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1.
Environ Sci Technol ; 56(19): 13845-13857, 2022 10 04.
Artigo em Inglês | MEDLINE | ID: mdl-36129192

RESUMO

We analyzed 72 children's textile products marketed as stain-resistant from US and Canadian stores, particularly school uniforms, to assess if clothing represents a significant route of exposure to per- and polyfluoroalkyl substances (PFAS). Products were first screened for total fluorine (total F) using particle-induced γ-ray emission (PIGE) spectroscopy (n = 72), followed by targeted analysis of 49 neutral and ionic PFAS (n = 57). PFAS were detected in all products from both markets, with the most abundant compound being 6:2 fluorotelomer alcohol (6:2 FTOH). Total targeted PFAS concentrations for all products collected from both countries ranged from 0.250 to 153 000 ng/g with a median of 117 ng/g (0.0281-38 100 µg/m2, median: 24.0 µg/m2). Total targeted PFAS levels in school uniforms were significantly higher than in other items such as bibs, hats, stroller covers, and swimsuits, but comparable to outdoor wear. Higher total targeted PFAS concentrations were found in school uniforms made of 100% cotton than synthetic blends. Perfluoroalkyl acids (PFAAs) precursors were abundant in school uniforms based on the results of hydrolysis and total oxidizable precursor assay. The estimated median potential children's exposure to PFAS via dermal exposure through school uniforms was 1.03 ng/kg bw/day. Substance flow analysis estimated that ∼3 tonnes/year (ranging from 0.05 to 33 tonnes/year) of PFAS are used in US children's uniforms, mostly of polymeric PFAS but with ∼0.1 tonne/year of mobile, nonpolymeric PFAS.


Assuntos
Fluorocarbonos , Canadá , Ácidos Carboxílicos/análise , Criança , Vestuário , Monitoramento Ambiental , Flúor/análise , Fluorocarbonos/análise , Humanos
2.
Lab Invest ; 99(10): 1454-1469, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31148594

RESUMO

Somatic APC (adenomatous polyposis coli), TP53, KRAS mutations are present in roughly 80%, 60%, and 40%, respectively, of human colorectal cancers (CRCs). Most TP53 mutant alleles in CRCs encode missense mutant proteins with loss-of-function (LOF) of p53's transcriptional activity and dominant negative (DN) effects on wild-type p53 function. Missense mutant p53 proteins have been reported to exert gain-of-function (GOF) effects in cancer. We compared the phenotypic effects of the common human cancer-associated TP53 R273H missense mutation to p53 null status in a genetically engineered mouse CRC model. Inactivation of one allele of Apc together with activation of a Kras mutant allele in mouse colon epithelium instigated development of serrated and hyperplastic epithelium and adenomas (AK mice). Addition of a Trp53R270H or Trp53null mutant allele to the model (AKP mice) led to markedly shortened survival and increased tumor burden relative to that of AK mice, including adenocarcinomas in AKP mice. Comparable life span and tumor burden were seen in AKP mice carrying Trp53R270H or Trp53null alleles, along with similar frequencies of spontaneous metastasis to lymph nodes, lung, and liver. The fraction of adenocarcinomas with submucosa or deeper invasion was higher in AKP270/fl mice than in AKPfl/fl mice, but the incidence of adenocarcinomas per mouse did not differ significantly between AKPfl/fl and AKP270/fl mice. In line with their comparable biological behaviors, mouse primary tumors and tumor-derived organoids with the Trp53R270H or Trp53null alleles had highly similar gene expression profiles. Human CRCs with TP53 R273 missense mutant or null alleles also had essentially homogeneous gene expression patterns. Our findings indicate the R270H/R273H p53 mutant protein does not manifest definite GOF biological effects in mouse and human CRCs, suggesting possible GOF effects of mutant p53 in cancer phenotypes are likely allele-specific and/or context-dependent.


Assuntos
Adenocarcinoma/genética , Neoplasias Colorretais/genética , Proteína Supressora de Tumor p53/genética , Animais , Carcinogênese , Progressão da Doença , Transição Epitelial-Mesenquimal , Expressão Gênica , Humanos , Camundongos Transgênicos , Mutação de Sentido Incorreto , Invasividade Neoplásica , Metástase Neoplásica
3.
J Pathol ; 243(1): 16-25, 2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28608929

RESUMO

Recent studies have suggested that the most common and lethal type of 'ovarian' cancer, i.e. high-grade serous carcinoma (HGSC), usually arises from epithelium on the fallopian tube fimbriae, and not from the ovarian surface epithelium. We have developed Ovgp1-iCreERT2 mice in which the Ovgp1 promoter controls expression of tamoxifen-regulated Cre recombinase in oviductal epithelium - the murine equivalent of human fallopian tube epithelium (FTE). We employed Ovgp1-iCreERT2 mice to show that FTE-specific inactivation of several different combinations of tumour suppressor genes that are recurrently mutated in human HGSCs - namely Brca1, Trp53, Rb1, and Nf1 - results in serous tubal intraepithelial carcinomas (STICs) that progress to HGSC or carcinosarcoma, and to widespread metastatic disease in a subset of mice. The cancer phenotype is highly penetrant and more rapid in mice carrying engineered alleles of all four tumour suppressor genes. Brca1, Trp53 and Pten inactivation in the oviduct also results in STICs and HGSCs, and is associated with diffuse epithelial hyperplasia and mucinous metaplasia, which are not observed in mice with intact Pten. Oviductal tumours arise earlier in these mice than in those with Brca1, Trp53, Rb1 and Nf1 inactivation. Tumour initiation and/or progression in mice lacking conditional Pten alleles probably require the acquisition of additional defects, a notion supported by our identification of loss of the wild-type Rb1 allele in the tumours of mice carrying only one floxed Rb1 allele. Collectively, the models closely recapitulate the heterogeneity and histological, genetic and biological features of human HGSC. These models should prove useful for studying the pathobiology and genetics of HGSC in vivo, and for testing new approaches for prevention, early detection, and treatment. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.


Assuntos
Biomarcadores Tumorais/genética , Carcinoma in Situ/genética , Carcinossarcoma/genética , Neoplasias das Tubas Uterinas/genética , Tubas Uterinas/patologia , Neoplasias Císticas, Mucinosas e Serosas/genética , Animais , Biomarcadores Tumorais/metabolismo , Carcinoma in Situ/metabolismo , Carcinoma in Situ/patologia , Carcinossarcoma/patologia , Neoplasias das Tubas Uterinas/metabolismo , Neoplasias das Tubas Uterinas/patologia , Tubas Uterinas/metabolismo , Feminino , Genes BRCA1 , Genes da Neurofibromatose 1 , Genes do Retinoblastoma/genética , Genes p53 , Predisposição Genética para Doença , Glicoproteínas/genética , Humanos , Hiperplasia , Integrases/genética , Metaplasia , Camundongos Transgênicos , Mutação , Gradação de Tumores , Neoplasias Císticas, Mucinosas e Serosas/metabolismo , Neoplasias Císticas, Mucinosas e Serosas/patologia , PTEN Fosfo-Hidrolase/genética , Fenótipo , Regiões Promotoras Genéticas
4.
PLoS Genet ; 11(11): e1005638, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26528816

RESUMO

Adenomatous polyposis coli (APC) inactivating mutations are present in most human colorectal cancers and some other cancers. The APC protein regulates the ß-catenin protein pool that functions as a co-activator of T cell factor (TCF)-regulated transcription in Wnt pathway signaling. We studied effects of reduced dosage of the Ctnnb1 gene encoding ß-catenin in Apc-mutation-induced colon and ovarian mouse tumorigenesis and cell culture models. Concurrent somatic inactivation of one Ctnnb1 allele, dramatically inhibited Apc mutation-induced colon polyposis and greatly extended Apc-mutant mouse survival. Ctnnb1 hemizygous dose markedly inhibited increases in ß-catenin levels in the cytoplasm and nucleus following Apc inactivation in colon epithelium, with attenuated expression of key ß-catenin/TCF-regulated target genes, including those encoding the EphB2/B3 receptors, the stem cell marker Lgr5, and Myc, leading to maintenance of crypt compartmentalization and restriction of stem and proliferating cells to the crypt base. A critical threshold for ß-catenin levels in TCF-regulated transcription was uncovered for Apc mutation-induced effects in colon epithelium, along with evidence of a feed-forward role for ß-catenin in Ctnnb1 gene expression and CTNNB1 transcription. The active ß-catenin protein pool was highly sensitive to CTNNB1 transcript levels in colon cancer cells. In mouse ovarian endometrioid adenocarcinomas (OEAs) arising from Apc- and Pten-inactivation, while Ctnnb1 hemizygous dose affected ß-catenin levels and some ß-catenin/TCF target genes, Myc induction was retained and OEAs arose in a fashion akin to that seen with intact Ctnnb1 gene dose. Our findings indicate Ctnnb1 gene dose exerts tissue-specific differences in Apc mutation-instigated tumorigenesis. Differential expression of selected ß-catenin/TCF-regulated genes, such as Myc, likely underlies context-dependent effects of Ctnnb1 gene dosage in tumorigenesis.


Assuntos
Neoplasias do Colo/genética , Genes APC , Mutação , Neoplasias Ovarianas/genética , beta Catenina/metabolismo , Animais , Feminino , Camundongos
5.
PLoS Genet ; 9(12): e1004036, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24367282

RESUMO

Roberts Syndrome (RBS) and Cornelia de Lange Syndrome (CdLS) are severe developmental maladies that present with nearly an identical suite of multi-spectrum birth defects. Not surprisingly, RBS and CdLS arise from mutations within a single pathway--here involving cohesion. Sister chromatid tethering reactions that comprise cohesion are required for high fidelity chromosome segregation, but cohesin tethers also regulate gene transcription, promote DNA repair, and impact DNA replication. Currently, RBS is thought to arise from elevated levels of apoptosis, mitotic failure, and limited progenitor cell proliferation, while CdLS is thought to arise, instead, from transcription dysregulation. Here, we review new information that implicates RBS gene mutations in altered transcription profiles. We propose that cohesin-dependent transcription dysregulation may extend to other developmental maladies; the diagnoses of which are complicated through multi-functional proteins that manifest a sliding scale of diverse and severe phenotypes. We further review evidence that cohesinopathies are more common than currently posited.


Assuntos
Proteínas de Ciclo Celular/genética , Proteínas Cromossômicas não Histona/genética , Segregação de Cromossomos/genética , Anormalidades Craniofaciais/genética , Síndrome de Cornélia de Lange/genética , Ectromelia/genética , Hipertelorismo/genética , Apoptose , Proteínas de Ciclo Celular/metabolismo , Proliferação de Células , Proteínas Cromossômicas não Histona/metabolismo , Anormalidades Craniofaciais/patologia , Síndrome de Cornélia de Lange/patologia , Ectromelia/patologia , Humanos , Hipertelorismo/patologia , Redes e Vias Metabólicas/genética , Mutação , Coesinas
6.
Behav Pharmacol ; 24(7): 598-609, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23969615

RESUMO

Neuropathic pain challenges healthcare professionals and researchers to develop new strategies of treatment and experimental models to better understand the pathophysiology of this condition. In the present study, the efficacy of gabapentin on thermal sensitivity following spinal nerve ligation and spinal cord compression was evaluated. The method of behavioral assessment was a well-validated cortically dependent operant escape task. Spinal nerve ligation produced peripheral neuropathic pain whereas spinal cord compression, achieved with an expanding polymer placed extradurally, produced a condition of central neuropathic pain. Changes in thermal sensitivity were also observed in animals undergoing nerve ligation surgery without nerve injury. Gabapentin (50 and 100 mg/kg) significantly reduced thermal sensitivity to 10 and 44.5 °C in surgically naive animals as well as those undergoing spinal nerve ligation and spinal cord compression. In conclusion, an operant method of behavioral assessment was used to show that spinal nerve ligation and spinal cord compression produced increases in sensitivity to noxious cold and heat stimuli. A decrease in thermal sensitivity was observed following administration of gabapentin. The results achieved with these methods are consistent with the clinical profile of gabapentin in treating conditions of neuropathic pain.


Assuntos
Aminas/farmacologia , Analgésicos/farmacologia , Comportamento Animal/efeitos dos fármacos , Ácidos Cicloexanocarboxílicos/farmacologia , Neuralgia/tratamento farmacológico , Ácido gama-Aminobutírico/farmacologia , Aminas/administração & dosagem , Analgésicos/administração & dosagem , Animais , Condicionamento Operante/efeitos dos fármacos , Ácidos Cicloexanocarboxílicos/administração & dosagem , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Reação de Fuga/efeitos dos fármacos , Gabapentina , Masculino , Ratos , Ratos Long-Evans , Compressão da Medula Espinal , Nervos Espinhais/lesões , Temperatura , Ácido gama-Aminobutírico/administração & dosagem
7.
RSC Chem Biol ; 4(12): 1082-1095, 2023 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-38033726

RESUMO

New design and synthetic strategies were developed to generate functional phenyl boronic acid (BA)-based fluorescent probes incorporating the 1,8-naphthalimide (NI) tag. This fluorescent core was anchored onto the BA unit through small organic linkers consisting of nitrogen groups which can arrest, and internally stabilise the phenyl-boronate units. The newly synthesised fluorophores were characterised spectroscopically by NMR spectroscopy and mass spectrometry and evaluated for their ability to bind to a naturally occurring polysaccharide, ß-d-glucan in DMSO and simultaneously as act as in vitro cell imaging reagents. The uptake of these new NI-boronic acid derivatives was studied living cancer cells (HeLa, PC-3) in the presence, and absence, of ß-d-glucan. Time-correlated single-photon counting (TCSPC) of DMSO solutions and two-photon fluorescence-lifetime imaging microscopy (FLIM) techniques allowed an insight into the probes' interaction with their environment. Their cellular uptake and distributions were imaged using laser scanning confocal fluorescence microscopy under single- and two-photon excitation regimes (λmax 910 nm). FLIM facilitated the estimation of the impact of the probe's cellular surroundings using the fluorophore lifetime. The extent to which this was mediated by the ß-d-glucan was visualised by 2-photon FLIM in living cells. The fluorescence lifetime observed under a range of temperatures varied appreciably, indicating that changes in the environment can be sensed by these probes. In all cases, the cellular membrane penetration of these new probes was remarkable even under variable temperature conditions and localisation was widely concentrated in the cellular cytoplasm, without specific organelle trapping: we conclude that these new probes show promise for cellular imaging in living cancer cells.

8.
Nutrients ; 14(1)2022 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-35011080

RESUMO

This study aimed to explore the diagnostic accuracy of the Patient-Generated Subjective Global Assessment (PG-SGA) malnutrition risk screening tool when used to score patients based on their electronic medical records (EMR), compared to bedside screening interviews. In-patients at a rural health service were screened at the bedside (n = 50) using the PG-SGA, generating a bedside score. Clinical notes within EMRs were then independently screened by blinded researchers. The accuracy of the EMR score was assessed against the bedside score using area under the receiver operating curve (AUC), sensitivity, and specificity. Participants were 62% female and 32% had conditions associated with malnutrition, with a mean age of 70.6 years (SD 14.9). The EMR score had moderate diagnostic accuracy relative to PG-SGA bedside screen, AUC 0.74 (95% CI: 0.59-0.89). The accuracy, specificity and sensitivity of the EMR score was highest for patients with a score of 7, indicating EMR screen is more likely to detect patients at risk of malnutrition. This exploratory study showed that applying the PG-SGA screening tool to EMRs had enough sensitivity and specificity for identifying patients at risk of malnutrition to warrant further exploration in low-resource settings.


Assuntos
Desnutrição/diagnóstico , Programas de Rastreamento/métodos , Testes Imediatos/estatística & dados numéricos , População Rural , Idoso , Idoso de 80 Anos ou mais , Apetite , Austrália , Registros Eletrônicos de Saúde , Feminino , Humanos , Masculino , Programas de Rastreamento/estatística & dados numéricos , Pessoa de Meia-Idade , Avaliação Nutricional , Estado Nutricional , Fatores de Risco , Sensibilidade e Especificidade
9.
ANZ J Surg ; 91(1-2): 139-144, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33205533

RESUMO

BACKGROUND: Non-melanoma skin cancer is the most commonly diagnosed malignancy in Australia. Lesions of the head and neck are often outside the scope of primary care providers. The challenges of cancer care in regional Australia necessitate careful resource planning. This study presents an outpatient model that minimizes health service cost with local general practitioner follow-up. METHODS: A retrospective review of 105 patients with 122 skin lesions in a dedicated Facial Lesion Assessment Management and Excision clinic was performed from July 2018 to 2019. Clinical outcomes, patient travel and cost analysis/comparison were recorded. RESULTS: There were 85 malignant cases with 59 basal cell carcinomas and 25 squamous cell carcinomas. For basal cell carcinoma, clear margins (≥3 mm), close margins (<3 mm) and positive margins were achieved in 24 (48%), 23 (46%) and three (6%) cases, respectively. For squamous cell carcinoma, clear margins (≥5 mm), close margins (<5 mm) and positive margins were achieved in seven (38.8%), 11 (61.1%) and none (0%) of the cases, respectively. Complications included one haematoma and two wound infections. For 37% of patients living >100 km from the department, 72.3% had local general practitioner follow-up. Inpatient cost was $2870, $5697 and $9300 for primary closure, local flap and full-thickness skin graft, respectively, and outpatient cost was $746 for a single facial lesion. CONCLUSION: This study presents a cost-effective model for the management of non-melanoma skin cancers with improved departmental efficiency and streamlined patient care in an outpatient skin cancer management model in a regional centre.


Assuntos
Carcinoma Basocelular , Neoplasias de Cabeça e Pescoço , Neoplasias Cutâneas , Austrália/epidemiologia , Carcinoma Basocelular/cirurgia , Neoplasias de Cabeça e Pescoço/cirurgia , Humanos , Pacientes Ambulatoriais , Estudos Retrospectivos , Neoplasias Cutâneas/cirurgia
10.
Artigo em Inglês | MEDLINE | ID: mdl-32824018

RESUMO

In-patient malnutrition leads to poor outcomes and mortality, and it is largely uninvestigated in non-urban populations. This study sought to: (1) retrospectively estimate the prevalence of malnutrition as diagnosed by dietetics in the rural Australian setting; (2) establish the proportion of all patients at "nutritional risk"; and (3) explore associations between demographic and clinical factors with malnutrition diagnosis and nutritional risk. A retrospective census was undertaken of medical files of all patients aged ≥18 years admitted to a rural hospital setting over a 12-month period. Logistic regression was used to explore associations between malnutrition diagnosis, nutritional risk and patient-related factors. In total, 711 admissions were screened during the 12-month period comprising 567 patients. Among the 125 patients seen by dietitians, 70.4% were diagnosed with malnutrition. Across the total sample, 77.0% had high levels of nutrition related symptoms warranting a need for further assessment by dietitians. Malnutrition diagnosis by dietitians was associated with being over the age of 65 years, and patients had higher odds of being admitted to a residential aged care facility following discharge. In this rural sample, the diagnosis rate of malnutrition appeared to be high, indicating that rural in-patients may be at a high risk of malnutrition. There was also a high proportion of patients who had documentation in their files that indicated they may have benefited from dietetic assessment and intervention, beyond current resourcing.


Assuntos
Censos , Desnutrição/epidemiologia , Austrália/epidemiologia , Feminino , Humanos , Masculino , Avaliação Nutricional , Estado Nutricional , Prevalência , Estudos Retrospectivos , População Rural
11.
Aust J Gen Pract ; 48(6): 373-377, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31220883

RESUMO

BACKGROUND: Laryngectomy stomas are formed following excision of the larynx, usually for the treatment of an underlying malignancy. This is a permanent stoma in which the trachea is separated from the oesophagus and brought to an opening in the neck. The complication rate of laryngectomy stomas is reported to be more than 60%. OBJECTIVE: The purpose of this article is to provide an overview of total laryngectomy stomas and inform general practitioners (GPs) of the frequently encountered complications, to improve stoma-related care and ultimately patient outcomes. DISCUSSION: Numerous early and late complications can be encountered by a GP, some of which are potentially life-threatening and require prompt recognition. Care of patients who have had a laryngectomy is multi-disciplinary, and GPs are often the first point of contact. The importance of a well-informed GP who can treat the patient and identify when they require referral to a stomal therapy nurse, speech pathologist or surgeon cannot be understated.


Assuntos
Laringectomia/métodos , Laringectomia/reabilitação , Obstrução das Vias Respiratórias/etiologia , Obstrução das Vias Respiratórias/fisiopatologia , Obstrução das Vias Respiratórias/terapia , Estenose Esofágica/etiologia , Estenose Esofágica/fisiopatologia , Estenose Esofágica/terapia , Fístula/etiologia , Fístula/fisiopatologia , Fístula/terapia , Medicina Geral/métodos , Medicina Geral/tendências , Hemorragia/etiologia , Hemorragia/fisiopatologia , Hemorragia/terapia , Humanos , Dermatopatias/etiologia , Dermatopatias/fisiopatologia , Dermatopatias/terapia
12.
Neuropeptides ; 41(6): 399-410, 2007 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-17980908

RESUMO

Nociceptin/orphanin FQ (N/OFQ) is an opioid-related neuropeptide that is widely distributed in limbic regions of the brain. After intracerebroventricular (icv) injections in rodents, N/OFQ produces elevations in hypothalamic-pituitary-adrenal (HPA) axis activity, and has been reported to produce both anxiogenic and anxiolytic actions. We examined the neuroanatomical basis of these effects with injections of N/OFQ (0.01-1.0nmol) into the lateral ventricle, the amygdala, and the bed nucleus of stria terminalis (BNST) in independent groups of well-handled rats under low stress conditions. Anxiety-related behaviors were evaluated in a neophobic test of anxiety. The latency to enter, total time spent in, and number of entries into an unfamiliar open field and its central zone were measured. After the open field testing, plasma samples were obtained for analysis of HPA axis activity. The N/OFQ-treated rats displayed more anxiety-related behaviors than vehicle-treated rats did with all three of the injection types. However, these effects were greater and more consistent after the icv injections (0.01-1.0nmol) than they were after the amygdala (0.10-1.0nmol) or BNST (1.0nmol) injections. The icv and BNST injections also produced elevations in circulating corticosterone, indicating that the HPA axis was activated in these rats. Intra-amygdaloid injections did not affect corticosterone levels during the open field testing. These results indicate that the amygdala and BNST participate in the anxiogenic behavioral effects of N/OFQ. However, since the most potent effects were seen after icv N/OFQ injections, the anxiogenic and HPA axis-activating effects of N/OFQ appear to occur through additive actions in multiple limbic (and perhaps cortical and brainstem) sites.


Assuntos
Tonsila do Cerebelo/fisiologia , Ansiedade/fisiopatologia , Sistema Hipotálamo-Hipofisário/metabolismo , Sistema Límbico/fisiologia , Peptídeos Opioides/farmacologia , Fragmentos de Peptídeos/farmacologia , Sistema Hipófise-Suprarrenal/metabolismo , Animais , Ansiedade/induzido quimicamente , Comportamento Animal , Corticosterona/análise , Sistema Hipotálamo-Hipofisário/efeitos dos fármacos , Masculino , Peptídeos Opioides/administração & dosagem , Fragmentos de Peptídeos/administração & dosagem , Sistema Hipófise-Suprarrenal/efeitos dos fármacos , Ratos , Ratos Long-Evans
13.
Elife ; 62017 01 10.
Artigo em Inglês | MEDLINE | ID: mdl-28072391

RESUMO

While 20-30% of colorectal cancers (CRCs) may arise from precursors with serrated glands, only 8-10% of CRCs manifest serrated morphology at diagnosis. Markers for distinguishing CRCs arising from 'serrated' versus 'conventional adenoma' precursors are lacking. We studied 36 human serrated CRCs and found CDX2 loss or BRAF mutations in ~60% of cases and often together (p=0.04). CDX2Null/BRAFV600E expression in adult mouse intestinal epithelium led to serrated morphology tumors (including carcinomas) and BRAFV600E potently interacted with CDX2 silencing to alter gene expression. Like human serrated lesions, CDX2Null/BRAFV600E-mutant epithelium expressed gastric markers. Organoids from CDX2Null/BRAFV600E-mutant colon epithelium showed serrated features, and partially recapitulated the gene expression pattern in mouse colon tissues. We present a novel mouse tumor model based on signature defects seen in many human serrated CRCs - CDX2 loss and BRAFV600E. The mouse intestinal tumors show significant phenotypic similarities to human serrated CRCs and inform about serrated CRC pathogenesis.


Assuntos
Fator de Transcrição CDX2/metabolismo , Carcinogênese , Neoplasias Colorretais/fisiopatologia , Proteínas Proto-Oncogênicas B-raf/metabolismo , Animais , Fator de Transcrição CDX2/genética , Colo/patologia , Neoplasias Colorretais/patologia , Modelos Animais de Doenças , Perfilação da Expressão Gênica , Mucosa Intestinal/patologia , Camundongos , Organoides , Proteínas Proto-Oncogênicas B-raf/genética
14.
Eur J Pain ; 14(1): 11-6, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19261494

RESUMO

In our previous studies, psychological stress was shown to enhance operant escape responding of male and female rats. The stressors that produced hyperalgesia were physical restraint and social defeat. Nociceptive input also elicits stress reactions, generating the prediction that pain would facilitate pain under certain circumstances. For example, the usual method of evaluating stress in laboratory animals is to test for effects after termination of the stressor. Accordingly, operant escape performance of male and female rats was evaluated during two successive trials involving nociceptive thermal stimulation. The intent was to determine whether nociceptive sensitivity differed on first trials and during pain-induced stress on second trials. Compared to a first trial of 44.5 degrees C stimulation, escape responding increased during a second trial of 44.5 degrees C stimulation (preceded by an escape trial of 10 degrees C). Similarly, escape from cold (10 degrees C) was enhanced when preceded by escapable 44.5 degrees C stimulation. Thus, prior nociceptive stimulation enhanced escape from aversive thermal stimulation. Facilitation of pain by a preceding pain experience is consistent with stress-induced hyperalgesia and contrasts with other models of pain inhibition by concurrent nociceptive stimulation.


Assuntos
Reação de Fuga/fisiologia , Temperatura Alta , Dor/psicologia , Estresse Psicológico/psicologia , Animais , Temperatura Baixa , Interpretação Estatística de Dados , Feminino , Masculino , Ratos , Ratos Long-Evans , Caracteres Sexuais
15.
Neuropeptides ; 43(6): 507-14, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19720395

RESUMO

Antagonists of the NOP receptor have antidepressant effects in rodent models, suggesting that the N/OFQ-NOP system may play an important role in affective disorders. Furthermore, multiple lines of experimental evidence link N/OFQ neurotransmission with physiological and behavioral responses to stress. One possibility is that disregulated expression of the N/OFQ peptide neurotransmitter and/or the NOP receptor may participate in the etiology of stress-induced psychopathology. In the present set of experiments, we compared gene expression for prepro-N/OFQ and NOP receptor in groups of rats that were exposed to differing regimens of social defeat stress. Male Long-Evans rats were exposed to no social defeat, a single, acute social defeat or to repeated social defeats with or without an acute defeat on the final day. In situ hybridization was conducted with (35)S-labelled riboprobes aimed at prepro-N/OFQ mRNA or NOP receptor mRNA. Expression was analyzed by quantification of optical density in limbic and extra-limbic forebrain regions. There were no statistically significant changes in prepro-N/OFQ mRNA expression after stress exposure in any of the brain regions analyzed. However, the rats that were exposed to acute social defeat displayed elevations in NOP receptor mRNA expression in the central and basomedial nuclei of the amygdala and in the paraventricular nucleus of the hypothalamus. Additionally, the rats that were acutely stressed after a history of repeated social defeat also displayed elevated levels of NOP receptor mRNA expression in the paraventricular nucleus of the hypothalamus. These results suggest that the N/OFQ-NOP receptor system is affected by acute stress exposure, particularly in limbic regions. This stress-induced upregulation of NOP receptor gene expression further supports the possibility that disregulation of the N/OFQ-NOP system may contribute to behavioral and hormonal disregulation following stress.


Assuntos
Regulação da Expressão Gênica , Peptídeos Opioides/metabolismo , Receptores Opioides/metabolismo , Comportamento Social , Estresse Psicológico , Animais , Encéfalo/anatomia & histologia , Encéfalo/metabolismo , Feminino , Masculino , Peptídeos Opioides/genética , Precursores de Proteínas/genética , Precursores de Proteínas/metabolismo , RNA Mensageiro/metabolismo , Distribuição Aleatória , Ratos , Ratos Long-Evans , Receptores Opioides/genética , Receptor de Nociceptina , Nociceptina
16.
Brain Res ; 1251: 112-20, 2009 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-19059227

RESUMO

Higher-order processing of nociceptive input is distributed in corticolimbic regions of the brain, including the anterior cingulate, parieto-insular and prefrontal cortices, as well as subcortical structures such as the bed nucleus of stria terminalis and amygdala. In addition to their role in pain processing, these regions encode or modulate emotional, motivational and sensory responses to stress. Thus, pain and stress pathways in the brain intersect at cortical and subcortical forebrain structures. Accordingly, previous work has shown that acute restraint stress in female rats induces heat hyperalgesia in a forebrain-dependent operant test of thermal escape. In the present study, we investigated the effects of social defeat stress in male rats on the operant escape task, as well as in a test of nociceptive thermal preference. After establishing baseline behaviors in these tests, separate groups of rats were socially defeated by dominant "resident" male rats. They were tested for thermal preference after 5 successive social defeat sessions. Escape from cold, heat and a neutral warm temperature also was evaluated after social defeat. Defeated rats exhibited a significant increase in cold preference after social defeat compared to the baseline. In the escape task, the rats exhibited increased escape from warm and nociceptive cold and heat temperatures. Thus, chronic social stress produces hyperalgesia for both hot and cold stimuli in male rats, suggesting a mutually facilitatory cross-regulation between central pathways regulating stress and pain.


Assuntos
Hiperalgesia/fisiopatologia , Hiperalgesia/psicologia , Dor/fisiopatologia , Dor/psicologia , Estresse Psicológico/complicações , Estresse Psicológico/fisiopatologia , Animais , Encéfalo/fisiopatologia , Doença Crônica/psicologia , Temperatura Baixa/efeitos adversos , Condicionamento Operante/fisiologia , Modelos Animais de Doenças , Feminino , Hierarquia Social , Temperatura Alta/efeitos adversos , Masculino , Vias Neurais/fisiopatologia , Nociceptores/fisiologia , Limiar da Dor/fisiologia , Estimulação Física , Ratos , Ratos Long-Evans , Comportamento Social , Sensação Térmica/fisiologia
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