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2.
Nature ; 604(7906): 525-533, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35388223

RESUMO

Over the past few decades, neuroimaging has become a ubiquitous tool in basic research and clinical studies of the human brain. However, no reference standards currently exist to quantify individual differences in neuroimaging metrics over time, in contrast to growth charts for anthropometric traits such as height and weight1. Here we assemble an interactive open resource to benchmark brain morphology derived from any current or future sample of MRI data ( http://www.brainchart.io/ ). With the goal of basing these reference charts on the largest and most inclusive dataset available, acknowledging limitations due to known biases of MRI studies relative to the diversity of the global population, we aggregated 123,984 MRI scans, across more than 100 primary studies, from 101,457 human participants between 115 days post-conception to 100 years of age. MRI metrics were quantified by centile scores, relative to non-linear trajectories2 of brain structural changes, and rates of change, over the lifespan. Brain charts identified previously unreported neurodevelopmental milestones3, showed high stability of individuals across longitudinal assessments, and demonstrated robustness to technical and methodological differences between primary studies. Centile scores showed increased heritability compared with non-centiled MRI phenotypes, and provided a standardized measure of atypical brain structure that revealed patterns of neuroanatomical variation across neurological and psychiatric disorders. In summary, brain charts are an essential step towards robust quantification of individual variation benchmarked to normative trajectories in multiple, commonly used neuroimaging phenotypes.


Assuntos
Encéfalo , Longevidade , Estatura , Encéfalo/anatomia & histologia , Humanos , Imageamento por Ressonância Magnética/métodos , Neuroimagem
3.
Transl Psychiatry ; 11(1): 199, 2021 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-33795659

RESUMO

Psychomotor dysfunction (PMD) is a core element and key contributor to disability in late life depression (LLD), which responds well to electroconvulsive therapy (ECT). The neurobiology of PMD and its response to ECT are not well understood. We hypothesized that PMD in LLD is associated with lower striatal volume, and that striatal volume increase following ECT explains PMD improvement. We analyzed data from a two-center prospective cohort study of 110 LLD subjects (>55 years) receiving ECT. Brain MRI and assessment of mood, cognition, and PMD was performed 1 week before, 1 week after, and 6 months after ECT. Volumetry of the caudate nucleus, putamen, globus pallidus, and nucleus accumbens was derived from automatically segmented brain MRIs using Freesurfer®. Linear multiple regression analyses were used to study associations between basal ganglia volume and PMD. Brain MRI was available for 66 patients 1 week post ECT and in 22 patients also six months post ECT. Baseline PMD was associated with a smaller left caudate nucleus. One week after ECT, PMD improved and volume increases were detected bilaterally in the caudate nucleus and putamen, and in the right nucleus accumbens. Improved PMD after ECT did not relate to the significant volume increases in these structures, but was predicted by a nonsignificant volume change in the right globus pallidus. No volume differences were detected 6 months after ECT, compared to baseline. Although PMD is related to lower striatal volume in LLD, ECT-induced increase of striatal volume does not explain PMD improvement.


Assuntos
Eletroconvulsoterapia , Gânglios da Base/diagnóstico por imagem , Depressão , Humanos , Estudos Longitudinais , Imageamento por Ressonância Magnética , Estudos Prospectivos
4.
J Digit Imaging ; 26(3): 563-71, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23129541

RESUMO

Craniofacial disorders are routinely diagnosed using computed tomography imaging. Corrective surgery is often performed early in life to restore the skull to a more normal shape. In order to quantitatively assess the shape change due to surgery, we present an automated method for intracranial space segmentation. The method utilizes a two-stage approach which firstly initializes the segmentation with a cascade of mathematical morphology operations. This segmentation is then refined with a level-set-based approach that ensures that low-contrast boundaries, where bone is absent, are completed smoothly. We demonstrate this method on a dataset of 43 images and show that the method produces consistent and accurate results.


Assuntos
Algoritmos , Craniossinostoses/diagnóstico por imagem , Interpretação de Imagem Radiográfica Assistida por Computador/métodos , Tomografia Computadorizada por Raios X/métodos , Mapeamento Encefálico/métodos , Feminino , Humanos , Imageamento Tridimensional , Masculino
5.
J Clin Virol ; 50(3): 205-8, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21169053

RESUMO

UNLABELLED: Barrett's esophagus (BE), a known precursor of esophageal adenocarcinoma has recently been associated with human papillomavirus (HPV). p16(INK4a) expression is a recognized surrogate marker of HPV infection in the cervix. OBJECTIVES: This study has assessed the possible role of human papillomavirus (HPV) infection in BE and esophageal adenocarcinoma, in the North American population by screening esophageal tissues for HPV by a combination of assays. STUDY DESIGN: Formalin-fixed, paraffin-embedded blocks from cases of Barrett's esophagus (n=84), esophageal adenocarcinoma (n=36) and normal gastro-esophageal junction (n=29) were examined for HPV by PCR, chromogenic in situ hybridization, and p16(INK4a) immunohistochemistry. RESULTS: HPV DNA was detected by PCR in 23 of 84 (27.4%) BE cases, 11 of 36 (31%) cases of adenocarcinoma and in 7 of 29 (24%) normal control cases (p=0.82). p16(INK4a) staining was positive in 10 (12%) cases of BE, 15 (42%) cases of adenocarcinoma and 6 (21%) cases of the control group. Positive p16(INK4a) staining was not statistically different between the three groups whether positive or negative for HPV DNA (p=0.91 and p=0.91 respectively). Similarly, negative p16(INK4a) staining did not show a difference between the three groups for whether positive or negative for HPV DNA (p=0.50 and p=0.28, respectively). HPV was not detected by CISH in the adenocarcinomas while in BE and control groups, CISH was non-contributory. CONCLUSIONS: These data suggest that while HPV is detectable in a subset of esophageal lesions and tumors, the HPV detected is unlikely to be of etiologic significance or a factor accounting for the increase in BE and esophageal adenocarcinoma cases in the United States.


Assuntos
Adenocarcinoma/virologia , Esôfago de Barrett/virologia , Neoplasias Esofágicas/virologia , Papillomaviridae/isolamento & purificação , Infecções por Papillomavirus/complicações , Infecções por Papillomavirus/virologia , Adenocarcinoma/etiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Esôfago de Barrett/etiologia , Neoplasias Esofágicas/etiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estados Unidos , Adulto Jovem
6.
J Dairy Sci ; 93(9): 3957-60, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20723669

RESUMO

This study examined whether regulatory on-site dairy farm inspection results correlated with reported laboratory somatic cell count (SCC), standard plate count (SPC), and beta-lactam drug residue (DR) results for individual farms. Results were obtained for Wisconsin grade A dairy farms in 2007 and 2008 (>11,000 farms, >1.4 million data points). The proportion of farms failing an on-site inspection ranged from 12% for farms that had never failed an SCC test (>750,000 cells/mL), an SPC test (>100,000 cfu/mL), or a DR test (drug detected) to 55% for farms that had failed at least 1 of each type of test. Conditional probability analysis showed that the probability of a farm failing an on-site farm inspection was higher if the farm had failed a DR test and increased as the proportion of samples failing SCC or SPC or both increased. However, the statistical correlations were weak (R

Assuntos
Indústria de Laticínios/normas , Inspeção de Alimentos , Leite/normas , Animais , Bovinos , Inspeção de Alimentos/normas , Inspeção de Alimentos/estatística & dados numéricos , Wisconsin
7.
Neurology ; 75(1): 49-56, 2010 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-20484681

RESUMO

OBJECTIVE: Niemann-Pick disease type C (NPC) is a progressive neurovisceral disorder with disrupted intracellular cholesterol metabolism that results in significant alterations to neuronal and axonal structure. Adult patients present with ataxia, gaze palsy, impaired cognition, and neuropsychiatric illness, but the neural substrate has not been well-characterized in vivo. Our aim was to investigate a well-characterized sample of adults with confirmed NPC for gray and white matter abnormalities. METHODS: We utilized a combination of optimized voxel-based morphometry of T1-weighted images and tract-based spatial statistics of diffusion tensor images to examine gray matter volume and white matter structural differences in 6 adult patients with NPC and 18 gender- and age-matched controls. RESULTS: Patients with NPC demonstrated bilateral gray matter reductions in large clusters in bilateral hippocampus, thalamus, superior cerebellum, and insula, in addition to smaller regions of inferoposterior cortex. Patients demonstrated widespread reductions in fractional anisotropy in major white matter tracts. Subsequent analysis of measures of axial and radial diffusivity suggest that these changes are contributed to by both impaired myelination and altered axonal structure. CONCLUSIONS: Findings in gray matter areas are broadly consistent with human and animal studies of selective vulnerability of neuronal populations to the neuropathology of NPC, whereas more widespread white matter changes are consistent with the hypothesis that disrupted myelination and axonal structure predate changes to the neuronal cell body. These findings suggest that volumetric analysis of gray matter and diffusion tensor imaging may be useful modalities for indexing illness stage and monitoring response to emerging treatment.


Assuntos
Córtex Cerebral/patologia , Fibras Nervosas Mielinizadas/patologia , Doença de Niemann-Pick Tipo C/patologia , Adolescente , Adulto , Estudos Transversais , Imagem de Tensor de Difusão/métodos , Feminino , Humanos , Masculino , Adulto Jovem
8.
Head Neck Pathol ; 4(2): 106-12, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20405251

RESUMO

This study investigated the role of human papillomavirus (HPV) in Schneiderian papillomas (SPs) to determine whether HPV is associated with the pathogenesis of particular histologic subtypes and whether p16(INK4a) can be used as a surrogate marker for HPV detection. Twenty-seven papilloma specimens (19 inverted [IPs], 6 exophytic [EPs], 1 oncocytic [OP] and 1 mixed) were collected from 23 patients. Purified SP DNA extracts were tested for HPV by PCR using GP5 +/GP6 + primers; HPV genotyping was performed by dot blot hybridization. PCR positive specimens were screened for HPV by biotinyl-tyramide-based chromogenic in situ hybridization (CISH). Immunohistochemsistry (IHC) for the HPV L1 capsid protein and for p16(INK4a) was performed on all specimens. HPV was detected by PCR in 16/27 (59.3%) SPs; 9/19 (47.4%) IPs; 6/6 (100%) EPs [p = 0.051], and 1/1 (100%) mixed SP. HPV was not detected in the single OP. High risk genotypes were detected in 4/9 IPs (44.4%) and 0/6 EPs (0%) [p = 0.10]. Seven of 16 PCR positive SPs were also CISH positive for HPV: 5/6 EPs (83.3%) and 1/9 IP (11.1%) [p = 0.01]. IHC for the L1 capsid protein was positive in 2 SPs (1 EP and 1 mixed). p16(INK4a) staining was seen in 14/16 (87.5%) PCR positive SPs and in 10/11 (90.9%) PCR negative SPs (p = 1.00). In summary, this study demonstrates a strong association between HPV and EPs, however, its role in IPs remains less well-defined. Further, p16(INK4a) is not a useful surrogate marker for HPV detection across the various SPs.


Assuntos
Inibidor p16 de Quinase Dependente de Ciclina/metabolismo , Mucosa Nasal/virologia , Neoplasias Nasais/virologia , Papiloma Invertido/virologia , Papillomaviridae/genética , Infecções por Papillomavirus/virologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores Tumorais/metabolismo , DNA Viral , Feminino , Humanos , Hibridização In Situ , Masculino , Pessoa de Meia-Idade , Mucosa Nasal/metabolismo , Mucosa Nasal/patologia , Neoplasias Nasais/patologia , Papiloma Invertido/metabolismo , Papiloma Invertido/patologia , Infecções por Papillomavirus/metabolismo , Infecções por Papillomavirus/patologia , Reação em Cadeia da Polimerase , Adulto Jovem
9.
J Clin Pathol ; 61(4): 541-3, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18006667

RESUMO

The prevalence and significance of human papillomavirus (HPV) integration among different grades of cervical lesions is uncertain. In this study, HPV physical status was examined by the combination of multiple displacement amplification (MDA) with Southern blot hybridisation (SBH). DNA extracts from 95 cervical cytology samples (NILM, ASC-US, LSIL, ASC-H, HSIL) were subject to whole genome amplification by MDA followed by SBH with [alpha-(32)P]-labelled HPV probes. Mixed HPV16 episomal/integrant sequences were detected in three ASC-US patients (two diagnosed with benign changes and one with cervical intraepithelial neoplasia (CIN)2/3 after biopsy follow-up), one ASC-H patient with CIN2/3 histological diagnosis, and one HSIL patient with benign changes. Additional follow-up cytological data available for three of these patients demonstrated series of lesion-free samples. The data support the view that integration can occur in low-grade lesions and that lesions with mixed episomal/integrant HPV can regress.


Assuntos
Papillomavirus Humano 16/fisiologia , Infecções por Papillomavirus/virologia , Displasia do Colo do Útero/virologia , Neoplasias do Colo do Útero/virologia , Integração Viral , Adulto , Southern Blotting/métodos , Colo do Útero/virologia , DNA Viral/análise , Feminino , Seguimentos , Papillomavirus Humano 16/isolamento & purificação , Humanos , Técnicas de Amplificação de Ácido Nucleico/métodos , Infecções por Papillomavirus/patologia , Neoplasias do Colo do Útero/patologia , Esfregaço Vaginal , Displasia do Colo do Útero/patologia
10.
Exp Cell Res ; 263(1): 55-64, 2001 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-11161705

RESUMO

We report the cloning of a BrdU-sensitive transcript of 4.1 kb from an immortalized quail heart cell line containing an open reading frame of 940 amino acids (110 kDa, pI approximately 5.18). The mRNA encoding P110 appears in the heart and neural tube by 36 h of avian development, at a time when these organs are rapidly developing. Analysis of the DNA-deduced protein sequence revealed a bipartite nuclear localization signal, and a highly charged domain rich in both acidic and basic residues. Immunofluorescent staining with polyclonal antibodies raised against a P110 peptide localized the protein to the nucleolus of avian and mammalian cells. Although database search showed significant homology with an uncharacterized cDNA from human brain and several human and mouse Expressed Sequence Tags, there was no close homology to known nucleolar proteins. Immunoprecipitation of P110 from cell sonicates revealed it contained U3 small nucleolar RNA, but no significant amounts of other box C/D small nucleolar RNAs. These data suggest that P110 is one of the U3 small nucleolar ribonucleoproteins that are involved in rRNA processing.


Assuntos
Nucléolo Celular/química , RNA Nucleolar Pequeno/análise , Ribonucleoproteínas Nucleolares Pequenas/genética , Ribonucleoproteínas Nucleolares Pequenas/metabolismo , Sequência de Aminoácidos , Animais , Northern Blotting , Western Blotting , Bromodesoxiuridina/farmacologia , Ciclo Celular/fisiologia , Linhagem Celular , Embrião de Galinha , Clonagem Molecular , Dactinomicina/farmacologia , Embrião não Mamífero/fisiologia , Coração/embriologia , Humanos , Imuno-Histoquímica , Hibridização In Situ , Dados de Sequência Molecular , Miocárdio/citologia , Codorniz , RNA Mensageiro/análise , Ribonucleoproteínas Nucleolares Pequenas/química , Homologia de Sequência de Aminoácidos
11.
Behav Processes ; 49(3): 149-161, 2000 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-10922528

RESUMO

The discriminative performance of students was assessed on a delayed-matching-to-sample task (DMST) using disks, presented by a computer, as stimuli. The size of the non-matching comparison stimuli was changed, for each participant, until each was 100% correct at 0.05 s delay. Then delays of 0.05, 2, 4, 8 and 16 s were paired with each of one, four, eight, 16, and 32 sample stimuli. Accuracy generally decreased over the one, four and eight samples, did not change consistently over the largest sample-set sizes and decreased as delay increased. Both delay and sample-set size had statistically significant main effects, their interaction was not significant. Fitted exponential functions gave a measure of discrimination at zero delay, a, and a measure of the rate of decrement in performance with increasing delay, b. As number of sample stimuli increased there was no systematic change in b, while a decreased most over one to four samples, decreased less with eight samples, and decreased least from 16 to 32 samples. These results suggest that the effects of varying sample-set size depends on the range of sizes studied, thus, they provide a possible explanation for some previous disparate findings. They also suggest that it might be proactive interference that leads to decreases in accuracy with increasing sample-set size.

12.
AIDS Res Hum Retroviruses ; 16(3): 259-71, 2000 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-10710214

RESUMO

We have analyzed factors that might influence the in vitro quantitation of the T-proliferative response to HIV-1 Gag antigens, a common and increasingly used clinical measurement of helper T cell function in the context of HIV-1 infection. We have compared the rate and extent of T cell proliferation in freshly prepared and previously frozen PBMC samples, and have concluded that frozen cells can be used successfully; we have assessed whether the suppression of any HIV-1 replication in the PBMC cultures affects the extent of T cell proliferation; we have studied which forms of the Gag antigens are the most efficient at inducing T cell proliferation. From the latter experiments, we conclude that Gag proteins that include p17, and perhaps also p7, sequences flanking the central p24 capsid protein, are better stimulants than proteins that comprise only p24 sequences.


Assuntos
Proteínas do Capsídeo , Produtos do Gene gag/imunologia , Antígenos HIV/imunologia , HIV-1/imunologia , Linfócitos T/imunologia , Proteínas Virais , Fármacos Anti-HIV/farmacologia , Capsídeo/imunologia , Divisão Celular , Células Cultivadas , Eletroforese em Gel de Poliacrilamida/métodos , Congelamento , Proteína do Núcleo p24 do HIV/imunologia , Inibidores da Protease de HIV/farmacologia , Humanos , Microscopia Eletrônica/métodos , Nelfinavir/farmacologia , Nevirapina/farmacologia , Inibidores da Transcriptase Reversa/farmacologia , Linfócitos T/citologia , Linfócitos T/efeitos dos fármacos , Fatores de Tempo , Produtos do Gene gag do Vírus da Imunodeficiência Humana
13.
Biochem J ; 342 ( Pt 1): 97-103, 1999 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-10432305

RESUMO

The cDNA for a human homologue (hIF2) of bacterial (bIF2) and yeast (yIF2) translation initiation factor two (IF2) has been identified during a screen for proteins which interact with HIV-1 matrix. The hIF2 cDNA encodes a 1220-amino-acid protein with a predicted relative molecular mass of 139 kDa, though endogeneous hIF2 migrates anomalously on SDS/PAGE at 180 kDa. hIF2 has an extended N-terminus compared with its homologues, although its central GTP-binding domain and C-terminus are highly conserved, with 58% sequence identity with yIF2. We have confirmed that hIF2 is required for general translation in human cells by generation of a point mutation in the P-loop of the GTP-binding domain. This mutant protein behaves in a transdominant manner in transient transfections and leads to a significant decrease in the translation of a reporter gene. hIF2 interacts directly with HIV-1 matrix and Gag in vitro, and the protein complex can be immunoprecipitated from human cells. This interaction appears to block hIF2 function, since purified matrix protein inhibits translation in a reticulocyte lysate. hIF2 does not correspond to any of the previously characterized translation initiation factors identified in mammals, but its essential role in translation appears to have been conserved from bacteria to humans.


Assuntos
Fator de Iniciação 2 em Eucariotos/genética , Fator de Iniciação 2 em Eucariotos/metabolismo , Produtos do Gene gag/metabolismo , Antígenos HIV/metabolismo , Proteínas Virais , Sequência de Aminoácidos , Linhagem Celular , Clonagem Molecular , Sequência Conservada/genética , Fator de Iniciação 2 em Eucariotos/antagonistas & inibidores , Fator de Iniciação 2 em Eucariotos/química , Produtos do Gene gag/genética , Genes Dominantes , Antígenos HIV/genética , HIV-1/genética , HIV-1/metabolismo , Células HeLa , Humanos , Modelos Biológicos , Dados de Sequência Molecular , Peso Molecular , Mutação , Fator de Iniciação 2 em Procariotos , Ligação Proteica , Biossíntese de Proteínas , RNA Mensageiro/análise , RNA Mensageiro/genética , Proteínas Recombinantes de Fusão/antagonistas & inibidores , Proteínas Recombinantes de Fusão/química , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Transfecção , Leveduras/genética , Produtos do Gene gag do Vírus da Imunodeficiência Humana
15.
Hear Res ; 129(1-2): 111-27, 1999 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10190757

RESUMO

The marginal cells of the stria vascularis possess distinctive morphological characteristics associated with their role in endolymph production. Interestingly, when stria-derived epithelial cells are grown in association with the underlying mesenchyme, the final differentiation of these cell types does not occur. Beyond the rudimentary polarity that is established, similar to that shown in epithelial monolayers, cells in culture bear only a slight resemblance to their marginal cell counterparts in vivo. The ultrastructural features that typify these epithelia, extensive cytoplasmic invaginations, with an abundance of mitochondria, and darkly stained cytoplasm, are not evident under standard culture conditions. In order to determine whether fluid transport, a key function of the stria vascularis, has an effect on the ultrastructural morphology, we examined de novo stria vascularis tissues that formed a fluid-filled cyst in vitro. We found that only cells associated with the luminal structure demonstrated dark cytoplasmic staining and amplification of the basolateral membrane of the marginal cells. Additionally, other epithelial features, such as mitochondria-rich and microvilli-rich cells, were observed in cyst-forming tissues. The enhancement of the marginal cell specializations was not as robust as that observed in vivo; however, they were clearly more extensive when compared to cells in the same culture that were not associated with a fluid-filled lumen. Thus it appears that fluid transport may be necessary to maximize differentiation of stria vascularis tissues in vitro.


Assuntos
Estria Vascular/citologia , Animais , Diferenciação Celular , Membrana Celular/ultraestrutura , Técnicas de Cultura , Cistos/patologia , Endolinfa/fisiologia , Camundongos , Microscopia Eletrônica , Microvilosidades/ultraestrutura , Estria Vascular/fisiologia
16.
Neurobiol Aging ; 20(5): 513-9, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10638524

RESUMO

The effects of 2-(4-Morpholinyl)-8-phenyl-4H-1-benzopyran-4-one (LY294002), an inhibitor of mammalian phosphatidylinositol 3-OH kinase, was tested on an insulin signaling-like pathway in the nematode Caenorhabditis elegans. Populations of C. elegans were treated with LY294002 at different stages of the life cycle, and its effects on development, thermotolerance and longevity were assessed. At concentrations of 160 microM and above, LY294002 significantly induced both dauer formation and thermotolerance. Treatment of adult worms also resulted in a small, but significant, increase in life span. The results presented are consistent with the view that a neuroendocrine signaling pathway functions in adult worms to determine stress resistance and longevity.


Assuntos
Caenorhabditis elegans/fisiologia , Cromonas/farmacologia , Inibidores Enzimáticos/farmacologia , Longevidade/efeitos dos fármacos , Morfolinas/farmacologia , Inibidores de Fosfoinositídeo-3 Quinase , Animais , Caenorhabditis elegans/crescimento & desenvolvimento , Temperatura Alta , Insulina/fisiologia , Larva/química , Larva/enzimologia , Larva/crescimento & desenvolvimento , Fosfatidilinositol 3-Quinases/metabolismo , Receptor de Insulina/fisiologia , Transdução de Sinais/fisiologia
17.
J Comp Neurol ; 402(1): 129-39, 1998 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-9831050

RESUMO

The neurotrophins brain-derived neurotrophin (BDNF) and neurotrophin-3 (NT-3) synergistically enhance survival of spiral ganglion neurons such that simultaneous exposure to both compounds produces a larger response than would be expected from their individual effects. To elucidate the functional role of this neurotrophin interaction, we examined its temporal and cell-type specificity in vitro for both mouse and gerbil spiral ganglion neurons. Synergistic effects were transient; they were maximal within the first two postnatal days and declined during the first postnatal week. Both neurotrophins were, however, still efficacious at increasing cell survival. After postnatal day 10, the effects of coexposure to BDNF and NT-3 were additive rather than synergistic. Synergism declined more rapidly in mouse than gerbil neurons, reflecting the difference in cochlear development for each species. Only neurons without peripherin epitopes, putative type I neurons, showed synergistic survival effects; survival of peripherin-expressing neurons was purely additive. Therefore, during a restricted time period, identical neurotrophin stimuli are capable of preferentially enhancing survival of one class of neurons that compose approximately 95% of the adult spiral ganglion.


Assuntos
Fator Neurotrófico Derivado do Encéfalo/farmacologia , Fatores de Crescimento Neural/farmacologia , Neurônios Aferentes/efeitos dos fármacos , Gânglio Espiral da Cóclea/citologia , Animais , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Relação Dose-Resposta a Droga , Sinergismo Farmacológico , Gerbillinae , Neurônios Aferentes/citologia , Neurotrofina 3 , Fatores de Tempo
18.
J Mol Cell Cardiol ; 30(3): 537-50, 1998 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-9515030

RESUMO

Glypicans are a group of membrane-bound heparan sulfate proteoglycans (HSPG) that are tissue specific and developmentally regulated. Transcripts for avian glypican are found in endocardial cushions, limb buds, somites and forebrain of early chick embryos. Since avian glypican is not well characterized, the cellular localization, regulation of expression, and possible function during cardiac development have been studied. A polyclonal antibody was raised against a 20-amino acid peptide corresponding to an antigenic sequence within avian glypican core protein. The antibody recognized the expressed core protein in bacterial lysates and the endogenous HSPG in the proteoglycan fraction from chick forebrain. Immunolocalization studies indicated that the core protein is associated with cell membranes. The level of mRNA for avian glypican in MEQC (myc embryonic quail cardiomyocytes) grown in medium containing 10% fetal calf serum was compared to the message levels in cells grown without serum for 3 days. By Northern analysis, glypican transcripts were increased markedly after serum starvation. Up-regulation of glypican transcripts by serum withdrawal was partially prevented by addition of TGFbeta-1 and bFGF, suggesting that these growth factors may regulate its expression. MEQC cells deprived of serum migrated into clumps that could be blocked by an antisense OND (oligodeoxynucleotide) to the mRNA encoding the avian glypican. The same antisense OND inhibited the migration of endothelial cells from chick tubular heart explants over the surface of collagen gels. These results indicate that avian glypican may play a role in cell migration during development of endocardial cushions.


Assuntos
Proteoglicanas de Heparan Sulfato/química , Proteoglicanas de Heparan Sulfato/fisiologia , Sequência de Aminoácidos , Animais , Sequência de Bases , Divisão Celular/efeitos dos fármacos , Linhagem Celular , Movimento Celular/efeitos dos fármacos , Movimento Celular/fisiologia , Embrião de Galinha , Meios de Cultura Livres de Soro , Endocárdio/citologia , Endocárdio/embriologia , Endocárdio/metabolismo , Expressão Gênica/efeitos dos fármacos , Glicosaminoglicanos/química , Substâncias de Crescimento/farmacologia , Proteoglicanas de Heparan Sulfato/genética , Dados de Sequência Molecular , Miocárdio/citologia , Miocárdio/metabolismo , Oligonucleotídeos Antissenso/genética , Oligonucleotídeos Antissenso/farmacologia , Codorniz , RNA Mensageiro/genética , RNA Mensageiro/metabolismo
19.
Md Med J ; 46(10): 530-7, 1997.
Artigo em Inglês | MEDLINE | ID: mdl-9392942

RESUMO

Ankle sprains are a common, costly, and potentially disabling problem. The proper history and physical examination will determine the need for radiological evaluation and treatment. Complications of ankle trauma like osteochondral fractures, peroneal tendon injuries, fracture of the os trigonum, synovial impingement, tarsal tunnel syndrome, Achilles tendon inflammation or rupture, and nerve injury are reviewed. The treatment of ankle sprains is based on the severity of the injury. Treatment begins with rest, ice, compression, and elevation. Casting and orthotics may be needed to facilitate healing. Primary rehabilitation, functional rehabilitation, and performance testing and the assessment of efficacy for each of these modalities are critical parts of proper treatment for ankle sprains.


Assuntos
Traumatismos do Tornozelo/terapia , Entorses e Distensões , Tornozelo/diagnóstico por imagem , Tornozelo/cirurgia , Traumatismos do Tornozelo/diagnóstico por imagem , Traumatismos do Tornozelo/reabilitação , Humanos , Radiografia
20.
Neurochem Int ; 30(4-5): 411-5, 1997.
Artigo em Inglês | MEDLINE | ID: mdl-9106255

RESUMO

Tetrabenazine and dihydrotetrabenzaine (TBZOH) are potent inhibitors of substrate transport by the predominant forms of the vesicular monoamine transporter (VMAT) present in bovine brain synaptic vesicles and bovine adrenal medullary chromaffin vesicles. Radiolabeled TBZOH binds to these preparations with apparent dissociation constants in the low nanomolar range. However, tetrabenazine is a much less potent inhibitor of transport by rVMAT1, a form of the transporter cloned from a rat pheochromocytoma (PC12) cDNA library and expressed in CHO cells. Reported attempts to observe binding of [3H]TBZOH to rVMAT1 have not been successful. We examined binding of [3H]TBZOH to a crude membrane fraction from PC12 cells. Computerized nonlinear least squares curve fitting revealed two classes of binding sites (Kd1 = 1.5 nM, R1 = 0.2 pmol/mg protein, Kd2 = 340 nM, R2 = 15.2 pmol/mg protein). While the identity of the higher affinity sites is not certain, their high affinity for TBZOH suggests that they may be associated with rVMAT2. The lower affinity sites are likely to be associated with rVMAT1 on the basis of their affinity for TBZOH and sensitivity to inhibition of TBZOH binding by transporter substrates and inhibitors. NGF-treated PC12 cells also exhibited two classes of sites (Kd1 = 1.9 nM, R1 = 0.18 pmol/mg protein; Kd2 = 370 nM, R2 = 23.7 pmol/mg protein). While there were no significant differences between control and NGF-treated cells in binding capacity of the higher affinity sites, nor in apparent dissociation constants for either class of sites, there was a highly significant increase in number of lower affinity binding sites in the NGF-treated cells (p = 0.001). These results provide direct evidence that the differential sensitivity of rat brain and adrenal catecholamine stores to depletion by tetrabenazine and its derivatives is due to a much lower affinity of rVMAT1 for these compounds, and that NGF treatment may increase levels of rVMAT1 expression in PC12 cells.


Assuntos
Proteínas de Membrana Transportadoras , Fatores de Crescimento Neural/farmacologia , Neuropeptídeos , Tetrabenazina/análogos & derivados , Animais , Sítios de Ligação , Transporte Biológico/efeitos dos fármacos , Bovinos , Cinética , Glicoproteínas de Membrana/metabolismo , Neurotransmissores/metabolismo , Células PC12 , Ratos , Tetrabenazina/metabolismo , Proteínas Vesiculares de Transporte de Aminas Biogênicas , Proteínas Vesiculares de Transporte de Monoamina
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