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1.
AJNR Am J Neuroradiol ; 44(6): 722-729, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-37169540

RESUMO

BACKGROUND AND PURPOSE: Important information regarding fluoroscopically guided lumbar puncture (FGLP) performance and referrals is lacking. The purpose of our study was to elucidate the success rate for initial FGLP attempts and re-attempts, reasons for unsuccessful FGLPs, and the relationship between clinical indications and whether patients will undergo a fluoroscopically guided re-attempt, among others. MATERIALS AND METHODS: This retrospective study analyzed failed FGLP attempts in hospitalized adult patients at an academic hospital between June 2016 and March 2022. Unsuccessful FGLPs were labeled as insufficient CSF egress. FGLP reports and patients' clinical charts were analyzed for pertinent information such as clinical indication, reason for failure, whether patients received IV fluid before fluoroscopically guided spinal puncture attempt, and which patients returned for another FGLP attempt. Patients' ages and sex were analyzed using descriptive statistics. The OR was used to investigate the relationship between the clinical indications to perform FGLP and whether patients returned for a re-attempt. RESULTS: Sixty-three of 1389 (4.5%) patients (median age, 62 years) had failed the initial FGLPs administered by 39 trainees. Twenty-eight of 63 (44.4%) patients (median age, 64 years) underwent a re-attempt within a median of 2 days after the first attempt, and 27/28 (96.4%) re-attempts were successful. A dry tap, no egress of CSF was the top reason (58.7%) for failed FGLP, and 12/13 of patients had a successful FGLP after IV hydration. Twenty-seven of 63 (43%) patients did not undergo a repeat attempt, and 100% were subsequently discharged from the hospital. There was no difference (P > .05) in the likelihood of patients returning for a repeat FGLP based on the clinical indications. CONCLUSIONS: Initial and repeat FGLPs have very high success rates. No difference exists in the likelihood of patients returning for a re-attempt based on clinical indication.


Assuntos
Hospitais , Punção Espinal , Adulto , Humanos , Pessoa de Meia-Idade , Estudos Retrospectivos , Fluoroscopia
2.
AJNR Am J Neuroradiol ; 43(12): 1827-1833, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36328409

RESUMO

BACKGROUND AND PURPOSE: Referrals to perform fluoroscopy-guided lumbar punctures by neuroradiologists have increased. The purpose of our study was to determine the management of fluoroscopy-guided lumbar puncture referrals in different practice settings. MATERIALS AND METHODS: We sent an online questionnaire to neuroradiologists and radiology trainees between May and June 2020 to survey their handling of fluoroscopy-guided lumbar puncture requests, preprocedural work-up, and the use of physician extenders/trainees to perform fluoroscopy-guided lumbar punctures, among other questions. Categories were compared using ORs. RESULTS: Of the 123 US respondents, 81.3% were in combined academic and 18.7% in combined private practice groups. Regarding fluoroscopy-guided lumbar puncture referrals, 27.6% of respondents did not require a bedside lumbar puncture attempt before a fluoroscopy-guided lumbar puncture. Of private practice, 95.7%, and of academic respondents, 85.0%, were often asked to perform fluoroscopy-guided lumbar punctures by clinicians because of the clinician's lack of procedural competence. Of those, 74.8% stated that they always or sometimes agreed to the request. 41.5% of respondents stated that they would always comply with patients' requests for a fluoroscopy-guided lumbar puncture without a bedside lumbar puncture attempt, a 5.26 times higher likelihood (95% CI, 2.04-14.29) for private practice respondents. To perform fluoroscopy-guided lumbar punctures, 32.0% of academic respondents and 47.8% of private practice respondents use physician extenders. 75.0% of academic respondents reported that trainees perform >50% of their fluoroscopy-guided lumbar punctures. CONCLUSIONS: This survey demonstrates that many academic and private practice neuroradiologists engage in practices that may promote an increase in fluoroscopy-guided lumbar puncture referrals including not requiring a non-image-guided lumbar puncture attempt, complying with clinicians' requests for a fluoroscopy-guided lumbar puncture due to lack of competence in performing lumbar punctures, and fulfilling patient requests for fluoroscopy-guided lumbar punctures.


Assuntos
Radiologia , Punção Espinal , Humanos , Fluoroscopia
3.
Patient Educ Couns ; 99(7): 1121-1129, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-26969412

RESUMO

OBJECTIVES: To optimize their training, predictors of physicians' satisfaction with their management of uncertainty should be examined. This study investigated these predictors by using a simulated advanced stage cancer patient. METHODS: Physicians (n=85) rated their satisfaction with their management of uncertainty (Visual Analog Scale-100mm) after a decision-making encounter. Communication predictors were examined with the: Observing Patient Involvement scale (OPTION), Multidimensional analysis of Patient Outcome Predictions (MD.POP) and Communication Content Analysis Software (LaComm). Psychological predictors were assessed with the: Intolerance of Uncertainty Inventory (IUI), Physicians' Reactions to Uncertainty scale (PRU), Decisional Conflict Scale (DCS), and Jefferson Scale of Physician Empathy (JSPE). RESULTS: Physicians' satisfaction (mean=67mm; standard deviation=17mm) was not predicted by their communication, but by their anxiety due to uncertainty (PRU) (ß=-.42; p=<.001) and their perceived empathy (JSPE) (ß=.26; p=.009). These variables accounted for 25% of variance in physicians' satisfaction. CONCLUSIONS: Physicians' satisfaction with their management of uncertainty was not affected by their communication performance, but by their psychological characteristics. PRACTICE IMPLICATIONS: Training programs should increase physicians' awareness regarding the communication performance required in decision-making encounters under conditions of uncertainty.


Assuntos
Comunicação , Tomada de Decisões , Neoplasias/psicologia , Participação do Paciente , Simulação de Paciente , Médicos/psicologia , Incerteza , Adulto , Feminino , Humanos , Masculino , Satisfação do Paciente
4.
Br J Cancer ; 87(1): 1-7, 2002 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-12085247

RESUMO

The emotional content of health care professionals-cancer patient communication is often considered as poor and has to be improved by an enhancement of health care professionals empathy. One hundred and fifteen oncology nurses participating in a communication skills training workshop were assessed at three different periods. Nurses randomly allocated to a control group arm (waiting list) were assessed a first time and then 3 and 6 months later. Nurses allocated to the training group were assessed before training workshop, just after and 3 months later. Each nurse completed a 20-min clinical and simulated interview. Each interview was analysed by three content analysis systems: two computer-supported content analysis of emotional words, the Harvard Third Psychosocial Dictionary and the Martindale Regressive Imagery Dictionary and an observer rating system of utterances emotional depth level, the Cancer Research Campaign Workshop Evaluation Manual. The results show that in clinical interviews there is an increased use of emotional words by health care professionals right after having been trained (P=0.056): training group subjects use 4.3 (std: 3.7) emotional words per 1000 used before training workshop, and 7.0 (std: 5.8) right after training workshop and 5.9 (std: 4.3) 3 months later compared to control group subjects which use 4.5 (std: 4.8) emotional words at the first assessment point, 4.3 (std: 4.1) at the second and 4.4 (std: 3.3) at the third. The same trend is noticeable for emotional words used by health care professionals in simulated interviews (P=0.000). The emotional words registry used by health care professionals however remains stable over time in clinical interviews (P=0.141) and is enlarged in simulated interviews (P=0.041). This increased use of emotional words by trained health care professionals facilitates cancer patient emotion words expressions compared to untrained health care professionals especially 3 months after training (P=0.005). This study shows that health care professionals empathy may be improved by communication skills training workshop and that this improvement facilitates cancer patients emotions expression.


Assuntos
Comunicação , Emoções , Neoplasias/enfermagem , Relações Enfermeiro-Paciente , Enfermagem Oncológica/normas , Adulto , Empatia , Feminino , Humanos , Idioma , Masculino , Enfermeiros Administradores , Satisfação do Paciente , Desempenho de Papéis , Desenvolvimento de Pessoal
5.
Clin Exp Immunol ; 119(3): 544-52, 2000 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10691929

RESUMO

IgG anti-filaggrin autoantibodies (AFA) are the most specific serological markers of rheumatoid arthritis (RA). They include the so-called 'anti-keratin antibodies' (AKA) and anti-perinuclear factor (APF), and recognize human epidermal filaggrin and other (pro)filaggrin-related proteins of various epithelial tissues. In this study we demonstrate that AFA are produced in rheumatoid synovial joints. In 31 RA patients, AFA levels were assayed at equal IgG concentrations in paired synovial fluids (SF) and sera. AFA titre-like values determined by indirect immunofluorescence and immunoblotting and AFA concentrations determined by ELISA were non-significantly different in serum and SF, clearly indicating that AFA are not concentrated in SF. In contrast, we demonstrated that AFA are enriched in RA synovial membranes, since the ELISA-determined AFA in low ionic-strength extracts of synovial tissue from four RA patients represented a 7.5-fold higher proportion of total IgG than in paired sera. When small synovial tissue explants from RA patients were cultured for a period of 5 weeks, the profile of IgG and AFA released in the culture supernatants was first consistent with passive diffusion of the tissue-infiltrating IgG (including AFA) over the first day of culture, then with a de novo synthesis of IgG and AFA. Therefore, AFA-secreting plasma cells are present in the synovial tissue of RA patients and AFA can represent a significant proportion of the IgG secreted within the rheumatoid pannus.


Assuntos
Artrite Reumatoide/imunologia , Autoanticorpos/imunologia , Proteínas de Filamentos Intermediários/imunologia , Plasmócitos/imunologia , Artrite Reumatoide/sangue , Biomarcadores , Epiderme/imunologia , Epiderme/patologia , Proteínas Filagrinas , Humanos , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Plasmócitos/patologia , Líquido Sinovial/imunologia
6.
J Immunol ; 162(1): 585-94, 1999 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-9886436

RESUMO

Antifilaggrin autoantibodies (AFA) are a population of IgG autoantibodies associated to rheumatoid arthritis (RA), which includes the so-called "antikeratin" Abs and antiperinuclear factor. AFA are the most specific serological markers of RA. We previously showed that they recognize human epidermal filaggrin and other profilaggrin-related proteins of various epithelial tissues. Here, we report further characterization of the protein Ags and epitopes targeted by AFA. All the Ags that exhibit numerous neutral/ acidic isoelectric variants were immunochemically demonstrated to be deiminated proteins. In vitro deimination of a recombinant human filaggrin by a peptidylarginine deiminase generated AFA epitopes on the protein. Moreover, two of three filaggrin-derived synthetic peptides with a citrulline in the central position were specifically and widely recognized by AFA affinity-purified from a series of RA sera. These results indicate that citrulline residues are constitutive of the AFA epitopes, but only in the context of specific amino acid sequences of filaggrin. In competition experiments, the two peptides abolished the AFA reactivity of RA sera, showing that they present major AFA epitopes. These data should help in the identification of a putative deiminated AFA-inducing or cross-reactive articular autoantigen and provide new insights into the pathogenesis of RA. They could also open the way toward specific immunosuppressive and/or preventive therapy of RA.


Assuntos
Arginina/metabolismo , Artrite Reumatoide/imunologia , Autoanticorpos/biossíntese , Epitopos/metabolismo , Proteínas de Filamentos Intermediários/imunologia , Precursores de Proteínas/imunologia , Processamento de Proteína Pós-Traducional/imunologia , Sequência de Aminoácidos , Substituição de Aminoácidos , Artrite Reumatoide/sangue , Artrite Reumatoide/metabolismo , Autoanticorpos/sangue , Autoanticorpos/metabolismo , Citrulina/metabolismo , Epiderme/imunologia , Epitélio/imunologia , Epitélio/metabolismo , Proteínas Filagrinas , Humanos , Hidrolases/metabolismo , Proteínas de Filamentos Intermediários/genética , Proteínas de Filamentos Intermediários/metabolismo , Dados de Sequência Molecular , Fragmentos de Peptídeos/síntese química , Fragmentos de Peptídeos/imunologia , Fragmentos de Peptídeos/metabolismo , Precursores de Proteínas/genética , Precursores de Proteínas/metabolismo , Proteína-Arginina Desiminase do Tipo 4 , Desiminases de Arginina em Proteínas , Proteínas Recombinantes/imunologia , Proteínas Recombinantes/metabolismo
7.
J Rheumatol ; 25(5): 838-46, 1998 May.
Artigo em Inglês | MEDLINE | ID: mdl-9598877

RESUMO

OBJECTIVE: We previously reported that so-called antikeratin antibodies (AKA) and antiperinuclear factor (APF) recognize epitope(s) present on human epidermal filaggrin. In the present study, we developed a new diagnostic test for rheumatoid arthritis (RA) based on detection of antifilaggrin autoantibodies (AFA) by immunoblotting. METHODS: We tested 670 serum samples, including 190 RA. AFA titers were estimated by immunoblotting on filaggrin enriched human epidermis extracts, and AKA titers by indirect immunofluorescence (IIF) on rat esophagus epithelium. Diagnostic values of the tests were compared. RESULTS: Each test resulted in diagnosis of more than 40% of RA samples, with a specificity of 0.99. Although the tests were strongly correlated, their association allowed the diagnosis of more than 60% of RA samples, with the same specificity. CONCLUSION: Immunoblot detection of AFA, a simple and standardizable test, may be an alternative or complement to conventional IIF detection of AKA.


Assuntos
Artrite Reumatoide/diagnóstico , Artrite Reumatoide/imunologia , Autoanticorpos/sangue , Proteínas de Filamentos Intermediários/imunologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Artrite Reumatoide/sangue , Autoanticorpos/análise , Epiderme/química , Epitélio/química , Esôfago/química , Feminino , Proteínas Filagrinas , Técnica Indireta de Fluorescência para Anticorpo , Humanos , Immunoblotting , Queratinas/imunologia , Masculino , Pessoa de Meia-Idade , Ratos
8.
Mol Med ; 3(2): 145-56, 1997 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-9085257

RESUMO

BACKGROUND: The so-called antikeratin antibodies and the antiperinuclear factor are the most specific serological markers of rheumatoid arthritis (RA). They were recently shown to be largely the same autoantibodies and to recognize human epidermal filaggrins and profilaggrin-related proteins of buccal epithelial cells (collectively referred to as (pro)filaggrin). MATERIALS AND METHODS: To further characterize the target antigens, we investigated their expression by normal human epidermal keratinocytes cultured in differentiating conditions, using immunofluorescence and immunoblotting with RA sera and three different monoclonal antibodies to (pro)filaggrin. RESULTS: On the cornified, stratified epithelial sheets obtained in vitro, RA sera with anti(pro)filaggrin autoantibodies (AFA) produced granular staining of the stratum granulosum and diffuse staining of the stratum corneum. The antigens recognized by RA sera strictly colocalized with (pro)filaggrin in keratohyalin granules. Following sequential extraction of the proteins from the epithelial sheets, the RA sera and the three monoclonal antibodies to (pro)filaggrin, recognized a series of low-salt-soluble molecules, including a neutral/acidic isoform of filaggrin and several proteins with sizes and pI intermediates between this isoform and profilaggrin. They also recognized urea-soluble high-molecular-weight profilaggrin-related molecules. CONCLUSIONS: These results show that in vitro epidermal keratinocytes express various molecular forms of (pro) filaggrin that bear epitopes targeted by AFA of RA sera, and that some of these are absent from epidermis. Moreover, these epitopes, which are present on the keratohyalin granules of buccal epithelial cells but not on those of epidermal cells, are present on the granules of the cultured keratinocytes. This work completes the molecular characterization of the proteins targeted by AFA.


Assuntos
Artrite Reumatoide/imunologia , Autoanticorpos/imunologia , Proteínas de Filamentos Intermediários/metabolismo , Queratinócitos/metabolismo , Precursores de Proteínas/metabolismo , Células 3T3 , Animais , Células Cultivadas , Proteínas Filagrinas , Humanos , Imuno-Histoquímica , Proteínas de Filamentos Intermediários/imunologia , Camundongos , Pele/citologia , Pele/metabolismo
9.
J Biol Chem ; 272(50): 31770-6, 1997 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-9395522

RESUMO

Using monoclonal antibodies, we identified a new protein in mammalian epidermis, which we called corneodesmosin. It is located in the extracellular part of the modified desmosomes in the cornified layer of the tissue, and its proteolysis (from 52-56 to 33 kDa) is thought to be a major prerequisite of desquamation. We have now further characterized human corneodesmosin. Proteolysis of purified cornified cell envelopes produced immunoreactive fragments, confirming the covalent linkage of the protein to these structures. Sequential extraction of epidermal proteins indicated that the 52-56-kDa precursor form of the protein exists in two distinct pools, one extracted with a nondenaturing hypotonic buffer, and the other with urea. Two-dimensional gel analysis and reactivity with phosphoserine-specific antibodies showed that it is a basic phosphoprotein. Deglycosylation experiments, reactivity with lectins, and chromatography on concanavalin A-Sepharose indicated that corneodesmosin is N-glycosylated. Partial sequences, 10 and 15 amino acids long, of the purified 52-56-kDa corneodesmosin showed identity with sequences predicted from a previously cloned gene, proved to be expressed in the epidermis and designated S. This indicates that corneodesmosin is probably encoded by the S gene, the function of which was unknown until now. A model of corneodesmosin maturation during cornification is proposed.


Assuntos
Desmossomos/química , Glicoproteínas/química , Queratinócitos/química , Sequência de Aminoácidos , DNA Complementar/química , Eletroforese em Gel Bidimensional , Epiderme/química , Glicoproteínas/isolamento & purificação , Glicosilação , Humanos , Peptídeos e Proteínas de Sinalização Intercelular , Dados de Sequência Molecular , Peso Molecular , Fosfoproteínas/química
10.
J Clin Invest ; 95(6): 2672-9, 1995 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-7539459

RESUMO

The so-called antikeratin antibodies (AKA) and the antiperinuclear factor (APF) are the most specific serological markers of RA. Using indirect immunofluorescence, AKA label the stratum corneum of various cornified epithelia and APF the keratohyalin granules of human buccal mucosa epithelium. We recently demonstrated that AKA recognize human epidermal filaggrin. Here, we report the identification of the major APF antigen as a diffuse protein band of 200-400 kD. This protein is seen to be closely related to human epidermal (pro) filaggrin since it was recognized by four antifilaggrin mAbs specific for different epitopes, and since the APF titers of RA sera were found to be correlated to their AKA titers and to their immunoblotting reactivities to filaggrin. Immunoabsorption of RA sera on purified epidermal filaggrin abolished their reactivities to the granules of buccal epithelial cells and to the 200-400-kD antigen. Moreover, antifilaggrin autoantibodies, i.e., AKA, affinity purified from RA sera, were shown to immunodetect the 200-400-kD antigen and to stain these granules. These results indicate that AKA and APF are largely the same autoantibodies. They recognize human epidermal filaggrin and (pro) filaggrin-related proteins of buccal epithelial cells. Identification of the epitopes recognized by these autoantibodies, which we propose to name antifilaggrin autoantibodies, will certainly open new paths of research into the pathophysiology of RA.


Assuntos
Anticorpos Antinucleares/imunologia , Artrite Reumatoide/imunologia , Autoanticorpos/imunologia , Autoantígenos/imunologia , Proteínas de Filamentos Intermediários/imunologia , Queratinas/imunologia , Especificidade de Anticorpos , Biomarcadores , Western Blotting , Proteínas Filagrinas , Imunofluorescência , Humanos , Peso Molecular , Mucosa Bucal/imunologia
11.
Eur J Immunol ; 24(9): 2006-12, 1994 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-7522157

RESUMO

CD14, a glycolipid-anchored membrane glycoprotein, acts as a high affinity lipopolysaccharide receptor on leukocytes. We previously reported that the Mono-Mac-6 cell line releases two different soluble forms of CD14 (sCD14) (Labeta et al., Eur. J. Immunol. 1993. 23: 2144). Here we show that the two sCD14, which we now refer to as sCD14 alpha (low M(r)) and sCD14 beta (high M(r)), are also synthesized and released by normal human monocytes and present in normal plasma. Their mechanism of release was examined by using the Mono-Mac-6 cell line, chinese hamster ovary cell (CHO)/CD14+ transfectants and plasma from paroxysmal nocturnal hemoglobinuria (PNH) patients. It was found that: (1) sCD14 beta is released faster than sCD14 alpha and that the release of the latter is a lengthy process. (2) Monensin blocked the biosynthesis of membrane-bound CD14 (mCD14) and sCD14, additionally, a 50-kDa CD14 polypeptide accumulated in the cell lysate, suggesting that the different forms of CD14 may have a common precursor. (3) Monensin also blocked the release of sCD14 alpha from surface-labeled cells, suggesting that conversion of mCD14 to sCD14 alpha involves a mechanism of endocytosis followed by exocytosis. Interestingly, (4) sCD14 alpha and sCD14 beta were detected in PNH plasma, indicating that sCD14 alpha may also derive from an endogenous pathway. (5) Phospholipase C-released CD14 was identical in size to mCD14, thus differed from sCD14 beta by approximately 2000, indicating that release of sCD14 beta involves further processing. (6) CHO cells transfected with a CD14 cDNA coding for an eight C-terminal amino acids shorter product released an sCD14 beta-like form; thus absence of the eight C-terminal amino acids prevented mCD14 expression but not the secretion of sCD14 beta. The characterization of sCD14 alpha and sCD14 beta reported here may be useful for better understanding of variations in sCD14 levels in pathological conditions and the contribution of each sCD14 in sepsis and other, as yet unknown functions.


Assuntos
Antígenos CD/sangue , Antígenos CD/química , Antígenos de Diferenciação Mielomonocítica/sangue , Antígenos de Diferenciação Mielomonocítica/química , Monócitos/imunologia , Receptores Imunológicos/química , Animais , Western Blotting , Células CHO , Linhagem Celular , Cricetinae , Cricetulus , Eletroforese em Gel de Poliacrilamida , Humanos , Receptores de Lipopolissacarídeos , Monensin/farmacologia , Fosfatidilinositol Diacilglicerol-Liase , Diester Fosfórico Hidrolases , Polissacarídeos/química , Testes de Precipitina , Receptores Imunológicos/metabolismo , Solubilidade , Transfecção
12.
Eur J Immunol ; 24(8): 1937-40, 1994 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-7520002

RESUMO

The human B cell line RPMI 8226 exhibits variable staining with the CD14 antibody My4. We have isolated three stable clones from this line with clones 1 and 2 being My4 positive and clone 3 My4 negative. Similar to previous results in monocytes, immunoprecipitation with the My4 antibody revealed a 54-kDa cell surface molecule, analysis of supernatants showed soluble CD14, and Northern blotting demonstrated a 1.4-kb transcript in clones 1 and 2, but not in clone 3, which suggests that the My4 antibody detects CD14 in clones 1 and 2. This CD14 molecule was functional in that lipopolysaccharide stimulation induced interleukin (IL)-6 and IL-10 in clones 1 and 2 but not in clone 3. Furthermore, the My4 antibody was capable of blocking these responses at the transcript and protein levels. Finally, peripheral blood B cells were highly purified by cell sorting (> 98% CD19 positive). These cells produced IL-6 in response to lipopolysaccharide, and this response was blocked by anti-CD14 antiserum. Thus, our findings demonstrated that human B cells can express functionally active CD14.


Assuntos
Antígenos CD/biossíntese , Antígenos CD/fisiologia , Antígenos de Diferenciação Mielomonocítica/biossíntese , Antígenos de Diferenciação Mielomonocítica/fisiologia , Linfócitos B/imunologia , Lipopolissacarídeos/farmacologia , Separação Celular , Células Clonais , Imunofluorescência , Humanos , Receptores de Lipopolissacarídeos , Testes de Precipitina , Receptores Imunológicos/biossíntese , Receptores Imunológicos/fisiologia , Células Tumorais Cultivadas
13.
Immunology ; 80(3): 415-23, 1993 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-7507090

RESUMO

To evaluate the role of the high-affinity monocyte receptor for lipopolysaccharide (LPS), CD14, in the process of tolerance to LPS, the human monocytic cell line Mono-Mac-6 was cultured in the absence or presence of different amounts of LPS. The kinetics of CD14 modulation in these cells showed an initial 4-day period characterized by increased cell-surface expression, rate of biosynthesis (peaking at 48 hr) and release of its soluble forms (sCD14) which correlated with the amount of LPS in the culture. At this time, tolerance to LPS was already established, as measured by tumour necrosis factor-alpha (TNF-alpha) induction, it was LPS dose dependent and persisted up to 15 days. LPS also reduced the cell proliferation rate in a dose-dependent manner. After 8 days and up to 15 days, the CD14 biosynthesis, cell-surface expression and release of sCD14 inversely correlated with the level of LPS in the culture. The 48-hr LPS-pretreated cells showed a slightly decreased CD14 affinity for LPS, a relative high number of CD14 molecules per cells, and desensitization also to a phorbol 12-myristate 13-acetate (PMA) challenge. An anti-CD14 monoclonal antibody (mAb) protected the cells from tolerization when added at the beginning of culture, as revealed by challenge with LPS and PMA. The data indicate that in this model tolerization to LPS (1) precedes CD14 down-modulation, (2) operates by alteration of the receptor affinity for LPS and by a mechanism which affects a protein kinase C (PKC)-dependent signalling pathway, and (3) that CD14 plays a critical role in the establishment of tolerance to LPS. In addition, analysis of the data suggests the existence of a PKC-independent signalling pathway for LPS tolerization and a CD14-independent mechanism for establishing tolerance.


Assuntos
Antígenos CD/imunologia , Antígenos de Diferenciação Mielomonocítica/imunologia , Tolerância Imunológica/imunologia , Lipopolissacarídeos/imunologia , Monócitos/imunologia , Antígenos CD/metabolismo , Antígenos de Diferenciação Mielomonocítica/metabolismo , Células Cultivadas , Humanos , Cinética , Receptores de Lipopolissacarídeos , Lipopolissacarídeos/metabolismo , Acetato de Tetradecanoilforbol/farmacologia , Fator de Necrose Tumoral alfa/biossíntese
14.
Eur J Immunol ; 23(9): 2144-51, 1993 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-7690322

RESUMO

Lipopolysaccharide (LPS) stimulates mononuclear phagocytes to synthesize and secrete immunoregulatory and inflammatory molecules such as interleukin-1 (IL-1), IL-6, and tumor necrosis factor-alpha (TNF-alpha). LPS forms complexes with either the serum protein termed LPS-binding protein or a serum factor, septin. These complexes are more stimulatory than LPS alone. The myeloid differentiation antigen CD14 is known to be the receptor for such complexes. In the present study, by using a monocytic cell line, we demonstrate the release of two different soluble forms of CD14 (sCD14) which are secreted by different mechanisms. We show that the two sCD14 forms differ in their electrophoretic mobility, two-dimensional gel electrophoretic patterns, sensitivity to endoglycosidases and peptide maps. One of the sCD14 molecules, apparent molecular mass 48 kDa, was found in supernatants of both surface iodinated and [35S]methionine biosynthetically labeled cells. The other sCD14 molecule (56 kDa) was found labeled only in supernatants of [35S]methionine-labeled cells. Furthermore, purified 48 kDa sCD14 enhanced the LPS-induced TNF-alpha and IL-6 release by the monocytic cells suggesting that a cell-surface signal transducer molecule may be involved in signaling. The data suggest a possible novel role for sCD14 in the monocyte response to LPS.


Assuntos
Antígenos CD/análise , Antígenos de Diferenciação Mielomonocítica/análise , Monócitos/metabolismo , Receptores Imunológicos/análise , Antígenos CD/biossíntese , Antígenos CD/química , Antígenos de Diferenciação Mielomonocítica/biossíntese , Antígenos de Diferenciação Mielomonocítica/química , Linhagem Celular , Eletroforese em Gel Bidimensional , Humanos , Interleucina-6/biossíntese , Receptores de Lipopolissacarídeos , Lipopolissacarídeos/farmacologia , Mapeamento de Peptídeos , Fator de Necrose Tumoral alfa/biossíntese
15.
Lipids ; 28(2): 151-5, 1993 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-8441340

RESUMO

Microtiter plate methods were developed for the enzymatic determination of serum total cholesterol (TC), high density lipoprotein cholesterol (HDL-C) and triglyceride (TG), and for the turbidometric determination of apolipoproteins. The micromethods resulted in accurate, precise values that were in good agreement with the conventional spectrophotometric assays. The coefficient of variation for TC determinations was 4.5% or less and bias was 5% or less. The lipid micromethod assays are sensitive to 10 mg/dL or less, and the apolipoprotein assay to 1 mg/dL. Less than 100 microL of serum suffices for TC, TG and apoprotein assays; HDL-C requires an additional 100 microL of serum. Advantages of the micromethods include reductions in assay time and in the amount of reagents required.


Assuntos
Apolipoproteínas/sangue , HDL-Colesterol/sangue , Colesterol/sangue , Triglicerídeos/sangue , Apolipoproteína A-I/análise , Apolipoproteína A-II/análise , Apolipoproteínas B/sangue , Precipitação Química , Colorimetria , Humanos , Microquímica , Nefelometria e Turbidimetria , Espectrofotometria
16.
Artery ; 18(2): 99-106, 1991.
Artigo em Inglês | MEDLINE | ID: mdl-2021354

RESUMO

It is known that cultured fibroblasts from familial hypercholesterolemia (FH) patients lack the normal cell receptor for low density lipoprotein (LDL) and that the absence of receptor-mediated transport of LDL cholesterol into these cells results in increased cellular synthesis of cholesterol. After 20 h perincubation in lipid-free medium, cultured FH fibroblasts incorporated significantly greater amounts of [14C]glycerol into cellular lipids than did normal fibroblasts. Relative to the control medium which contained only bovine serum albumin (BSA), preincubation with 5% fetal bovine serum or 50 micrograms LDL/ml decreased [14C]glycerol incorporation by both cell types. FH cells utilized more [14C]glycerol for phospholipid synthesis and less for triglyceride synthesis than normal cells. This study indicates that LDL may be important in the transport of glycerides, as well as cholesterol, to cells.


Assuntos
Fibroblastos/metabolismo , Glicerol/metabolismo , Hiperlipoproteinemia Tipo II/metabolismo , Radioisótopos de Carbono , Linhagem Celular , Humanos , Valores de Referência , Timidina/metabolismo , Trítio
18.
Biochim Biophys Acta ; 615(1): 158-66, 1980 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-6448639

RESUMO

The steady-state kinetic parameters of the tripeptides D-Val-Leu-Lys-, Ala-Phe-Lys-, and < Glu-Phe-Lys- in which the free carboxyl group was substituted with p-nitroaniline (substrate) or chloromethane (inhibitor), towards the serine proteinases plasmin (EC 3.4.21.7), thrombin (EC 3.4.21.5), urokinase, factor Xa, and trypsin (EC 3.4.21.4) were investigated. The p-nitroanilide derives were found to be very good substrates for plasmin, 2.5--40-times less efficient towards trypsin and very poor (100--10 000-times less efficient) substrates for thrombin, factor Xa and urokinase. The chloromethyl ketone derivatives were comparably efficient inhibitors of plasmin and trypsin and in general very poor (100--10 000-times weaker) inhibitors of thrombin, factor Xa and urokinase. D-Val-Leu-Lys-pNA however was a very poor substrate but D-Val-Leu-Lys-CH2Cl a very efficient inhibitor for thrombin. The variability in susceptibility of the substrates towards the enzymes was due to differences in their Michaelis constant, in their deacylation rate constant or both. the variable efficiency of the inhibitors was mostly due to differences in their dissociation constant and much less to differences in their alkylation rate constant. Only a poor correlation (r = 0.25) was found between the efficiency of the p-nitroanilides as substrate and their homologous chloromethyl ketones as inhibitor. The most notable discrepancy was observed with the D-Val-Leu-Lys derivatives towards thrombin.


Assuntos
Clorometilcetonas de Aminoácidos/farmacologia , Endopeptidases/metabolismo , Fator X/metabolismo , Oligopeptídeos/farmacologia , Tosilina Clorometil Cetona/farmacologia , Fator Xa , Fibrinolisina/metabolismo , Humanos , Cinética , Trombina/metabolismo , Tosilina Clorometil Cetona/análogos & derivados , Tripsina/metabolismo , Ativador de Plasminogênio Tipo Uroquinase/metabolismo
19.
Ann Endocrinol (Paris) ; 37(3): 215-6, 1976.
Artigo em Francês | MEDLINE | ID: mdl-798539

RESUMO

PIP: The Luteinizing hormone-releasing hormone (LH-RH), and the follicle stimulating hormone-releasing hormone (FSH-RH) have been synthesized by a new procedure involving solid phase and conventional solution coupling. The release of LH and FSH by this synthetic product has been measured in both laboratory animals and in men. Results coincide exactly with those in the published literature.^ieng


Assuntos
Hormônio Liberador de Gonadotropina/síntese química , Métodos
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