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1.
Phys Rev Lett ; 131(22): 222503, 2023 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-38101393

RESUMO

Isomers close to doubly magic _{28}^{78}Ni_{50} provide essential information on the shell evolution and shape coexistence near the Z=28 and N=50 double shell closure. We report the excitation energy measurement of the 1/2^{+} isomer in _{30}^{79}Zn_{49} through independent high-precision mass measurements with the JYFLTRAP double Penning trap and with the ISOLTRAP multi-reflection time-of-flight mass spectrometer. We unambiguously place the 1/2^{+} isomer at 942(10) keV, slightly below the 5/2^{+} state at 983(3) keV. With the use of state-of-the-art shell-model diagonalizations, complemented with discrete nonorthogonal shell-model calculations which are used here for the first time to interpret shape coexistence, we find low-lying deformed intruder states, similar to other N=49 isotones. The 1/2^{+} isomer is interpreted as the bandhead of a low-lying deformed structure akin to a predicted low-lying deformed band in ^{80}Zn, and points to shape coexistence in ^{79,80}Zn similar to the one observed in ^{78}Ni. The results make a strong case for confirming the claim of shape coexistence in this key region of the nuclear chart.

2.
Phys Rev Lett ; 130(12): 122502, 2023 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-37027859

RESUMO

The excited states of N=44 ^{74}Zn were investigated via γ-ray spectroscopy following ^{74}Cu ß decay. By exploiting γ-γ angular correlation analysis, the 2_{2}^{+}, 3_{1}^{+}, 0_{2}^{+}, and 2_{3}^{+} states in ^{74}Zn were firmly established. The γ-ray branching and E2/M1 mixing ratios for transitions deexciting the 2_{2}^{+}, 3_{1}^{+}, and 2_{3}^{+} states were measured, allowing for the extraction of relative B(E2) values. In particular, the 2_{3}^{+}→0_{2}^{+} and 2_{3}^{+}→4_{1}^{+} transitions were observed for the first time. The results show excellent agreement with new microscopic large-scale shell-model calculations, and are discussed in terms of underlying shapes, as well as the role of neutron excitations across the N=40 gap. Enhanced axial shape asymmetry (triaxiality) is suggested to characterize ^{74}Zn in its ground state. Furthermore, an excited K=0 band with a significantly larger softness in its shape is identified. A shore of the N=40 "island of inversion" appears to manifest above Z=26, previously thought as its northern limit in the chart of the nuclides.

3.
Mol Psychiatry ; 23(8): 1687-1698, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29158583

RESUMO

Ras/MAPK pathway signaling is a major participant in neurodevelopment, and evidence suggests that BRAF, a key Ras signal mediator, influences human behavior. We studied the role of the mutation BRAFQ257R, the most common cause of cardiofaciocutaneous syndrome (CFC), in an induced pluripotent stem cell (iPSC)-derived model of human neurodevelopment. In iPSC-derived neuronal cultures from CFC subjects, we observed decreased p-AKT and p-ERK1/2 compared to controls, as well as a depleted neural progenitor pool and rapid neuronal maturation. Pharmacological PI3K/AKT pathway manipulation recapitulated cellular phenotypes in control cells and attenuated them in CFC cells. CFC cultures displayed altered cellular subtype ratios and increased intrinsic excitability. Moreover, in CFC cells, Ras/MAPK pathway activation and morphological abnormalities exhibited cell subtype-specific differences. Our results highlight the importance of exploring specific cellular subtypes and of using iPSC models to reveal relevant human-specific neurodevelopmental events.


Assuntos
Displasia Ectodérmica/metabolismo , Insuficiência de Crescimento/metabolismo , Cardiopatias Congênitas/metabolismo , Células-Tronco Pluripotentes Induzidas/metabolismo , Sistema de Sinalização das MAP Quinases , Neurogênese/fisiologia , Neurônios/metabolismo , Proteínas Proto-Oncogênicas B-raf/metabolismo , Técnicas de Cultura de Células , Displasia Ectodérmica/patologia , Fácies , Insuficiência de Crescimento/patologia , Cardiopatias Congênitas/patologia , Humanos , Células-Tronco Pluripotentes Induzidas/efeitos dos fármacos , Células-Tronco Pluripotentes Induzidas/patologia , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Sistema de Sinalização das MAP Quinases/fisiologia , Mutação , Neurogênese/efeitos dos fármacos , Neurogênese/genética , Neurônios/efeitos dos fármacos , Neurônios/patologia , Fenótipo , Fosfatidilinositol 3-Quinases/metabolismo , Inibidores de Fosfoinositídeo-3 Quinase , Proteínas Proto-Oncogênicas B-raf/genética , Proteínas Proto-Oncogênicas c-akt/antagonistas & inibidores , Proteínas Proto-Oncogênicas c-akt/metabolismo
4.
Cell Tissue Bank ; 17(4): 561-571, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27761677

RESUMO

For successful transplantation, allografts should be free of microorganisms that may cause harm to the allograft recipient. Before or during recovery and subsequent processing, tissues can become contaminated. Effective tissue recovery methods, such as minimizing recovery times (<24 h after death) and the number of experienced personnel performing recovery, are examples of factors that can affect the rate of tissue contamination at recovery. Additional factors, such as minimizing the time after asystole to recovery and the total time it takes to perform recovery, the type of recovery site, the efficacy of the skin prep performed immediately prior to recovery of tissue, and certain technical recovery procedures may also result in control of the rate of contamination. Due to the heterogeneity of reported recovery practices and experiences, it cannot be concluded if the use of other barriers and/or hygienic precautions to avoid contamination have had an effect on bioburden detected after tissue recovery. Qualified studies are lacking which indicates a need exists for evidence-based data to support methods that reduce or control bioburden.


Assuntos
Aloenxertos/microbiologia , Aloenxertos/virologia , Descontaminação/métodos , Esterilização/métodos , Bancos de Tecidos , Técnicas de Cultura de Células/métodos , Humanos , Manejo de Espécimes/métodos , Transplante Homólogo
5.
Cell Tissue Bank ; 17(4): 573-584, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27665294

RESUMO

Musculoskeletal allografts are typically disinfected using antibiotics, irradiation or chemical methods but protocols vary significantly between tissue banks. It is likely that different disinfection protocols will not have the same level of microorganism kill; they may also have varying effects on the structural integrity of the tissue, which could lead to significant differences in terms of clinical outcome in recipients. Ideally, a disinfection protocol should achieve the greatest bioburden reduction with the lowest possible impact on tissue integrity. A systematic review of three databases found 68 laboratory and clinical studies that analyzed the microbial bioburden or contamination rates of musculoskeletal allografts. The use of peracetic acid-ethanol or ionizing radiation was found to be most effective for disinfection of tissues. The use of irradiation is the most frequently published method for the terminal sterilization of musculoskeletal allografts; it is widely used and its efficacy is well documented in the literature. However, effective disinfection results were still observed using the BioCleanse™ Tissue Sterilization process, pulsatile lavage with antibiotics, ethylene oxide, and chlorhexidine. The variety of effective methods to reduce contamination rate or bioburden, in conjunction with limited high quality evidence provides little support for the recommendation of a single bioburden reduction method.


Assuntos
Aloenxertos/microbiologia , Aloenxertos/virologia , Transplante Ósseo , Desinfecção/métodos , Músculos/transplante , Esterilização/métodos , Transplante Ósseo/efeitos adversos , Osso e Ossos/microbiologia , Osso e Ossos/virologia , Técnicas de Cultura de Células/métodos , Humanos , Músculos/microbiologia , Músculos/virologia , Bancos de Tecidos , Transplante Homólogo
6.
Epidemiol Infect ; 141(4): 776-88, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22846369

RESUMO

The domestic poultry population in Vietnam has been vaccinated against highly pathogenic avian influenza (HPAI) H5N1 since 2005. Since then, outbreaks have continued to occur without a clear understanding of the mechanisms involved. The general objective of this study was to understand the epidemiology of the disease in the context of vaccination and to draw some conclusions about vaccination efficacy in the domestic poultry population of the Red River Delta area. Five cross-sectional surveys to measure the serological and virological prevalence in vaccinated and unvaccinated poultry were performed from the end of 2008 to June 2010. The global seroprevalence was 24% (95% confidence interval 19·9-28·2). Determinants of vaccine immunogenicity were identified separately in chickens and ducks as well as determinants of the seroconversion in unvaccinated birds. The results highlight the difficulties in maintaining good flock immunity in poultry populations using inactivated vaccine in the field with two vaccination rounds per year, and in preventing circulation of virus in co-existing unvaccinated poultry.


Assuntos
Galinhas/virologia , Patos/virologia , Gansos/virologia , Virus da Influenza A Subtipo H5N1/imunologia , Vacinas contra Influenza/uso terapêutico , Influenza Aviária/prevenção & controle , Animais , Estudos Transversais , Surtos de Doenças/veterinária , Glicoproteínas de Hemaglutininação de Vírus da Influenza/sangue , Virus da Influenza A Subtipo H5N1/isolamento & purificação , Influenza Aviária/epidemiologia , Reação em Cadeia da Polimerase , Estudos Soroepidemiológicos , Vacinação/veterinária , Vietnã/epidemiologia
7.
J Cell Biol ; 171(3): 549-58, 2005 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-16260500

RESUMO

Actin-based protrusions can form prominent structures on the apical surface of epithelial cells, such as microvilli. Several cytoplasmic factors have been identified that control the dynamics of actin filaments in microvilli. However, it remains unclear whether the plasma membrane participates actively in microvillus formation. In this paper, we analyze the function of Drosophila melanogaster cadherin Cad99C in the microvilli of ovarian follicle cells. Cad99C contributes to eggshell formation and female fertility and is expressed in follicle cells, which produce the eggshells. Cad99C specifically localizes to apical microvilli. Loss of Cad99C function results in shortened and disorganized microvilli, whereas overexpression of Cad99C leads to a dramatic increase of microvillus length. Cad99C that lacks most of the cytoplasmic domain, including potential PDZ domain-binding sites, still promotes excessive microvillus outgrowth, suggesting that the amount of the extracellular domain determines microvillus length. This study reveals Cad99C as a critical regulator of microvillus length, the first example of a transmembrane protein that is involved in this process.


Assuntos
Caderinas/genética , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/metabolismo , Precursores de Proteínas/genética , Animais , Proteínas Relacionadas a Caderinas , Proteínas de Drosophila/genética , Drosophila melanogaster/genética , Feminino , Humanos , Microvilosidades/fisiologia , Microvilosidades/ultraestrutura , Oogênese , Folículo Ovariano/fisiologia , Folículo Ovariano/ultraestrutura , Estrutura Terciária de Proteína
8.
Sci Adv ; 6(22): eaay2671, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32518818

RESUMO

The thermal excitation, regulation, and detection of charge carriers in solid-state electronics have attracted great attention toward high-performance sensing applications but still face major challenges. Manipulating thermal excitation and transport of charge carriers in nanoheterostructures, we report a giant temperature sensing effect in semiconductor nanofilms via optoelectronic coupling, termed optothermotronics. A gradient of charge carriers in the nanofilms under nonuniform light illumination is coupled with an electric tuning current to enhance the performance of the thermal sensing effect. As a proof of concept, we used silicon carbide (SiC) nanofilms that form nanoheterostructures on silicon (Si). The sensing performance based on the thermal excitation of charge carriers in SiC is enhanced by at least 100 times through photon excitation, with a giant temperature coefficient of resistance (TCR) of up to -50%/K. Our findings could be used to substantially enhance the thermal sensing performance of solid-state electronics beyond the present sensing technologies.

10.
J Phys Chem B ; 111(28): 7963-71, 2007 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-17592866

RESUMO

To get some information on the aggregation behaviors of the products derived from different organotrialkoxysilanes, the hydrolysis-condensation processes of some organotrialkoxysilanes have been examined by means of pyrene as fluorescent probe. The organotrialkoxysilanes used in the research were n-octadecyltri-methoxysilane (ODTMS), n-octyltrimethoxysilane (OTMS), 3-glycidoxypropyltrimethoxysilane (GTMS), 3-methacryloxypropyltrimethoxysilane (MAPTMS), and propyltrimethoxy-silane (PTMS). The results show that pyrene as fluorescence probe can respond sensitively not only to the organization state of the hydrolysates but also to the change in the organization state during the condensation process. The organization states during the hydrolysis and condensation can be explained in terms of structures of the products. In the initial stage, the silanols with long organic chains are amphiphilic molecules, and such nature of the silanols can be compared to that of a surfactant. Therefore, the excimer emission of pyrene is extremely obvious because of such silanols being prone to form aggregates. In the case of silanols having short alkyl groups or epoxy groups, these silanols homogenously disperse in solution, which results in the appearance of an only monomer emission of pyrene. In the late stage, the fluorescence behavior of pyrene is also sensitive to structural evolution of the silicates. The fluorescence spectra of pyrene during the condensation of the silanols with short alkyl groups or epoxy groups are almost in silence, indicating that the condensation products, with a low condensation degree, homogeneously disperse in solution. For the silanols with long hydrophobic substituents in different lengths, the changes in fluorescence spectra of pyrene during the condensation are varied. Commonly, the excimer emission is noticeable, implying that the condensation products with high condensation degree inhomogenously disperse in solution. However, the relative excimer/monomer fluorescence intensity is alkyl chain-length dependent. The longer alkyl chains in the condensation products result in the appearance of the obvious excimer emission. These phenomena imply that the condensation degree of the products increases with the length of the alkyl chains. Additionally, the distorted spectrum of pyrene appears in the case of the organotrialkoxysilanes with side chain substituent, illustrating that the steric hindrance between the substituents can be monitored by fluorescence of pyrene. All these results are verified by the fluorescence-quenching measurements. The approach in the present study gives new insights into the local structure and dynamics in hydrolysis-condensation process of organotrialkoxysilanes and emphasizes the influence of the self-assembling behavior.

11.
Laryngoscope ; 117(4): 674-9, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17429874

RESUMO

OBJECTIVE: To evaluate the therapeutic efficacy of bevacizumab and cetuximab, alone and in combination, in an orthotopic model of anaplastic thyroid carcinoma (ATC) in athymic nude mice. STUDY DESIGN AND SETTING: This was a randomized, controlled in vivo study. MATERIALS AND METHODS: The ATC cell line, ARO, was used to establish orthotopic xenografts of ATC in athymic nude mice. Mice were randomized to therapy for 4 weeks in one of four treatment groups: placebo, cetuximab, bevacizumab, or the combination of cetuximab and bevacizumab. A second study compared the antitumor efficacy of the cetuximab-bevacizumab combination with doxorubicin. In both studies, tumor volumes on completion were measured and compared. Immunohistochemical analysis was performed with antiCD31 and antiproliferating cell nuclear antigen (PCNA) antibodies to assess the in vivo mechanisms of action of these agents. RESULTS: Cetuximab decreased the production of vascular endothelial growth factor by ATC cell lines in vitro. Mean tumor volumes for the control, bevacizumab, cetuximab, and combination groups at the end of the in vivo study were 291, 213, 94, and 42 mm(3), respectively. The differences in mean tumor volume for the control versus treatment groups were statistically significant. Immunohistochemical analysis showed decreased microvessel density and PCNA positivity in the treatment groups. In the doxorubicin comparison study, mean tumor volumes for control, doxorubicin, and combination antibody treatment groups were 175, 162, and 22 mm(3), respectively. CONCLUSIONS: Cetuximab and bevacizumab alone and in combination inhibit tumor growth and angiogenesis in an in vivo model of ATC. Also, this therapy was superior to doxorubicin therapy.


Assuntos
Anticorpos Monoclonais/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Carcinoma/tratamento farmacológico , Neoplasias da Glândula Tireoide/tratamento farmacológico , Animais , Antibióticos Antineoplásicos/farmacologia , Antibióticos Antineoplásicos/uso terapêutico , Anticorpos Monoclonais/farmacologia , Anticorpos Monoclonais Humanizados , Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Bevacizumab , Western Blotting , Carcinoma/imunologia , Carcinoma/patologia , Contagem de Células , Linhagem Celular Tumoral , Cetuximab , Doxorrubicina/farmacologia , Doxorrubicina/uso terapêutico , Receptores ErbB/antagonistas & inibidores , Imuno-Histoquímica , Masculino , Camundongos , Camundongos Nus , Antígeno Nuclear de Célula em Proliferação/imunologia , Distribuição Aleatória , Receptores de Fatores de Crescimento do Endotélio Vascular/antagonistas & inibidores , Neoplasias da Glândula Tireoide/imunologia , Neoplasias da Glândula Tireoide/patologia
12.
Genes Brain Behav ; 16(5): 495-505, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28186690

RESUMO

Genetic variation in CACNA1C, which codes for the L-type calcium channel (LTCC) Cav 1.2, is associated with clinical diagnoses of bipolar disorder, depression and schizophrenia. Dysregulation of the mesolimbic-dopamine (ML-DA) system is linked to these syndromes and LTCCs are required for normal DAergic neurotransmission between the ventral tegmental area (VTA) and nucleus accumbens (NAc). It is unclear, however, how variations in CACNA1C genotype, and potential subsequent changes in expression levels in these regions, modify risk. Using constitutive and conditional knockout mice, and treatment with the LTCC antagonist nimodipine, we examined the role of Cacna1c in DA-mediated behaviors elicited by psychomotor stimulants. Using fast-scan cyclic voltammetry, DA release and reuptake in the NAc were measured. We find that subsecond DA release in Cacna1c haploinsufficient mice lacks normal sensitivity to inhibition of the DA transporter (DAT). Constitutive haploinsufficiency of Cacna1c led to attenuation of hyperlocomotion following acute administration of stimulants specific to DAT, and locomotor sensitization of these mice to the DAT antagonist GBR12909 did not reach the same level as wild-type mice. The maintenance of sensitization to GBR12909 was attenuated by administration of nimodipine. Sensitization to GBR12909 was attenuated in mice with reduced Cacna1c selectively in the VTA but not in the NAc. Our findings show that Cacna1c is crucial for normal behavioral responses to DA stimulants and that its activity in the VTA is required for behavioral sensitization. Cacna1c likely exerts these effects through modifications to presynaptic ML-DA system function.


Assuntos
Canais de Cálcio Tipo L/metabolismo , Proteínas da Membrana Plasmática de Transporte de Dopamina/metabolismo , Núcleo Accumbens/metabolismo , Área Tegmentar Ventral/metabolismo , Animais , Bloqueadores dos Canais de Cálcio/farmacologia , Canais de Cálcio Tipo L/genética , Sensibilização do Sistema Nervoso Central , Dopamina/metabolismo , Proteínas da Membrana Plasmática de Transporte de Dopamina/antagonistas & inibidores , Proteínas da Membrana Plasmática de Transporte de Dopamina/genética , Inibidores da Captação de Dopamina/farmacologia , Feminino , Locomoção , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Nimodipina/farmacologia , Núcleo Accumbens/efeitos dos fármacos , Núcleo Accumbens/fisiologia , Piperazinas/farmacologia , Área Tegmentar Ventral/efeitos dos fármacos , Área Tegmentar Ventral/fisiologia
13.
Clin Cancer Res ; 11(5): 1713-21, 2005 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-15755992

RESUMO

PURPOSE: To develop an orthotopic model of anaplastic thyroid carcinoma (ATC) in athymic nude mice. EXPERIMENTAL DESIGN: Various thyroid carcinoma cell lines were injected into the thyroid gland of athymic nude mice to determine whether such injection was technically feasible. ATC cells were then injected into the thyroid gland or the subcutis of nude mice at various concentrations, and the mice were then followed for tumor development. The tumors were examined histopathologically for local invasion or regional or distant metastasis. RESULTS: Injection of tumor cells into the thyroid glands of nude mice was technically feasible and resulted in the formation of thyroid tumors. The ATC cell line DRO showed significantly higher tumorigenicity in the thyroid gland than in the subcutis. In contrast, oral squamous cell carcinoma cell line TU167 shows no significantly higher tumorigenicity in the thyroid gland than in the subcutis. ATC tumors established in the thyroid gland also produced symptomatic compression of the esophagus and the trachea. Local invasion of the larynx and trachea was as well as high rates of pulmonary metastasis were also observed. Immunohistochemical staining showed higher microvessel density as well as higher expression of vascular endothelial growth factor and interleukin-8 in the orthotopic thyroid tumors than in ectopic tumors. CONCLUSION: An orthotopic model of ATC in athymic nude mice was developed that closely recapitulates the clinical findings of human ATC. This model should facilitate the understanding of the pathogenesis of ATC and aid in the development of novel therapies against ATC.


Assuntos
Carcinoma/patologia , Carcinoma/veterinária , Modelos Animais de Doenças , Neoplasias da Glândula Tireoide/patologia , Neoplasias da Glândula Tireoide/veterinária , Animais , Regulação Neoplásica da Expressão Gênica , Humanos , Imuno-Histoquímica , Masculino , Camundongos , Camundongos Nus , Invasividade Neoplásica , Metástase Neoplásica , Transplante Heterólogo , Células Tumorais Cultivadas
14.
Zoonoses Public Health ; 63(2): 112-28, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26146982

RESUMO

Economic evaluations are critical for the assessment of the efficiency and sustainability of animal health surveillance systems and the improvement of their efficiency. Methods identifying and quantifying costs and benefits incurred by public and private actors of passive surveillance systems (i.e. actors of veterinary authorities and private actors who may report clinical signs) are needed. This study presents the evaluation of perceived costs and benefits of highly pathogenic avian influenza (HPAI) passive surveillance in Vietnam. Surveys based on participatory epidemiology methods were conducted in three provinces in Vietnam to collect data on costs and benefits resulting from the reporting of HPAI suspicions to veterinary authorities. A quantitative tool based on stated preference methods and participatory techniques was developed and applied to assess the non-monetary costs and benefits. The study showed that poultry farmers are facing several options regarding the management of HPAI suspicions, besides reporting the following: treatment, sale or destruction of animals. The option of reporting was associated with uncertain outcome and transaction costs. Besides, actors anticipated the release of health information to cause a drop of markets prices. This cost was relevant at all levels, including farmers, veterinary authorities and private actors of the upstream sector (feed, chicks and medicine supply). One benefit associated with passive surveillance was the intervention of public services to clean farms and the environment to limit the disease spread. Private actors of the poultry sector valued information on HPAI suspicions (perceived as a non-monetary benefit) which was mainly obtained from other private actors and media.


Assuntos
Criação de Animais Domésticos/métodos , Conhecimentos, Atitudes e Prática em Saúde , Influenza Aviária/economia , Vigilância da População/métodos , Doenças das Aves Domésticas/economia , Criação de Animais Domésticos/economia , Animais , Análise Custo-Benefício , Notificação de Doenças , Surtos de Doenças/prevenção & controle , Humanos , Virus da Influenza A Subtipo H5N1/isolamento & purificação , Virus da Influenza A Subtipo H5N1/patogenicidade , Influenza Aviária/epidemiologia , Influenza Aviária/prevenção & controle , Influenza Aviária/psicologia , Entrevistas como Assunto , Aves Domésticas , Doenças das Aves Domésticas/epidemiologia , Doenças das Aves Domésticas/prevenção & controle , Doenças das Aves Domésticas/psicologia , Vietnã/epidemiologia
15.
Leukemia ; 8(8): 1280-4, 1994 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-8057662

RESUMO

Deletion of the retinoblastoma gene (Rb-1) was found in more than 50% (12/23) of patients with multiple myeloma (MM) by fluorescence in situ hybridization (FISH). Myeloma cells were highly purified from bone marrow aspirates by flow cytometry and analyzed using probes specific for the Rb-1 gene and the centromeric region of chromosomes 13 and 21. Routine cytogenetics revealed abnormal chromosome 13 in only 17% (4/23) of these patients. No correlation between Rb-1 deletion and tumor stage, immunoglobulin isotype, anemia, serum beta-2 microglobulin levels, patient age or the extent of prior therapy was found. However, the high incidence of Rb-1 deletion detected by FISH suggests a role of this tumor suppressor gene in the biology of MM. Although allelic loss of the Rb-1 gene is unlikely to be the only genetic change necessary for the development of MM, it may be a relatively early event in MM unrelated to chemotherapeutic intervention. Since the Rb-1 gene suppresses IL-6 production and secretion, Rb-1 deletion may result in deregulation of IL-6 expression and hence expansion of IL-6 dependent myeloma clones.


Assuntos
Aberrações Cromossômicas , Cromossomos Humanos Par 13 , Cromossomos Humanos Par 21 , Deleção de Genes , Genes do Retinoblastoma , Mieloma Múltiplo/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Medula Óssea/patologia , Cosmídeos , DNA de Neoplasias/análise , Éxons , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Hibridização in Situ Fluorescente , Interleucina-1/biossíntese , Cariotipagem , Masculino , Pessoa de Meia-Idade , Mieloma Múltiplo/patologia
16.
Clin Cancer Res ; 9(8): 3183-9, 2003 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-12912971

RESUMO

PURPOSE: Because survival for patients with oral cancer has not improved over the past 25 years, new approaches for treatment are needed. Targeted molecular therapy against epidermal growth factor receptor (EGFR) has shown promise as an adjuvant therapy in preliminary studies in several solid tumors, including head and neck cancer. The objective of this study was to determine the efficacy of paclitaxel and PKI166, a novel inhibitor of EGFR, against oral cavity cancer. EXPERIMENTAL DESIGN AND RESULTS: JMAR human oral cancer cells were pretreated for 1 h with PKI166 and then stimulated with epidermal growth factor. EGFR-specific tyrosine kinase autophosphorylation measured by Western immunoblotting was inhibited by PKI166 in a dose-dependent fashion at all doses tested (0.01-1 micro M). Next, the induction of apoptosis in JMAR cells treated with paclitaxel (0.001 to 0.1 micro M) with or without PKI166 (0, 1, or 2 micro M) was determined using a propidium iodide assay. The addition of 2.0 micro M PKI166 significantly increased tumor cell death, shifting the amount of paclitaxel needed to induce apoptosis in 50% of cells from 0.1 to 0.001 micro M. These in vitro findings were confirmed using an orthotopic model of oral cancer. JMAR oral cancer cells were implanted into the tongues of nude mice. After lingual tumors developed, mice were randomized into four groups (n = 10): (a) oral PKI166 (100 mg/kg); (b) i.p. paclitaxel (200 micro g/wk); (c) PKI166 and paclitaxel; or (d) placebo. Mice treated with PKI166/paclitaxel demonstrated a significant increase in survival (P = 0.028). After necropsy, all tongue tumors were evaluated for apoptosis by the terminal deoxynucleotidyl transferase-mediated nick end labeling assay. A greater apoptotic fraction of tumor cells was found in tumors of mice treated with paclitaxel and PKI166 as compared with the other treatment groups (136.4 versus 37.8; P = 0.016). CONCLUSIONS: Combination therapy with paclitaxel and PKI166 prolongs survival in an orthotopic preclinical model of tongue cancer by increasing programmed cell death of oral cancer.


Assuntos
Antineoplásicos Fitogênicos/uso terapêutico , Apoptose , Receptores ErbB/antagonistas & inibidores , Neoplasias Bucais/tratamento farmacológico , Neoplasias Bucais/mortalidade , Paclitaxel/uso terapêutico , Pirimidinas/uso terapêutico , Pirróis/uso terapêutico , Animais , Western Blotting , Morte Celular , Linhagem Celular Tumoral , Relação Dose-Resposta a Droga , Neoplasias de Cabeça e Pescoço/patologia , Humanos , Marcação In Situ das Extremidades Cortadas , Ligantes , Masculino , Camundongos , Camundongos Nus , Microscopia de Fluorescência , Neoplasias Bucais/metabolismo , Neoplasias/patologia , Fosforilação , Propídio/uso terapêutico , Língua/patologia , Neoplasias da Língua/tratamento farmacológico , Tirosina/metabolismo
17.
Hypertension ; 15(1): 56-67, 1990 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-2295514

RESUMO

To determine the effect of elevated blood pressure on the ultrastructure of rat aorta, hypertension (average mean pressure 163 +/- 17 mm Hg) was produced by suprarenal aortic coarctation. After 3 weeks, the subendothelium of the hypertensive thoracic aorta showed significantly increased volume measurements for mononuclear leukocytes and basement membrane-like material compared with the sham-operated control group. Focal areas of rarefaction of the subendothelial extracellular material were associated with the nearby presence of mononuclear leukocytes. None of these alterations were found in the normotensive abdominal aorta. The tunica media of hypertensive thoracic aorta also contained significantly increased basement membrane-like material. This new finding in an animal hypertension model is the direct result of the quantitative morphological approach employed in this study. In some rats, the partially constricting aortic ligature compromised the right renal artery leading to ischemic atrophy of the right kidney and hyperreninemia in addition to hypertension. In this group, excluded from the previous analysis and evaluated separately, subendothelial thickening and accumulation of basement membrane-like material in the thoracic aorta were greatly increased compared with the control group and other hypertensive rats. This result could not be attributed to an effect of blood pressure alone and might have been caused in part by humoral factors. Basement membrane accumulation appears to be an important early response of the arterial wall to hypertension or other factors in this rat model.


Assuntos
Aorta/ultraestrutura , Hipertensão/patologia , Animais , Aorta Abdominal/ultraestrutura , Aorta Torácica/ultraestrutura , Membrana Basal/ultraestrutura , Cateterismo , Espaço Extracelular , Masculino , Microscopia Eletrônica , Ratos , Ratos Endogâmicos
18.
Biochem Pharmacol ; 32(7): 1197-200, 1983 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-6342624

RESUMO

When rats were fed a diet containing 0.4% (w/w) butylated hydroxytoluene (BHT), glutathione (GSH) S-transferase activity towards 1-chloro-2,4-dinitrobenzene (CDNB) increased approximately 3-fold in the liver. Immunotitration studies using the antibodies raised against rat liver GSH S-transferase B and GSH S-transferase A and C indicated that the increase in GSH S-transferase activity was probably due to de novo protein synthesis. Since some forms of rat liver GSH S-transferases express GSH peroxidase II activity, a concomitant increase in GSH peroxidase II was expected. However, GSH peroxidase II activity in the liver of BHT-treated rats remained unchanged. Gel filtration of supernatant fractions from livers of control and BHT-treated rats, followed by isoelectric focusing, indicated that BHT induced the activity of hepatic GSH S-transferases, without any apparent effect on GSH peroxidase II activity.


Assuntos
Hidroxitolueno Butilado/farmacologia , Glutationa Peroxidase/biossíntese , Isoenzimas/biossíntese , Fígado/enzimologia , Peroxidases/biossíntese , Animais , Dinitroclorobenzeno/metabolismo , Indução Enzimática/efeitos dos fármacos , Técnicas de Imunoadsorção , Fígado/efeitos dos fármacos , Masculino , Ratos , Ratos Endogâmicos
19.
J Neuroendocrinol ; 15(9): 865-70, 2003 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-12899681

RESUMO

Gonadotropin-releasing hormone (GnRH), which is essential for reproductive function, is made by neurones that migrate from the nasal region into the brain during early embryonic development. This migration begins in chick when the olfactory pit is formed. This is approximately the time that GnRH neurones can be detected immunocytochemically. The present study investigated (i). how early in development the GnRH gene is expressed and (ii). the sites of its expression. Accordingly, reverse transcriptase-polymerase chain reaction (PCR) and in situ hybridization were performed on chick embryos before gastrulation up until the stage by which GnRH neurones have begun to migrate into the central nervous system. Primers were made to the 5'- and 3'-UTR region of the message for cGnRH-I, the form of the peptide that is essential for reproductive function in the chicken. PCR product was found in all stages and the sequences of products from all stages were identical. Thus, the GnRH gene is expressed continuously throughout embryonic development. In situ hybridization with a digoxygenin labelled riboprobe revealed staining along the primitive streak immediately before gastrulation. In later stages, cGnRH-I gene expression was seen in association with the anterior neural ridge. The expression was subsequently restricted to a narrow, clearly defined region, which is associated with the presumptive nasal cavity and olfactory placode. Later, GnRH neurones could be seen in their migratory routes by both in situ hybridization and immunocytochemistry. Expression of the GnRH gene has been described in preimplantation stages in mammals and there is evidence that the neuropeptide plays a role in formation and maintenance of the placenta. What role (if any) it may play in early avian development remains unknown. The demonstration of sites of GnRH expression during the early period of neurulation suggests that GnRH neurones arise before olfactory placode formation.


Assuntos
Embrião de Galinha/fisiologia , Hormônio Liberador de Gonadotropina/metabolismo , Animais , Sequência de Bases/genética , Embrião de Galinha/metabolismo , Hormônio Liberador de Gonadotropina/genética , Imuno-Histoquímica , Hibridização In Situ , Dados de Sequência Molecular , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Homologia de Sequência do Ácido Nucleico , Distribuição Tecidual
20.
Am J Trop Med Hyg ; 56(5): 503-7, 1997 May.
Artigo em Inglês | MEDLINE | ID: mdl-9180598

RESUMO

The pharmacokinetics of artemisinin was studied in 11 Vietnamese patients with uncomplicated falciparum malaria after a single 500 mg oral dose. Curative treatment with mefloquine (15 mg/kg) was provided 24 hr after the artemisinin dose. Artemisinin concentrations were measured by high-performance liquid chromatography with electrochemical detection. The following pharmacokinetic results were found (all mean +/- SD); calculated volume of distribution/bioavailability = 22.8 +/- 16.6 L.kg-1, mean absorption time = 1.16 +/- 0.92 hr, calculated maximum concentration = 364 +/- 250 micrograms.L-1 occurring at 2.88 +/- 1.71 hr after drug intake, and an elimination half-life of 2.72 +/- 1.76 hr. Bioavailability was low. These results do not differ from results in healthy subjects. Parasites disappeared rapidly, with a mean parasite clearance time of 36 hr. No relationship was found between pharmacokinetics and the parasite elimination rate. Tolerance to the single dose of artemisinin was good. No adverse effects were detected. In conclusion, pharmacokinetics of a single dose of artemisinin for uncomplicated falciparum malaria is not different from findings in healthy subjects. A single dose of 500 mg of artemisinin is effective in reducing parasitemia in nonsevere lalciparum malaria and is well-tolerated.


Assuntos
Antimaláricos/farmacocinética , Artemisininas , Malária Falciparum/tratamento farmacológico , Sesquiterpenos/farmacocinética , Adulto , Humanos , Malária Falciparum/metabolismo
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