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2.
J Transl Genet Genom ; 5(4): 423-442, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-35342877

RESUMO

Aim: To molecularly characterize the tumor microenvironment and evaluate immunologic parameters in canine glioma patients before and after treatment with oncolytic human IL-12-expressing herpes simplex virus (M032) and in treatment naïve canine gliomas. Methods: We assessed pet dogs with sporadically occurring gliomas enrolled in Stage 1 of a veterinary clinical trial that was designed to establish the safety of intratumoral oncoviral therapy with M032, a genetically modified oncolytic herpes simplex virus. Specimens from dogs in the trial and dogs not enrolled in the trial were evaluated with immunohistochemistry, NanoString, Luminex cytokine profiling, and multi-parameter flow cytometry. Results: Treatment-naive canine glioma microenvironment had enrichment of Iba1 positive macrophages and minimal numbers of T and B cells, consistent with previous studies identifying these tumors as immunologically "cold". NanoString mRNA profiling revealed enrichment for tumor intrinsic pathways consistent with suppression of tumor-specific immunity and support of tumor progression. Oncolytic viral treatment induced an intratumoral mRNA transcription signature of tumor-specific immune responses in 83% (5/6) of canine glioma patients. Changes included mRNA signatures corresponding with interferon signaling, lymphoid and myeloid cell activation, recruitment, and T and B cell immunity. Multiplexed protein analysis identified a subset of oligodendroglioma subjects with increased concentrations of IL-2, IL-7, IL-6, IL-10, IL-15, TNFα, GM-CSF between 14 and 28 days after treatment, with evidence of CD4+ T cell activation and modulation of IL-4 and IFNγ production in CD4+ and CD8+ T cells isolated from peripheral blood. Conclusion: These findings indicate that M032 modulates the tumor-immune microenvironment in the canine glioma model.

3.
J Clin Neurosci ; 70: 102-107, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31447361

RESUMO

OBJECTIVES: Repeat Gamma Knife stereotactic radiosurgery (GKSR) for refractory trigeminal neuralgia (TGN) is an increasingly common practice. Prior studies have reported varying success rates and incidence of trigeminal nerve dysfunction following repeated GKSR. We report treatment outcomes and toxicity in patients following repeat GKSR for TGN at the University of Alabama at Birmingham (UAB) with a focused review of the literature. METHODS: We retrospectively reviewed medical records of 55 TGN patients re-treated with radiosurgery using the Leksell Gamma Knife® at the University of Alabama at Birmingham between 1996 and 2012. Outcomes were defined using the Modified Marseille Scale. Demographics, prior treatments and symptom duration were correlated with outcomes. RESULTS: Eighteen patients (33%) achieved Marseille Class I or II, 14 (25%) Class III or IV, and 23 (42%) Class V at a mean follow-up of 14.4 months. Twenty-five patients (45%) developed new trigeminal nerve dysfunction after re-treatment. Of these, four (16%) did not develop dysfunction until subsequent microvascular decompression (MVD) for inadequate symptom relief. CONCLUSIONS: Although more than half of the patients undergoing repeat GKSR for refractory TGN maintained excellent or good outcomes (Marseille classes I-IV) at an average follow-up of 14.4 months, neither age, gender, nor pre-treatment duration of symptoms or interval between treatments had a statistically significant effect on outcomes. Following repeat GKSR, patients have increased risk for new-onset trigeminal nerve dysfunction and those undergoing MVD after repeat GKSR may have an increased risk for new-onset trigeminal nerve dysfunction.


Assuntos
Complicações Pós-Operatórias , Radiocirurgia/efeitos adversos , Radiocirurgia/métodos , Reoperação/efeitos adversos , Neuralgia do Trigêmeo/cirurgia , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/etiologia , Reoperação/métodos , Resultado do Tratamento
4.
Rehabilitation (Stuttg) ; 56(3): 167-172, 2017 Jun.
Artigo em Alemão | MEDLINE | ID: mdl-28371962

RESUMO

Digital media offer new possibilities in rehabilitation aftercare. This study investigates the rehabilitants' willingness to use new media (sms, internet, social networks) in rehabilitation aftercare and factors that are associated with the willingness to use media-based aftercare. 92 rehabilitants (patients with obesity) filled in a questionnaire on the willingness to use new media in rehabilitation aftercare. In order to identify influencing factors, binary logistic regression models were calculated. 3 quarters of the rehabilitants (76.1%) reported that they would be willing to use new media in rehabilitation aftercare. The binary logistic regression model yielded two factors that were associated with the willingness to use media-based aftercare: the possession of a smartphone and the willingness to receive telephone counseling for aftercare. The majority of the rehabilitants was willing to use new media in rehabilitation aftercare. The reasons for refusal of media-based aftercare need to be examined more closely.


Assuntos
Assistência ao Convalescente/estatística & dados numéricos , Atitude Frente a Saúde , Obesidade/psicologia , Aceitação pelo Paciente de Cuidados de Saúde/estatística & dados numéricos , Educação de Pacientes como Assunto/estatística & dados numéricos , Reabilitação/educação , Consulta Remota/estatística & dados numéricos , Adolescente , Adulto , Idoso , Aconselhamento/estatística & dados numéricos , Feminino , Alemanha/epidemiologia , Inquéritos Epidemiológicos , Linhas Diretas/estatística & dados numéricos , Humanos , Internet/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade , Reabilitação/estatística & dados numéricos , Adulto Jovem
5.
Endocrinology ; 157(2): 482-96, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26646205

RESUMO

Receptor activator of nuclear factor κB ligand (RANKL) is expressed by a number of cell types to participate in diverse physiological functions. We have previously identified 10 distal RANKL enhancers. Earlier studies have shown that RL-D5 is a multifunctional RANKL enhancer. Deletion of RL-D5 from the mouse genome leads to lower skeletal and lymphoid tissue RANKL, causing a high bone mass phenotype. Herein, we determine the physiological role and lineage specificity of 2 additional RANKL enhancers, RL-D6 and RL-T1, which are located 83 and 123 kb upstream of the gene's transcriptional start site, respectively. Lack of RL-D6 or RL-T1 did not alter skeletal RANKL or bone mineral density up to 48 weeks of age. Although both RL-D5 and RL-T1 contributed to activation induction of T-cell RANKL, RL-T1 knockout mice had drastically low lymphocyte and lymphoid tissue RANKL levels, indicating that RL-T1 is the major regulator of lymphocyte RANKL. Moreover, RL-T1 knockout mice had lower circulating soluble RANKL, suggesting that lymphocytes are important sources of circulating soluble RANKL. Under physiological conditions, lack of RL-D6 did not alter RANKL expression. However, lack of RL-D5 or RL-D6, but not of RL-T1, blunted the oncostatin M and lipopolysaccharide induction of RANKL ex vivo and in vivo, suggesting that RL-D5 and RL-D6 coregulate the inflammation-mediated induction of RANKL in osteocytes and osteoblasts while lack of RL-D6 did not alter secondary hyperparathyroidism or lactation induction of RANKL or bone loss. These results suggest that although RL-D5 mediates RANKL expression in multiple lineages, other cell type- or factor-specific enhancers are required for its appropriate control, demonstrating the cell type-specific and complex regulation of RANKL expression.


Assuntos
Elementos Facilitadores Genéticos , Inflamação/genética , Ligante RANK/genética , Ligante RANK/metabolismo , Animais , Linhagem da Célula/genética , Células Cultivadas , Feminino , Regulação da Expressão Gênica , Inflamação/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Especificidade de Órgãos/genética , Ligação Proteica
6.
Klin Padiatr ; 228(1): 1-10, 2016 Jan.
Artigo em Alemão | MEDLINE | ID: mdl-26302179

RESUMO

BACKGROUND: Current guidelines for the prevention of obesity in childhood and adolescence are presented. METHODS: A literature search was performed in Medline via PubMed, and appropriate studies were analysed. RESULTS: Programs to prevent childhood obesity were to date mainly school-based. Effects were limited to date. Analyses tailored to different age groups show that prevention programs have the best effects in younger children (< 12 years). Evidence based recommendations for preschool- and early school age imply the need for interventions addressing parents and teachers alike. During adolescence, school-based interventions were most effective when adolescents were directly addressed. To date, obesity prevention programs have mainly focused on behavior oriented prevention. Recommendations for condition oriented prevention have been suggested by the German Alliance of Non-communicable Diseases and include one hour of physical activity at school, promotion of healthy food choices by taxing unhealthy foods, mandatory quality standards for meals at kindergarten and schools as well as a ban on unhealthy food advertisement addressing children. CONCLUSION: Behavior oriented prevention programs showed hardly any or only limited effects in the long term. Certain risk groups for the development of obesity are not reached effectively by available programs. Due to the heterogeneity of available studies, universally valid conclusions cannot be drawn. The combination with condition oriented prevention, which has to counteract on an obesogenic environment, is crucial for sustainable success of future obesity prevention programs.


Assuntos
Obesidade Infantil/prevenção & controle , Guias de Prática Clínica como Assunto , Adolescente , Terapia Comportamental , Criança , Pré-Escolar , Terapia Combinada , Dietoterapia , Exercício Físico , Humanos , Ensaios Clínicos Controlados Aleatórios como Assunto , Serviços de Saúde Escolar , Meio Social , Resultado do Tratamento
8.
Gene Ther ; 22(4): 348-55, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25427614

RESUMO

Pathophysiological hypoxia, which fosters the glioma stem-like cell (GSC) phenotype, is present in high-grade gliomas and has been linked to tumor development, invasiveness and resistance to chemotherapy and radiation. Oncolytic virotherapy with engineered herpes simplex virus-1 (HSV-1) is a promising therapy for glioblastoma; however, the efficacy of γ(1)34.5-deleted HSVs, which have been used in clinical trials, was diminished in hypoxia. We investigated the ability of a chimeric human cytolomegalovirus (HCMV)/HSV-1 virus, which expresses the human CMV protein kinase R evasion gene IRS1 and is in preparation for clinical trials, to infect and kill adult and pediatric patient-derived glioblastoma xenografts in hypoxia and normoxia. Infectivity, cytotoxicity and viral recovery were significantly greater with the chimeric virus compared with the γ(1)34.5-deleted virus, regardless of oxygen tension. The chimeric virus infected and killed CD133+ GSCs similarly to wild-type HSV-1. Increased activation of mitogen-activated protein kinase p38 and its substrate heat-shock protein 27 (Hsp27) was seen after viral infection in normoxia compared with hypoxia. Hsp27 knockdown or p38 inhibition reduced virus recovery, indicating that the p38 pathway has a role in the reduced efficacy of the γ(1)34.5-deleted virus in hypoxia. Taken together, these findings demonstrate that chimeric HCMV/HSV-1 efficiently targets both CD133+ GSCs and glioma cells in hypoxia.


Assuntos
Citomegalovirus/metabolismo , Glioblastoma/terapia , Herpesvirus Humano 1/genética , Terapia Viral Oncolítica , Proteínas Quinases/metabolismo , Proteínas Virais/metabolismo , Animais , Hipóxia Celular , Linhagem Celular Tumoral , Citomegalovirus/genética , Glioblastoma/metabolismo , Proteínas de Choque Térmico HSP27/metabolismo , Humanos , Camundongos Nus , Organismos Geneticamente Modificados , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
9.
Gene Ther ; 21(11): 984-90, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25119379

RESUMO

Limited expression and distribution of nectin-1, the major herpes simplex virus (HSV) type-1 entry-receptor, within tumors has been proposed as an impediment to oncolytic HSV (oHSV) therapy. To determine whether resistance to oHSVs in malignant peripheral nerve sheath tumors (MPNSTs) was explained by this hypothesis, nectin-1 expression and oHSV viral yields were assessed in a panel of MPNST cell lines using γ134.5-attenuated (Δγ134.5) oHSVs and a γ134.5 wild-type (wt) virus for comparison. Although there was a correlation between nectin-1 levels and viral yields with the wt virus (R=0.75, P =0.03), there was no correlation for Δγ134.5 viruses (G207, R7020 or C101) and a modest trend for the second-generation oHSV C134 (R=0.62, P=0.10). Nectin-1 overexpression in resistant MPNST cell lines did not improve Δγ134.5 oHSV output. While multistep replication assays showed that nectin-1 overexpression improved Δγ134.5 oHSV cell-to-cell spread, it did not confer a sensitive phenotype to resistant cells. Finally, oHSV yields were not improved with increased nectin-1 in vivo. We conclude that nectin-1 expression is not the primary obstacle of productive infection for Δγ134.5 oHSVs in MPNST cell lines. In contrast, viruses that are competent in their ability to counter the antiviral response may derive benefit with higher nectin-1 expression.


Assuntos
Moléculas de Adesão Celular/metabolismo , Neoplasias de Bainha Neural/metabolismo , Vírus Oncolíticos/fisiologia , Receptores Virais/metabolismo , Simplexvirus/fisiologia , Animais , Linhagem Celular Tumoral , Chlorocebus aethiops , Cricetulus , Humanos , Camundongos , Nectinas , Neoplasias de Bainha Neural/virologia , Terapia Viral Oncolítica , Vírus Oncolíticos/metabolismo
10.
Gene Ther ; 18(11): 1098-102, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21544094

RESUMO

Oncolytic viruses have been combined with standard cancer therapies to increase therapeutic efficacy. Given the sequential activation of herpes viral genes (herpes simplex virus-1, HSV-1) and the temporal cellular changes induced by ionizing radiation, we hypothesized an optimal temporal sequence existed in combining oncolytic HSV-1 with ionizing radiation. Murine U-87 glioma xenografts were injected with luciferase encoding HSV-1, and ionizing radiation (IR) was given at times before or after viral injection. HSV-1 replication and tumor-volume response were followed. Radiation given 6-9 h after HSV-1 injection resulted in maximal viral luciferase expression and infectious viral production in tumor xenografts. The greatest xenograft regression was also seen with radiation given 6 h after viral injection. We then tested if HSV-1 replication had a dose response to ionizing radiation. HSV-1 luciferase expression exhibited a dose response as xenografts were irradiated from 0 to 5 Gy. There was no difference in viral luciferase expression as IR dose increased from 5 Gy up to 20 Gy. These results suggest that the interaction of IR with the HSV-1 lytic cycle can be manipulated for therapeutic gain by delivering IR at a specific time within viral replicative cycle.


Assuntos
Neoplasias Encefálicas/terapia , Glioma/terapia , Herpesvirus Humano 1/crescimento & desenvolvimento , Terapia Viral Oncolítica/métodos , Radiação Ionizante , Replicação Viral/efeitos da radiação , Animais , Terapia Combinada , Relação Dose-Resposta à Radiação , Herpesvirus Humano 1/efeitos da radiação , Camundongos , Camundongos Nus , Vírus Oncolíticos/crescimento & desenvolvimento , Vírus Oncolíticos/efeitos da radiação , Replicação Viral/genética
11.
AJNR Am J Neuroradiol ; 31(9): 1729-31, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20019104

RESUMO

SUMMARY: We report DTI and fiber tractography findings in a case of hypertrophic olivary degeneration. A 51-year-old man presented with an abnormal gait and visual difficulties. MR imaging showed enlargement of the right medullary olive and a vascular lesion in the right pontine tegmentum. Fiber tractography showed decreased volume of the right central tegmental tract, supporting a diagnosis of HOD.


Assuntos
Imagem de Tensor de Difusão/métodos , Degeneração Neural/patologia , Núcleo Olivar/patologia , Humanos , Hipertrofia/patologia , Masculino , Pessoa de Meia-Idade
12.
Cancer Gene Ther ; 16(10): 794-805, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19363468

RESUMO

Malignant forms of glioma, the most common primary brain tumors, remain poorly responsive to multimodality therapeutic interventions, including chemotherapy. Suppressed apoptosis and extraordinary invasiveness are important distinctive features that contribute to the malignant phenotype of glioma. We have developed the vascular endothelial growth factor receptor 1 (VEGFR-1/flt-1) conditional replicating adenoviral vector (CRAdRGDflt-IL24) encoding the interleukin-24 (IL-24) gene. We investigated whether a combination of CRAdRGDflt-IL24-mediated oncolytic virotherapy and chemotherapy using temozolomide (TMZ) produces increased cytotoxicity against human glioma cells in comparison with these agents alone. Combination of CRAdRGDflt-IL24 and TMZ significantly enhanced cytotoxicity in vitro, inhibited D54MG tumor growth and prolonged survival of mice harboring intracranial human glioma xenografts in comparison with CRAdRGDflt-IL24 or TMZ alone. These data indicate that combined treatment with CRAdRGDflt-IL24-mediated oncolytic virotherapy and TMZ chemotherapy provides a promising approach for glioma therapy.


Assuntos
Neoplasias Encefálicas/terapia , Dacarbazina/análogos & derivados , Glioma/terapia , Interleucinas/genética , Terapia Viral Oncolítica/métodos , Receptor 1 de Fatores de Crescimento do Endotélio Vascular/genética , Adenoviridae/genética , Animais , Antineoplásicos Alquilantes/farmacologia , Apoptose/efeitos dos fármacos , Apoptose/genética , Neoplasias Encefálicas/tratamento farmacológico , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/virologia , Processos de Crescimento Celular/genética , Linhagem Celular Tumoral , Terapia Combinada , Dacarbazina/farmacologia , Feminino , Terapia Genética/métodos , Vetores Genéticos/genética , Glioma/tratamento farmacológico , Glioma/genética , Glioma/virologia , Humanos , Camundongos , Camundongos Nus , Regiões Promotoras Genéticas , Proteínas Recombinantes/farmacologia , Temozolomida , Fator A de Crescimento do Endotélio Vascular/farmacologia , Receptor 1 de Fatores de Crescimento do Endotélio Vascular/biossíntese , Ensaios Antitumorais Modelo de Xenoenxerto
13.
Gene Ther ; 14(13): 1045-54, 2007 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-17429445

RESUMO

Oncolytic herpes simplex virus (HSV)-1 gamma(1)34.5-deletion mutants (Deltagamma(1)34.5 HSV) are promising agents for tumor therapy. The attenuating mutation renders the virus aneurovirulent but also limits late viral protein synthesis and efficient replication in many tumors. We tested whether one function of gamma(1)34.5 gene, which mediates late viral protein synthesis through host protein kinase R (PKR) antiviral response evasion, could be restored, without restoring the neurovirulence. We have previously reported the construction of two chimeric Deltagamma(1)34.5 HSV vectors (chimeric HSV), C130 and C134, which express the human cytomegalovirus (HCMV) PKR-evasion genes TRS1 and IRS1, respectively. We now demonstrate the following. The HCMV/HSV-1 chimeric viruses (i) maintain late viral protein synthesis in the human malignant glioma cells tested (D54-MG, U87-MG and U251-MG); (ii) replicate to higher titers than Deltagamma(1)34.5 HSV in malignant glioma cells in vitro and in vivo; (iii) are aneurovirulent; and (iv) are superior to other Deltagamma(1)34.5 HSV with both improved reduction of tumor volumes in vivo, and improved survival in two experimental murine brain tumor models. These findings demonstrate that transfer of HCMV IRS1 or TRS1 gene into Deltagamma(1)34.5 HSV significantly improves replication in malignant gliomas without restoring wild-type neurovirulence, resulting in enhanced tumor reduction and prolonged survival.


Assuntos
Neoplasias Encefálicas/terapia , Citomegalovirus/genética , Terapia Genética/métodos , Glioblastoma/terapia , Herpesvirus Humano 1/genética , Terapia Viral Oncolítica/métodos , Animais , Neoplasias Encefálicas/patologia , Linhagem Celular Tumoral , Quimera , Engenharia Genética , Glioblastoma/patologia , Glioma , Camundongos , Camundongos SCID , Transplante de Neoplasias , Neuroblastoma , Neurônios/patologia , Neurônios/virologia , Vírus Oncolíticos/genética , Vírus Oncolíticos/fisiologia , Transplante Heterólogo , Replicação Viral
14.
Clin Neuropathol ; 26(2): 59-67, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17416104

RESUMO

BACKGROUND: Neurosarcoid affects approximately 5% of patients with sarcoidosis. A significantly more rare entity, necrotizing sarcoidosis affecting the central nervous system, has been confirmed previously in only three case reports. This paper documents three additional cases of necrotizing neurosarcoid, involving a wide spectrum of central nervous system (CNS) locations. RESULTS: One patient presented to the emergency department after being found unresponsive. The second patient was referred due to hearing loss and the third patient sought care due to weakness and numbness of his left lower extremity. Locations of involvement were diverse and included diffuse leptomeningeal involvement, a cerebellopontine angle mass and a thoracic spinal cord lesion. All patients eventually underwent surgical biopsy, and histologic review of tissue samples revealed necrotizing granulomatous inflammation. Serum ACE levels were available for two of the patients and were within normal limits. Once the diagnosis of necrotizing neurosarcoid was confirmed, all patients were treated with systemic corticosteroid therapy; one patient was also treated with an immunosuppressive agent. CONCLUSIONS: Necrotizing neurosarcoid may occur more commonly than previously described and should be considered in the differential diagnosis of patients without systemic manifestations of sarcoidosis.


Assuntos
Doenças do Sistema Nervoso Central/diagnóstico , Sistema Nervoso Central/patologia , Sarcoidose/diagnóstico , Corticosteroides/uso terapêutico , Adulto , Doenças do Sistema Nervoso Central/tratamento farmacológico , Doenças do Sistema Nervoso Central/patologia , Diagnóstico Diferencial , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Necrose/diagnóstico , Necrose/patologia , Sarcoidose/tratamento farmacológico , Sarcoidose/patologia
15.
Cancer Gene Ther ; 14(1): 45-56, 2007 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-16990846

RESUMO

Lack of effective therapy of primary brain tumors has promoted the development of novel experimental approaches utilizing oncolytic viruses combined with gene therapy. Towards this end, we have assessed a conditionally replication-competent, gamma(1)34.5-deleted herpes simplex virus type 1 (HSV-1) expressing cytosine deaminase (CD) for treatment of malignant brain tumors. Our results are summarized as follows: (i) a recombinant HSV (M012) was constructed in which both copies of the gamma(1)34.5 gene were replaced with the bacterial CD gene, under the control of the cellular promoter Egr-1; (ii) M012-infected cells in vitro efficiently convert 5-fluorocytosine (5-FC) to 5-fluorouracil, thereby enhancing cytotoxicity of neighboring, uninfected cells; (iii) both direct and bystander cytotoxicity of murine neuroblastoma and human glioma cell lines after infection with M012 were demonstrated; (iv) direct intracerebral inoculation of A/J mice demonstrated lack of neurotoxicity at doses similar to G207, a gamma(1)34.5-deleted HSV with demonstrated safety in human patient trials and (v) intratumoral injection of M012 into Neuro-2a flank tumors in combination with 5-FC administration significantly reduced tumor growth versus tumors treated with R3659 combined with 5-FC, or treated with M012 alone. Thus, M012 is a promising new oncolytic HSV vector with an enhanced prodrug-mediated, antineoplastic effect that is safe for intracranial administration.


Assuntos
Bactérias/enzimologia , Neoplasias Encefálicas/terapia , Citosina Desaminase/genética , Simplexvirus/genética , Animais , Neoplasias Encefálicas/tratamento farmacológico , Chlorocebus aethiops , Feminino , Fluoruracila/uso terapêutico , Engenharia Genética , Humanos , Camundongos , Células Vero
16.
Heredity (Edinb) ; 92(4): 306-15, 2004 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-14735140

RESUMO

Comprehensive long-term studies of isolated populations provide valuable comparative data that may be used to evaluate different methods for quantifying the relationship between genetic diversity and fitness. Here, we report on data collected from large and well-characterized cohorts of the two numerically dominant species of Darwin's finches on Isla Daphne Major, Galápagos, Ecuador - Geospiza fortis and G. scandens. Multilocus microsatellite (SSR) genetic diversity estimates (heterozygosity and d2) and pedigree-based estimates of the inbreeding coefficient (f) were compared to each other and to two fitness components: lifespan and recruitment. In the larger sample of G. fortis, heterozygosity (H) was correlated with both fitness components, but no relationship was detected in the smaller sample of G. scandens. Analyses of the inbreeding coefficient detected highly significant relationships between f and recruitment, but no relationship between f and overall lifespan. The d2 statistic showed no relationship to either fitness component. When the two SSR-based estimators were compared to f, d2 was correlated with f in G. fortis in the predicted direction, while in G. scandens the relationship was positive. Multilocus heterozygosity was correlated with f in G. fortis but not in the G. scandens sample. A pedigree simulation demonstrated that the variation in true autozygosity can be large among individuals with the same level of inbreeding. This observation may supplement the interpretation of patterns relevant to the local (locus-specific) and general (genome-wide) effects hypotheses, which have been proposed to explain the mechanism responsible for associations between genetic diversity and fitness.


Assuntos
Variação Genética , Heterozigoto , Endogamia , Aves Canoras/genética , Alelos , Animais , Frequência do Gene , Longevidade/genética , Linhagem
17.
Gene Ther ; 9(1): 75-80, 2002 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11850725

RESUMO

The herpes simplex virus (HSV) recombinant virus R7020 is an attenuated virus designed as a candidate for immunization against both HSV-1 and HSV-2 infections. It was extensively tested in an experimental animal system and in a healthy human adult population without significant untoward effects. We report on the use of R7020 with ionizing radiation as an oncolytic agent for hepatomas. Two hepatoma cell lines were studied, Hep3B and Huh7. R7020 replicated to higher titers in Hep3B cells than in Huh7 cells. Tissue culture studies correlated with hepatoma xenograft responses to R7020. R7020 was more effective in mediating Hep3B tumor xenograft regression compared with Huh7. Ionizing radiation combined with R7020 also showed differential results in antitumor efficacy between the two cell lines in tumor xenografts. Ionizing radiation enhanced the replication of R7020 in Hep3B xenografts. Moreover, the combination of ionizing radiation and virus caused a greater regression of xenograft volume than either R7020 or radiation alone. Ionizing radiation had no effect on the replication of R7020 virus in Huh7 xenografts. These results indicate that a regimen involving infection with an appropriate herpesvirus such as R7020 in combination with ionizing radiation can be highly effective in eradicating certain tumor xenografts.


Assuntos
Terapia Genética/métodos , Vacinas contra o Vírus do Herpes Simples/administração & dosagem , Herpesvirus Humano 1 , Herpesvirus Humano 2 , Neoplasias Hepáticas Experimentais/terapia , Animais , Terapia Combinada , Humanos , Neoplasias Hepáticas Experimentais/radioterapia , Camundongos , Camundongos Nus , Transplante de Neoplasias , Células Tumorais Cultivadas , Replicação Viral/efeitos da radiação
18.
Phys Rev Lett ; 88(9): 097002, 2002 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-11864044

RESUMO

We present scanning tunneling spectroscopy measurements of the CuO chain plane in YBa(2)Cu(3)O(6+x), showing an approximately 25 meV gap in the local density of states (LDOS) filled by numerous intragap resonances: intense peaks in LDOS spectra associated with one-dimensional, Friedel-like oscillations. We discuss how these phenomena shed light on recent results from other probes, as well as their implications for phenomena in the superconducting CuO(2) plane.

19.
J Biol Chem ; 276(42): 38755-61, 2001 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-11514582

RESUMO

Members of the degenerin/epithelial Na(+) channel superfamily of ion channels subserve many functions, ranging from whole body sodium handling to mechanoelectrical transduction. We studied brain Na(+) channel 2 (BNaC-2) in planar lipid bilayers to examine its single channel properties and regulation by Ca(2+). Upon incorporation of vesicles made from membranes of oocytes expressing either wild-type (WT) BNaC-2 or BNaC-2 with a gain-of-function (GF) point mutation (G433F), functional channels with different properties were obtained. WT BNaC-2 resided in a closed state with short openings, whereas GF BNaC-2 was constitutively activated; a decrease in the pH in the trans compartment of the bilayer activated WT BNaC-2 and decreased its permeability for Na(+) over K(+). Moreover, these maneuvers made the WT channel more resistant to amiloride. In contrast, GF BNaC-2 did not respond to a decrease in pH, and its amiloride sensitivity and selectivity for Na(+) over K(+) were unaffected by this pH change. Buffering the bathing solutions with EGTA to reduce the free [Ca(2+)] to <10 nm increased WT single channel open probability 10-fold, but not that of GF BNaC-2. Ca(2+) blocked both WT and GF BNaC-2 in a dose- and voltage-dependent fashion; single channel conductances were unchanged. A drop in pH reduced the ability of Ca(2+) to inhibit these channels. These results show that BNaC-2 is an amiloride-sensitive sodium channel and suggest that pH activation of these channels could be, in part, a consequence of H(+) "interference" with channel regulation by Ca(2+).


Assuntos
Encéfalo/metabolismo , Cálcio/metabolismo , Concentração de Íons de Hidrogênio , Canais Iônicos/química , Bicamadas Lipídicas/metabolismo , Proteínas do Tecido Nervoso/química , Proteínas do Tecido Nervoso/genética , Canais de Sódio/química , Canais de Sódio/genética , Canais Iônicos Sensíveis a Ácido , Animais , Quelantes/farmacologia , Clonagem Molecular , Canais de Sódio Degenerina , Ácido Egtázico/farmacologia , Canais Epiteliais de Sódio , Cinética , Proteínas de Membrana , Proteínas do Tecido Nervoso/metabolismo , Oócitos/metabolismo , Mutação Puntual , Ligação Proteica , Canais de Sódio/metabolismo , Xenopus
20.
Mol Ecol ; 10(6): 1471-88, 2001 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-11412369

RESUMO

Although there is mounting evidence that speciation can occur under sympatric conditions, unambiguous examples from nature are rare and it is almost always possible to propose alternative allopatric or parapatric scenarios. To identify an unequivocal case of sympatric speciation it is, therefore, necessary to analyse natural settings where recent monophyletic species flocks have evolved within a small and confined spatial range. We have studied such a case with a cichlid species flock that comprises five Tilapia forms endemic to a tiny lake (Lake Ejagham with a surface area of approximately 0.49 km2) in Western Cameroon. Analysis of mitochondrial D-Loop sequences shows that the flock is very young (approximately 10(4) years) and has originated from an adjacent riverine founder population. We have focused our study on a particular pair of forms within the lake that currently appears to be in the process of speciation. This pair is characterized by an unique breeding colouration and specific morphological aspects, which can serve as synapomorphic characters to prove monophyly. It has differentiated into a large inshore and a small pelagic form, apparently as a response to differential utilization of food resources. Still, breeding and brood care occurs in overlapping areas, both in time and space. Analysis of nuclear gene flow on the basis of microsatellite polymorphisms shows a highly restricted gene flow between the forms, suggesting reproductive isolation between them. This reproductive isolation is apparently achieved by size assortative mating, although occasional mixed pairs can be observed. Our findings are congruent with recent theoretical models for sympatric speciation, which show that differential ecological adaptations in combination with assortative mating could easily lead to speciation in sympatry.


Assuntos
Ecologia , Genética Populacional , Comportamento Sexual Animal , Tilápia/genética , Fatores Etários , Animais , Sequência de Bases , Constituição Corporal , Peso Corporal , Cruzamento , Camarões , DNA Mitocondrial , Feminino , Água Doce , Masculino , Repetições de Microssatélites , Dados de Sequência Molecular , Comportamento Sexual Animal/fisiologia , Tilápia/anatomia & histologia , Tilápia/classificação
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