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1.
Phys Biol ; 20(1)2022 11 21.
Artigo em Inglês | MEDLINE | ID: mdl-36343366

RESUMO

Cancer invasion and metastasis require remodeling of the adjacent extracellular matrix (ECM). In this mini review, we will cover the mechanisms of proteolytic degradation and the mechanical remodeling of the ECM by cancer cells, with a focus on invadopodia. Invadopodia are membrane protrusions unique to cancer cells, characterized by an actin core and by the focal degradation of ECM via matrix metalloproteases (MMPs). While ECM can also be remodeled, at lower levels, by focal adhesions, or internal collagen digestion, invadopodia are now recognized as the major mechanism for MMP-dependent pericellular ECM degradation by cancer cells. Recent evidence suggests that the completion of epithelial-mesenchymal transition may be dispensable for invadopodia and metastasis, and that invadopodia are required not only for mesenchymal, single cell invasion, but also for collective invasion. During collective invasion, invadopodia was then shown to be located in leader cells, allowing follower cells to move via cooperation. Collectively, this suggests that invadopodia function may be a requirement not only for later steps of metastasis, but also for early invasion of epithelial cells into the stromal tissue. Over the last decade, invadopodia studies have transitioned into in 3D andin vivosettings, leading to the confirmation of their essential role in metastasis in preclinical animal models. In summary, invadopodia may hold a great potential for individual risk assessment as a prognostic marker for metastasis, as well as a therapeutic target.


Assuntos
Neoplasias , Podossomos , Animais , Proteólise , Matriz Extracelular , Adesões Focais
2.
J Eur Acad Dermatol Venereol ; 36 Suppl 5: 21-29, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35315152

RESUMO

BACKGROUND: We have developed innovative base formulations that were designed to mimic the skin with respect to its components and galenic structure. Components include water, proteins, lipids, sugars and minerals. OBJECTIVES: We characterized formulations and their skin penetration using in vitro methods and evaluated their impact on skin hydration in a clinical trial. METHODS: Scanning electron microscopy (SEM) imaging and X-ray diffraction were used to analyse formulations as well as formulation impact on the stratum corneum (SC) structure. Mass spectrometry imaging (MSI) was used to compare formulation ingredients with SC components and to detect their distribution in the skin. Clinical studies were performed to confirm effects on skin hydration and investigate potential adverse skin effects (irritation and sensitization). RESULTS: SEM and X-ray diffraction of the formulations showed that lipids were organized in sheets similar to SC lipids. MSI demonstrated similarities between formulation components and skin constituents, as well as a good penetration into the skin. The formulations did not modify the lamellar organization of the SC lipids, but they increased the relative proportion of the crystallized lipids and some of the amorphous lipids. In in vivo studies, a high level of hydration was maintained over 24 h after application with an intense and 'very good hydration'. Both formulations were shown to be non-(photo)sensitizers with excellent tolerance. Sensorial evaluation indicated the formulations were not oily or sticky and maintained the skin's suppleness over time. Formulations had a 'nude skin' touch and created a natural protective film. CONCLUSIONS: The two formulations were well-tolerated and increased skin hydration in clinical subjects, an effect that could contribute to the alleviation of sensitive skin. The formulations were shown to resemble the lipid organization of the stratum corneum, as well as penetrate the skin without disrupting the lipid lamella organization.


Assuntos
Epiderme , Pele , Humanos , Técnicas In Vitro , Óleos/análise , Óleos/metabolismo , Pele/diagnóstico por imagem , Pele/metabolismo , Água/metabolismo
3.
Angew Chem Int Ed Engl ; 59(43): 19304-19310, 2020 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-32667118

RESUMO

Controlled radical polymerization of ethylene using different commercially available, cheap, and non-toxic iodo alkyls is performed by iodine transfer polymerization (ITP) under mild conditions (≤100 °C and ≤200 bar). The formed well-defined iodo end-capped polyethylene (PE-I) species is very stable upon storage. Narrow molar-mass distributions (dispersities around 1.6) were obtained up to number average molar masses of 7300 g mol-1 . The ethylene copolymerization by ITP (ITcoP) with vinyl acetate allowed to form a broad range of poly(ethylene-co-vinyl acetate) (EVA) containing from 0 to 85 mol % of VAc unit. In addition, EVA-b-PE block copolymers or EVA-b-EVA gradient block copolymers with different content of VAc in the blocks were obtained for the first time using ITP. Finally, reactivity trends were explored by a theoretical mechanistic study. This highly versatile synthetic platform provides a straightforward access to a diverse range of well-defined PE based polymer materials.

4.
Clin Genet ; 93(6): 1205-1209, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29451301

RESUMO

Oral-facial-digital (OFD) syndromes are a subgroup of ciliopathies distinguished by the co-occurrence of hamartomas and/or multiple frenula of the oral region and digital anomalies. Several clinical forms of OFD syndromes are distinguished by their associated anomalies and/or inheritance patterns, and at least 20 genetic types of OFD syndromes have been delineated. We describe here a child with preaxial and postaxial polydactyly, lingual hamartoma, a congenital heart defect, delayed development and cerebellar peduncles displaying the molar tooth sign. Whole-exome sequencing and SNP array identified compound heterozygous variants in the INTU gene, which encodes a protein involved in the positioning of the ciliary basal body. INTU is a subunit of the CPLANE multiprotein complex essential for the assembly of IFT-A particles and intraflagellar transport. This report of a second patient with INTU-related OFD syndrome and the further delineation of its neuroimaging and skeletal phenotype now allow INTU-related OFD syndromes to be classified within the OFD syndrome type VI group. Patients display a phenotype similar to that of mice with a hypomorphic mutation of Intu, but with the addition of a heart defect.


Assuntos
Proteínas do Citoesqueleto/genética , Proteínas de Membrana/genética , Síndromes Orofaciodigitais/genética , Humanos , Lactente , Recém-Nascido , Imageamento por Ressonância Magnética , Masculino , Síndromes Orofaciodigitais/diagnóstico por imagem
5.
Clin Genet ; 91(6): 868-880, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28229453

RESUMO

The group of chondrodysplasia with multiple dislocations includes several entities, characterized by short stature, dislocation of large joints, hand and/or vertebral anomalies. Other features, such as epiphyseal or metaphyseal changes, cleft palate, intellectual disability are also often part of the phenotype. In addition, several conditions with overlapping features are related to this group and broaden the spectrum. The majority of these disorders have been linked to pathogenic variants in genes encoding proteins implicated in the synthesis or sulfation of proteoglycans (PG). In a series of 30 patients with multiple dislocations, we have performed exome sequencing and subsequent targeted analysis of 15 genes, implicated in chondrodysplasia with multiple dislocations, and related conditions. We have identified causative pathogenic variants in 60% of patients (18/30); when a clinical diagnosis was suspected, this was molecularly confirmed in 53% of cases. Forty percent of patients remain without molecular etiology. Pathogenic variants in genes implicated in PG synthesis are of major importance in chondrodysplasia with multiple dislocations and related conditions. The combination of hand features, growth failure severity, radiological aspects of long bones and of vertebrae allowed discrimination among the different conditions. We propose key diagnostic clues to the clinician.


Assuntos
Deficiência Intelectual/genética , Anormalidades Musculoesqueléticas/genética , Osteocondrodisplasias/genética , Adolescente , Adulto , Criança , Pré-Escolar , Feminino , Estudos de Associação Genética , Humanos , Lactente , Recém-Nascido , Deficiência Intelectual/diagnóstico , Deficiência Intelectual/diagnóstico por imagem , Deficiência Intelectual/fisiopatologia , Masculino , Anormalidades Musculoesqueléticas/diagnóstico , Anormalidades Musculoesqueléticas/diagnóstico por imagem , Anormalidades Musculoesqueléticas/fisiopatologia , Osteocondrodisplasias/diagnóstico , Osteocondrodisplasias/diagnóstico por imagem , Osteocondrodisplasias/fisiopatologia , Radiografia , Sequenciamento do Exoma
6.
Arch Gynecol Obstet ; 292(1): 135-41, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25534161

RESUMO

BACKGROUND: The number of obese and morbidly obese patients within the developed world is dramatically increasing within the last 20 years. Apart from demographical changes, obese patients are especially prone to have oestrogen-dependent morbidities and neoplasias, of which laparoscopic treatment should be the standard of care. The increasing number of patients with BMI >40 is concerning, making it necessary to summarise considerations for safe and effective Gynaecological Laparoscopic Surgery. CONSIDERATIONS: The sequel to successful laparoscopic surgery in obese patients comprises an interdisciplinary appreciation of laparoscopy. Preoperatively, anaesthetics and medical review are suggested to optimise treatment of comorbidities (i.e. infections and blood sugar levels). Positioning of the patient should consider anti-slip options and pannus fixation to ease laparoscopic access and decrease pressure to the chest. There is no standard port placement in obese patients and landmarks have to be the bony structures of the pelvis and ribs. Retraction of the bowel is essential and mobilisation of the sigmoid with fan retractors or endoloops can accomplish adequate vision. 30° scopes can be considered for vision "around the obstacle". An experienced assistant with anticipation of surgical steps is favourable for successful surgery completion. Intra-operatively, good surgical techniques are essential. Vessel sealing systems reduce the need for instrument changes and may be helpful in following visualised tissue planes. A transvaginal vault closure may be advantageous compared to laparoscopic closure and Endostiches may be preferred to close the fascia of large trocar sites under vision.


Assuntos
Procedimentos Cirúrgicos em Ginecologia/métodos , Laparoscopia/métodos , Obesidade Mórbida/fisiopatologia , Comorbidade , Feminino , Humanos , Laparoscopia/efeitos adversos , Obesidade Mórbida/complicações , Instrumentos Cirúrgicos
8.
Clin Genet ; 82(2): 187-92, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21554265

RESUMO

ICF (immunodeficiency, centromeric region instability, facial anomalies) syndrome is a rare autosomal recessive disorder characterised by severe immunodeficiency, craniofacial anomalies and chromosome instability. Chromosome analyses from blood samples show a high frequency of decondensation of pericentromeric heterochromatin (PH) and rearrangements involving chromosomes 1 and 16. It is the first and, as far as we know, the only disease associated with a mutation in a DNA methyltransferase gene, DNMT3B, with significant hypomethylation of the classical satellite DNA, the major component of the juxtacentromeric heterochromatin. To better understand the complex links between the hypomethylation of the satellite DNA, the cytogenetic anomalies and the clinical features of ICF syndrome, we performed three-dimensional (3D) FISH on preserved cells from a patient with a suspected ICF phenotype. Analysis of DNMT3B did not reveal any mutation in our patient, making this case an ICF type 2. The results of 3D-FISH showed a statistically significant change in the intranuclear position of PH of chromosome 1 in cells of the patient as compared to normal cells. It is difficult to understand how a defect in the methylation pathway can be responsible for the various symptoms of this condition. From our observations we suggest a mechanistic link between the reorganisation of the nuclear architecture and the altered gene expression.


Assuntos
Núcleo Celular/genética , Centrômero , Heterocromatina/química , Síndromes de Imunodeficiência/diagnóstico , Síndromes de Imunodeficiência/genética , Adolescente , Aberrações Cromossômicas , Cromossomos Humanos Par 1 , Cromossomos Humanos Par 9 , Metilação de DNA , DNA Satélite , Face/anormalidades , Feminino , Humanos , Hibridização in Situ Fluorescente , Doenças da Imunodeficiência Primária
9.
Orphanet J Rare Dis ; 17(1): 100, 2022 03 03.
Artigo em Inglês | MEDLINE | ID: mdl-35241104

RESUMO

BACKGROUND: Individuals with pathogenic variants in SATB2 display intellectual disability, speech and behavioral disorders, dental abnormalities and often features of Pierre Robin sequence. SATB2 encodes a transcription factor thought to play a role in bone remodeling. The primary aim of our study was to systematically review the skeletal manifestations of SATB2-associated syndrome. For this purpose, we performed a non-interventional, multicenter cohort study, from 2017 to 2018. We included 19 patients, 9 females and 10 males ranging in age from 2 to 19 years-old. The following data were collected prospectively for each patient: clinical data, bone markers and calcium and phosphate metabolism parameters, skeletal X-rays and bone mineral density. RESULTS: Digitiform impressions were present in 8/14 patients (57%). Vertebral compression fractures affected 6/17 patients (35%). Skeletal demineralization (16/17, 94%) and cortical thinning of vertebrae (15/17) were the most frequent radiological features at the spine. Long bones were generally demineralized (18/19). The distal phalanges were short, thick and abnormally shaped. C-telopeptide (CTX) and Alkaline phosphatase levels were in the upper normal values and osteocalcin and serum procollagen type 1 amino-terminal propeptide (P1NP) were both increased. Vitamin D insufficiency was frequent (66.7%). CONCLUSION: We conclude that SATB2 pathogenic variants are responsible for skeletal demineralization and osteoporosis. We found increased levels of bone formation markers, supporting the key role of SATB2 in osteoblast differentiation. These results support the need for bone evaluation in children and adult patients with SATB2-associated syndrome (SAS).


Assuntos
Fraturas por Compressão , Proteínas de Ligação à Região de Interação com a Matriz , Fraturas da Coluna Vertebral , Fatores de Transcrição , Adolescente , Adulto , Biomarcadores , Densidade Óssea/genética , Osso e Ossos , Criança , Pré-Escolar , Estudos de Coortes , Feminino , Fraturas por Compressão/genética , Fraturas por Compressão/metabolismo , Fraturas por Compressão/patologia , Humanos , Masculino , Proteínas de Ligação à Região de Interação com a Matriz/genética , Proteínas de Ligação à Região de Interação com a Matriz/metabolismo , Estudos Prospectivos , Fraturas da Coluna Vertebral/genética , Fraturas da Coluna Vertebral/metabolismo , Fraturas da Coluna Vertebral/patologia , Síndrome , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Adulto Jovem
10.
Rev Med Brux ; 32(1): 14-7, 2011.
Artigo em Francês | MEDLINE | ID: mdl-21485459

RESUMO

In the framework of implementation of his national program for control and prevention of cardiovascular diseases, Cameroonian government has set up a cardiac surgery project. We report in this manuscript results of one year follow up of the patients operated during the pilot phase. From September 22 till 26, 2008, 11 patients have been operated in Cameroun. Surgical procedures were 5 mitral mechanic valve replacement, 2 aortic mechanic valve replacement, 1 atrial septal defect closure, 2 pace maker implantation. No intrahospital death was observed. One patient died at 11th month after the operation due to mitral valve thrombosis and attributed to lack of compliance. One patient presented low cardiac output, pneumonia and a pleural effusion. 2 patients presented 2 minor complications consisting of pericarditis and superficial wound infection. The results of the pilot phase of cardiac surgery in Cameroon are effective. However, the sustainability of the program require human, material capacity building, and funding mechanism as well.


Assuntos
Procedimentos Cirúrgicos Cardíacos/estatística & dados numéricos , Adulto , Camarões , Feminino , Cardiopatias/cirurgia , Humanos , Masculino , Projetos Piloto , Complicações Pós-Operatórias/epidemiologia
11.
Ultrason Sonochem ; 70: 105277, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32750656

RESUMO

Luminescence and chemiluminescence have been experimentally investigated in hydrodynamic cavitating flows. By using dedicated microdevices inserted inside a light tight box, photons counting has been made possible. Luminescence has been investigated with deionized water as the working fluid; chemiluminescence has resulted from cavitating alkaline luminol solutions, and has been correlated to hydroxyl radicals formation. For the first time, luminescent and chemiluminescent phenomena have been considered together on the same devices submitted to similar cavitating flow regimes. Degassed solutions enhance the luminescence and also the hydroxyl radical yield. Due to the small sizes of the channels, the lifetimes of the collapsing bubbles correspond to pseudo frequencies matching the range of optimal frequencies used in sonochemistry. New perspectives for the study of hydrodynamic cavitation as an advanced oxidation process are suggested.

12.
J Exp Med ; 143(2): 271-89, 1976 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-1082488

RESUMO

Immunofluorescence studies showed that properdin (P) and factor B bind to C3-C3b receptor bearing human lymphoblastoid cells (Raji, Daudi) and B type human peripheral lymphocytes (HPL). P bound to Raji cells first incubated with normal human serum (NHS). EDTA, but not EGTA, halted the binding of P to cells incubated with NHS. However, fixation of P to Raji cells, after incubation with NHS first reacted with inulin, was independent of Ca++ and -g++ ions. Fixation of P to Raji cells depended on the presence of C3 or C3b and occurred in the absence of factor D and factor B. Binding of P to B type HPL was detectable only after incubation of these cells with NHS first reacted with inulin; under these conditions binding of P to Raji cells was also greatly enhanced. With both Raji cells and HPL, factor B was detectable on cell surfaces only after incubation of these cells with NHS first reacted with activators of the P system. Binding of factor B to cells required the presence of C3b and binding or stabilization of cell bound factor B necessitated the presence of activated P. P and factor B were detectable only on cultured cells having C3-C3b receptors. However, incubation of NHS with all lymphoblastoid cell lines studied resulted in activation of P and cleavage of factor B. Binding of P and factor B to cells may follow one of three sequences; (a) activated P in fluid phase combines with C3, factor D, and factor B, and the whole complex fixes to cellular C3-C3b receptors via its C3 moiety; (b) C3b generated in fluid phase combines with P, C3, factor D, and factor B and binds to C3-C3b receptors; or (c) C3 or C3b first binds onto the C3-C3b receptors and thereafter interacts with P, factor D, And factor B. Binding of components of the P system to cells or other particles may relate to such biological phenomena as lysis, phagocytosis, proliferation, attraction of other cell types, and alteration of responsiveness to external stimuli.


Assuntos
Linfócitos B/imunologia , Sítios de Ligação de Anticorpos , Linfócitos/imunologia , Properdina/metabolismo , Sistema ABO de Grupos Sanguíneos , Membrana Celular/imunologia , Células Cultivadas , Complemento C3/metabolismo , Humanos , Técnicas In Vitro , Ativação Linfocitária
13.
J Exp Med ; 146(4): 949-69, 1977 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-302316

RESUMO

After vaccinia virus vaccination of human volunteers, local indurations developed within 10 days, and regional adenopathy was detected in half of the individuals. Their peripheral blood lymphocytes (PBL) harvested at different days after vaccination showed specific activity against target cells infected with vaccinia virus with a peak activity at day 7. The specificity of the cytotoxic activity was not related to HLA markers, since autologous, homologous, and heterologous infected target cells were lysed with the same efficiency. The cytotoxic activity was caused by PBL that did not rosette with sheep erythrocytes and could be depleted by more than 90 percent by removing Fc receptor-bearing cells. T-cell- depleted PBL showed a one-half to two times greater cytotoxicity than intact PBL. The cytotoxic activity could also be abrogated by more than 95 percent by rabbit Fab(2) anti-human IgG. On the other hand, nonimmune PBL lysed vaccinia-infected target cells in the presence of specific antibodies against vaccinia virus, thus demonstrating that ADCC could be efficient in lysing vaccinia-infected target cells. We conclude that after vaccination, antibody-forming cells arise and provide specific anti-viral antibody and that the cytotoxic cells detected in this reaction are K cells. These experiments suggest that antibody-dependent cell cytotoxicity may be of major importance in the recovery of man to virus infections.


Assuntos
Antígenos HLA , Antígenos de Histocompatibilidade , Imunidade Celular , Linfócitos/imunologia , Vaccinia virus/imunologia , Vacinas Virais , Adulto , Anticorpos Antivirais , Reações Antígeno-Anticorpo , Testes Imunológicos de Citotoxicidade , Humanos , Memória Imunológica , Terapia de Imunossupressão , Macrófagos/imunologia , Monócitos/imunologia , Linfócitos T/imunologia , Fatores de Tempo , Vacinação
14.
J Exp Med ; 160(2): 441-51, 1984 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-6381635

RESUMO

Plasmodium falciparum polypeptides of 200 and 140 K mol wt exposed at the surface of merozoites and/or schizonts were purified by affinity chromatography and by electroelution from sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Monkeys were separated into three groups of four and immunized either with one of the two polypeptides or with saline (control). After intravenous challenge with 2.5 X 10(7) P. falciparum asexual blood stages, two monkeys of the control group had to be treated and two recovered spontaneously after peak parasitemia of 9 and 11%. The four monkeys immunized with the 140 K polypeptide recovered without treatment after peak parasitemia between 1.5 and 4.5%. Monkeys immunized with the 200 K polypeptide had similar peak parasitemia except one monkey who suffered from a large skin excoriation and who recovered spontaneously after a peak parasitemia of 11%. Prechallenge sera of the immunized monkeys reacted only with the polypeptide used for immunization except for one serum of the 140 K group, which precipitated an additional polypeptide of 39 K, and a polypeptide of 31 K weakly precipitated by the four sera of monkeys immunized with the 200 K polypeptide. The relatedness between the 200 and 140 K polypeptides was investigated using tryptic digestion and reverse phase chromatography. No clear analogy was found between the two polypeptides, which suggests that immunization with either of two independent surface components of P. falciparum asexual blood stages is able to induce at least a partial protective immunity in immunized hosts.


Assuntos
Antígenos de Superfície/administração & dosagem , Imunização , Malária/imunologia , Plasmodium falciparum/fisiologia , Animais , Reações Antígeno-Anticorpo , Antígenos de Superfície/imunologia , Antígenos de Superfície/isolamento & purificação , Feminino , Humanos , Malária/sangue , Malária/parasitologia , Masculino , Peso Molecular , Peptídeos/imunologia , Peptídeos/isolamento & purificação , Plasmodium falciparum/imunologia , Reprodução Assexuada , Saimiri
15.
J Exp Med ; 143(5): 1027-41, 1976 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-177712

RESUMO

Antibody-mediated C-dependent lysis of cell lines infected with herpes simplex type 1 virus, influenza A degrees virus, measles virus, and mumps virus occurred by the alternative C pathway with the participation of IgG antibodies. Lysis occurred only with immune human sera, Mg++ EGTA immune sera, and immune sera depleted of C4 or treated with Fab anti-C4. Lysis did not occur with nonimmune sera, Mg++ EDTA immune sera, and immune sera heated 50 degrees C for 25 min, depleted of factor B or treated with Fab antifactor B. Lysis was restored to heated and factor B immunodepleted immune sera by addition of factor B, but not by addition of an excess of C2. Further studies showed that lysis of HeLa cells infected with measles virus was induced by both immune IgG and F(ab')2 but not Fab' in the presence of a nonantibody-containing human C source. Lysis of measles virus-infected cells was also indpendent of movement of viral antigens on the surface of the infected cells, as inhibition of viral antigen capping by cytochalasin B or sodium azide was not associated with abrogation of immune lysis.


Assuntos
Anticorpos Antivirais , Reações Antígeno-Anticorpo , Proteínas do Sistema Complemento/metabolismo , Fragmentos Fab das Imunoglobulinas , Imunoglobulina G/metabolismo , Especificidade de Anticorpos , Antígenos Virais , Linhagem Celular , Membrana Celular/efeitos dos fármacos , Membrana Celular/imunologia , Complemento C3/metabolismo , Citocalasina B/farmacologia , Testes Imunológicos de Citotoxicidade , Vírus da Influenza A/imunologia , Magnésio/farmacologia , Vírus do Sarampo/imunologia , Vírus da Caxumba/imunologia , Properdina/metabolismo , Simplexvirus/imunologia
16.
J Exp Med ; 150(3): 445-54, 1979 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-479760

RESUMO

The dependence of antibody-and-complement-mediated lysis of virus-infected cells on the alternative pathway was examined utilizing the isolated cytolytic alternative pathway--a system consisting of the six purified proteins of the alternative pathway of activation (C3, factors B and D, beta 1H, C3b inactivator and properdin), and the five proteins of the membrane attack pathway (C5--9) of complement. HeLa cells acutely infected with measles virus were lysed by anti-viral IgG and the isolated cytolytic alternative pathway with an efficiency comparable to whole human serum. IgG and its F(ab')2 fragment were equally effective in inducing lysis by the isolated cytolytic alternative pathway, binding of approximately equal to 5 X 10(7) molecules per cell being required for 50% lysis; in contrast, no lysis occurred when equivalen or greater amounts of Fab' were bound to the virus-infected cell. Properdin was required for lysis. No lysis occurred if properdin was deleted from the isolated cytolytic alternative pathway, and lysis was diminished by 80% in properdin-depleted serum. Uptake of [125I]C3b from the isolated alternative pathway onto measles virus-infected cells occurred in the absence of properdin, but was accelerated in the presence of properdin. The 11 proteins of the isolated cytolytic alternative pathway are thus sufficient for lysis of measles virus-infected cells bearing anti-viral IgG or F(ab')2 without any other serum protein.


Assuntos
Anticorpos Antivirais/administração & dosagem , Citotoxicidade Celular Dependente de Anticorpos , Transformação Celular Viral , Ativação do Complemento , Via Alternativa do Complemento , Vírus do Sarampo/imunologia , Células HeLa , Humanos , Fragmentos Fab das Imunoglobulinas , Imunoglobulina G
17.
J Exp Med ; 187(8): 1295-303, 1998 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-9547340

RESUMO

We investigated CD4+ and CD8+ T cell turnover in both healthy and HIV-1-infected adults by measuring the nuclear antigen Ki-67 specific for cell proliferation. The mean growth fraction, corresponding to the expression of Ki-67, was 1.1% for CD4(+) T cells and 1.0% in CD8(+) T cells in healthy adults, and 6.5 and 4.3% in HIV-1-infected individuals, respectively. Analysis of CD45RA+ and CD45RO+ T cell subsets revealed a selective expansion of the CD8+ CD45RO+ subset in HIV-1-positive individuals. On the basis of the growth fraction, we derived the potential doubling time and the daily turnover of CD4+ and CD8+ T cells. In HIV-1-infected individuals, the mean potential doubling time of T cells was five times shorter than that of healthy adults. The mean daily turnover of CD4+ and CD8+ T cells in HIV-1-infected individuals was increased 2- and 6-fold, respectively, with more than 40-fold interindividual variation. In patients with <200 CD4+ counts, CD4+ turnover dropped markedly, whereas CD8+ turnover remained elevated. The large variations in CD4+ T cell turnover might be relevant to individual differences in disease progression.


Assuntos
Linfócitos T CD4-Positivos/citologia , Linfócitos T CD8-Positivos/citologia , Infecções por HIV/imunologia , HIV-1/imunologia , Antígeno Ki-67/análise , Adulto , Contagem de Linfócito CD4 , Ciclo Celular , Citometria de Fluxo/métodos , Meia-Vida , Humanos , Antígenos Comuns de Leucócito , Ativação Linfocitária , Subpopulações de Linfócitos T/citologia
18.
Clin Infect Dis ; 49(10): 1570-8, 2009 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-19845472

RESUMO

BACKGROUND: Most persons with human immunodeficiency virus (HIV) infection in the United States present to care with advanced disease, and many patients discontinue therapy prematurely. We sought to evaluate sex and racial/ethnic disparities in life-years lost as a result of risk behavior, late presentation, and early discontinuation of HIV care, and we compared these survival losses for HIV-infected persons with losses attributable to high-risk behavior and HIV disease itself. METHODS: With use of a state-transition model of HIV disease, we simulated cohorts of HIV-infected persons and compared them with uninfected individuals who had similar demographic characteristics. We estimated non-HIV-related mortality with use of risk-adjusted standardized mortality ratios, as well as years of life lost because of late presentation and early discontinuation of antiretroviral therapy (ART) for HIV infection. Data from the national HIV Research Network, stratified by sex and race/ethnicity, were used for estimating CD4+ cell counts at ART initiation. RESULTS: For HIV-uninfected persons in the United States who have risk profiles similar to those of individuals with HIV infection, the projected life expectancy, starting at 33 years of age, was 34.58 years, compared with 42.91 years for the general US population. Those with HIV infection lost an additional 11.92 years of life if they received HIV care concordant with guidelines; late treatment initiation resulted in 2.60 additional years of life lost, whereas premature ART discontinuation led to 0.70 more years of life lost. Losses from late initiation and early discontinuation were greatest for Hispanic individuals (3.90 years). CONCLUSIONS: The high-risk profile of HIV-infected persons, HIV infection itself, as well as late initiation and early discontinuation of care, all lead to substantial decreases in life expectancy. Survival disparities resulting from late initiation and early discontinuation of therapy are most pronounced for Hispanic HIV-infected men and women. Interventions focused on risk behaviors, as well as on earlier linkage to and better retention in care, will lead to improved survival for HIV-infected persons in the United States.


Assuntos
Fármacos Anti-HIV/uso terapêutico , Terapia Antirretroviral de Alta Atividade/métodos , Infecções por HIV/epidemiologia , Infecções por HIV/mortalidade , Expectativa de Vida/tendências , Cooperação do Paciente/estatística & dados numéricos , Assunção de Riscos , Adulto , Feminino , Infecções por HIV/tratamento farmacológico , Humanos , Masculino , Grupos Raciais , Fatores Sexuais , Análise de Sobrevida , Estados Unidos/epidemiologia
19.
Science ; 195(4281): 878-80, 1977 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-402691

RESUMO

Human cultured lymphoblastoid cells incubated in normal human serum activate the properdin complement pathway without antibody. However, only cells bearing C3b immune adherence receptors bind components of the properdin complement pathway and undergo lysis. A similar surveillance mechanism may exist in man to limit growth of malignant B cells bearing C3b immune adherence receptors.


Assuntos
Linfócitos B/imunologia , Complemento C3/metabolismo , Proteínas do Sistema Complemento/metabolismo , Properdina/imunologia , Linfócitos B/metabolismo , Sítios de Ligação , Linhagem Celular , Testes Imunológicos de Citotoxicidade , Ácido Edético/farmacologia , Ácido Egtázico/farmacologia , Humanos , Cinética
20.
Science ; 240(4855): 1036-8, 1988 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-3285469

RESUMO

Immunization with a 41-kilodalton blood stage antigen (p41) of Plasmodium falciparum induces immunity to malaria in monkeys. However, antigenic polymorphism and repetitive amino acids commonly found in protective antigens complicate vaccine development. The gene encoding p41 has now been cloned and analyzed. Sequencing and hybridization studies revealed that the gene structure is highly conserved in 14 parasite isolates from three continents. This finding and the lack of repetitive amino acids in the translated DNA sequence may indicate that p41 has an essential function. In this study the protein was found to be 60 percent homologous to the key glycolytic enzyme aldolase from vertebrates, and the affinity-purified p41 protein from parasites showed aldolase activity.


Assuntos
Antígenos de Protozoários/imunologia , Frutose-Bifosfato Aldolase/metabolismo , Plasmodium falciparum/imunologia , Animais , Anticorpos Antiprotozoários/imunologia , Complexo Antígeno-Anticorpo/análise , Antígenos de Protozoários/genética , Frutose-Bifosfato Aldolase/genética , Frutose-Bifosfato Aldolase/imunologia , Cinética , Plasmodium falciparum/enzimologia , Polimorfismo Genético
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