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1.
Bone Joint J ; 98-B(10): 1369-1375, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27694591

RESUMO

AIMS: The surgical management of ankle arthritis with tibiotalar arthrodesis is known to alter gait, as compared with normal ankles. The purpose of this study was to assess post-operative gait function with gait before arthrodesis. PATIENTS AND METHODS: We prospectively studied 20 patients who underwent three-dimensional gait analysis before and after tibiotalar arthrodesis. Cadence, step length, walking velocity and total support time were assessed. Kinetic parameters, including the moment and power of the ankle in the sagittal plane and hip power were also recorded. RESULTS: Significant improvement was recorded across numerous parameters compared with pre-operative measurements. Temporal-spatial data demonstrated a significant increase in step length (p = 0.003) and velocity (p = < 0.001). Total support time decreased for the unaffected limb (p = 0.01). Kinematic results demonstrated that in the affected limb, total sagittal range of movement did not change significantly (p = 0.1259). However, the arc of movement had a near congruent shift with mean maximal dorsiflexion increasing from 5° (-17° to 16°) to 12° (5° to 18°) (p < 0.001) and mean maximal plantarflexion decreasing from 6.8° (6° to 21°) to 0.9° (-9° to 8°) (p = 0.003). Mean hip joint range of movement increased by 6° (-7° to 24°; p = 0.003). Kinetic results demonstrated no statistically significant change in ankle power (p = 0.1292). However, there was an increase in ankle moment (p = 0.04) and hip power (p = 0.01) in the surgically treated extremity. Sagittal plane range of movement was not reduced after tibiotalar fusion. CONCLUSION: Although following tibiotalar arthrodesis the gait demonstrated never matched the gait shown in unaffected ankles, compared with the pre-operative analysis there was improvement in numerous temporal-spatial, kinematic, and kinetic measures. Cite this article: Bone Joint J 2016;98-B:1369-75.


Assuntos
Articulação do Tornozelo/cirurgia , Artrite/cirurgia , Artrodese/métodos , Marcha/fisiologia , Imageamento Tridimensional/métodos , Amplitude de Movimento Articular/fisiologia , Caminhada/fisiologia , Articulação do Tornozelo/diagnóstico por imagem , Articulação do Tornozelo/fisiopatologia , Artrite/diagnóstico , Artrite/fisiopatologia , Fenômenos Biomecânicos , Seguimentos , Humanos , Estudos Prospectivos , Radiografia , Resultado do Tratamento
2.
Neurology ; 71(2): 93-100, 2008 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-18509092

RESUMO

BACKGROUND: In adult patients, autoantibodies targeting the water channel aquaporin-4 (AQP4) are a biomarker for a spectrum of CNS inflammatory demyelinating disorders with predilection for optic nerves and spinal cord (neuromyelitis optica [NMO]). Here we describe the neurologic, serologic, and radiographic findings associated with CNS AQP4 autoimmunity in childhood. METHODS: A total of 88 consecutive seropositive children were identified through service evaluation for NMO-IgG. Sera of 75 were tested for coexisting autoantibodies. Clinical information was available for 58. RESULTS: Forty-two patients (73%) were non-Caucasian, and 20 (34%) had African ethnicity. Median age at symptom onset was 12 years (range 4-18). Fifty-seven (98%) had attacks of either optic neuritis (n = 48; 83%) or transverse myelitis (n = 45; 78%), or both. Twenty-six (45%) had episodic cerebral symptoms (encephalopathy, ophthalmoparesis, ataxia, seizures, intractable vomiting, or hiccups). Thirty-eight (68%) had brain MRI abnormalities, predominantly involving periventricular areas (in descending order of frequency): the medulla, supratentorial and infratentorial white matter, midbrain, cerebellum, thalamus, and hypothalamus. Additional autoantibodies were detected in 57 of 75 patients (76%), and 16 of 38 (42%) had a coexisting autoimmune disorder recorded (systemic lupus erythematosus, Sjögren syndrome, juvenile rheumatoid arthritis, Graves disease). Attacks were recurrent in 54 patients (93%; median follow-up, 12 months). Forty-three of 48 patients (90%) had residual disability: 26 (54%) visual impairment and 21 (44%) motor deficits (median Expanded Disability Status Scale 4.0 at 12 months). CONCLUSIONS: Aquaporin-4 autoimmunity is a distinctive recurrent and widespread inflammatory CNS disease in children.


Assuntos
Aquaporina 4/imunologia , Autoanticorpos/análise , Mielite Transversa/imunologia , Neuromielite Óptica/imunologia , Adolescente , Autoimunidade , Biomarcadores/análise , Encéfalo/patologia , Criança , Pré-Escolar , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Metilprednisolona/uso terapêutico , Mielite Transversa/diagnóstico , Mielite Transversa/tratamento farmacológico , Neuromielite Óptica/diagnóstico , Neuromielite Óptica/tratamento farmacológico , Recidiva , Testes Sorológicos
4.
J Atten Disord ; 6(2): 49-60, 2002 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-12142861

RESUMO

Twenty-four adults (24 to 53 years old) with Attention-Deficit/Hyperactivity Disorder (ADHD), Combined Type, were studied in a double-blind, placebo-controlled, crossover study of Pycnogenol and methylphenidate. Pycnogenol is an antioxidant derived from the bark of the French maritime pine tree. Methylphenidate is a standard pharmaceutical intervention for ADHD. Anecdotal reports suggest that Pycnogenol improves concentration in adults with ADHD without adverse side effects. Participants received Pycnogenol, methylphenidate, and placebo, each for three weeks, in a randomized and counterbalanced order. Although ADHD symptoms improved during treatment, neither methylphenidate nor Pycnogenol outperformed the placebo control, as measured by self-report rating scales, rating scales completed by the individual's significant other, and a computerized continuous performance test. The conservative dosage levels and relatively brief length of treatment may have contributed to the absence of significant differences among treatment conditions. Implications for future research are noted.


Assuntos
Adjuvantes Imunológicos/uso terapêutico , Transtorno do Deficit de Atenção com Hiperatividade/tratamento farmacológico , Estimulantes do Sistema Nervoso Central/uso terapêutico , Flavonoides/uso terapêutico , Metilfenidato/uso terapêutico , Adulto , Transtorno do Deficit de Atenção com Hiperatividade/diagnóstico , Humanos , Masculino , Pessoa de Meia-Idade , Extratos Vegetais , Índice de Gravidade de Doença
5.
Cell ; 107(4): 477-87, 2001 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-11719188

RESUMO

Fragile X syndrome results from the absence of the RNA binding FMR protein. Here, mRNA was coimmunoprecipitated with the FMRP ribonucleoprotein complex and used to interrogate microarrays. We identified 432 associated mRNAs from mouse brain. Quantitative RT-PCR confirmed some to be >60-fold enriched in the immunoprecipitant. In parallel studies, mRNAs from polyribosomes of fragile X cells were used to probe microarrays. Despite equivalent cytoplasmic abundance, 251 mRNAs had an abnormal polyribosome profile in the absence of FMRP. Although this represents <2% of the total messages, 50% of the coimmunoprecipitated mRNAs with expressed human orthologs were found in this group. Nearly 70% of those transcripts found in both studies contain a G quartet structure, demonstrated as an in vitro FMRP target. We conclude that translational dysregulation of mRNAs normally associated with FMRP may be the proximal cause of fragile X syndrome, and we identify candidate genes relevant to this phenotype.


Assuntos
Química Encefálica , Síndrome do Cromossomo X Frágil/genética , Proteínas do Tecido Nervoso/fisiologia , Análise de Sequência com Séries de Oligonucleotídeos , Biossíntese de Proteínas , RNA Mensageiro/metabolismo , Proteínas de Ligação a RNA/fisiologia , Sequência de Aminoácidos , Animais , Centrifugação com Gradiente de Concentração , Modelos Animais de Doenças , Proteína do X Frágil da Deficiência Intelectual , Humanos , Ligantes , Substâncias Macromoleculares , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Modelos Genéticos , Dados de Sequência Molecular , Proteínas do Tecido Nervoso/deficiência , Proteínas do Tecido Nervoso/genética , Reação em Cadeia da Polimerase , Testes de Precipitina , Ligação Proteica , RNA Mensageiro/química , RNA Mensageiro/isolamento & purificação , Proteínas de Ligação a RNA/genética , Sequências Reguladoras de Ácido Nucleico , Ribossomos/metabolismo , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos
6.
Proc Natl Acad Sci U S A ; 97(26): 14085-90, 2000 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-11121017

RESUMO

Genomic array technologies provide a means for profiling global changes in gene expression under a variety of conditions. However, it has been difficult to assess whether transcriptional or posttranscriptional regulation is responsible for these changes. Additionally, fluctuations in gene expression in a single cell type within a complex tissue like a tumor may be masked by overlapping profiles of all cell types in the population. In this paper, we describe the use of cDNA arrays to identify subsets of mRNAs contained in endogenous messenger ribonucleoprotein complexes (mRNPs) that are cell type specific. We identified mRNA subsets from P19 embryonal carcinoma stem cells by using mRNA-binding proteins HuB, eIF-4E, and PABP that are known to play a role in translation. The mRNA profiles associated with each of these mRNPs were unique and represented gene clusters that differed from total cellular RNA. Additionally, the composition of mRNAs detected in HuB-mRNP complexes changed dramatically after induction of neuronal differentiation with retinoic acid. We suggest that the association of structurally related mRNAs into mRNP complexes is dynamic and may help regulate posttranscriptional events such as mRNA turnover and translation. Recovering proteins specifically associated with mRNP complexes to identify and profile endogenously clustered mRNAs should provide insight into structural and functional relationships among gene transcripts and/or their protein products. We have termed this approach to functional genomics ribonomics and suggest that it will provide a useful paradigm for organizing genomic information in a biologically relevant manner.


Assuntos
Proteínas do Tecido Nervoso/metabolismo , Fatores de Iniciação de Peptídeos/metabolismo , RNA Mensageiro/metabolismo , Proteínas de Ligação a RNA/metabolismo , Ribonucleoproteínas/metabolismo , Animais , DNA Complementar , Proteínas ELAV , Proteína Semelhante a ELAV 2 , Fator de Iniciação 4E em Eucariotos , Camundongos , Proteínas do Tecido Nervoso/genética , Análise de Sequência com Séries de Oligonucleotídeos , Proteínas de Ligação a Poli(A) , Proteínas de Ligação a RNA/genética , Tretinoína/farmacologia , Células Tumorais Cultivadas
8.
Lancet ; 349(9050): 449-54, 1997 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-9040573

RESUMO

BACKGROUND: Local complications (encapsulation, rashes, rupture, and leakage) can occur after placement of silicone gel-containing breast implants (SBI). Whether SBI exposure results in systemic manifestations in some recipients is controversial. We have carried out a blinded study to assess whether there is any difference between SBI recipients and non-exposed controls in the proportions positive for serum antibodies directed against polymeric substances. METHODS: We recruited female SBI recipients (including those without symptoms) who presented to a single rheumatology clinic. A physician global assessment was used to classify SBI recipients who did not meet criteria for specific autoimmune diseases according to the severity of local and systemic signs and symptoms. Controls were recruited from among clinic staff and their acquaintances. Results of the antipolymer antibody (APA) assay were compared with those of an assay for antinuclear antibodies (ANA) and with the severity of the signs and symptoms. FINDINGS: Positive APA results were found in one (3%) of 34 SBI recipients with limited symptoms, two (8%) of 26 with mild symptoms, seven (44%) of 16 with moderate symptoms, and 13 (68%) of 19 with advanced symptoms. Four (17%) of 23 healthy non-SBI-exposed controls and two (10%) of 20 non-exposed women with classic autoimmune diseases were positive for APA. Thus, women with moderate or advanced symptoms were significantly more likely than those with limited or mild symptoms, or non-exposed controls to have APA (p < 0.001). The proportion with positive ANA results was higher for women with classic autoimmune diseases 14 (70%) of 20 than for any SBI-exposed subgroup (0-33%). INTERPRETATION: The APA assay can objectively contribute to distinguishing between SBI recipients with limited or mild signs and symptoms. SBI recipients with more severe manifestations, and patients with specific autoimmune diseases. Further studies will be needed to define the signs and symptoms associated with exposure to SBI.


Assuntos
Autoanticorpos/sangue , Doenças Autoimunes/imunologia , Implantes de Mama/efeitos adversos , Polímeros/efeitos adversos , Silicones/efeitos adversos , Adulto , Anticorpos Antinucleares/sangue , Doenças Autoimunes/etiologia , Feminino , Humanos , Immunoblotting , Pessoa de Meia-Idade , Sensibilidade e Especificidade , Índice de Gravidade de Doença
9.
Kidney Int ; 51(2): 579-84, 1997 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-9027743

RESUMO

Synthesis of erythropoietin (Epo), the glycoprotein hormone that regulates red blood cell formation, is induced in response to low oxygen stress (hypoxia), and is regulated at both transcriptional and post-transcriptional levels. We have previously described an Epo RNA binding protein (ERBP) which specifically binds to the 3'-untranslated region of Epo mRNA and is likely involved in the regulation of Epo mRNA stability. Since heat shock proteins (hsps) are induced in response to a variety of stresses, including hypoxia, we tested the possibility that hsps are involved in ERBP-Epo RNA complex formation. When human anti-hsp70 antibody was added to ERBP-containing human hepatoma cell (Hep3B) lysates, the ERBP-Epo RNA complex was inhibited in an electrophoretic mobility band shift assay. In addition, the anti-hsp70 antibody-inhibited complex could be rescued if lysates were pretreated with purified inducible hsp70, but not with bovine serum albumin (BSA). In vivo studies using quercetin to inhibit hsp70 induction support the notion that hsp70 is involved in ERBP-Epo RNA complex formation. Taken together, these findings suggest involvement of hsp70 in ERBP-Epo mRNA complex formation, and our model suggests a novel role for hsps in the regulation of EPO mRNA stability.


Assuntos
Eritropoetina/genética , Eritropoetina/metabolismo , Proteínas de Choque Térmico HSP70/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Proteínas de Ligação a RNA/metabolismo , Animais , Bovinos , Linhagem Celular , Proteínas de Choque Térmico HSP70/antagonistas & inibidores , Humanos , Técnicas In Vitro , Substâncias Macromoleculares , Modelos Biológicos , Quercetina/farmacologia
10.
J Clin Endocrinol Metab ; 81(6): 2271-9, 1996 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-8964863

RESUMO

We have previously reported that over 85% of patients with Graves' disease have detectable serum antibodies against a human intracisternal type A retroviral particle (HIAP), which are not present in age- and gender-matched controls, suggesting a role for HIAP in triggering the autoimmune process leading to Graves' disease. To investigate the interaction of this viral particle with genetic factors, 35 members of 3 kindreds, selected because of a high family prevalence of Graves' disease (a total of 11 members affected), were examined for clinical signs of thyroid dysfunction, goiter, and opthalmopathy. Thyroid function tests and autoimmune serological profiles were also obtained. In addition, subjects were tested for the presence of antibodies against HIAP by means of immunoblot analysis of their sera, and their human leukocyte antigen (HLA) class II alleles were determined by DNA methodology. Molecular genetic analyses enabled the detection of postulated HLA susceptibility haplotypes in each family. These families had 8, 4, and 5 members, respectively, with such apparent susceptibility genes and 11, 5, and 9 members, respectively, with immunological evidence of retroviral exposure. In the presence of both factors (codetected in a total of 15 members of the 3 kindreds), the incidence of Graves' disease was 100%, 67%, and 80%, respectively. One additional member of family B and 3 in family C with both viral and genetic susceptibility factors were found to have serological abnormalities and/or goiter and ocular signs consistent with evolving or preclinical Graves' disease. In families A and C, tight linkage between HLA haplotypes and Graves' disease was demonstrated in a manner consistent with recessive inheritance. The association between the occurrence of both anti-HIAP-I antibody positivity and HLA susceptibility and the presence of Graves' disease was highly significant (P < 0.001). The pathogenesis of Graves' disease in these families appears to be attributable to the interaction between the immune response to an intracisternal type A retroviral particle and immunogenetic susceptibility, leading to the autoimmune processes that underlie Graves' disease, with subsequent development of the characteristic features of the illness. Data from these families suggest that both of these factors are necessary for final disease expression. These results imply that serological evidence of retroviral exposure together with genetic HLA susceptibility are the two major predisposing factors underlying the pathogenesis of Graves' disease. Further studies will establish whether prospective identification of persons at risk for Graves' disease is possible by this means.


Assuntos
Genes , Doença de Graves/genética , Antígenos de Histocompatibilidade Classe II/genética , Retroviridae/fisiologia , Vírion/fisiologia , Adulto , Anticorpos Antivirais/análise , Autoanticorpos/análise , Feminino , Predisposição Genética para Doença , Doença de Graves/imunologia , Doença de Graves/fisiopatologia , Haplótipos , Humanos , Masculino , Pessoa de Meia-Idade , Retroviridae/imunologia , Glândula Tireoide/fisiopatologia
11.
AIDS Res Hum Retroviruses ; 12(3): 235-9, 1996 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-8835202

RESUMO

Cytotoxic CD8+ lymphocytes (CTLs) kill virally infected target cells by releasing cytotoxic granules. The primary objective of this study was to determine whether the activity of granzyme A, a serine protease in the killing granules of CTLs is altered in HIV-infected hemophiliacs. A sensitive colorimetric assay that measures cleavage of a synthetic substrate, N alpha-benzyloxycarbonyl-L-lysine thiobenzyl ester (BLT), was used to quantitate granzyme A activity. Granzyme A activities from hemophiliacs were normalized to to granzyme A activities of healthy donors run concurrently. Granzyme A activity in CD8+ T cells from HIV-seropositive hemophiliacs was significantly lower than granzyme A activity in cells from HIV-seronegative hemophiliacs (0.48 units +/- 0.086/CD8+ T cell and 1.573 +/- 0.434 units/CD8+ T cell, respectively; p < 0.005). These results indicate that cytotoxic cells in HIV-infected hemophiliacs have reduced granzyme A activity, which may result in a defect in CTL-mediated cell killing in these patients.


Assuntos
Soropositividade para HIV/complicações , Hemofilia A/enzimologia , Hemofilia B/enzimologia , Serina Endopeptidases/metabolismo , Linfócitos T Citotóxicos/enzimologia , Estudos de Coortes , Feminino , Granzimas , Soronegatividade para HIV , Soropositividade para HIV/sangue , Soropositividade para HIV/enzimologia , Hemofilia A/sangue , Hemofilia A/complicações , Hemofilia B/sangue , Hemofilia B/complicações , Humanos , Lisina/análogos & derivados , Lisina/metabolismo , Masculino
12.
J Rheumatol ; 22(2): 236-40, 1995 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-7738944

RESUMO

OBJECTIVE: Recent evidence suggests that immunologic abnormalities are not uncommon in individuals with silicone breast implants. The purpose of our study was to evaluate in a consecutive manner, the prevalence of autoimmunity as assessed by the presence of antinuclear antibodies in a larger number of patients with silicone breast implants. METHODS: Antinuclear antibody (ANA) testing using an indirect immunofluorescence technique was performed on 813 individuals with silicone breast implants. All subjects except for 3 transsexual males, were female. The overwhelming majority, over 99%, were white. The average age of the subjects was 46.2, with a range of 17 to 72 years. RESULTS: ANA positivity was found in 244 of 813 individuals (30%) using a mouse kidney substrate; and in 470 of 813 (57.8%) using a HEp-2 cell line. The most common immunofluorescent pattern found using HEp-2 was speckled, present in 341 (72.5%) individuals, followed by homogeneous pattern in 113 (24%), nucleolar in 63 (13.4%), and 5 (1.06%) were anticentromere. Anti-dsDNA antibodies measured by an ELISA assay were found in 6 of 71 patients (8%). Rheumatoid factor and C-reactive protein were found above healthy controls in less than 10% of cases studied. The high prevalence of ANA found in patients with silicone breast implants agrees with similar observations by others. The finding of anticentromere and nucleolar patterns has great interest and relevance. These fairly distinct ANA patterns are most commonly seen in the idiopathic form of scleroderma and related conditions. CONCLUSION: These findings suggest that ANA positivity is relatively common in individuals with silicone breast implants, and may support the existence of autoimmune mechanisms in the pathogenesis of the clinical manifestations seen in this population.


Assuntos
Anticorpos Antinucleares/análise , Mama/cirurgia , Próteses e Implantes , Silicones , Adolescente , Adulto , Idoso , Proteína C-Reativa/análise , Centrômero/imunologia , DNA/imunologia , Ensaio de Imunoadsorção Enzimática , Feminino , Imunofluorescência , Humanos , Masculino , Pessoa de Meia-Idade , Fator Reumatoide/análise
13.
Autoimmunity ; 20(2): 135-42, 1995.
Artigo em Inglês | MEDLINE | ID: mdl-7578870

RESUMO

An apparently high frequency of Graves' disease encountered in New Orleans, Louisiana, prompted an investigation for a possible infectious agent that might be triggering the disease in genetically susceptible individuals. We studied 40 patients with Graves' disease, and compared them to the following groups of controls: age and gender matched healthy subjects; patients with multinodular goiter (non-autoimmune thyroid controls); patients with chronic lymphocytic thyroiditis (autoimmune thyroid disease controls) and additional organ or tissue specific autoimmune controls exclusive of thyroid autoimmunity, including patients with Type I diabetes and other endocrine autoimmune complex disorders. Serum antibodies against a prototypic strain of a human intracisternal A-type retroviral particle type 1 (HIAP-1) were detected by a sensitive and specific immunoblotting assay. In 87.5% (35/40) of the Graves' disease patients there was a positive reaction against several HIAP-1-associated proteins, predominantly 97 Kd and 80 Kd, with only 5 showing no reactivity to any. In contrast, 2% (2/105) of sera from normal controls showed positive reactivity. Furthermore, only 10% (1/10) of sera from multinodular goiter control patients and 10% (1/10) of Hashimoto's patients showed reactivity (p < 0.0005). Sera from 3 of 20 (15%) of Type I diabetic patients none of whom had Graves' disease, showed reactivity but there was no reactivity in 9 other patients with one or more of the endocrine autoimmune complex disorders, including Addison's disease, vitiligo, myasthenia gravis and pernicious anemia. In addition we studied two individuals with Graves' disease from each of two families residing outside Louisiana, all of whom were positive for these antibodies.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Doença de Graves/virologia , Infecções por Retroviridae/imunologia , Adulto , Feminino , Genes de Partícula A Intracisternal/imunologia , Doença de Graves/etiologia , Doença de Graves/imunologia , Humanos , Masculino , Pessoa de Meia-Idade , Proteínas dos Retroviridae/isolamento & purificação
17.
Am J Clin Hypn ; 33(1): 40-9, 1990 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-2220655

RESUMO

We exposed 24 subjects high in hypnotic susceptibility and 24 subjects low in hypnotic susceptibility to a cold-pressor pain stimulus under either hypnotic or waking conditions, using each of two pain-reduction strategies (analgesia and distraction) separately. Trance depth level was held constant for hypnotized subjects. We used pain-tolerance levels as measures of pain, and we analyzed them by survival analysis. High susceptibles reported significantly lower pain ratings and kept their hands immersed longer in the cold water than low-susceptible subjects. There were no significant differences between hypnotic and waking condition subjects or between the different strategies. We have discussed the results in terms of a relationship in the literature between choice of experimental design (between-subjects or within-subjects) and the effectiveness of a hypnotic induction for suggested pain reduction.


Assuntos
Hipnose Anestésica , Medição da Dor , Sugestão , Nível de Alerta , Humanos , Testes de Personalidade
18.
JPEN J Parenter Enteral Nutr ; 10(1): 74-7, 1986.
Artigo em Inglês | MEDLINE | ID: mdl-3945046

RESUMO

We have shown previously that supplemental vitamin A (Vit. A) increases the early inflammatory response to wounding and enhances the collagen content of the intestine of normal and injured rats. We now report the effect of dietary supplementation with Vit. A on the prevention of duodenal ulcer (DU) in rats caused by intragastric administration of cysteamine-HCl. A major way cysteamine-HCl induces DU formation is by enhancing gastric acid secretion. Adult male rats were divided into two groups: (1) rats fed a standard rat Chow (Purina) (15 IU Vit. A/g diet) containing two to three times the National Research Council recommended daily allowance for Vit. A for normal rats; (2) rats fed the same supplemented with 150 IU of Vit. A palmitate per/g Chow. One week later, all rats were given 1 ml of cysteamine-HCl (135 mg) intragastrically. The rats were maintained on their respective diets. Two days later, all rats were killed with ether, the stomach and duodenum excised, and examined for the presence of ulcers. No gastric ulcers were found in either group. There was a statistically significant decrease in the incidence of DUs in the Vit. A-supplemented group when compared to the control group (p less than 0.01) 48 hr following cysteamine-HCl administration; 32% of the Vit. A-supplemented rats developed a DU whereas 74% of rats fed standard Chow had DUs. Most rats had a single DU in the first part of the duodenum, occasionally a second ulcer was noted in the same area. Dietary supplementation with Vit. A had no effect on gastric acid production. In conclusion, our data show that Vit. A dietary supplementation is effective in preventing formation of DUs caused by cysteamine-HCl administration to rats. This effect does not appear to be due to reduction of gastric acid output.


Assuntos
Úlcera Duodenal/prevenção & controle , Vitamina A/uso terapêutico , Animais , Cisteamina , Dieta , Úlcera Duodenal/induzido quimicamente , Ácido Gástrico/metabolismo , Masculino , Ratos , Ratos Endogâmicos , Vitamina A/administração & dosagem
19.
Cell Biol Toxicol ; 1(1): 1-9, 1984 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-6401124

RESUMO

A quantitative in vitro method for phototoxic evaluation of chemicals has been developed and validated. The assay uses Saccharomyces cerevisiae, seeded in an agar overlay on top of a plate count agar base. 8-Methoxy psoralen is used as a reference standard against which materials are measured. Activity is quantified by cytotoxicity measured as zones of inhibition. Several known phototoxins (heliotropine, lyral, phantolid, and bergamot oil) and photoallergens (6-methyl coumarin and musk ambrette) are used to validate the assay. An excellent correlation is observed between in vivo studies employing Hartley albino guinea pigs and the in vitro assay for several fragrance raw materials and other chemicals. The in vitro assay exhibits a greater sensitivity from 2-500 fold. For three fragrance oils, the in vitro assay detects low levels of photobiological activity while the in vivo assay is negative. Although the in vitro assay does not discriminate between phototoxins and photoallergens, it can be used for screening of raw materials so that reduction in animal usage can be achieved while maintaining the protection of the consumer.


Assuntos
Administração Tópica , Transtornos de Fotossensibilidade/induzido quimicamente , Animais , Bioensaio/métodos , Feminino , Cobaias , Metoxaleno/farmacologia , Saccharomyces cerevisiae/efeitos dos fármacos
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