restriction digest 'fingerprints' of overlapping genomic clones into contigs. To improve the rate of assembling contigs from large fingerprint databases we have adapted FPC so that it can be run in parallel on multiple processors and servers. The current version of 'parallelized FPC' has been used in our laboratory to assemble mammalian BAC fingerprint databases, each containing more than 300000 BAC fingerprints. AVAILABILITY: This parallelized version of FPC is available under the GNU GPL licence, and can be downloaded from ftp://ftp.bcgsc.bc.ca/pub/fpcd.
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Algoritmos , Clonación Molecular , Metodologías Computacionales , Mapeo Contig/métodos , Bases de Datos Genéticas , Animales , Secuencia de Bases , Mapeo Contig/estadística & datos numéricos , Dermatoglifia del ADN/métodos , Humanos , Internet , Ratones , Datos de Secuencia Molecular , Mapeo Restrictivo , Sensibilidad y Especificidad , Lugares Marcados de Secuencia , Programas Informáticos , Factores de TiempoRESUMEN
While functioning as a general practitioner at the Camp Pendleton Marine Base, the first author treated numerous patients with recurrent genital herpes. Beginning in 1998, a number of these patients failed to return for periodic acyclovir therapy. Inquiries revealed that these patients had all commenced supplemental creatine after their last outbreak, and had experienced no further outbreaks. A literature search uncovered a report that cyclocreatine, a synthetic compound structurally and functionally homologous to creatine, inhibits the replication of cytomegalovirus, varicella-zoster, and herpes simplex types 1 and 2, in low millimolar concentrations; furthermore, dietary cyclocreatine reduces morbidity and mortality in mice infected with HSV-2. The fact that both creatine and cyclocreatine exert neuroprotective and cancer-retardant effects in rodents, encourages the speculation that creatine shares the anti-viral activity of cyclocreatine. Pilot studies to assess the impact of creatine loading on recurrence of oral and genital herpes appear warranted; the impact of creatine on shingles occurrence in high-risk patients could also be explored. Although initially conceived as an aid to athletic performance, creatine loading may prove to have broad preventive and therapeutic applications.
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Creatina/uso terapéutico , Herpes Genital/prevención & control , Animales , Herpes Genital/tratamiento farmacológico , Herpes Genital/fisiopatología , Herpesvirus Humano 1/fisiología , Herpesvirus Humano 2/fisiología , Humanos , Ratones , Recurrencia , Replicación ViralRESUMEN
The vertebrate A-Myb, B-Myb, and c-Myb proteins comprise a family of related transcription factors that share a highly conserved DNA binding domain. Although all three proteins are capable of binding the same sites in DNA, they have distinct, but overlapping patterns of expression and are presumed to be regulated independently. Here we show that the transcriptional activity of all three vertebrate Myb proteins can be severely inhibited by coexpression of a dominant-negative allele of p100, a coactivator protein that interacts with Myb DNA binding domains. Thus, the conserved Myb domains mediate interactions with common sites in DNA, as well as common regulators, suggesting that the proteins provide alternative or complementary responses to common upstream signaling pathways.
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Proteínas de Ciclo Celular , Proteínas de Unión al ADN/genética , Proteínas Proto-Oncogénicas c-myb/genética , Proteínas Proto-Oncogénicas/genética , Transactivadores/genética , Animales , Sitios de Unión/genética , Línea Celular , Secuencia Conservada , ADN/genética , Unión Proteica , Transcripción GenéticaRESUMEN
Genes causing nonsyndromic autosomal recessive deafness (DFNB12) and deafness associated with retinitis pigmentosa and vestibular dysfunction (USH1D) were previously mapped to overlapping regions of chromosome 10q21-q22. Seven highly consanguineous families segregating nonsyndromic autosomal recessive deafness were analyzed to refine the DFNB12 locus. In a single family, a critical region was defined between D10S1694 and D10S1737, approximately 0.55 cM apart. Eighteen candidate genes in the region were sequenced. Mutations in a novel cadherin-like gene, CDH23, were found both in families with DFNB12 and in families with USH1D. Six missense mutations were found in five families with DFNB12, and two nonsense and two frameshift mutations were found in four families with USH1D. A northern blot analysis of CDH23 showed a 9.5-kb transcript expressed primarily in the retina. CDH23 is also expressed in the cochlea, as is demonstrated by polymerase chain reaction amplification from cochlear cDNA.
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Alelos , Cadherinas/genética , Sordera/genética , Genes Recesivos/genética , Pérdida Auditiva Sensorineural/genética , Mutación/genética , Retinitis Pigmentosa/genética , Secuencia de Aminoácidos , Secuencia de Bases , Proteínas Relacionadas con las Cadherinas , Mapeo Cromosómico , Consanguinidad , Análisis Mutacional de ADN , Cartilla de ADN , Exones/genética , Femenino , Frecuencia de los Genes/genética , Humanos , Intrones/genética , Escala de Lod , Masculino , Linaje , ARN Mensajero/análisis , ARN Mensajero/genética , SíndromeRESUMEN
The nucleotide sequence of chicken invariant chain (Ii) was determined, and the amino acid sequence similarity with human Ii is 61%. Certain regions important for the biological function of human Ii are highly conserved between chicken and mammals. The cytoplasmic tail of chicken Ii fused to the plasma membrane reporter molecule neuraminidase relocated the protein to endosomes. Moreover, like the mammalian orthologs, the cytoplasmic tail was found to contain two independent leucine-based endosomal sorting signals. Chicken Ii was found to interact with human Ii and crosslinking studies also indicate that chicken Ii assembles as a trimer. The chicken Ii can furthermore bind the human MHC class II (HLA-DR1). Many of the functional properties between the chicken Ii and its mammalian orthologs are thus maintained in spite of their sequence differences.
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Antígenos de Diferenciación de Linfocitos B/genética , Antígenos de Diferenciación de Linfocitos B/inmunología , Endocitosis/inmunología , Antígenos de Histocompatibilidad Clase II/genética , Antígenos de Histocompatibilidad Clase II/inmunología , Transducción de Señal/inmunología , Animales , Antígenos de Diferenciación de Linfocitos B/análisis , Membrana Celular/química , Membrana Celular/inmunología , Pollos , Clonación Molecular , ADN Complementario , Endosomas/química , Endosomas/inmunología , Expresión Génica/inmunología , Antígenos de Histocompatibilidad Clase II/análisis , Humanos , Leucina , Mamíferos , Datos de Secuencia Molecular , Señales de Clasificación de Proteína/genética , Señales de Clasificación de Proteína/inmunología , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/inmunología , Homología de Secuencia de Aminoácido , TransfecciónRESUMEN
Transition state analogue boronic acid inhibitors mimicking the structures and interactions of good penicillin substrates for the TEM-1 beta-lactamase of Escherchia coli were designed using graphic analyses based on the enzyme's 1.7 A crystallographic structure. The synthesis of two of these transition state analogues, (1R)-1-phenylacetamido-2-(3-carboxyphenyl)ethylboronic acid (1) and (1R)-1-acetamido-2-(3-carboxy-2-hydroxyphenyl)ethylboronic acid (2), is reported. Kinetic measurements show that, as designed, compounds 1 and 2 are highly effective deacylation transition state analogue inhibitors of TEM-1 beta-lactamase, with inhibition constants of 5.9 and 13 nM, respectively. These values identify them as among the most potent competitive inhibitors yet reported for a beta-lactamase. The best inhibitor of the current series was (1R)-1-phenylacetamido-2-(3-carboxyphenyl)ethylboronic acid (1, K(I) = 5.9 nM), which resembles most closely the best known substrate of TEM-1, benzylpenicillin (penicillin G). The high-resolution crystallographic structures of these two inhibitors covalently bound to TEM-1 are also described. In addition to verifying the design features, these two structures show interesting and unanticipated changes in the active site area, including strong hydrogen bond formation, water displacement, and rearrangement of side chains. The structures provide new insights into the further design of this potent class of beta-lactamase inhibitors.