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1.
Br J Ophthalmol ; 94(7): 915-7, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20606025

RESUMO

PURPOSE: Genetic factors influence an individual's risk for developing age-related macular degeneration (AMD), a leading cause of irreversible vision loss. Previous studies investigating the potential association between all AMD subtypes and the SERPING1 gene, which encodes a key regulator of the classic complement pathway, have yielded conflicting results. The purpose of this study is to determine whether variations in SERPING1 are associated with neovascular AMD. METHODS: A total of 556 patients with neovascular AMD and 256 ethnically matched controls were genotyped for polymorphisms in SERPING1. A tagging single nucleotide polymorphism (tSNP) approach was used to cover the SERPING1 gene plus 2 kb on each side, spanning the promoter and the 3' untranslated regions. Ten SNPs with a minor allele frequency of 0.10 were covered by three tSNPs (rs1005510, rs11603020, rs2511989). RESULTS: SERPING1 SNPs rs1005510 and rs2511989 were significantly associated with neovascular AMD in our cohort, with rs1005510 conferring an adverse risk effect (OR 1.49, 95% CI 1.18 to 1.88) and rs2511989 conferring a protective effect (OR 0.73, 95% CI 0.59 to 0.90). For both tSNPs, logistic regression of individual genotypes demonstrated statistically significant stepwise changes in the risk of developing AMD. Combined analysis of rs1005510 with variants in CFH and HTRA1 confirmed an independent risk effect. The rs11603020 variant had no effect on AMD susceptibility in this study (OR 0.98, 95% CI 0.78 to 1.24). CONCLUSIONS: The SERPING1 gene is comprehensively investigated in this study (using three tSNPs), and its genetic variants are evaluated in the largest neovascular AMD cohort to date. The hypothesis that SERPING1 has a modest effect on the risk of neovascular AMD is supported by our results.


Assuntos
Neovascularização de Coroide/genética , Proteínas Inativadoras do Complemento 1/genética , Degeneração Macular/genética , Idoso , Proteína Inibidora do Complemento C1 , Feminino , Predisposição Genética para Doença , Genótipo , Humanos , Masculino , Polimorfismo de Nucleotídeo Único , Estudos Retrospectivos
2.
Eye (Lond) ; 23(3): 626-31, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18292785

RESUMO

AIM: To determine whether there is an association between complement factor H (CFH) or LOC387715 genotypes and response to treatment with photodynamic therapy (PDT) for exudative age-related macular degeneration (AMD). METHODS: Sixty-nine patients being treated for neovascular AMD with PDT were genotyped for the CFH Y402H and LOC387715 A69S polymorphisms by allele-specific digestion of PCR products. AMD phenotypes were characterized by clinical examination, fundus photography, and fluorescein angiography. RESULTS: Adjusting for age, pre-PDT visual acuity (VA), and lesion type, mean VA after PDT was significantly worse for the CFH TT genotype than for the TC or CC genotypes (P=0.05). Post-PDT VA was significantly worse for the CFH TT genotype in the subgroup of patients with predominantly classic choroidal neovascular lesions (P=0.04), but not for the patients with occult lesions (P=0.22). For the LOC387715 A69S variant, there was no significant difference among the genotypes in response to PDT therapy. CONCLUSIONS: The CFH Y402H variant was associated with a response to PDT treatment in this study. Patients with the CFH TT genotype fared significantly worse with PDT than did those with the CFH TC and CC genotypes, suggesting a potential relationship between CFH genotype and response to PDT.


Assuntos
Degeneração Macular/tratamento farmacológico , Degeneração Macular/genética , Fotoquimioterapia , Proteínas/genética , Idoso , Idoso de 80 Anos ou mais , Neovascularização de Coroide/tratamento farmacológico , Neovascularização de Coroide/genética , Neovascularização de Coroide/fisiopatologia , Fator H do Complemento/genética , Feminino , Genótipo , Humanos , Degeneração Macular/fisiopatologia , Masculino , Pessoa de Meia-Idade , Fenótipo , Prognóstico , Resultado do Tratamento , Acuidade Visual/genética , Acuidade Visual/fisiologia
3.
Br J Ophthalmol ; 93(5): 610-3, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-19091853

RESUMO

AIMS: To determine whether complement factor H (CFH) genotypes have a pharmacogenetic effect on the treatment of exudative age-related macular degeneration (AMD) with ranibizumab. METHODS: A retrospective study of 156 patients with exudative AMD treated with intravitreal ranibizumab monotherapy was conducted. AMD phenotypes were characterised by clinical examination, visual acuity, fundus photography, fluorescein angiography and injection timing. Patients received intravitreal ranibizumab injections as part of routine ophthalmological care and were followed for a minimum of 9 months. Each patient was genotyped for the single nucleotide polymorphism rs1061170 (Y402H) in the CFH gene. RESULTS: Baseline lesion size and angiographic type, as well as mean visual acuities at baseline, 6 months, and 9 months were similar among the three CFH genotypes. Over 9 months, patients with both risk alleles received approximately one more injection (p = 0.09). In a recurrent event analysis, patients homozygous for the CFH Y402H risk allele had a 37% significantly higher risk of requiring additional ranibizumab injections (p = 0.04). CONCLUSIONS: In this study cohort, the response to treatment of AMD with ranibizumab differed according to CFH genotype, suggesting that determining patients' CFH genotype may be helpful in the future in tailoring treatment for exudative AMD with intravitreal ranibizumab.


Assuntos
Inibidores da Angiogênese/uso terapêutico , Anticorpos Monoclonais/uso terapêutico , Degeneração Macular/genética , Idoso , Idoso de 80 Anos ou mais , Anticorpos Monoclonais Humanizados , Fator H do Complemento/genética , Feminino , Genótipo , Humanos , Degeneração Macular/tratamento farmacológico , Degeneração Macular/fisiopatologia , Masculino , Ranibizumab , Estudos Retrospectivos , Resultado do Tratamento , Acuidade Visual/efeitos dos fármacos
4.
Br J Ophthalmol ; 91(12): 1650-5, 2007 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18024811

RESUMO

AIM: To determine the frequency and nature of mutations in the gene ABCA4 in a cohort of patients with bull's-eye maculopathy (BEM). METHODS: A panel of 49 subjects (comprising 40 probands/families, 7 sibling pairs and a set of three sibs) with BEM, not attributable to toxic causes, was ascertained. Blood samples from each patient were used to extract genomic DNA, with subsequent mutation screening of the entire coding sequence of ABCA4, using single-strand conformational polymorphism (SSCP) analysis and direct sequencing. RESULTS: Fourteen probands (35%) were found to have a potentially disease-causing ABCA4 sequence variant on at least one allele. Three patients had a Gly1961Glu missense mutation, the most common variant in Stargardt disease (STGD), with 2 of these subjects having a macular dystrophy (MD) phenotype and a second ABCA4 variant previously associated with STGD. The second most common STGD mutation, Ala1038Val, was seen in one patient with cone-rod dystrophy (CORD). Five novel ABCA4 variants were detected. Two sibships were identified with a similar intra-familial phenotype but discordant ABCA4 variants. CONCLUSIONS: Variations in the ABCA4 gene are common in BEM. Two sibships showed discordant ABCA4 variants. One of these sibships illustrates that ABCA4 variants can be identified in families that have another molecular cause for their disease, due to the high prevalence of ABCA4 disease alleles in the population. The discordance evident in the second sibship may yet also be a chance finding in families with macular disease of another genetic cause, or it may represent a complex mode of inheritance determined/modified by the combination of ABCA4 alleles.


Assuntos
Transportadores de Cassetes de Ligação de ATP/genética , Alelos , Macula Lutea , Mutação , Doenças Retinianas/genética , Irmãos , Adolescente , Adulto , Idoso , Alanina , Estudos de Coortes , Feminino , Ácido Glutâmico , Glicina , Humanos , Masculino , Pessoa de Meia-Idade , Mutação de Sentido Incorreto , Linhagem , Fenótipo , Valina
5.
Klin Monbl Augenheilkd ; 221(5): 427-30, 2004 May.
Artigo em Inglês | MEDLINE | ID: mdl-15162299

RESUMO

BACKGROUND: The neuronal ceroid lipofuscinoses (Batten disease) are a heterogeneous group of autosomal recessively inherited disorders causing progressive neurological failure, mental deterioration, seizures and visual loss secondary to retinal dystrophy. The juvenile type is of special interest to the ophthalmologist as visual loss is the earliest symptom of the disorder. HISTORY AND SIGNS: We present two siblings with severe retinal dystrophy due to juvenile Batten disease. Sibling A (age 10) presented with visual loss, photophobia and night blindness, starting at age 4. His vision was perception of light by the age of 10.5 years. Fundus examination revealed severe pigmentary retinopathy. Sibling B (age 7) presented with night vision difficulties. Fundus examination revealed a bull's eye maculopathy with minimal peripheral atrophic changes. In vivo autofluorescence level was found to be very low. Electroretinography (ERG) showed generalized retinal dysfunction involving both cone and rod systems, with an electronegative maximal response. In both siblings vacuolated lymphocytes were found on a peripheral blood film and on molecular genetic testing both were homozygous for the commonly reported 1.02-kb deletion of the CLN3 gene. THERAPY AND OUTCOME: Although there is no effective treatment, the early diagnosis allowed accurate genetic and social counseling. CONCLUSIONS: Juvenile Batten disease should be considered in children with a retinal dystrophy, especially where there is a bull's eye maculopathy and an abnormal full field ERG. The novel finding of very low in vivo autofluorescence is consistent with histopathological studies and may be secondary to photoreceptor cell loss.


Assuntos
Deleção Cromossômica , Cromossomos Humanos Par 16 , Distrofias Hereditárias da Córnea/genética , Análise Mutacional de DNA , Glicoproteínas de Membrana/genética , Chaperonas Moleculares/genética , Lipofuscinoses Ceroides Neuronais/genética , Fenótipo , Degeneração Retiniana/genética , Cegueira/diagnóstico , Cegueira/genética , Criança , Distrofias Hereditárias da Córnea/diagnóstico , Progressão da Doença , Eletrorretinografia , Feminino , Angiofluoresceinografia , Homozigoto , Humanos , Masculino , Lipofuscinoses Ceroides Neuronais/diagnóstico , Cegueira Noturna/diagnóstico , Cegueira Noturna/genética , Degeneração Retiniana/diagnóstico
6.
Br J Ophthalmol ; 88(1): 36-8, 2004 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-14693769

RESUMO

AIM: To investigate the association between posterior uveal melanoma and iris freckles, iris naevi, and choroidal naevi. METHODS: Cross sectional study of 65 patients with posterior uveal melanoma and 218 controls. Iris colour, iris freckles, iris naevi, and choroidal naevi were recorded for each eye of each patient. RESULTS: Iris freckles were present in 40 (61.5%) patients with melanoma and 135 (61.9%) controls (p = 0.494). Iris naevi were present in four (6.2%) patients with melanoma and nine (4.1%) controls (p = 0.955). Choroidal naevi were present in 12 (18.5%) patients with melanoma and 38 (17.4%) controls (p = 0.815). CONCLUSION: This study did not detect an association between posterior uveal melanoma and iris freckles, iris naevi, or choroidal naevi.


Assuntos
Neoplasias da Coroide/patologia , Doenças da Íris/patologia , Melanoma/patologia , Neoplasias Primárias Múltiplas/patologia , Neoplasias Uveais/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos Transversais , Feminino , Humanos , Neoplasias da Íris/patologia , Masculino , Melanose/patologia , Pessoa de Meia-Idade , Nevo/patologia , Estudos Prospectivos
7.
Br J Ophthalmol ; 88(1): 39-43, 2004 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-14693770

RESUMO

BACKGROUND/AIMS: It is well known that light skin pigmentation is a risk factor for cutaneous melanoma. The aim of this study was to investigate the analogous association between choroidal pigmentation and posterior uveal melanoma. METHODS: Cross sectional study of 65 consecutive patients diagnosed with posterior uveal melanoma (melanoma group) and 218 consecutive patients referred for general retinal evaluation (control group). All patients were white. A clinical grading system for estimating choroidal pigmentation was developed and histologically validated in seven patients. RESULTS: Melanoma patients with light iris colour were significantly more likely to have darker choroidal pigmentation than controls (p = 0.005). Darker choroidal pigmentation was associated histologically with increased density of choroidal melanocytes (p = 0.005). CONCLUSIONS: Increased choroidal pigmentation, as a result of an increase in the density of pigmented choroidal melanocytes, is not protective but may actually be a risk factor for the development of posterior uveal melanoma in white patients. This finding may have implications for understanding the pathogenesis of uveal melanoma.


Assuntos
Corioide/fisiopatologia , Melanoma/fisiopatologia , Pigmentação , Neoplasias Uveais/fisiopatologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Corioide/patologia , Estudos Transversais , Cor de Olho , Feminino , Humanos , Masculino , Melanócitos/patologia , Melanoma/patologia , Pessoa de Meia-Idade , Neoplasias Uveais/patologia
8.
Adv Exp Med Biol ; 493: 89-101, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11727786

RESUMO

A 2-yr study on effects of morphine on lymphocyte circulation in rhesus monkeys (Macaca mulatta) showed that, over time, a well-maintained morphine-dependency caused biphasic depressive effects on circulating lymphocyte levels. Depression of T cell circulation by opiates actually was a relative effect. Morphine exposure basically stabilized T cell circulation in the context of concurrent increases in controls. Biphasic effects of morphine were attributable to distinctions in circulation kinetics of CD4+/CD62L (+ & -) T cells. That is, levels of CD4+/CD62L+ T cells were selectively depressed by opiates through the first 32wk after initiation of drug, and levels of CD4+/CD62L- T cells were selectively depressed thereafter. Regression analyses also showed that morphine stabilized lymphocyte recirculation. Circulating levels of resting and activated-memory types of T cells were positively correlated in opiate-exposed monkeys during the first 32wk after opiate exposure--an effect not seen with control monkeys. Considerations of changes in the types of experimental stressors extant during the study suggested that temporally differential effects of opiates on T cell recirculation were connected with changes in the stress environment and the ability of morphine to modulate these changes. Thus, morphine, and by inference the endogenous opioid system, are involved in homeostasis of lymphocyte recirculation, probably through effects on central mediation of the stress axis.


Assuntos
Macaca mulatta/imunologia , Morfina/toxicidade , Linfócitos T/efeitos dos fármacos , Animais , Movimento Celular/efeitos dos fármacos , Feminino , Homeostase/efeitos dos fármacos , Memória Imunológica , Contagem de Leucócitos , Ativação Linfocitária , Macaca mulatta/sangue , Dependência de Morfina/sangue , Dependência de Morfina/imunologia , Norepinefrina/imunologia , Estresse Fisiológico/imunologia , Subpopulações de Linfócitos T/efeitos dos fármacos , Subpopulações de Linfócitos T/imunologia , Linfócitos T/citologia
9.
Ocul Immunol Inflamm ; 9(1): 1-8, 2001 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11262663

RESUMO

Retinoblastoma, a rare pediatric eye tumor, has served as an important model for the heritable predisposition to cancer. The retinoblastoma protein, Rb, functions as a tumor suppressor by controlling progression through the cell cycle. Rb function is regulated primarily by its phosphorylation state, which is determined by the complex interaction of multiple kinases and their inhibitors that together form the 'Rb pathway'. This pathway has been found to be functionally inactivated in almost all types of cancer. Despite recent advances in our understanding of Rb function, the precise role of Rb loss in the development of retinoblastoma remains unclear. Recent work in genetically altered mice has suggested that an additional mutation in another gene is required for retinal tumor formation. An alternative model presented here is based on the noncell-autonomous functions of Rb contributing to tumorigenesis.


Assuntos
Neoplasias da Retina , Neoplasias da Retina/genética , Retinoblastoma , Retinoblastoma/genética , Genes do Retinoblastoma/genética , Humanos , Lactente , Recém-Nascido , Biologia Molecular , Fosforilação , Neoplasias da Retina/metabolismo , Retinoblastoma/metabolismo , Proteína do Retinoblastoma/metabolismo
10.
J Acoust Soc Am ; 108(5 Pt 1): 2366-76, 2000 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11108377

RESUMO

Three adaptive feedback-reduction algorithms were implemented in a laboratory-based digital hearing aid system and evaluated with dynamic feedback paths and hearing-impaired subjects. The evaluation included measurements of maximum stable gain and subjective quality ratings. The continuously adapting CNN algorithm (Closed-loop processing with No probe Noise) provided the best performance: 8.5 dB of added stable gain (ASG) relative to a reference algorithm averaged over all subjects, ears, and vent conditions. Two intermittently adapting algorithms, ONO (Open-loop with Noise when Oscillation detected) and ONQ (Open-loop with Noise when Quiet detected), provided an average of 5 dB of ASG. Subjects with more severe hearing losses received greater benefits: 13 dB average ASG for the CNN algorithm and 7-8 dB average ASG for the ONO and ONQ algorithms. These values are conservative estimates of ASG because the fitting procedure produced a frequency-gain characteristic that already included precautions against feedback. Speech quality ratings showed no substantial algorithm effect on pleasantness or intelligibility, although subjects informally expressed strong objections to the probe noise used by the ONO and ONQ algorithms. This objection was not reflected in the speech quality ratings because of limitations of the experimental procedure. The results clearly indicate that the CNN algorithm is the most promising choice for adaptive feedback reduction in hearing aids.


Assuntos
Algoritmos , Retroalimentação , Auxiliares de Audição , Idoso , Feminino , Transtornos da Audição/terapia , Humanos , Masculino , Pessoa de Meia-Idade , Ajuste de Prótese
11.
Am J Pathol ; 157(6): 1795-801, 2000 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11106551

RESUMO

Uveal melanoma is the most common primary eye cancer, yet its molecular pathogenesis is poorly understood. In this study, we investigated the immunohistochemical expression of proteins in the Rb and p53 tumor suppressor pathways in 33 uveal melanomas from enucleated eyes. Strong nuclear staining for Rb was present in most tumors. However, a few cases displayed weak nuclear staining and strong cytoplasmic staining (possibly indicating Rb mutation), and this aberrant staining correlated strongly with failed radiotherapy or thermotherapy before enucleation. Staining for cyclin D1 was positive in most tumors and was associated with advanced age and larger tumor size, which are both poor prognostic factors. Generally, immunostaining for p53 was weak (suggesting a lack of p53 mutations), although p53 positivity correlated strongly with staining for phosphorylated Rb, supporting the notion that inappropriate phosphorylation of Rb can induce p53. Strong immunostaining for MDM2, which can functionally block p53 activity, was observed in most tumors and correlated significantly with female sex. Strong cytoplasmic staining was observed for Bcl2, which can inhibit both p53-dependent and -independent apoptosis. We conclude that Rb and p53 are mutated infrequently in uveal melanoma, but their respective pathways may be functionally inactivated.


Assuntos
Melanoma/metabolismo , Proteínas Nucleares , Proteína do Retinoblastoma/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Neoplasias Uveais/metabolismo , Adulto , Idoso , Núcleo Celular/metabolismo , Ciclina D1/metabolismo , Feminino , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Fosforilação , Proteínas Proto-Oncogênicas/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Proteínas Proto-Oncogênicas c-mdm2 , Caracteres Sexuais
12.
Cancer Res ; 60(16): 4320-3, 2000 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-10969768

RESUMO

Uveal melanoma is the most common malignancy of the eye, but little is known about its underlying genetic defects. Melanomas of uveal origin, unlike those of the skin, are rarely familial and have not been linked consistently to mutations in tumor suppressor genes. Here, we investigated the Rb pathway in uveal melanoma. Most tumors displayed strong immunostaining for Rb and p16, suggesting that they were not mutationally inactivated. However, Rb was frequently phosphorylated at serine-807 and serine-811, and cyclin D1 was expressed in many of the tumors. Mutation of these serine residues prevented cyclin D-dependent phosphorylation from inactivating Rb in cultured cells. We conclude that Rb is frequently inactivated in uveal melanoma by phosphorylation of residues in the COOH-terminal region that regulate its activity, and one mechanism for this phosphorylation is overexpression of cyclin D.


Assuntos
Melanoma/metabolismo , Proteína do Retinoblastoma/antagonistas & inibidores , Neoplasias Uveais/metabolismo , Ciclina D , Ciclinas/biossíntese , Ciclinas/genética , Regulação Neoplásica da Expressão Gênica , Humanos , Imuno-Histoquímica , Melanoma/genética , Mutação , Inclusão em Parafina , Fosforilação , Proteína do Retinoblastoma/genética , Proteína do Retinoblastoma/metabolismo , Serina/metabolismo , Especificidade por Substrato , Transcrição Gênica , Transfecção , Células Tumorais Cultivadas , Neoplasias Uveais/genética
14.
Am J Public Health ; 89(5): 712-7, 1999 May.
Artigo em Inglês | MEDLINE | ID: mdl-10224983

RESUMO

OBJECTIVES: This study assessed the association between maternal cigarette smoking during pregnancy and the risk of invasive meningococcal disease during early childhood. METHODS: Using a retrospective cohort study design, cases from an active surveillance project monitoring all invasive meningococcal disease in the metropolitan Atlanta area from 1989 to 1995 were merged with linked birth and death certificate data files. Children who had not died or acquired meningococcal disease were assumed to be alive and free of the illness. The Cox proportional hazards analysis was used to assess the independent association between maternal smoking and meningococcal disease. RESULTS: The crude rate of meningococcal disease was 5 times higher for children whose mothers smoked during pregnancy than for children whose mothers did not smoke (0.05% vs 0.01%). Multivariate analysis revealed that maternal smoking (risk ratio [RR] = 2.9; 95% confidence interval [CI] = 1.5, 5.7) and a mother's having fewer than 12 years of education (RR = 2.1; 95% CI = 1.0, 4.2) were independently associated with invasive meningococcal disease. CONCLUSIONS: Maternal smoking, a likely surrogate for tobacco smoke exposure following delivery, appears to be a modifiable risk factor for sporadic meningococcal disease in young children.


Assuntos
Infecções Meningocócicas/epidemiologia , Infecções Meningocócicas/etiologia , Complicações na Gravidez , Fumar/efeitos adversos , Adulto , Análise de Variância , Declaração de Nascimento , Pré-Escolar , Estudos de Coortes , Atestado de Óbito , Feminino , Georgia/epidemiologia , Humanos , Lactente , Recém-Nascido , Masculino , Mães/educação , Vigilância da População , Gravidez , Modelos de Riscos Proporcionais , Estudos Retrospectivos , Fatores de Risco , Saúde da População Urbana
15.
Biochem Mol Med ; 61(2): 143-51, 1997 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-9259979

RESUMO

A collaborative March of Dimes study was designed to examine the utility of dried blood spot (DBS) materials routinely collected from newborns as a source for monitoring cocaine exposure and to assess the prevalence of cocaine use among childbearing women in Georgia. We used a modified urinary radioimmunoassay (RIA) to anonymously detect the cocaine metabolite benzoylecgonine (BE) in DBSs. Extensive efforts were undertaken to assure absolute nonlinkage of BE data to any individual. The positive results found by RIA were confirmed by a mass spectrometry (MS) method specifically developed to detect BE in DBSs. BE was measured in 23,141 DBSs collected during 2 months of routine newborn screening in Georgia. A good correlation was observed for RIA results versus MS results (r2 = 0.97). The estimated minimal statewide BE prevalence was 4.8 per 1000 childbearing women. We demonstrated that immunoassay testing for cocaine without confirmatory testing can yield falsely elevated prevalence rates. When proper confirmatory testing is done, DBSs are a valuable source for population-based monitoring of substance abuse among childbearing women.


Assuntos
Coleta de Amostras Sanguíneas/métodos , Cocaína/sangue , Triagem Neonatal/métodos , Detecção do Abuso de Substâncias/métodos , Estudos de Avaliação como Assunto , Feminino , Georgia/epidemiologia , Humanos , Recém-Nascido , Projetos Piloto , Gravidez , Prevalência
17.
Am J Public Health ; 82(3): 429-31, 1992 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-1536361

RESUMO

In 1988, we identified playground hazards at 58 child-care centers (CCCs) and intervened by showing the director the hazards and distributing safety information. In 1990, we evaluated the 58 intervention CCCs as well as 71 randomly selected control CCCs. Intervention centers had 9.4 hazards per playground; control centers had 8.0. We conclude that the intervention was ineffective.


Assuntos
Prevenção de Acidentes , Creches/normas , Jogos e Brinquedos , Segurança , Pessoal Administrativo/educação , Creches/organização & administração , Creches/estatística & dados numéricos , Pré-Escolar , Estudos de Avaliação como Assunto , Georgia , Humanos
18.
J Acoust Soc Am ; 90(3): 1340-54, 1991 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-1939899

RESUMO

This article describes further study of the finding reported by Green et al. [J. Acoust. Soc. Am. 73, 639-643 (1983)] and others that, in certain conditions, the threshold of detectability for an intensity increment to the center tone of a multitone reference spectrum decreased as the number of nonsignal tones increased. That result was considered remarkable since critical-band theory would predict that these nonsignal tones, spaced outside the "critical band" containing the signal, would have no effect on or, at most, slightly decrease within-band detectability--and certainly could not account for the result of improved detectability found in the study cited above. Recently, Henn and Turner [J. Acoust. Soc. Am. 88, 126-131 (1990)] were unable to replicate the result described above, concluding that the phenomenon exists only in "limited conditions" and that is "highly individual" in nature. Further, they speculated that the most likely reason for the discrepancy between their study and previous studies was the selection and/or training of the observers. The present study addressed the effects of the amount of subject training on the finding of Green et al. while controlling the potential effects of stimulus order. Specifically, for a group of three "naive" listeners, thresholds were measured for 3-, 7-, and 21-tone inharmonic complexes as a function of the amount of practice in a mixed-block design. In all cases the group mean thresholds decreased as the number of nonsignal tones increased both initially and after extensive practice for both fixed- and roving-level conditions. Thus the effect does not appear to be an artifact of the amount or order of training subjects receive. The possible role of subject sample size and the magnitude of individual differences in obtaining the effect remains an open question. Two hypotheses suggested to account for the improvement in threshold with increasing number of nonsignal tones were evaluated. The hypotheses were represented by simple mathematical models, referred to as the "multiple-comparison" and "pitch-cue" models. The predictions of both models were compared with the results of a series of detection experiments in which the independent variables were the number of nonsignal tones and amount of random, within-trial "amplitude perturbation" [cf. Kidd et al., J. Acoust. Soc. Am. 79, 1045-1053 (1986)] of the nonsignal tones. Neither model, as applied, provided a satisfactory account of the effects of the main variables of number of tones and amount of perturbation.(ABSTRACT TRUNCATED AT 400 WORDS)


Assuntos
Atenção , Limiar Auditivo , Percepção Sonora , Discriminação da Altura Tonal , Adulto , Humanos , Psicoacústica
19.
J Comput Assist Tomogr ; 14(1): 18-25, 1990.
Artigo em Inglês | MEDLINE | ID: mdl-2298991

RESUMO

The cavernous hemangioma (cavernoma) is increasingly recognized as a vascular malformation of the brain that may present with seizures, hemorrhage, or progressive neurological deficit. Since 1985 we have identified 13 cases of presumed cavernoma of the brain based on the findings on CT, selective angiography, and magnetic resonance (MR) imaging. In each case CT showed a high density lesion that was "occult" or "cryptic" on angiography. However, within all lesions MR revealed a complex internal structure consisting of reticulated patches of high and low intensity signal surrounded by a hypointense rim on T1- and T2-weighted pulse sequences. Of the nine operated cases, five resected specimens were compatible with pure arteriovenous malformations (AVMs), and the other four were mixtures of cavernoma with either AVM or venous angioma. Our experience strongly suggests that the above complex of radiographic findings is not at all specific for the cavernoma. We propose that the major common factor shared by such "cavernomatoid" malformations is low blood flow. We believe low flow lesions follow a relatively benign clinical course, and they readily lend themselves to surgical resection.


Assuntos
Neoplasias Encefálicas/diagnóstico , Hemangioma Cavernoso/diagnóstico , Adulto , Encéfalo/patologia , Feminino , Humanos , Malformações Arteriovenosas Intracranianas/diagnóstico , Imageamento por Ressonância Magnética , Masculino , Tomografia Computadorizada por Raios X
20.
Clin Imaging ; 13(4): 317-20, 1989 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-2598114

RESUMO

Mucormycosis is a rare fungal disease most often encountered in patients who are diabetic, immunocompromised, severely burned, or who have a history of intravenous drug abuse. Intracranial presentation includes the isolated cerebral and the more common rhinocerebral forms. The computed tomography picture in mucormycosis is well documented. The magnetic resonance (MR) findings associated with mucormycosis have not been previously described. We report a case of rhinocerebral mucormycosis in a poorly controlled diabetic man where the MR findings of cavernous sinus thrombosis and thrombosis of the cavernous portion of the internal carotid artery demonstrated progression of the patient's disease in spite of his stable clinica course. The results of the MR findings directly altered the patient's therapy, thus leading to a favorable outcome.


Assuntos
Encefalopatias/diagnóstico , Mucormicose/diagnóstico , Infecções Oportunistas/diagnóstico , Seio Cavernoso/patologia , Diabetes Mellitus Tipo 2/complicações , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Mucormicose/etiologia , Infecções Oportunistas/etiologia , Trombose dos Seios Intracranianos/diagnóstico , Seio Esfenoidal/patologia
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