Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 161
Filtrar
1.
Theriogenology ; 191: 141-152, 2022 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-35986940

RESUMO

The establishment and management of ex situ breeding and assurance populations around the globe are meant to provide short-term solutions to the formidable loss of amphibian diversity presently occurring. Large multi-scaled facilities, such as zoos and aquariums, can provide the infrastructure to safeguard species and populations. However, often even large, economically viable facilities lack the knowledge to efficiently cater to the plethora of environmentally controlled physiological strategies that amphibians possess. Anurans present a class of amphibians that have often been viewed as easy to maintain ex situ. However, while adult survival may be relatively successful it is rarely accompanied by good reproductive output, health, and fitness. Even more conspicuous is the low survivorship of offspring produced ex situ once they are translocated back into the wild. The mountain yellow-legged frog (R. muscosa) ex situ breeding program EBP is a prime example of the challenges that amphibians EBPs face. Although more research is needed, the R. muscosa program has increased reproductive output and health of its colony by incorporating reproductive technologies and strategic genetic management in conjunction with a greater understanding of the species' natural history, to produce and translocate viable animals each year. This paper highlights the EBPs past decade of research featuring the program's contribution to building empirical, multidisciplinary approaches that boost the robustness of an endangered species, by safeguarding existing genetic diversity and maximizing fitness and survival outcomes.


Assuntos
Conservação dos Recursos Naturais , Espécies em Perigo de Extinção , Animais , Anuros/genética , Reprodução , Técnicas Reprodutivas/veterinária
2.
Nat Commun ; 12(1): 5250, 2021 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-34475394

RESUMO

Understanding how the electron spin is coupled to orbital degrees of freedom, such as a valley degree of freedom in solid-state systems, is central to applications in spin-based electronics and quantum computation. Recent developments in the preparation of electrostatically-confined quantum dots in gapped bilayer graphene (BLG) enable to study the low-energy single-electron spectra in BLG quantum dots, which is crucial for potential spin and spin-valley qubit operations. Here, we present the observation of the spin-valley coupling in bilayer graphene quantum dots in the single-electron regime. By making use of highly-tunable double quantum dot devices we achieve an energy resolution allowing us to resolve the lifting of the fourfold spin and valley degeneracy by a Kane-Mele type spin-orbit coupling of ≈ 60 µeV. Furthermore, we find an upper limit of a potentially disorder-induced mixing of the [Formula: see text] and [Formula: see text] states below 20 µeV.

3.
Phys Rev Lett ; 127(25): 256802, 2021 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-35029428

RESUMO

We report on finite bias spectroscopy measurements of the two-electron spectrum in a gate defined bilayer graphene (BLG) quantum dot for varying magnetic fields. The spin and valley degree of freedom in BLG give rise to multiplets of six orbital symmetric and ten orbital antisymmetric states. We find that orbital symmetric states are lower in energy and separated by ≈ 0.4-0.8 meV from orbital antisymmetric states. The symmetric multiplet exhibits an additional energy splitting of its six states of ≈ 0.15-0.5 meV due to lattice scale interactions. The experimental observations are supported by theoretical calculations, which allow to determine that intervalley scattering and "current-current" interaction constants are of the same magnitude in BLG.

4.
Br J Oral Maxillofac Surg ; 59(1): 109-110, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-32636086

RESUMO

We report the case of a patient presenting with severe headache and progressive aphasia due to a large brain abscess. End-stage peri-implantitis on a dental implant in the upper jaw with contact to the maxillary sinus floor causing maxillary and frontal sinusitis could be identified as the source of infection. Multidisciplinary treatment included broad-spectrum antibiotics, craniotomy for abscess drainage, sinus surgery, and the removal of the implant. Despite all the care taken, the patient died, underlining the importance of oral hygiene and a frequent recall in patients with dental implants. To the best of our knowledge, this is the first report of a brain abscess caused by peri-implantitis in the literature.


Assuntos
Abscesso Encefálico , Implantes Dentários , Peri-Implantite , Levantamento do Assoalho do Seio Maxilar , Abscesso Encefálico/etiologia , Implantes Dentários/efeitos adversos , Humanos , Seio Maxilar , Peri-Implantite/etiologia
5.
Gynecol Obstet Fertil Senol ; 48(9): 671-678, 2020 09.
Artigo em Francês | MEDLINE | ID: mdl-32247856

RESUMO

INTRODUCTION: In the gynecology emergency departments, a pregnancy of uncertain viability is diagnosed in 29% of all first-trimester pregnancy medical consultations that require an ultrasound. The question of pregnancy viability is therefore common in our medical practice and comes along with human implications. In 2014, the French National College of Obstetricians and Gynecologists (CNGOF) promulgated clear guidelines regarding missed early miscarriage diagnosis and treatment. We wanted to evaluate our level of compliance with the diagnosis dimension of those guidelines and assess their optimization level since they were published. MATERIALS AND METHODS: This retrospective and descriptive study is based on all missed early miscarriage that were taken care of within the gynecology emergency department at the CHU in Tours (France) over the course of three non-consecutive years. The year 2013 has been considered - before the guidelines were promulgated, 2015 - just after the guidelines were promulgated and lastly, 2018 in order to have the necessary distance for the interpretation. The following criteria was assessed for each year: the diagnostic ultrasound criteria; when relevant, the monitoring ultrasound deadlines; and the details regarding any patient management errors if errors were made. Secondarily, the uterine evacuation treatment procedures were examined. RESULTS: The study population includes 297 women. The non-compliance with the guidelines affected 20% of the women in 2013, 12% in 2015 and 15% in 2018 (p = 0.25 when comparing the pre-guideline and post-guideline periods). An ultrasound performed too early is the most common error made each year even though its frequency has decreased (p = 0.03). The least experienced sonographers tend to be rather cautious, performing additional unnecessary examinations and scheduling excessive additional monitoring ultrasound deadlines. Only 13% of the medication-based therapies made uterine evacuation successful. If the initial use of prostaglandin substances was not successful, no additional dose of medication enabled any women patient to avoid surgery. CONCLUSION: The compliance with the guidelines regarding pregnancies of uncertain viability is not optimal. Partial improvements in our own patient care management have been made since the publication of the guidelines; however, the main risk at stake is to terminate the evolution of a normal pregnancy due to some remaining medical misjudgments. The introduction of quality scores for clinical ultrasound images would be an interesting topic to discuss.


Assuntos
Aborto Espontâneo , Ginecologia , Aborto Espontâneo/diagnóstico , Aborto Espontâneo/terapia , Feminino , Humanos , Gravidez , Primeiro Trimestre da Gravidez , Estudos Retrospectivos , Ultrassonografia
8.
BMC Anesthesiol ; 16(1): 105, 2016 10 24.
Artigo em Inglês | MEDLINE | ID: mdl-27776488

RESUMO

BACKGROUND: Midazolam is commonly used as a pre-anesthesia anxiolytic. It`s elimination may not be fast enough for short procedures. In orally premedicated patients we obtained midazolam plasma concentrations at the end of surgical procedures and compared those to concentrations at anesthesia induction. METHODS: The study was conducted prospectively with consent of the local ethics committee (Ethikkomission Kanton Thurgau, Switzerland) and carried out with written informed consent of each patient. Female patients aged 20 to 60 years undergoing elective procedures with general anesthesia were included, and were divided in two groups according to the planned surgical time: group S (<30 min) and group L (90-120 min), respectively. All patients received 7.5 mg Midazolam po as premedication. Blood samples were drawn at anesthesia induction, and at the end of surgery. Data were compared with t-test (independent samples; significance level p <0.05). RESULTS: Twenty-five patients per group were included. Four patients were excluded from analysis, since midazolam was not detectable in any samples. Time of premedication to the 1st blood sample was not statistically different between groups, neither were Midazolam plasma levels at this time point (p = 0.94). None of the patients from group L (n = 24), but five patients in group S (n = 22) did have a higher plasma level of Midazolam at the end of the case compared to the beginning. CONCLUSIONS: The elimination half-life of oral Midazolam can lead to higher plasma levels at the end of a short procedure compared to those at induction of anesthesia. TRIAL REGISTRATION: German Clinical Trials Register (Deutsches Register Klinischer Studien), DRKS00005429 ; date of registration 3rd January 2014.


Assuntos
Ansiolíticos/farmacocinética , Midazolam/farmacocinética , Pré-Medicação/métodos , Administração Oral , Adulto , Anestesia Geral/métodos , Ansiolíticos/administração & dosagem , Procedimentos Cirúrgicos Eletivos/métodos , Feminino , Meia-Vida , Humanos , Midazolam/administração & dosagem , Pessoa de Meia-Idade , Estudos Prospectivos , Suíça , Fatores de Tempo , Adulto Jovem
9.
Hautarzt ; 67(10): 816-821, 2016 Oct.
Artigo em Alemão | MEDLINE | ID: mdl-27613023

RESUMO

A detailed medical history and a careful clinical examination are the basis for developing a list of possible differential diagnoses in lesions of the oral mucosa. On this basis, it can be decided whether a lesion can be observed for 14 days after removal of possible causes or the start of a trial treatment, or whether a biopsy for histological examination must be taken immediately. An excisional biopsy is performed for small and presumably benign lesions, an incisional biopsy for large and presumably malignant lesions. If an autoimmune blistering disease is suspected, a second sample for examination by immunofluorescence is taken. Depending on the results of the histological examination further treatment steps are planned or regular appointments for follow-up are arranged.


Assuntos
Biópsia/métodos , Mucosa Bucal/patologia , Mucosa/patologia , Penfigoide Mucomembranoso Benigno/patologia , Estomatite/patologia , Diagnóstico Diferencial , Medicina Baseada em Evidências , Humanos , Mucosa Bucal/cirurgia , Mucosa/cirurgia , Penfigoide Mucomembranoso Benigno/cirurgia , Estomatite/cirurgia , Cirurgia Bucal/métodos , Resultado do Tratamento
10.
Oncoimmunology ; 5(7): e1164918, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27622019

RESUMO

Tumor-host interaction is determined by constant immune surveillance, characterized by tumor infiltration of myeloid and lymphoid cells. A malfunctioning or diverted immune response promotes tumor growth and metastasis. Recent advances had been made, by treating of certain tumor types, such as melanoma, with T-cell checkpoint inhibitors. This highlights the importance of understanding the molecular mechanisms underlying the crosstalk between tumors and their environment, in particular myeloid and lymphoid cells. Our aim was to study the contribution of the myeloid PI3K/PTEN-signaling pathway in the regulation of tumor-immune surveillance in murine models of cancer. We made use of conditional PTEN-deficient mice, which exhibit sustained activation of the PI3K-signaling axis in a variety of myeloid cell subsets such as macrophages and dendritic cells (DCs). In colitis-associated colon cancer (CAC), mice deficient in myeloid PTEN showed a markedly higher tumor burden and decreased survival. We attributed this observation to the increased presence of immune-modulatory conventional CD8α(+) DCs in the spleen, whereas other relevant myeloid cell subsets were largely unaffected. Notably, we detected enhanced surface expression of PD-L1 and PD-L2 on these DCs. As a consequence, tumoricidal T-cell responses were hampered or redirected. Taken together, our findings indicated an unanticipated role for the PI3K/PTEN-signaling axis in the functional regulation of splenic antigen-presenting cells (APCs). Our data pointed at potential, indirect, tumoricidal effects of subclass-specific PI3K inhibitors, which are currently under clinical investigation for treatment of tumors, via myeloid cell activation.

11.
Nanotechnology ; 26(2): 025302, 2015 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-25517943

RESUMO

We present a technique to pattern the charge density of a large-area epitaxial graphene sheet locally without using metallic gates. Instead, local intercalation of the graphene-substrate interface can selectively be established in the vicinity of graphene edges or predefined voids. It provides changes of the work function of several hundred meV, corresponding to a conversion from n-type to p-type charge carriers. This assignment is supported by photoelectron spectroscopy, scanning tunneling microscopy, scanning electron microscopy and Hall effect measurements. The technique introduces materials contrast to a graphene sheet in a variety of geometries and thus allows for novel experiments and novel functionalities.

12.
Urologe A ; 53(8): 1198-203, 2014 Aug.
Artigo em Alemão | MEDLINE | ID: mdl-24993061

RESUMO

Magnetic resonance imaging of rare cystic prostate cancers using multiparametric MRI (mp-MRI, 3 Tesla) shows, especially in solid tumor masses, the criteria of ESUR-MR classification with a PI-RADS >3 ("probably malignant"). In association with additional morphological evidence of intracystic hemorrhage and evidence of villous tumor nodules and irregular septa on the cyst wall, further malignancy criteria are met. MRI complementary to TRUS may be useful for targeted biopsy in solid tumor areas.


Assuntos
Carcinoma Adenoide Cístico/patologia , Imageamento por Ressonância Magnética/métodos , Imagem Multimodal/métodos , Neoplasias da Próstata/patologia , Idoso de 80 Anos ou mais , Diagnóstico Diferencial , Humanos , Masculino , Doenças Raras/patologia
13.
Phytomedicine ; 21(5): 753-7, 2014 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-24373544

RESUMO

INTRODUCTION: Poor sleep quality in pregnancy is frequent. A treatment with sedatives is problematic due to possible adverse effects for mother and embryo/foetus. In the present study, we investigated the sedative effect of Bryophyllum pinnatum, a phytotherapeutic medication used in anthroposophic medicine. In previous clinical studies on its tocolytic effect, B. pinnatum showed a good risk/benefit ratio for mother and child. A recent analysis of the prescribing pattern for B. pinnatum in a network of anthroposophic physicians revealed sleep disorders as one of the most frequent diagnoses for which these preparations are prescribed. MATERIALS AND METHODS: In this prospective, multi-centre, observational study, pregnant women suffering from sleep problems were treated with B. pinnatum (350mg tablets, 50% leaf press juice, Weleda AG, Arlesheim, dosage at physician's consideration). Sleep quality, daily sleepiness and fatigue were assessed with the aid of standardised questionnaires, at the beginning of the treatment and after 2 weeks. Possible adverse drug reactions perceived by the patients during the treatment were recorded. RESULTS: The number of wake-ups, as well as the subjective quality of sleep was significantly improved at the end of the treatment with B. pinnatum. The Epworth Sleeping Scale decreased, indicating a decrease of the tiredness during the day. There was, however, no evidence for prolongation of the sleep duration, reduction in the time to fall asleep, as well as change in the Fatigue Severity Scale after B. pinnatum. No serious adverse drug reactions were detected. CONCLUSION: B. pinnatum is a suitable treatment of sleep problems in pregnancy. The data of this study encourage further clinical investigations on the use of B. pinnatum in sleep disorders.


Assuntos
Kalanchoe , Fitoterapia , Preparações de Plantas/uso terapêutico , Complicações na Gravidez/tratamento farmacológico , Transtornos do Sono-Vigília/tratamento farmacológico , Adulto , Medicina Antroposófica , Fadiga/tratamento farmacológico , Feminino , Humanos , Pessoa de Meia-Idade , Gravidez , Estudos Prospectivos , Adulto Jovem
15.
Arthritis Rheum ; 65(3): 599-607, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23203906

RESUMO

OBJECTIVE: The binding of abatacept (CTLA-4Ig) to the B7 ligands CD80 and CD86 prevents the engagement of CD28 on T cells and thereby prevents effector T cell activation. In addition, a direct effect of CTLA-4Ig on antigen-presenting cells (APCs) could contribute to the therapeutic effect. To further elucidate the mechanism of CTLA-4Ig, we performed phenotype and functional analyses of APCs in patients with rheumatoid arthritis (RA) before and after the initiation of CTLA-4Ig therapy. METHODS: Peripheral blood mononuclear cells were analyzed before and at 2 and 4 weeks after the initiation of CTLA-4Ig therapy. Proportions of APCs were determined by flow cytometry. CD14+ monocytes were further analyzed for the expression of costimulatory and adhesion molecules and for their transendothelial migratory capacity in vitro. In addition, CD14+ monocytes from healthy controls were analyzed for their migratory and spreading capacity. RESULTS: Proportions and absolute numbers of monocytes were significantly increased in RA patients treated with CTLA-4Ig. The expression of several adhesion molecules was significantly diminished. In addition, monocytes displayed a significant reduction in their endothelial adhesion and transendothelial migratory capacity upon treatment with CTLA-4Ig. Likewise, isolated monocytes from healthy controls revealed a significant reduction in their migratory and spreading activity after preincubation with CTLA-4Ig or anti-CD80 and anti-CD86 antibodies. CONCLUSION: We describe direct effects of CTLA-4Ig therapy on phenotype and functional characteristics of monocytes in RA patients that might interfere with the migration of monocytes to the synovial tissue. This additional mechanism of CTLA-4Ig might contribute to the beneficial effects of CTLA-4Ig treatment in RA patients.


Assuntos
Artrite Reumatoide/tratamento farmacológico , Artrite Reumatoide/patologia , Movimento Celular/efeitos dos fármacos , Imunoconjugados/uso terapêutico , Monócitos/efeitos dos fármacos , Monócitos/patologia , Abatacepte , Células Apresentadoras de Antígenos/efeitos dos fármacos , Células Apresentadoras de Antígenos/metabolismo , Células Apresentadoras de Antígenos/patologia , Antirreumáticos/uso terapêutico , Antígeno B7-1/metabolismo , Antígeno B7-2/metabolismo , Moléculas de Adesão Celular/metabolismo , Feminino , Células Endoteliais da Veia Umbilical Humana , Humanos , Receptores de Lipopolissacarídeos/metabolismo , Masculino , Pessoa de Meia-Idade , Monócitos/metabolismo
16.
Clin Exp Rheumatol ; 30(1): 73-8, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22325451

RESUMO

OBJECTIVES: Heme oxygenase-1 (HO-1) which degrades Heme to free iron, biliverdin and carbon monoxide (CO) plays an important role in inflammation. There are, however, conflicting data concerning the role of HO-1 in rheumatoid arthritis (RA) and the therapeutic potential of individual heme degradation products remains to be determined. We therefore investigated the effect of CO and biliverdin upon therapeutic administration in the murine collagen induced arthritis (CIA) model of RA. METHODS: CIA was induced in DBA/1 mice. Anti-CII antibody levels were determined by ELISA. Mice were scored for paw swelling and grip strength. After the first clinical signs of arthritis one group of animals was treated with biliverdin, the second group was treated with CO. After 60 days all animals were sacrificed and analysed for histomorphological signs of arthritis. RESULTS: All animals immunised with CII developed serum anti-CII antibodies. Antibody levels were decreased in the CO-treated group. Both, Biliverdin and the CO-treated animals, showed an improvement in clinical disease activity. Histological analysis revealed significantly less inflammation, erosion and reduced numbers of osteoclasts in CO-treated animals only, whereas cartilage degradation was prevented in both biliverdin and CO-treated animals. CONCLUSIONS: Our data demonstrate a beneficial effect of CO, in particular, and biliverdin, on inflammation and bone destruction in the CIA mouse model.


Assuntos
Artrite Experimental/tratamento farmacológico , Biliverdina/uso terapêutico , Monóxido de Carbono/uso terapêutico , Heme Oxigenase-1/metabolismo , Articulações/efeitos dos fármacos , Administração por Inalação , Animais , Artrite Experimental/metabolismo , Artrite Experimental/patologia , Biliverdina/administração & dosagem , Biliverdina/metabolismo , Monóxido de Carbono/administração & dosagem , Monóxido de Carbono/metabolismo , Cartilagem Articular/efeitos dos fármacos , Cartilagem Articular/metabolismo , Cartilagem Articular/patologia , Inflamação/tratamento farmacológico , Inflamação/metabolismo , Inflamação/patologia , Articulações/metabolismo , Articulações/patologia , Camundongos
17.
Clin Exp Rheumatol ; 30(1): 64-72, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22261341

RESUMO

OBJECTIVES: It has been suggested that CD44 is involved in the pathogenesis of rheumatoid arthritis (RA). By alternative splicing, numerous CD44 isoforms can be generated which may play different roles the inflammatory process. We therefore studied the expression of various CD44 splicevariants in the circulation and synovial tissue of patients with RA and correlated expression with clinical features. METHODS: Expression of distinct CD44 splice variants was analysed by FACS in peripheral monocytes of 46 RA patients and 36 healthy controls. Expression of CD44 splice variants in synovial tissue of RA and OA patients was analysed by immunohistochemistry and the effects of blocking CD44v4 on RA-fibroblast like synoviocytes (FLS) were studied. RESULTS: On monocytes, the expression of CD44 and CD44v3 was significantly lower in patients with erosive disease than in those without radiographic progression (p<0.05 for CD44 and p<0.01 for CD44v3). CD44v6 on monocytes was significantly associated with the clinical disease activity index (r=0.34, p<0.05) and CRP-levels (r=0.37, p<0.02). Immunhistochemical analyses revealed that most variants were expressed to a significantly higher extent in RA than in OA synovial membranes. Particularly the variants CD44v4, CD44v6 and CD44v7-8 were highly expressed in the RA lining and also abundantly in the endothelium. Blocking CD44v4 in RA-FLS reduced the proliferation to 68±8% (p<0.02) when compared to control experiments and led to a reduction in IL-1ß mRNA expression (p<0.05). CONCLUSIONS: Expression of CD44 splice variants is generally increased in the synovial lining of RA patients when compared to OA. The inverse association of CD44v3 expression on monocytes with the development of erosive disease and the functional impacts of CD44v4 blockade in RA-FLS suggests a pathogenetic role of this splice variants which needs to be further investigated.


Assuntos
Artrite Reumatoide/metabolismo , Receptores de Hialuronatos/metabolismo , Monócitos/metabolismo , Membrana Sinovial/metabolismo , Proteína C-Reativa/metabolismo , Humanos , Interleucina-1beta/metabolismo , Pessoa de Meia-Idade , Osteoartrite/metabolismo , Isoformas de Proteínas/metabolismo , Fator de Necrose Tumoral alfa/metabolismo
18.
Pediatr Blood Cancer ; 59(4): 685-9, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22180290

RESUMO

BACKGROUND: Sickle cell disease (SCD) is characterized by frequent disease-related events that require acute care. It is unknown to what extent patients utilize multiple hospitals for acute care. We examined the continuity pattern of acute care visits to the hospital or emergency department. We hypothesized that among patients with multiple SCD related acute care visits, children experience more concentrated hospital care than adults and privately insured patients experience more concentrated hospital care than publicly insured patients. PROCEDURE: We conducted a retrospective cohort study using data from the 2005 and 2006 Healthcare Cost and Utilization Project State Inpatient Databases and State Emergency Department Databases. Subjects included patients with SCD ≥ 1 year of age. The primary outcome was proportion of patients with multiple acute care visits to a single hospital. RESULTS: A total of 13,533 patients made ≥ 2 acute SCD-related visits. Of the 5,030 children, 77.3% went to the same hospital for all visits. In contrast, of the 8,503 adults, only 51.3% visited the same hospital. Adolescents were more likely than adults to go to one hospital [adjusted relative risk (ARR) 1.40, confidence interval (CI) 1.35-1.45]. Those with public insurance and the uninsured had a decreased probability of using one hospital (ARR 0.96, CI 0.94-0.99, and ARR 0.83, CI 0.79-0.88, respectively). CONCLUSIONS: Adults and patients with public insurance or no insurance are more likely to use multiple hospitals for acute care. By receiving acute care at multiple hospitals, patients with SCD experience dispersed and fragmented care potentially leading to decreased care quality.


Assuntos
Anemia Falciforme/terapia , Serviço Hospitalar de Emergência/estatística & dados numéricos , Hospitais/estatística & dados numéricos , Doença Aguda , Adolescente , Adulto , Fatores Etários , Anemia Falciforme/complicações , Criança , Pré-Escolar , Continuidade da Assistência ao Paciente , Feminino , Humanos , Lactente , Masculino , Medicaid , Pessoas sem Cobertura de Seguro de Saúde , Estados Unidos , Adulto Jovem
19.
Oncogene ; 31(27): 3244-53, 2012 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-22081068

RESUMO

Many tumors exhibit elevated chromosome mis-segregation termed chromosome instability (CIN), which is likely to be a potent driver of tumor progression and drug resistance. Causes of CIN are poorly understood but probably include prior genome tetraploidization, centrosome amplification and mitotic checkpoint defects. This study identifies epigenetic alteration of the centromere as a potential contributor to the CIN phenotype. The centromere controls chromosome segregation and consists of higher-order repeat (HOR) alpha-satellite DNA packaged into two chromatin domains: the kinetochore, harboring the centromere-specific H3 variant centromere protein A (CENP-A), and the pericentromeric heterochromatin, considered important for cohesion. Perturbation of centromeric chromatin in model systems causes CIN. As cancer cells exhibit widespread chromatin changes, we hypothesized that pericentromeric chromatin structure could also be affected, contributing to CIN. Cytological and chromatin immunoprecipitation and PCR (ChIP-PCR)-based analyses of HT1080 cancer cells showed that only one of the two HORs on chromosomes 5 and 7 incorporate CENP-A, an organization conserved in all normal and cancer-derived cells examined. Contrastingly, the heterochromatin marker H3K9me3 (trimethylation of H3 lysine 9) mapped to all four HORs and ChIP-PCR showed an altered pattern of H3K9me3 in cancer cell lines and breast tumors, consistent with a reduction on the kinetochore-forming HORs. The JMJD2B demethylase is overexpressed in breast tumors with a CIN phenotype, and overexpression of exogenous JMJD2B in cultured breast epithelial cells caused loss of centromere-associated H3K9me3 and increased CIN. These findings suggest that impaired maintenance of pericentromeric heterochromatin may contribute to CIN in cancer and be a novel therapeutic target.


Assuntos
Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Centrômero/genética , Centrômero/metabolismo , Instabilidade Cromossômica , Heterocromatina/metabolismo , Neoplasias da Mama/patologia , Carcinoma Ductal de Mama/genética , Carcinoma Ductal de Mama/metabolismo , Carcinoma Ductal de Mama/patologia , Linhagem Celular Tumoral , Cromossomos Humanos Par 5/genética , Feminino , Histonas/metabolismo , Humanos , Histona Desmetilases com o Domínio Jumonji/metabolismo , Cinetocoros/metabolismo , Invasividade Neoplásica
20.
Neurology ; 75(13): 1141-9, 2010 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-20876468

RESUMO

OBJECTIVE: Health-related quality of life (HRQOL) is often much reduced among individuals with multiple sclerosis (MS), and incidences of depression, fatigue, and anxiety are high. We examined effects of a mindfulness-based intervention (MBI) compared to usual care (UC) upon HRQOL, depression, and fatigue among adults with relapsing-remitting or secondary progressive MS. METHODS: A total of 150 patients were randomly assigned to the intervention (n = 76) or to UC (n = 74). MBI consisted of a structured 8-week program of mindfulness training. Assessments were made at baseline, postintervention, and 6 months follow-up. Primary outcomes included disease-specific and disease-aspecific HRQOL, depression, and fatigue. Anxiety, personal goal attainment, and adherence to homework were secondary outcomes. RESULTS: Attrition was low in the intervention group (5%) and attendance rate high (92%). Employing intention-to-treat analysis, MBI, compared with UC, improved nonphysical dimensions of primary outcomes at postintervention and follow-up (p < 0.002); effect sizes, 0.4-0.9 posttreatment and 0.3-0.5 at follow-up. When analyses were repeated among subgroups with clinically relevant levels of preintervention depression, fatigue, or anxiety, postintervention and follow-up effects remained significant and effect sizes were larger than for the total sample. CONCLUSIONS: In addition to evidence of improved HRQOL and well-being, these findings demonstrate broad feasibility and acceptance of, as well as satisfaction and adherence with, a program of mindfulness training for patients with MS. The results may also have treatment implications for other chronic disorders that diminish HRQOL. CLASSIFICATION OF EVIDENCE: This trial provides Class III evidence that MBI compared with UC improved HRQOL, fatigue, and depression up to 6 months postintervention.


Assuntos
Depressão/reabilitação , Fadiga/reabilitação , Terapias Mente-Corpo/métodos , Esclerose Múltipla , Qualidade de Vida , Adulto , Análise de Variância , Depressão/etiologia , Avaliação da Deficiência , Método Duplo-Cego , Fadiga/etiologia , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Esclerose Múltipla/complicações , Esclerose Múltipla/psicologia , Esclerose Múltipla/reabilitação , Testes Neuropsicológicos , Resultado do Tratamento
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA