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1.
Orphanet J Rare Dis ; 17(1): 13, 2022 01 10.
Artigo em Inglês | MEDLINE | ID: mdl-35012600

RESUMO

BACKGROUND: Commonly known as Batten disease, the neuronal ceroid lipofuscinoses (NCLs) are a genetically heterogeneous group of rare pediatric lysosomal storage disorders characterized by the intracellular accumulation of autofluorescent material (known as lipofuscin), progressive neurodegeneration, and neurological symptoms. In 2002, a disease-causing NCL mutation in the CLN6 gene was identified (c.214G > T) in the Costa Rican population, but the frequency of this mutation among local Batten disease patients remains incompletely characterized, as do clinical and demographic attributes for this rare patient population. OBJECTIVE: To describe the main sociodemographic and clinical characteristics of patients with a clinical diagnosis for Batten Disease treated at the National Children's Hospital in Costa Rica and to characterize via molecular testing their causative mutations. METHODS: DNA extracted from buccal swabs was used for CLN6 gene sequencing. Participants' sociodemographic and clinical characteristics were also obtained from their medical records. RESULTS: Nine patients with a clinical diagnosis of Batten disease were identified. Genetic sequencing determined the presence of the previously described Costa Rican homozygous mutation in 8 of 9 cases. One patient did not have mutations in the CLN6 gene. In all cases where the Costa Rican CLN6 mutation was present, it was accompanied by a substitution in intron 2. Patients were born in 4 of the 7 Costa Rican provinces, with an average onset of symptoms close to 4 years of age. No parental consanguinity was present in pedigrees. Initial clinical manifestations varied between patients but generally included: gait disturbances, language problems, visual impairment, seizures and psychomotor regression. Cortical and cerebellar atrophy was a constant finding when neuroimaging was performed. Seizure medication was a common element of treatment regimens. CONCLUSIONS: This investigation supports that the previously characterized c.214G > T mutation is the most common causative NCL mutation in the Costa Rican population. This mutation is geographically widespread among Costa Rican NCL patients and yields a clinical presentation similar to that observed for CLN6 NCL patients in other geographies.


Assuntos
Lipofuscinoses Ceroides Neuronais , Criança , Costa Rica , Humanos , Proteínas de Membrana/genética , Mutação/genética , Lipofuscinoses Ceroides Neuronais/diagnóstico , Lipofuscinoses Ceroides Neuronais/genética , Linhagem
2.
Clin Transl Oncol ; 21(8): 1052-1060, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30632010

RESUMO

BACKGROUND: Integrins are highly attractive targets in oncology due to their involvement in angiogenesis in a wide spectrum of cancer entities. Among several integrin inhibitors, cilengitide is suggested to be one of the most promising inhibitors. However, little is known about the cellular processes induced during cilengitide chemotherapy in head and neck squamous cell carcinoma (HNSCC). MATERIALS AND METHODS: For the current study, 3 HNSCC cell lines, SCC4, SCC15 and SCC25; and 3 primary culture cells, TU53, TU57, and TU63 were used. CD90, cytokeratin, and vimentin were stained immunohistochemically to identify the biological characteristics of these cell lines and primary culture cells and the cytostatic effect of cilengitide was evaluated. Quantitative polymerase chain reaction (qPCR) arrays were applied to evaluate target protein genes ITGAV, ITGB3, and ITGB5 of integrin αvß3 and αvß5 at respective concentrations of 50 and 100 µM cilengitide for 72 h. RESULTS: Cilengitide has significantly inhibited the proliferation of HNSCC cells in a dose-dependent way. At the same concentration, cilengitide suppressed the proliferation of primary culture cells even more strongly than it did that of cell lines, suggesting that primary culture cells retain more of their internal biological characteristics than do cell lines. qPCR assay detected downregulation of ITGAV, ITGB3, and ITGB5 gene expression after exposure to 50 µM of cilengitide. However, after exposure to 100-µM cilengitide, expression of these genes significantly increased both in cell lines and primary culture cells. CONCLUSIONS: RGD-containing small-molecule synthetic peptides might be considered in tumor chemotherapy in the near future. The different reactions of primary culture cells and cell lines demonstrated that individualized chemotherapy plans may be a feasible option. However, research on the role of cilengitide in HNSCC therapy is still in its early stages, and further investigations are required.


Assuntos
Proliferação de Células/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Neoplasias de Cabeça e Pescoço/patologia , Cadeias beta de Integrinas/química , Integrina beta3/química , Venenos de Serpentes/farmacologia , Carcinoma de Células Escamosas de Cabeça e Pescoço/patologia , Apoptose/efeitos dos fármacos , Neoplasias de Cabeça e Pescoço/tratamento farmacológico , Neoplasias de Cabeça e Pescoço/metabolismo , Humanos , Cadeias beta de Integrinas/genética , Cadeias beta de Integrinas/metabolismo , Integrina beta3/genética , Integrina beta3/metabolismo , Carcinoma de Células Escamosas de Cabeça e Pescoço/tratamento farmacológico , Carcinoma de Células Escamosas de Cabeça e Pescoço/metabolismo , Células Tumorais Cultivadas
3.
J Neuroradiol ; 46(3): 179-185, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-29958847

RESUMO

BACKGROUND: This study explores whether objective, quantitative radiomic biomarkers derived from magnetic resonance (MR), positron emission tomography (PET), and computed tomography (CT) may be useful in reliably distinguishing malignant peripheral nerve sheath tumors (MPNST) from benign plexiform neurofibromas (PN). METHODS: A registration and segmentation pipeline was established using a cohort of NF1 patients with histopathological diagnosis of PN or MPNST, and medical imaging of the PN including MR and PET-CT. The corrected MR datasets were registered to the corresponding PET-CT via landmark-based registration. PET standard-uptake value (SUV) thresholds were used to guide segmentation of volumes of interest: MPNST-associated PET-hot regions (SUV≥3.5) and PN-associated PET-elevated regions (2.0

Assuntos
Biomarcadores Tumorais/análise , Transformação Celular Neoplásica , Imageamento por Ressonância Magnética , Neoplasias de Bainha Neural/diagnóstico por imagem , Neoplasias de Bainha Neural/patologia , Neurofibromatose 1/diagnóstico por imagem , Neurofibromatose 1/patologia , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Diagnóstico Diferencial , Feminino , Humanos , Interpretação de Imagem Assistida por Computador , Masculino , Reprodutibilidade dos Testes , Estudos Retrospectivos , Adulto Jovem
4.
Sci Rep ; 8(1): 13278, 2018 09 05.
Artigo em Inglês | MEDLINE | ID: mdl-30185885

RESUMO

Through the process of neuronal differentiation, newly born neurons change from simple, spherical cells to complex, sprawling cells with many highly branched processes. One of the first stages in this process is neurite initiation, wherein cytoskeletal modifications facilitate membrane protrusion and extension from the cell body. Hundreds of actin modulators and microtubule-binding proteins are known to be involved in this process, but relatively little is known about how upstream regulators bring these complex networks together at discrete locations to produce neurites. Here, we show that Myristoylated alanine-rich C kinase substrate (MARCKS) participates in this process. Marcks-/- cortical neurons extend fewer neurites and have less complex neurite arborization patterns. We use an in vitro proteomics screen to identify MARCKS interactors in developing neurites and characterize an interaction between MARCKS and a CDC42-centered network. While the presence of MARCKS does not affect whole brain levels of activated or total CDC42, we propose that MARCKS is uniquely positioned to regulate CDC42 localization and interactions within specialized cellular compartments, such as nascent neurites.


Assuntos
Substrato Quinase C Rico em Alanina Miristoilada/metabolismo , Neuritos/metabolismo , Neurônios/citologia , Actinas/metabolismo , Animais , Citoesqueleto/metabolismo , Feminino , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Microtúbulos/metabolismo , Neurônios/metabolismo , Fosforilação , Cultura Primária de Células , Ligação Proteica , Pseudópodes/metabolismo , Transdução de Sinais , Proteína cdc42 de Ligação ao GTP/metabolismo
5.
Mol Neurobiol ; 55(11): 8388-8402, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29546593

RESUMO

Axons of the corpus callosum (CC), the white matter tract that connects the left and right hemispheres of the brain, receive instruction from a number of chemoattractant and chemorepulsant cues during their initial navigation towards and across the midline. While it has long been known that the CC is malformed in the absence of Myristoylated alanine-rich C-kinase substrate (MARCKS), evidence for a direct role of MARCKS in axon navigation has been lacking. Here, we show that MARCKS is necessary for Netrin-1 (NTN1) signaling through the DCC receptor, which is critical for axon guidance decisions. Marcks null (Marcks-/-) neurons fail to respond to exogenous NTN1 and are deficient in markers of DCC activation. Without MARCKS, the subcellular distributions of two critical mediators of NTN1-DCC signaling, the tyrosine kinases PTK2 and SRC, are disrupted. Together, this work establishes a novel role for MARCKS in axon dynamics and highlights the necessity of MARCKS as an organizer of DCC signaling at the membrane.


Assuntos
Corpo Caloso/embriologia , Corpo Caloso/metabolismo , Receptor DCC/metabolismo , Substrato Quinase C Rico em Alanina Miristoilada/metabolismo , Netrinas/metabolismo , Transdução de Sinais , Animais , Axônios/metabolismo , Membrana Celular/metabolismo , Embrião de Mamíferos/metabolismo , Quinase 1 de Adesão Focal/metabolismo , Camundongos Endogâmicos C57BL , Modelos Biológicos , Fosforilação , Ligação Proteica , Quinases da Família src/metabolismo
6.
AJNR Am J Neuroradiol ; 38(5): 928-934, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28364004

RESUMO

BACKGROUND AND PURPOSE: The mechanism of early brain injury following subarachnoid hemorrhage is not well understood. We aimed to evaluate if cytotoxic and vasogenic edema are contributing factors. MATERIALS AND METHODS: A retrospective analysis was conducted in patients with SAH undergoing diffusion-weighted MR imaging within 72 hours of onset. Apparent diffusion coefficient values derived from DWI were evaluated by using whole-brain histograms and 19 prespecified ROIs in patients with SAH and controls with normal findings on MRI. Cytotoxic edema observed outside the ROIs was assessed in patients with SAH. The average median ADC values were compared between patients with SAH and controls and patients with SAH with mild (Hunt and Hess 1-3) versus severe early brain injury (Hunt and Hess 4-5). RESULTS: We enrolled 33 patients with SAH and 66 controls. The overall average median whole-brain ADC was greater for patients with SAH (808 × 10-6 mm2/s) compared with controls (788 × 10-6 mm2/s, P < .001) and was higher in patients with SAH across ROIs after adjusting for age: cerebral gray matter (826 versus 803 × 10-6 mm2/s, P = .059), cerebral white matter (793 versus 758 × 10-6 mm2/s, P = .023), white matter tracts (797 versus 739 × 10-6 mm2/s, P < .001), and deep gray matter (754 versus 713 × 10-6 mm2/s, P = .016). ADC values trended higher in patients with Hunt and Hess 4-5 versus those with Hunt and Hess 1-3. Early cytotoxic edema was observed in 13 (39%) patients with SAH and was more prevalent in those with severe early brain injury (87.5% of patients with Hunt and Hess 4-5 versus 24.0% of those with Hunt and Hess 1-3, P = .001). CONCLUSIONS: Age-adjusted ADC values were globally increased in patients with SAH compared with controls, even in normal-appearing brain regions, suggesting diffuse vasogenic edema. Cytotoxic edema was also present in patients with SAH and correlated with more severe early brain injury.


Assuntos
Edema Encefálico/etiologia , Hemorragia Subaracnóidea/complicações , Adulto , Idoso , Edema Encefálico/diagnóstico por imagem , Imagem de Difusão por Ressonância Magnética/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Hemorragia Subaracnóidea/diagnóstico por imagem
7.
Rev Sci Instrum ; 84(5): 055115, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23742597

RESUMO

We report on the first storage of ion beams in the Double ElectroStatic Ion Ring ExpEriment, DESIREE, at Stockholm University. We have produced beams of atomic carbon anions and small carbon anion molecules (C(n)(-), n = 1, 2, 3, 4) in a sputter ion source. The ion beams were accelerated to 10 keV kinetic energy and stored in an electrostatic ion storage ring enclosed in a vacuum chamber at 13 K. For 10 keV C2 (-) molecular anions we measure the residual-gas limited beam storage lifetime to be 448 s ± 18 s with two independent detector systems. Using the measured storage lifetimes we estimate that the residual gas pressure is in the 10(-14) mbar range. When high current ion beams are injected, the number of stored particles does not follow a single exponential decay law as would be expected for stored particles lost solely due to electron detachment in collision with the residual-gas. Instead, we observe a faster initial decay rate, which we ascribe to the effect of the space charge of the ion beam on the storage capacity.

8.
Rev Sci Instrum ; 82(6): 065112, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21721735

RESUMO

We describe the design of a novel type of storage device currently under construction at Stockholm University, Sweden, using purely electrostatic focussing and deflection elements, in which ion beams of opposite charges are confined under extreme high vacuum cryogenic conditions in separate "rings" and merged over a common straight section. The construction of this double electrostatic ion ring experiment uniquely allows for studies of interactions between cations and anions at low and well-defined internal temperatures and centre-of-mass collision energies down to about 10 K and 10 meV, respectively. Position sensitive multi-hit detector systems have been extensively tested and proven to work in cryogenic environments and these will be used to measure correlations between reaction products in, for example, electron-transfer processes. The technical advantages of using purely electrostatic ion storage devices over magnetic ones are many, but the most relevant are: electrostatic elements which are more compact and easier to construct; remanent fields, hysteresis, and eddy-currents, which are of concern in magnetic devices, are no longer relevant; and electrical fields required to control the orbit of the ions are not only much easier to create and control than the corresponding magnetic fields, they also set no upper mass limit on the ions that can be stored. These technical differences are a boon to new areas of fundamental experimental research, not only in atomic and molecular physics but also in the boundaries of these fields with chemistry and biology. For examples, studies of interactions with internally cold molecular ions will be particular useful for applications in astrophysics, while studies of solvated ionic clusters will be of relevance to aeronomy and biology.

9.
Anticancer Res ; 30(7): 2739-44, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20683007

RESUMO

UNLABELLED: Ovarian cancer (OC) is a disease with poor prognosis, and molecular markers are needed to improve understanding of disease progression and resultant treatment. Only limited data concerning the expression of maspin, a serine protease inhibitor, in ovarian cancer (OC) are available. This study investigates the prognostic value of maspin expression (ME) in various OC cell lines and clinical tissue specimens from OC patients. PATIENTS AND METHODS: Tumour purified mouse anti-human maspin monoclonal antibody was applied to tissue specimens from 87 OC patients. ME was recorded by an immunoreactive score, which was correlated with grading, stage, histopathological subtypes and overall survival. Additionally ME was evaluated in established ovarian cancer cell lines (HEY, SKOV3, OVCAR3/8) and paclitaxel- and docetaxel-resistant HEY cells by QRT-PCR. RESULTS: There was significant correlation between cytoplasmatic ME and overall survival (p<0.05). OC patients with high levels of ME had a median survival of 28 vs. 57 months for those with low levels. Significant differential ME was detected between benign, borderline ovarian lesions and OC, as well as among different tumour gradings. Normal ovarian epithelial cells expressed less maspin than ovarian cancer cells as measured by QRT-PCR. Docetaxel- and paclitaxel-resistant ovarian cell lines showed an even higher level of ME, suggesting an unfavourable role of ME in OC cell lines. CONCLUSION: Maspin is expressed differentially in OC, and low expression levels of maspin are correlated with a longer survival.


Assuntos
Adenocarcinoma/metabolismo , Neoplasias Ovarianas/metabolismo , Serina Proteases/metabolismo , Inibidores de Serina Proteinase/biossíntese , Serpinas/biossíntese , Adenocarcinoma/enzimologia , Adenocarcinoma/patologia , Linhagem Celular Tumoral , Núcleo Celular/metabolismo , Citoplasma/metabolismo , Feminino , Humanos , Imuno-Histoquímica , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Neoplasias Ovarianas/enzimologia , Neoplasias Ovarianas/patologia , Inibidores de Serina Proteinase/metabolismo , Serpinas/metabolismo
10.
Cytogenet Genome Res ; 114(3-4): 235-9, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16954659

RESUMO

We report on a family in which a daughter is described with mental retardation, as well as malformations of the heart, and of the brain (Dandy-Walker variant). The patient's phenotype suggests a chromosomal rearrangement. However, her karyotype was unremarkable by conventional cytogenetic analysis. In order to detect chromosome rearrangements overseen by this method, the subtelomere regions of suspicious chromosomes were verified by fluorescence in situ hybridization (FISH). A rearranged derivative chromosome 6 was identified. Further examinations by FISH-microdissection (FISH-MD) revealed a maternal complex balanced translocation. The patient inherited the derivative chromosome 6 from her mother and therefore carries a partial monosomy 6q26-->qter and a partial trisomy 11q23.3-->qter.


Assuntos
Desequilíbrio Alélico , Cromossomos Humanos Par 11 , Cromossomos Humanos Par 6 , Translocação Genética , Aberrações Cromossômicas , Mapeamento Cromossômico , Dissecação/métodos , Feminino , Humanos , Hibridização in Situ Fluorescente , Mães , Telômero/genética
11.
Chromosome Res ; 9(5): 395-402, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11448041

RESUMO

A technique disclosing most information about chromosome modifications is the technique of choice for the analysis of chromosome alterations. The newly developed method for microdissection of fluorescence-labeled chromosomes (FISH-MD) can improve upon this expectation in combination with 24-color spectral karyotyping (SKY). The highly efficient way to detect chromosome modifications by SKY and the detailed specification of aberrant chromosomes by FISH-MD prompted us to use both techniques in a combined approach called SKY-MD. First, an overview of chromosomal aberrations is obtained by spectral karyotyping and subsequently the derivative chromosomes recognized are characterized in a highly specific manner by microdissection and reverse painting. A small quantity of isolated material dissected directly from a 24-color metaphase is sufficient to obtain very detailed information about the chromosome regions and the breakpoints involved in the derivative chromosomes. Therefore, the combination of spectral karyotyping and microdissection in one procedure, and reverse painting can characterize chromosomal aberrations with a degree of specificity hitherto unknown from individual karyotyping experiments. In this article we compare the efficiency of both the SKY technique and that of classical microdissection with the efficiency obtained by SKY-MD.


Assuntos
Coloração Cromossômica/métodos , Cromossomos/ultraestrutura , Cariotipagem/métodos , Aberrações Cromossômicas , Bandeamento Cromossômico , Cromossomos Humanos Par 9/ultraestrutura , Feminino , Humanos , Hibridização In Situ , Hibridização in Situ Fluorescente/métodos , Masculino , Reação em Cadeia da Polimerase
12.
J Biomed Mater Res ; 57(1): 41-7, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11416847

RESUMO

The success of calcium phosphate (CaP) coatings used to accelerate initial bone growth onto dental implants can vary depending on the CaP phases present in the coating. In this study, the effect of CaP coating crystal structure and morphology on dissolution rates was investigated. RF magnetron-sputtered CaP coatings (NTC) were compared to a less strained coating (HTC) obtained from heat treatment of sputtered samples at 550 degrees C. Coating strain differences were apparent in XRD spectra where hydroxyapatite-like planes shifted by 0.5 degrees 2theta and 0.05 degrees 2theta for the NTC and HTC coatings, respectively. HTC XRD peak widths were broader than NTC peak widths, indicating smaller crystals or grain sizes. These differences in grain size were corroborated by imaging with scanning probe microscopy. NTC coatings dissolved at a 300% faster rate than HTC coatings. A major factor contributing to this kinetic effect was the level of strain in both coatings. These results suggest an alternate design for CaP coatings can be obtained through the manipulation of coating strain. Using this approach, delivery of different ionic gradients from CaP coatings to surrounding tissue environments can be obtained from surfaces having similar chemistries.


Assuntos
Fosfatos de Cálcio , Implantes Dentários , Materiais Dentários , Humanos
13.
Neurobiol Aging ; 21(6): 921-9, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-11124443

RESUMO

There are several adaptor proteins associated with clathrin coated vesicles. Among them are AP180 and AP-2. We and others have previously described synaptic localization of AP180. AP180 immunoreactivity is altered in both the superior frontal gyrus and hippocampus in Alzheimer's disease (AD). We here investigate the location and alteration of another adaptor protein, AP-2. In contrast to AP180, we have found that AP-2 is expressed by both neurons and glia. Furthermore, the only noticeable change of AP-2 in AD is a loss of its immunoreactivity in layer II of the superior frontal gyrus.


Assuntos
Lobo Frontal/citologia , Proteínas Monoméricas de Montagem de Clatrina , Proteínas do Tecido Nervoso/análise , Neuroglia/citologia , Neurônios/citologia , Fosfoproteínas/análise , Proteínas Adaptadoras de Transporte Vesicular , Idoso , Idoso de 80 Anos ou mais , Animais , Linhagem Celular , Inibidores Enzimáticos/análise , Feminino , Lobo Frontal/patologia , Humanos , Masculino , Camundongos , Pessoa de Meia-Idade , Neuroglia/patologia , Neurônios/patologia , Especificidade de Órgãos , Valores de Referência , Sinapses/patologia , Sinapses/ultraestrutura
14.
Cancer Genet Cytogenet ; 122(1): 7-12, 2000 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-11104025

RESUMO

Comparative genomic hybridization (CGH) is a valuable technique for cytogenetic analysis of solid tumors. To evaluate the reliability of CGH, we examined DNA of 10 ovarian carcinomas after CGH analysis with single- and double-locus fluorescence in situ hybridization (FISH). The FISH experiments, involving 5 chromosomes (chromosomes 3, 6, 8, 12, and 18) with different FISH probes, confirmed the CGH results in 66.2% of cases (92 of 139 investigated loci). In 4 patients, inconsistent results (41 loci) were related to polyploidy, because CGH cannot detect polyploid karyotypes. The remaining 6 discordant loci can be referred to limitations in both techniques. Re-evaluation of FISH and CGH results by one other is therefore recommended to overcome these technical artifacts. Nevertheless, CGH is of potential value in characterizing chromosomal alterations and might help in generating tumor-specific sets of FISH probes to obtain genetic information of prognostic value within a few days.


Assuntos
Interfase , Hibridização de Ácido Nucleico , Neoplasias Ovarianas/genética , Cromossomos Humanos , Feminino , Humanos , Hibridização in Situ Fluorescente , Neoplasias Ovarianas/patologia , Reprodutibilidade dos Testes
15.
Biomaterials ; 21(16): 1669-77, 2000 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10905408

RESUMO

Modular, head-stem, mixed-metal connections are susceptible to mechanically mediated electrochemical interactions. Any attempt to improve the performance of these connections should center around increasing their resistance to mechanical damage, particularly the titanium alloy (Ti64). This study investigated the effect of a nitrogen-diffusion-hardening process on Ti64, with specific reference to changes in composition, chemistry, electrochemistry and its ability to resist and/or repassivate scratch damage. The nitrogen-diffusion-hardened Ti64 alloy had TiN and TiNO complexes at the immediate surface and sub-surface layers. The diffusion-hardened samples also had a deeper penetration of oxygen compared to regular Ti64 alloy samples. The electrochemical impedance spectroscopy data corroborated the increased thickness of the barrier oxide on the diffusion-hardened samples. The nitrogen-diffusion-hardened samples were more resistant to scratch damage and repaired/repassivated faster after such damage. The results suggest that the nitrogen-diffusion-hardened titanium alloy should exhibit increased resistance to mechanical-electrochemical interactions in mixed-metal modular interfaces in total hip prostheses.


Assuntos
Ligas/química , Nitrogênio/química , Alumínio/química , Eletroquímica , Propriedades de Superfície , Titânio/química
16.
Int J Oral Maxillofac Implants ; 15(3): 355-63, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-10874800

RESUMO

This study examined the effects of different treatments (polished, electropolished, and grit-blasted) on the surface morphology and chemistry of commercially pure titanium and titanium-6% aluminum-4% vanadium. The structure and composition of the surfaces were evaluated using scanning electron microscopy, atomic force microscopy, energy dispersive spectroscopy, Auger microprobe analysis, and x-ray photoelectron spectroscopy. Surface roughness values at large scales were nearly identical for grit-blasted and electropolished samples, while at smaller scales, electropolished and polished samples had nearly identical quantitative roughness values. The surface oxide compositions were found to be primarily titanium dioxide on both materials for all surface treatments. No vanadium was seen with either x-ray photoelectron spectroscopy or Auger microprobe analysis for the alloy, indicating a possible surface depletion. Calcium was present on the grit-blasted samples, and calcium and chlorine were detected on the electropolished samples.


Assuntos
Ligas Dentárias/química , Titânio/química , Ligas , Corrosão , Polimento Dentário , Microanálise por Sonda Eletrônica , Teste de Materiais , Microscopia de Força Atômica , Microscopia Eletrônica de Varredura , Óxidos/análise , Análise Espectral/métodos , Propriedades de Superfície , Titânio/análise , Vanádio/análise , Raios X
17.
J Med Genet ; 37(6): 442-5, 2000 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10851255

RESUMO

We report on a male patient and members of his family with additional material in chromosome 3. This derivative chromosome 3 was transmitted from his mother who had a complex rearrangement between chromosomes 2, 3, and 7. It was possible to delineate her chromosomal rearrangement by microdissection and reverse painting and to exclude these aberrations from being responsible for neonatal deaths and several abortions in this family. Two members of this family suffer from ectrodactyly or split hand/foot malformations (SHFM) of the feet which possibly correlates with the derivative chromosome 7 containing a breakpoint in the SHFM1 critical region involving several homeobox genes.


Assuntos
Quebra Cromossômica/genética , Deformidades Congênitas do Pé/genética , Translocação Genética/genética , Bandeamento Cromossômico , Coloração Cromossômica , Cromossomos Humanos Par 2/genética , Cromossomos Humanos Par 3/genética , Cromossomos Humanos Par 7/genética , Feminino , Genes Homeobox/genética , Ligação Genética/genética , Genoma , Humanos , Lactente , Cariotipagem , Masculino , Mães , Hibridização de Ácido Nucleico , Linhagem
18.
Int J Oral Maxillofac Implants ; 15(2): 219-30, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-10795454

RESUMO

This study tested the following hypotheses: (1) acid-cleaned and passivated unalloyed titanium implants have higher surface energies (which are considered desirable for bone implants) than ethanol-cleaned titanium; (2) higher temperatures of heat treatment of unalloyed titanium result in higher surface energies; and (3) these changes can be related to changes in surface composition and roughness. Thus, unalloyed titanium specimens were either acid-cleaned and passivated (CP) or ethanol-cleaned (Et). Each set was then divided into 3 groups and heat-treated for 1 hour at 316 degrees C (600 degrees F), 427 degrees C (800 degrees F), and 538 degrees C (1,000 degrees F), respectively. Surface roughness values for each of these groups were determined using atomic force microscopy, while surface compositions were determined using Auger electron, x-ray photoelectron, and Raman spectroscopic techniques. Surface energies were estimated using a 2-liquid geometric mean technique and correlated with surface roughness, elemental composition, and elemental thickness. The CP surfaces were slightly rougher than the Et specimens, which had greater oxide thickness and hydrocarbon presence. The surface oxides were composed of TiO2, Ti2O3, and possibly titanium peroxide; those heat-treated at 427 degrees C or above were crystalline. The CP specimens had carbonaceous coverage that was of a different composition from that on Et specimens. The CP specimens had significantly higher surface energies, which showed statistically significant correlations with oxide thickness and carbonaceous presence. In conclusion, ethanol cleaning of unalloyed titanium dental implants may not provide optimal surface properties when compared to cleaning with phosphoric acid followed by nitric acid passivation.


Assuntos
Materiais Biocompatíveis/química , Implantes Dentários , Detergentes/química , Temperatura Alta , Titânio/química , Análise de Variância , Carbono/química , Cristalização , Microanálise por Sonda Eletrônica , Etanol/química , Humanos , Hidrocarbonetos/química , Microscopia de Força Atômica , Ácido Nítrico/química , Óxidos/química , Ácidos Fosfóricos/química , Solventes/química , Análise Espectral , Análise Espectral Raman , Propriedades de Superfície , Tensão Superficial , Molhabilidade
19.
Cytogenet Cell Genet ; 88(1-2): 114-8, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-10773683

RESUMO

We combined the techniques of fluorescence in situ hybridization (FISH) and chromosomal microdissection in one experiment (FISH-MD). This novel method permits rapid identification of the composition, origin, and breakpoints of rearranged chromosomes. Rearranged chromosomes are first identified by multicolor-FISH, then the fluorophore-labeled derivative chromosomes are directly isolated by microdissection and reverse painted to identify the breakpoints.


Assuntos
Aberrações Cromossômicas/genética , Coloração Cromossômica/métodos , Mapeamento Físico do Cromossomo/métodos , Bandeamento Cromossômico/métodos , Quebra Cromossômica/genética , Cor , Feminino , Corantes Fluorescentes/metabolismo , Humanos , Indóis/metabolismo , Cariotipagem/métodos , Luz , Linfócitos , Tumor Mulleriano Misto/genética , Mutagênese Insercional/genética , Reação em Cadeia da Polimerase , Translocação Genética/genética
20.
Chromosome Res ; 7(5): 355-62, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10515210

RESUMO

Microdissection in combination with reverse painting fluorescence in-situ hybridization (FISH) is a very effective method to identify breakpoints and rearrangements of derived chromosomes and reveal the chromosomal origin of marker chromosomes. We describe an innovation that allows a convenient, fast and safe isolation of microdissected fragments as currently available protocols. The microdissected chromosomes are harvested in a collection drop located in a movable micropipette adjusted to a second micromanipulator under microscopic observation. We used this technique to analyze several cytogenetic aberrations. In order to evaluate the efficiency of our microdissection procedure, we compared the results obtained with microdissection probes made from only one fragment with those obtained with more than six microdissected fragments. In all cases, the single-fragment microdissections were sufficient to provide probes.


Assuntos
Coloração Cromossômica/métodos , Cromossomos Humanos , Translocação Genética , Sondas de DNA , Feminino , Humanos , Cariotipagem , Linfócitos/ultraestrutura , Masculino , Reação em Cadeia da Polimerase
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