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1.
Surg Oncol ; 54: 102062, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38531288

RESUMO

BACKGROUND: De-escalation of axillary surgery in breast cancer (BC) patients diminishes sequelae without compromising cancer outcomes. Surgical management of the axilla is challenging after neoadjuvant treatment. We aimed to identify the factors associated with residual axillary disease amenable to lymphadenectomy in patients with positive sentinel lymph node biopsy (SLNB). METHODS: We conducted a retrospective observational study in Hospital 12 de Octubre (Spain). We included BC patients with positive SLNB who underwent axillary dissection after neoadjuvant chemotherapy. Univariate and multivariate logistic regression models were performed to identify independent predictors of residual axillary disease. We estimated the ratio of positive nodes in SLNB and assessed the diagnostic validity of this ratio in relation to residual axillary disease. RESULTS: We included 103 patients in the study. Residual axillary disease was identified in 54 patients (52.4%). Clinically node positive status at diagnosis (OR = 18.3, 95%CI: 4.0-83.6) and a ratio of positive nodes in SLNB ≥0.5 (OR = 6.5, 95%CI 41.7-23.7) were associated with residual axillary disease. The sensitivity and negative predictive value of a ratio of positive nodes in SLNB ≥0.5 were 87% (95%CI 75.1%-94.6%) and 75% (95%CI 55.1%-89.3%), respectively. CONCLUSIONS: In our study, for patients with positive SLNB after neoadjuvant chemotherapy, stage N+ at diagnosis and a ratio of positive nodes in SLNB ≥0.5 were independent risk factors of positive residual axillary disease. This ratio is a feasible measure with a good diagnostic validity for residual axillary disease and could be used as a guiding factor in the surgical management of these patients.


Assuntos
Axila , Neoplasias da Mama , Terapia Neoadjuvante , Biópsia de Linfonodo Sentinela , Linfonodo Sentinela , Humanos , Neoplasias da Mama/patologia , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/cirurgia , Feminino , Estudos Retrospectivos , Pessoa de Meia-Idade , Linfonodo Sentinela/patologia , Linfonodo Sentinela/cirurgia , Excisão de Linfonodo , Prognóstico , Seguimentos , Idoso , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Adulto , Metástase Linfática , Quimioterapia Adjuvante
2.
Neurologia (Engl Ed) ; 37(2): 91-100, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35279228

RESUMO

INTRODUCTION: Glucose transporter type 1 (GLUT1) deficiency syndrome may present a range of phenotypes, including epilepsy, intellectual disability, and movement disorders. The majority of patients present low CSF glucose levels and/or defects in the SLC2A1 gene; however, some patients do not present low CSF glucose or SLC2A1 mutations, and may have other mutations in other genes with compatible phenotypes. AIMS: We describe the clinical, biochemical, and genetic characteristics of the disease and perform a univariate analysis of a group of patients with clinical and biochemical phenotype of GLUT1 deficiency syndrome, with or without SLC2A1 mutations. MATERIAL AND METHODS: The study included 13 patients meeting clinical and biochemical criteria for GLUT1 deficiency syndrome. SLC2A1 sequencing and multiplex ligation-dependent probe amplification were performed; exome sequencing was performed for patients with negative results. RESULTS: Six patients presented the classic phenotype; 2 paroxysmal dyskinesia, 2 complex movement disorders, 2 early-onset absence seizures, and one presented drug-resistant childhood absence epilepsy. Six patients were positive for SLC2A1 mutations; in the other 5, another genetic defect was identified. No significant differences were observed between the 2 groups for age of onset, clinical presentation, microcephaly, intellectual disability, or response to ketogenic diet. Patients with SLC2A1 mutations presented more clinical changes in relation to diet (66.7%, vs 28.6% in the SLC2A1-negative group) and greater persistence of motor symptoms (66% vs 28.6%); these differences were not statistically significant. Significant differences were observed for CSF glucose level (34.5 vs 46mg/dL, P=.04) and CSF/serum glucose ratio (0.4 vs 0.48, P<.05). CONCLUSIONS: GLUT1 deficiency syndrome may be caused by mutations to genes other than SLC2A1 in patients with compatible phenotype, low CSF glucose level, and good response to the ketogenic diet.


Assuntos
Erros Inatos do Metabolismo dos Carboidratos , Epilepsia Tipo Ausência , Erros Inatos do Metabolismo dos Carboidratos/complicações , Erros Inatos do Metabolismo dos Carboidratos/diagnóstico , Erros Inatos do Metabolismo dos Carboidratos/genética , Criança , Humanos , Proteínas de Transporte de Monossacarídeos/deficiência , Proteínas de Transporte de Monossacarídeos/genética , Fenótipo
4.
Neurologia (Engl Ed) ; 2019 Apr 29.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-31047728

RESUMO

INTRODUCTION: Glucose transporter type 1 (GLUT1) deficiency syndrome may present a range of phenotypes, including epilepsy, intellectual disability, and movement disorders. The majority of patients present low CSF glucose levels and/or defects in the SLC2A1 gene; however, some patients do not present low CSF glucose or SLC2A1 mutations, and may have other mutations in other genes with compatible phenotypes. AIMS: We describe the clinical, biochemical, and genetic characteristics of the disease and perform a univariate analysis of a group of patients with clinical and biochemical phenotype of GLUT1 deficiency syndrome, with or without SLC2A1 mutations. MATERIAL AND METHODS: The study included 13 patients meeting clinical and biochemical criteria for GLUT1 deficiency syndrome. SLC2A1 sequencing and multiplex ligation-dependent probe amplification were performed; exome sequencing was performed for patients with negative results. RESULTS: Six patients presented the classic phenotype; 2 paroxysmal dyskinesia, 2 complex movement disorders, 2 early-onset absence seizures, and one presented drug-resistant childhood absence epilepsy. Six patients were positive for SLC2A1 mutations; in the other 5, another genetic defect was identified. No significant differences were observed between the 2 groups for age of onset, clinical presentation, microcephaly, intellectual disability, or response to ketogenic diet. Patients with SLC2A1 mutations presented more clinical changes in relation to diet (66.7% vs. 28.6% in the SLC2A1-negative group) and greater persistence of motor symptoms (66% vs. 28.6%); these differences were not statistically significant. Significant differences were observed for CSF glucose level (34.5 vs. 46mg/dL, P=.04) and CSF/serum glucose ratio (0.4 vs. 0.48, P<.05). CONCLUSIONS: GLUT1 deficiency syndrome may be caused by mutations to genes other than SLC2A1 in patients with compatible phenotype, low CSF glucose level, and good response to the ketogenic diet.

6.
Rev Neurol ; 64(s03): S49-S53, 2017 May 17.
Artigo em Espanhol | MEDLINE | ID: mdl-28524220

RESUMO

INTRODUCTION: Although the overall incidence of inborn errors of metabolism is low, their early diagnosis is essential, since some of them have a specific treatment. DEVELOPMENT: We review the main treatable inborn errors of metabolism that can present as early-onset epileptic encephalopathies, together with their biochemical markers and their treatment. CONCLUSIONS: It is important to think about the possibility of an inborn error of metabolism with a specific therapy, since it is crucial for this to be started as soon as possible in order to prevent permanent neurological damage.


TITLE: Abordaje metabolico en las encefalopatias epilepticas del lactante.Introduccion. Aunque la incidencia global de los errores congenitos del metabolismo es baja, su diagnostico precoz es fundamental, ya que algunos de ellos tienen tratamiento especifico. Desarrollo. Se revisan los principales errores congenitos del metabolismo tratables que pueden cursar como encefalopatia epileptica de inicio precoz, asi como sus marcadores bioquimicos y su tratamiento. Conclusiones. Es importante pensar en la posibilidad de un error congenito del metabolismo con terapia especifica, ya que es fundamental que esta comience lo antes posible para evitar un daño neurologico permanente.


Assuntos
Encefalopatias Metabólicas Congênitas/metabolismo , Epilepsia/metabolismo , Idade de Início , Biotina/uso terapêutico , Encefalopatias Metabólicas/tratamento farmacológico , Encefalopatias Metabólicas/metabolismo , Encefalopatias Metabólicas Congênitas/tratamento farmacológico , Encefalopatias Metabólicas Congênitas/terapia , Pré-Escolar , Creatina/metabolismo , Técnicas de Diagnóstico Neurológico , Epilepsia/tratamento farmacológico , Doenças Fetais/genética , Doenças Fetais/metabolismo , Deficiência de Holocarboxilase Sintetase/tratamento farmacológico , Deficiência de Holocarboxilase Sintetase/metabolismo , Humanos , Hipóxia-Isquemia Encefálica/tratamento farmacológico , Hipóxia-Isquemia Encefálica/metabolismo , Lactente , Recém-Nascido , Piridoxaminafosfato Oxidase/deficiência , Piridoxaminafosfato Oxidase/metabolismo , Piridoxina/uso terapêutico , Convulsões/tratamento farmacológico , Convulsões/metabolismo
8.
Neurologia ; 27(7): 407-13, 2012 Sep.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-22178048

RESUMO

INTRODUCTION: Mucopolysaccharidoses (MPS) are a group of inherited disorders due to lysosomal enzyme deficiencies. The aims of this study are to describe the neuroimaging findings in children evaluated in our hospital with this diagnosis, looking for a possible correlation of these alterations with the type of MPS and clinical severity, and finally to compare these findings with those previously reported. MATERIAL AND METHODS: We retrospectively analysed the medical records of 19 patients who had been diagnosed with MPS between 1992 and 2010: 7 had type I (5 with Hurler syndrome and 2 with Hurler-Scheie syndrome), 10 had type II or Hunter syndrome (4 with the severe form and 6 with the mild form), 1 had type III or Sanfilippo syndrome and 1 had type VI or Maroteaux-Lamy syndrome. We assessed the brain neuroimaging studies: computed axial tomography (CAT) in 5 patients, and magnetic resonance imaging (MRI) in 15. RESULTS: We observed a broad spectrum of neuroimaging anomalies. In CAT: mega cisterna magna (3/5, 60%). In brain MRI: dilated Virchow-Robin perivascular spaces (11/15, 73%), white matter abnormalities (11/15, 73%), and ventriculomegaly (5/15, 33%). CONCLUSIONS: Abnormal findings in neuroimaging studies are frequent in MPS (dilated Virchow-Robin perivascular spaces, white matter abnormalities and ventriculomegaly). Thus, given these abnormalities we should be aware of this possible diagnosis, particularly when typical signs and symptoms are present. However, we did not find a correlation between these findings and either any specific type of MPS or clinical severity.


Assuntos
Mucopolissacaridoses/diagnóstico , Neuroimagem , Encéfalo/diagnóstico por imagem , Encéfalo/patologia , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Testes de Inteligência , Imageamento por Ressonância Magnética , Masculino , Testes Neuropsicológicos , Tomografia Computadorizada por Raios X
10.
Rev Neurol ; 46(6): 321-5, 2008.
Artigo em Espanhol | MEDLINE | ID: mdl-18368673

RESUMO

INTRODUCTION: Para-infectious seizures are afebrile convulsions that are associated with banal infectious processes and have a good overall prognosis. AIM: To determine the natural history of para-infectious seizures in children. PATIENTS AND METHODS: We conducted a retrospective study of children who were admitted to our hospital between January 2000 and January 2005 with seizures associated to an infectious process that did not satisfy the criteria of febrile seizures. Data collected included age, sex, season of the year, personal and familial history, type of infection, symptoms of the seizures, complementary examinations, treatments that were used and progression. RESULTS: The sample finally included 22 girls and 12 boys with ages ranging from 6 to 38 months (mean: 20.26 +/- 8.29 months) and previous psychomotor development was seen to be normal. Three of them had a family history of epilepsy and three others had suffered previous febrile seizures. Twenty-three children developed seizures associated to gastroenteritis and in 11 cases they were linked to upper respiratory infections. The average interval between onset of the infection and seizures was 2.26 days, and the average number of seizures was 3.38. Eight patients had recurring seizures (23.5%), usually in the form of para-infectious or febrile seizures, and secondary seizures were observed in only one case. CONCLUSIONS: It is important to be familiar with this condition because many of these patients are initially diagnosed with an encephalitic syndrome. These seizures are usually associated with gastroenteritis, with cluster seizures and with normal later psychomotor development. The risk of developing secondary seizures developmentally is low.


Assuntos
Convulsões/microbiologia , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Estudos Retrospectivos , Convulsões/diagnóstico , Convulsões/tratamento farmacológico
11.
Parasite Immunol ; 27(10-11): 395-405, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-16179033

RESUMO

During helminthic infections, strong Th2 type-biased responses concomitant with impaired cell-proliferative responses to parasitic and unrelated antigens are major immunological hallmarks. Parasite glycan structures have been proposed to play a role in modulating these responses. To understand early events related to immune modulation during cestode infection, we have examined the role of intact glycans of antigens from Taenia crassiceps in the recruitment of innate cells. Soluble antigens from this cestode contained higher levels of carbohydrates than proteins. Intraperitoneal injection of the antigens rapidly recruited a cell population expressing F4/80(+)/Gr-1(+)surface markers, which adoptively suppressed naïve T-cell proliferation in vitro in response to anti-CD3/CD28 MAb stimulation in a cell-contact dependent manner. Soluble antigens with altered glycans by treatment with sodium periodate significantly reduced the recruitment of F4/80(+)/Gr1(+)cells, concomitantly their suppressive activity was abrogated, indicating that glycans have a role in the early activation of these suppressor cells. Using C3H/HeJ and STAT6-KO mice, we found that expansion and suppressive activity of F4/80(+)Gr1(+)cells induced by T. crassiceps intact antigens was TLR4 and Th2-type cytokine independent. Together with previous studies on nematode and trematode parasites, our data support the hypothesis that glycans can be involved on a similar pathway in the immunoregulation by helminths.


Assuntos
Antígenos de Helmintos/imunologia , Cestoides/imunologia , Infecções por Cestoides/imunologia , Células Mieloides/imunologia , Polissacarídeos/imunologia , Animais , Anticorpos Monoclonais/imunologia , Antígenos de Diferenciação/análise , Antígenos de Helmintos/química , Antígenos de Helmintos/isolamento & purificação , Antígenos CD28/imunologia , Complexo CD3/imunologia , Técnicas de Cocultura , Citocinas/imunologia , Feminino , Citometria de Fluxo , Camundongos , Receptores de Quimiocinas/análise , Receptor 4 Toll-Like/imunologia
12.
Scand J Immunol ; 60(5): 463-70, 2004 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-15541038

RESUMO

Cholesterol- and sphingolipid-rich membrane microdomains (lipid rafts) are widely recognized as portals for pathogenic micro-organisms. A growing body of evidence demonstrates mobilization of host plasma cell membrane lipid rafts towards the site of contact with several pathogens as well as a strict dependence on cholesterol for appropriate internalization. The fate of lipid rafts once the pathogen has been internalized and the nature of the pathogen components that interact with them is however less understood. To address both these issues, infection of the J774 murine cell line with Mycobacterium avium was used as a model. After demonstrating that M. avium induces lipid raft mobilization and that M. avium infects J774 by a cholesterol-dependent mechanism, it is shown here that mycobacterial phagosomes harbour lipid rafts, which are, at least in part, of plasma cell membrane origin. On the other hand, by using latex microbeads coated with any of the three fractions of M. avium-derived lipids of different polarity, we provide evidence that high-polarity, in contrast to low-polarity and intermediate-polarity, mycobacterial lipids or uncoated latex beads have a strong capacity to induce lipid raft mobilization. These results suggest that high-polarity mycobacterial lipid(s) interact with host cell cholesterol-enriched microdomains which may in turn influence the course of infection.


Assuntos
Metabolismo dos Lipídeos , Macrófagos/metabolismo , Microdomínios da Membrana/metabolismo , Mycobacterium avium/metabolismo , Animais , Adesão Celular/imunologia , Adesão Celular/fisiologia , Colesterol/metabolismo , Lipídeos/imunologia , Macrófagos/imunologia , Microdomínios da Membrana/imunologia , Camundongos , Mycobacterium avium/imunologia , Fagossomos/imunologia , Fagossomos/metabolismo
13.
Anticancer Res ; 23(6D): 5139-41, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-14981979

RESUMO

This study was designed to establish the role of microsatellite instability (MSI) in the development of sporadic tumors of the ovary. The instability of 6 microsatellites (BAT25, BAT26, NME1, D17S250, D5S346 and D2S123) was determined by comparing MSI in healthy and tumoral tissue in each of 40 patients undergoing surgery for a sporadic ovarian tumor. BAT26 and D2S123 instability was detected in borderline tumors, and ovarian carcinomas were found to present instability in the microsatellites BAT25, NME1 and D17S250. Our findings indicate that microsatellite instability lacks a significant role in the appearance or progression of sporadic ovarian tumors.


Assuntos
Repetições de Microssatélites/genética , Neoplasias Ovarianas/genética , Adulto , Idoso , Feminino , Humanos , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Neoplasias Ovarianas/patologia
14.
Clin Diagn Lab Immunol ; 8(6): 1081-8, 2001 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11687444

RESUMO

2,3-Di-O-acyl-trehalose (DAT) is a glycolipid located on the outer layer of the Mycobacterium tuberculosis cell envelope. Due to its noncovalent linkage to the mycobacterial peptidoglycan, DAT could easily interact with host cells located in the focus of infection. The aim of the present work was to study the effects of DAT on the proliferation of murine spleen cells. DAT was purified from reference strains of M. tuberculosis, or M. fortuitum as a surrogate source of the compound, by various chromatography and solvent extraction procedures and then chemically identified. Incubation of mouse spleen cells with DAT inhibited in a dose-dependent manner concanavalin A-stimulated proliferation of the cells. Experiments, including the propidium iodide exclusion test, showed that these effects were not due to death of the cells. Tracking of cell division by labeling with 5,6-carboxyfluorescein diacetate succinimidyl ester revealed that DAT reduces the rounds of cell division. Immunofluorescence with an anti-CD3 monoclonal antibody indicated that T lymphocytes were the population affected in our model. Our experiments also suggest that the extent of the suppressive activity is strongly dependent on the structural composition of the acyl moieties in DATs. Finally, the inhibitory effect was also observed on antigen-induced proliferation of mouse spleen cells specific for Toxoplasma gondii. All of these data suggest that DAT could have a role in the T-cell hyporesponsiveness observed in chronic tuberculosis.


Assuntos
Antígenos de Bactérias/farmacologia , Mycobacterium tuberculosis/imunologia , Linfócitos T/citologia , Trealose/farmacologia , Tuberculose Pulmonar/microbiologia , Animais , Antígenos de Bactérias/isolamento & purificação , Divisão Celular/efeitos dos fármacos , Divisão Celular/imunologia , Células Cultivadas , Concanavalina A , Feminino , Citometria de Fluxo , Técnicas In Vitro , Camundongos , Camundongos Endogâmicos BALB C , Mycobacterium fortuitum/química , Mycobacterium fortuitum/imunologia , Mycobacterium tuberculosis/química , Linfócitos T/efeitos dos fármacos , Linfócitos T/imunologia , Trealose/análogos & derivados , Trealose/química , Tuberculose Pulmonar/imunologia
15.
J Ultrasound Med ; 19(10): 695-9, 2000 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11026582

RESUMO

We studied the role of color Doppler ultrasonography in the distinction between endometriomas and other adnexal masses. Three hundred and fifty-two ovarian lesions were studied, comparing sonographic diagnosis with pathologic findings. On color Doppler sonography, an endometriotic cyst usually appeared as a cystic lesion with diffuse internal echoes and low vascularization. The sensitivity and specificity of color Doppler transvaginal sonography in detecting endometriotic cysts were 91.8% and 95.3%, respectively. The positive and negative predictive values were 95.5% and 91.5%, respectively. In our experience, transvaginal sonography with color Doppler interrogation is a useful technique in the diagnosis of pathologic ovarian conditions, including cystic endometriosis.


Assuntos
Cistos/diagnóstico por imagem , Endometriose/diagnóstico por imagem , Doenças Ovarianas/diagnóstico por imagem , Ultrassonografia Doppler em Cores , Adulto , Feminino , Humanos , Pessoa de Meia-Idade , Sensibilidade e Especificidade , Vagina
16.
Eur J Gynaecol Oncol ; 20(4): 302-5, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10475128

RESUMO

OBJECTIVE: Review of epidemiological data on pre-invasive cervical lesions. MATERIAL AND METHODS: Literature review and analysis of data from our Department. RESULTS: Prevalence of data on preinvasive cervical lesions varies widely and depends on factors such as differences among countries or regions and among ethnic groups, and especially, differences in the type of population studied. Most important risk factors are: number of sexual partners, smoking, contraceptive use, HPV, age at first intercourse, and screening. CONCLUSIONS: In order to reduce risk, pap smears should be performed regularly, safe sex practices should be recommended, and the use of tobacco products should be avoided.


Assuntos
Displasia do Colo do Útero/epidemiologia , Neoplasias do Colo do Útero/epidemiologia , Adulto , Fatores Etários , Idoso , Feminino , Humanos , Pessoa de Meia-Idade , Teste de Papanicolaou , Infecções por Papillomavirus , Prevalência , Fatores de Risco , Comportamento Sexual , Fumar , Fatores Socioeconômicos , Infecções Tumorais por Vírus , Neoplasias do Colo do Útero/diagnóstico , Neoplasias do Colo do Útero/prevenção & controle , Esfregaço Vaginal/estatística & dados numéricos , Displasia do Colo do Útero/diagnóstico , Displasia do Colo do Útero/prevenção & controle
18.
Am J Respir Crit Care Med ; 154(6 Pt 1): 1864-7, 1996 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-8970382

RESUMO

Glycolipids belonging to the family of acylated trehaloses were isolated from Mycobacterium fortuitum, a rapidly growing mycobacterial species, and tested in the serologic diagnosis of human pulmonary tuberculosis by enzyme-linked immunosorbent assay. Di- and tri-O-acylated trehaloses from M. fortuitum reacted with serum antibodies of patients with pulmonary tuberculosis at higher titers than did with sera from healthy donors. With both glycolipids, the sensitivity of the test was above 0.80 at a chosen specificity of 0.98. Individuals with treated tuberculosis showed lower antibody titers compared with their initial reactivities. These data show that M. fortuitum could be used as a surrogate source of antigens for tuberculosis serodiagnosis.


Assuntos
Anticorpos Antibacterianos/análise , Ensaio de Imunoadsorção Enzimática , Micobactérias não Tuberculosas/imunologia , Trealose/imunologia , Tuberculose Pulmonar/diagnóstico , Acetilação , Humanos , Micobactérias não Tuberculosas/metabolismo , Sensibilidade e Especificidade , Testes Sorológicos , Trealose/isolamento & purificação , Trealose/metabolismo , Tuberculose Pulmonar/tratamento farmacológico
19.
Eur J Biochem ; 238(1): 270-9, 1996 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-8665946

RESUMO

Among the fast-growing mycobacteria, members of the Mycobacterium fortuitum complex are the most-commonly cited opportunistic human pathogens, notably in post-surgical infections. Previous studies showed that this complex was composed of four well-identified species and a group of isolates that did not correspond to recognized species, which has been referred to as the third biovariant complex. The occurrence and chemical structure of the glycolipid antigens of six strains that belong to this latter group were examined in the present study. Based on the TLC profiles, resistance to alkali and seroreactivities of their glycolipids, the examined strains were classified into three groups: one group was devoid of species-specific glycolipid and the two other groups contained alkali-stable or alkali-labile glycoconjugates. The structures of the major glycolipid antigens of the latter two groups were elucidated by fast-atom-bombardment MS, one-dimensional and two-dimensional NMR spectroscopy and conventional chemical analyses. The alkali-stable glycolipids were structurally identical to the C-mycoside-type glycopeptidolipids characterized in the taxonomically related species Mycobacterium peregrinum. The major alkali-labile glycolipid was identified as beta-Glcp-1 --> 6)-alpha-Glcp2Acyl-(1 --> 1)-alpha-GLcp3,4,6Acyl3. The acyl substituents consisted on one acetyl group and three fatty acyl residues composed mainly of tetradecanoyl residues, but significant amounts of 2-methylhexadecanoyl and 2-methyloctadecanoyl substituents were also present. The heterogeneity of the glycolipid content of members of the third biovariant complex of M. fortuitum demonstrated in the present study confirms the heterogeneity of the complex. In addition, the occurrence of a species-specific glycolipid in some strains supports the hypothesis that some strains of this complex of M. fortuitum may belong to a new mycobacterial species.


Assuntos
Antígenos de Bactérias/química , Glicolipídeos/química , Mycobacterium/química , Mycobacterium/imunologia , Sequência de Carboidratos , Carboidratos/análise , Cromatografia em Camada Fina , Ácidos Graxos/análise , Lipídeos/análise , Lipídeos/química , Espectroscopia de Ressonância Magnética/métodos , Espectrometria de Massas/métodos , Dados de Sequência Molecular , Mycobacterium/classificação , Sorotipagem
20.
Biochemistry ; 33(23): 7056-61, 1994 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-8003470

RESUMO

Glycopeptidolipids (GPLs) are specific constituents of mycobacteria known as opportunistic pathogens. The influence of the carbohydrate moiety on GPL-induced membrane alterations was examined with GPLs bearing 1-5 sugar residues (GPL-1 to GPL-5) and a sulfated GPL (S-GPL-2). GPLs decreased the ADP/O ratio and increased controlled respiration of isolated mitochondria. The more polar GPLs were the less active, with the following order of efficiency: GPL-1 > GPL-2 > S-GPL-2 = GPL-3 = GPL-5. GPL-1 and GPL-2 increased passive permeability of liposomes to carboxyfluorescein (GPL-1 > GPL-2), while GPL-3 and GPL-5 were inactive. GPL-2 and GPL-3 decreased the transmembrane electrical potential (delta psi) in isolated mitochondria (GPL-2 > GPL-3). These results suggest that GPLs uncouple oxidative phosphorylation by increasing the passive permeability of the mitochondrial membrane to protons. Compression isotherms of GPL-2 monolayers showed that, at low surface pressure, the area per GPL-2 molecule was about 5 times that of an acyl chain: it is likely that the peptide moiety was at the air/water interface. With an increase in the surface pressure, its area decreased, down to that of a tightly packed acyl chain. It is postulated that the glycopeptidic moiety can be either at in the interface or dipping into the water.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Metabolismo dos Carboidratos , Glicopeptídeos/metabolismo , Lipídeos de Membrana/metabolismo , Mycobacterium/metabolismo , Animais , Sequência de Carboidratos , Membrana Celular/metabolismo , Membrana Celular/fisiologia , Permeabilidade da Membrana Celular , Potenciais da Membrana , Dados de Sequência Molecular , Fosforilação Oxidativa , Ratos
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