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1.
Eur Cell Mater ; 37: 60-73, 2019 01 28.
Artigo em Inglês | MEDLINE | ID: mdl-30687909

RESUMO

Osteoinductive calcium phosphate (CaP) bone grafts have equivalent performance to autografts in repairing critical-size bone defects. The osteoinductive potential of CaP is linked to the size of the surface topographical features. In the present study, two novel biphasic calcium phosphate (BCP) bone grafts were synthesised with either sub-micron- (BCP<µm) or micron-scale (BCPµm) needle-shaped surface topography and compared to dimensionally similar tricalcium phosphate (TCP) with grain-shaped surface structures (TCP<µm and TCPµm). To clarify the possible function of the surface morphology (needle-like vs. grain-like) in initiating bone formation, the four CaP test materials were physicochemically characterised and implanted for 12 weeks in the dorsal muscle of beagles. The sub-micron needle-shaped topography of BCP<µm triggered earlier bone formation (3-6 weeks) as compared to the grain-shaped surface topography of TCP<µm, which formed bone at 6-9 weeks. After 12 weeks, the amount of induced bone formation in both materials was equivalent, based on histomorphometry. The micron-sized needle-shaped surface topography of BCPµm led to limited formation of new bone tissue, whereas its counterpart, TCPµm with grain-shaped surface topography, failed to trigger de novo bone formation. The relative strength of the parameters affecting CaP-driven bone induction was as follows: surface feature size > surface feature morphology > substrate chemistry. BCP materials with needle-shaped sub-micron surface topography gave rise to accelerated bone formation and slower rate of resorption than a comparable TCP. These characteristics may be translated to improve bone healing in orthotopic defects.


Assuntos
Fosfatos de Cálcio/química , Fosfatos de Cálcio/farmacologia , Osteogênese , Tamanho da Partícula , Adsorção , Animais , Calcificação Fisiológica/efeitos dos fármacos , Bovinos , Cães , Íons , Osteogênese/efeitos dos fármacos , Implantação de Prótese , Soroalbumina Bovina/metabolismo , Propriedades de Superfície
2.
Hipertens Riesgo Vasc ; 41(2): 95-103, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38508877

RESUMO

INTRODUCTION: Evidence about nefroprotective effect with RAAS blockers in elderly patients with chronic kidney disease (CKD) without proteinuria is lacking. The primary outcome of our study is to evaluate the impact of RAAS blockers in CKD progression in elderly patients without proteinuria. MATERIALS AND METHODS: Multicenter open-label, randomized controlled clinical trial including patients over 65 year-old with hypertension and CKD stages 3-4 without proteinuria. Patients were randomized in a 1:1 ratio to either receive RAAS blockers or other antihypertensive drugs and were followed up for three years. Primary outcome is estimated glomerular filtration rate (eGFR) decline at 3 years. Secondary outcome measures include BP control, renal and cardiovascular events and mortality. RESULTS: 88 patients were included with a mean age of 77.9±6.1 years and a follow up period of 3 years: 40 were randomized to RAAS group and 48 to standard treatment. Ethiology of CKD was: 53 vascular, 16 interstitial and 19 of unknown ethiology. In the RAAS group eGFR slope during follow up was -4.3±1.1ml/min, whereas in the standard treatment group an increase on eGFR was observed after 3 years (+4.6±0.4ml/min), p=0.024. We found no differences in blood pressure control, number of antihypertensive drugs, albuminuria, potassium serum levels, incidence of cardiovascular events nor mortality during the follow up period. CONCLUSIONS: In elderly patients without diabetes nor cardiopathy and with non proteinuric CKD the use of RAAS blockers does not show a reduction in CKD progression. The PROERCAN (PROgresión de Enfermedad Renal Crónica en ANcianos) trial (trial registration: NCT03195023).


Assuntos
Hipertensão , Insuficiência Renal Crônica , Humanos , Idoso , Idoso de 80 Anos ou mais , Sistema Renina-Angiotensina , Anti-Hipertensivos/farmacologia , Anti-Hipertensivos/uso terapêutico , Inibidores da Enzima Conversora de Angiotensina/farmacologia , Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Hipertensão/complicações , Hipertensão/tratamento farmacológico , Insuficiência Renal Crônica/complicações , Insuficiência Renal Crônica/tratamento farmacológico , Proteinúria/tratamento farmacológico , Proteinúria/etiologia
4.
Radiol Med ; 117(4): 690-714, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22095424

RESUMO

PURPOSE: The authors sought to define treatment results according to the different accrual periods and clinical-therapeutic features in a large series of nasopharyngeal cancer (NPC) patients treated in two Italian centres over more than two decades. MATERIALS AND METHODS: A total of 883 patients consecutively treated with radiotherapy between 1977 and 2000 at the Florence (FLO) and Brescia (IRA) Radiation Oncology centres were studied. Five-year overall (OS) and disease-specific (DSS) actuarial survival rates in the different pathological, clinical and therapeutic subgroups were calculated, along with the actuarial local-regional control (LRC) probability. RESULTS: At univariate analysis, survival and local control rates were significantly better in the more recent accrual periods and in the more favourable disease presentations; treatment-related parameters mainly affect LRC. At multivariate analysis, patient- and disease-related factors had a more evident prognostic effect than did therapeutic factors, although dose to the nasopharynx and treatment technique had a marginally significant impact on DSS and OS. CONCLUSIONS: Results of this benchmark study may be useful for understanding the development of new radio-therapy techniques for NPC, such as three-dimensional conformal radiotherapy (3D-CRT) and particularly intensity-modulated radiotherapy (IMRT).


Assuntos
Neoplasias Nasofaríngeas/radioterapia , Adulto , Benchmarking , Diagnóstico por Imagem , Feminino , Humanos , Itália/epidemiologia , Masculino , Pessoa de Meia-Idade , Neoplasias Nasofaríngeas/diagnóstico , Neoplasias Nasofaríngeas/epidemiologia , Neoplasias Nasofaríngeas/patologia , Estadiamento de Neoplasias , Prognóstico , Dosagem Radioterapêutica , Estudos Retrospectivos , Taxa de Sobrevida , Resultado do Tratamento
5.
Sci Total Environ ; 759: 143506, 2021 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-33261866

RESUMO

The transparency, heterogeneity and hypotheses considered in the calculation of the environmental impacts of roads are still barriers to the identification of low-carbon solutions. To overcome this problem, this study presents an analysis of 94 papers obtained in a systematic literature review of the Scopus, Science Direct, Mendeley, Springer Link, and Web of Science databases. From a total of 417 road case studies, only 18% were found to be fully transparent, reproducible, and likely to present reliable results. The road design parameters of the speed limit were provided in 11% of the cases, and the average annual daily traffic data were provided in 42%. Limited data were found for the dimensions of road elements such as the number (77%) and width of lanes (33%), shoulders (15%), footpaths (5%), berms (1%) and foreslope (4%). The source of the life cycle inventory was presented in 57% of the case studies, impact assessment method was indicated in 22%, and the software utilized was listed in 50%. A lack of information was noted in the description of the types of materials employed in road projects. In addition, the large heterogeneity in the definitions of the functional unit, system boundary and in the reference study period of repair, replacement, rehabilitation or end-of-life for both flexible and rigid pavement does not support the identification of the most environmentally friendly solutions. Based on the results of the analysis, several recommendations for design parameters and life cycle assessment aspects are proposed to support a harmonized calculation of the environmental impacts of road projects.

6.
Hipertens Riesgo Vasc ; 38(2): 63-71, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33759767

RESUMO

INTRODUCTION: Obesity is a major health problem worldwide. It carries a markedly increased risk for multiple diseases such as type 2 diabetes mellitus, hypertension, cardiovascular disease (CVD) and chronic kidney disease (CKD). To complicate an already difficult topic a new subtype of obesity has been defined lately, the metabolically healthy obese. Our study aimed to clarify the association between obesity, metabolic syndrome and kidney disease progression. METHODS: Observational retrospective single centre study including 212 patients with stage 3-4 CKD with no previous history of rapid kidney disease progression. Patients were divided according to BMI status and presence of metabolic syndrome. Anthropometric, clinical and laboratory data were collected to follow-up. Propensity score matching was performed for age, albuminuria and baseline renal function. During follow-up renal and cardiovascular events were recorded. RESULTS: After a mean follow-up of 88.44±36.07 months a total of 18 patients reached the renal outcome in the non-obese group and 21 in the obese group. Differences were not statistically significant (log rank=0.21: p=0.64). Multiple Cox regression analysis showed that obesity was not predictor for worse renal outcomes [HR 1.01, 95% CI 0.45-2.24; p=0.97]. When stratifying the sample according to baseline metabolic syndrome and obesity presence there was no difference in renal survival (log rank=0.852; p=0.35) A total of 48 cardiovascular events were registered: seventeen in the non-obese group and thirty-one in the obese group. Differences in event-free time between both groups were statistically significant (log rank=4.44;p=0.035), especially after four years of follow-up. After stratifying for MS and obesity presence at baseline the event-free time differences where again statistically significant (log rank=16.86;p=0.001), specially for the obese patients with metabolic syndrome. CONCLUSIONS: Obesity has little impact on chronic kidney disease progression despite the presence or absence of metabolic syndrome in a cohort matched for age, baseline renal function and albuminuria. Obesity conferred greater cardiovascular risk when combined with metabolic syndrome.


Assuntos
Doenças Cardiovasculares , Diabetes Mellitus Tipo 2 , Síndrome Metabólica , Obesidade , Insuficiência Renal Crônica , Albuminúria/epidemiologia , Albuminúria/etiologia , Doenças Cardiovasculares/epidemiologia , Doenças Cardiovasculares/etiologia , Progressão da Doença , Humanos , Síndrome Metabólica/complicações , Síndrome Metabólica/epidemiologia , Obesidade/complicações , Obesidade/epidemiologia , Pontuação de Propensão , Insuficiência Renal Crônica/complicações , Insuficiência Renal Crônica/epidemiologia , Estudos Retrospectivos , Fatores de Risco
7.
J Exp Med ; 178(2): 381-9, 1993 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-8340750

RESUMO

The c-fes protooncogene is expressed at high levels in the terminal stages of granulocytic differentiation, but so far no definite function has been attributed to the product of this oncogene. To tackle this problem, the c-fes protooncogene expression has been inhibited in HL60 cells, and fresh leukemic promyelocytes of acute promyelocytic leukemia have been induced to differentiate with retinoic acid (RA) and dimethylsulfoxide (DMSO). Inhibition was obtained by incubating the cells with a specific c-fes antisense oligodeoxynucleotide. It was observed that the cells, rather than differentiating, underwent premature cell death showing the morphological and molecular characteristics of apoptosis. This process was inhibited by granulocyte and granulocyte/macrophage colony-stimulating factor, but not by interleukin 3 (IL-3), IL-6, or stem cell factor. Our present results demonstrate that the loss of cell viability that occurs during the in vitro differentiation of myeloid cells, after the complete inhibition of the c-fes gene product and treatment with RA-DMSO, is due to activation of programmed cell death. It is concluded that a possible role of the c-fes gene product is to exert an antiapoptotic effect during granulocytic differentiation.


Assuntos
Apoptose/genética , Expressão Gênica/efeitos dos fármacos , Granulócitos/citologia , Oligonucleotídeos Antissenso/farmacologia , Proteínas Tirosina Quinases/genética , Proteínas Proto-Oncogênicas/genética , Apoptose/efeitos dos fármacos , Sequência de Bases , Diferenciação Celular/efeitos dos fármacos , Diferenciação Celular/genética , Células Cultivadas , Dimetil Sulfóxido/farmacologia , Humanos , Dados de Sequência Molecular , Proteínas Proto-Oncogênicas c-fes , Tretinoína/farmacologia
8.
Eur Cell Mater ; 19: 252-61, 2010 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-20526989

RESUMO

To render polymeric materials osteoinductive, nano-sized calcium phosphate apatite particles (CaP) were introduced into a low molecular weight poly(D,L-lactide). Homogenous composites were made with 10%, 20% and 40% by weight of apatite content while pure polylactide was used as control. Thereafter porous samples (pore size 300-400 microm, 60% porosity) were fabricated and sterilized. In vitro studies showed that calcium ions were released from the composites depending on the apatite content, while surface mineral deposition was observed only on the 40% CaP composites in simulated body fluid (SBF) within 14 days. After 12 weeks of intramuscular implantation in dogs, only the 40% CaP composite implant retained its shape and showed ectopic bone formation within the pores. In conclusion, adding a content of 40% apatite into poly(D,L-lactide) could lead to an osteoinductive material. Future studies will focus on understanding this phenomenon of material-directed osteoinduction in order to develop a promising bone graft substitute.


Assuntos
Substitutos Ósseos/química , Nanocompostos/química , Osteogênese/efeitos dos fármacos , Animais , Apatitas , Líquidos Corporais , Cães , Implantes Experimentais , Teste de Materiais , Nanocompostos/uso terapêutico , Poliésteres , Porosidade
10.
Hipertens Riesgo Vasc ; 37(3): 101-107, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32156479

RESUMO

INTRODUCTION: Blood pressure (BP) control is fundamental to the care of patients with chronic kidney disease (CKD), and is relevant at all stages of CKD. Renin-angiotensin-aldosterone system (RAAS) blockers have shown to be effective, not only in BP control but also in reducing proteinuria and slowing CKD progression. However, there is a lack of evidence for recommending RAAS blockers in elderly patients with CKD without proteinuria. The primary outcome of the present study is to evaluate the impact of RAAS blockers on CKD progression in elderly patients without proteinuria. MATERIALS AND METHODS: The PROERCAN trial (trial registration, NCT03195023) is a multicentre open-label, randomized controlled clinical trial with 110 participants over 65 years-old with hypertension and CKD stages 3-4 without proteinuria. Patients will be randomized in a 1:1 ratio to either receive RAAS blockers or other antihypertensive drugs, and will be followed up for three years. Primary outcome is the estimated glomerular filtration rate (eGFR) decline at 3 years. Secondary outcomes include BP control, renal and cardiovascular events, and mortality. RESULTS AND CONCLUSIONS: The design of this trial is presented here. The results will show if antihypertensive treatment with RAAS blockers has an impact on CKD progression in elderly patients without proteinuria. Any differences in BP control, cardiovascular events, and mortality with each antihypertensive treatment will be also clarified.


Assuntos
Anti-Hipertensivos/farmacologia , Hipertensão/tratamento farmacológico , Insuficiência Renal Crônica/tratamento farmacológico , Sistema Renina-Angiotensina/efeitos dos fármacos , Idoso , Inibidores da Enzima Conversora de Angiotensina/administração & dosagem , Inibidores da Enzima Conversora de Angiotensina/farmacologia , Anti-Hipertensivos/administração & dosagem , Pressão Sanguínea/efeitos dos fármacos , Progressão da Doença , Taxa de Filtração Glomerular , Humanos , Hipertensão/fisiopatologia , Insuficiência Renal Crônica/fisiopatologia
11.
Mol Oral Microbiol ; 33(3): 257-269, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29524318

RESUMO

We report the whole genome sequence of the serotype e Cbm+ strain LAR01 of Streptococcus mutans, a dental pathogen frequently associated with extra-oral infections. The LAR01 genome is a single circular chromosome of 2.1 Mb with a GC content of 36.96%. The genome contains 15 phosphotransferase system gene clusters, seven cell wall-anchored (LPxTG) proteins, all genes required for the development of natural competence and genes coding for mutacins VI and K8. Interestingly, the cbm gene is genetically linked to a putative type VII secretion system that has been found in Mycobacteria and few other Gram-positive bacteria. When compared with the UA159 type strain, phenotypic characterization of LAR01 revealed increased biofilm formation in the presence of either glucose or sucrose but similar abilities to withstand acid and oxidative stresses. LAR01 was unable to inhibit the growth of Strpetococcus gordonii, which is consistent with the genomic data that indicate absence of mutacins that can kill mitis streptococci. On the other hand, LAR01 effectively inhibited growth of other S. mutans strains, suggesting that it may be specialized to outcompete strains from its own species. In vitro and in vivo studies using mutational and heterologous expression approaches revealed that Cbm is a virulence factor of S. mutans by mediating binding to extracellular matrix proteins and intracellular invasion. Collectively, the whole genome sequence analysis and phenotypic characterization of LAR01 provides new insights on the virulence properties of S. mutans and grants further opportunities to understand the genomic fluidity of this important human pathogen.


Assuntos
Proteínas de Bactérias/genética , Fenótipo , Sorogrupo , Streptococcus mutans/genética , Streptococcus mutans/fisiologia , Bacteriocinas/genética , Composição de Bases , Biofilmes/crescimento & desenvolvimento , Proteínas de Transporte , Colágeno , Cárie Dentária/microbiologia , Células Endoteliais , Genoma Bacteriano , Humanos , Família Multigênica , Estresse Oxidativo , Análise de Sequência , Streptococcus gordonii/crescimento & desenvolvimento , Streptococcus mutans/isolamento & purificação , Sistemas de Secreção Tipo VII/genética , Virulência , Fatores de Virulência/metabolismo , Sequenciamento Completo do Genoma
12.
Biochim Biophys Acta ; 1152(1): 78-82, 1993 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-8399308

RESUMO

Large unilamellar vesicles, prepared with dioctadecyldimethylammonium chloride, entrap nitroblue tetrazolium. Addition of solid KO2, or production of superoxide anion by riboflavin photolysis, to nitroblue tetrazolium-containing dioctadecyldimethylammonium vesicles results in the formation of monoformazan above the phase-transition temperature of the bilayer. Below the phase-transition temperature the yield of monoformazan is negligible. These results demonstrate that superoxide anion permeates vesicles above the phase-transition temperature of the bilayer.


Assuntos
Bicamadas Lipídicas/química , Superóxidos/química , Ânions/química , Micelas , Fotólise , Compostos de Amônio Quaternário , Temperatura
13.
Biochim Biophys Acta ; 1501(1): 51-62, 2000 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-10727849

RESUMO

Pseudoxanthoma elasticum (PXE) is a genetic connective tissue disease, whose gene and pathogenesis are still unknown. Dermal fibroblasts from patients affected by PXE have been compared in vitro with fibroblasts taken from sex and age-matched normal individuals. Cells were grown and investigated in monolayer, into three-dimensional collagen gels and in suspension. Compared with normal cells, PXE fibroblasts cultured in monolayer entered more rapidly within the S phase and exhibited an increased proliferation index; on the contrary, similarly to normal fibroblasts, PXE cells did not grow in suspension. Furthermore, compared with normal fibroblasts, PXE cells exhibited lower efficiency in retracting collagen type I lattices and lower adhesion properties to collagen type I and to plasma fibronectin. This behavior was associated with higher expression of integrin subunits alpha2, alpha5, alphav, whereas beta1 subunit as well as alpha2beta1 and alpha5beta1 integrin expression was lower than in controls. Compared to controls, PXE fibroblasts had higher CAM protein expression in accordance with their high tendency to form cellular aggregates, when kept in suspension. The demonstration that PXE fibroblasts have altered cell-cell and cell-matrix interactions, associated with modified proliferation capabilities, is consistent with the hypothesis that the gene responsible for PXE might have a broad regulatory role on the cellular machinery.


Assuntos
Pseudoxantoma Elástico/genética , Pele/patologia , Adulto , Biópsia , Adesão Celular , Ciclo Celular , Divisão Celular , Tamanho Celular , Feminino , Fibroblastos/patologia , Fibroblastos/ultraestrutura , Humanos , Integrinas/metabolismo , Pseudoxantoma Elástico/metabolismo , Pseudoxantoma Elástico/patologia , Pele/metabolismo
14.
Cell Death Differ ; 4(6): 497-505, 1997 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16465271

RESUMO

Although VDR is expressed in all the acute myeloid leukemia cell populations studied, most of these leukemias do not exhibit any phenotypic response when exposed to VD. To determine whether VD resistance is related to an altered VDR function, we performed an analysis of VDR expression, phosphorylation, DNA binding capacity and transactivation activity in several leukemic myeloid cell lines arrested at different levels of maturation. Our results indicate that VD induces a clear phenotypic effect, i.e. terminal monocytic differentiation, only in leukemic cells of M2/M3 (intermediate myeloblasts) and M5 (monoblasts) types but not in erythroid precursor cells, early leukemic myeloblasts (M0/M1 type) and promyelocytes (M3 type). VDR expression and function are evident in all the nuclear extracts obtained from the different myeloid cell lines after 12 h of VD treatment, but VD activation of monocytic differentiation is limited to a narrow differentiation window characterized by the M2 type myeloid cellular context.

15.
Leukemia ; 8 Suppl 1: S91-4, 1994 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-8152313

RESUMO

The c-fes protooncogene is expressed at high levels in the terminal stages of granulocytic differentiation. Its product, p92c-fes, exhibits a tyrosine-kinase activity and is involved in the cellular response to GM-CSF, but its role is not yet clarified. To study this problem, the c-fes protooncogene expression has been inhibited in HL60 cells and in fresh leukemic blast cells of Acute Promyelocytic Leukemia (APL) induced to differentiate with All-Trans-Retinoic Acid (ATRA). Inhibition of c-fes function was obtained by treatment of the cells with a specific antisense oligomer complementary to the 5' region of the c-fes mRNA. It was observed that the cells, rather then differentiate to granulocytes, underwent premature cell death showing the morphological and molecular characteristics of apoptosis. Superimposable results are obtained on blast cells from APL. It is possible to conclude that the loss of cell viability that occurs during the in vitro differentiation of myeloid cells, after the complete inhibition of c-fes expression and treatment with ATRA, is due to activation of programmed cell death rather than an accelerated differentiation. Our data suggest that the c-fes product is essential for the survival of myeloid cells during differentiation.


Assuntos
Apoptose , Granulócitos/citologia , Proteínas Tirosina Quinases , Proteínas Proto-Oncogênicas/genética , Proto-Oncogenes , Diferenciação Celular , Expressão Gênica , Humanos , Leucemia Promielocítica Aguda/patologia , Oligonucleotídeos Antissenso/farmacologia , Proteínas Proto-Oncogênicas c-fes , Células Tumorais Cultivadas
16.
J Biomed Mater Res B Appl Biomater ; 103(4): 841-52, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25132540

RESUMO

The influence of fluoride in poly(d,l-lactide)/apatite composites on ectopic bone formation was evaluated in sheep. Nano-apatite powders with different replacement levels of OH groups by fluoride (F) (0% (F0), 50% (F50), 100% (F100), and excessive (F200)) were co-extruded with poly (d,l-lactide) at a weight ratio of 1:1. Fluoride release from the composites (CF0, CF50, CF100, and CF200) was evaluated in vitro and bone formation was assessed after intramuscular implantation in sheep. After 24 weeks in simulated physiological solution, CF0 and CF50 showed negligible fluoride release, whereas it was considerable from the CF100 and CF200 composites. Histology showed that the incidence of de novo bone formation decreased in implants with increasing fluoride content indicating a negative influence of fluoride on ectopic bone formation. Furthermore, a significant decrease in resorption of the high fluoride-content composites and a reduction in the number of multinucleated giant cells were seen. These results show that instead of promoting, the presence of fluoride in poly(d,l-lactide)/apatite composites seemed to suppresses their resorption and osteoinductive potential in non-osseous sites.


Assuntos
Implantes Absorvíveis , Apatitas , Substitutos Ósseos , Fluoretos , Osteogênese/efeitos dos fármacos , Poliésteres , Animais , Apatitas/química , Apatitas/farmacologia , Substitutos Ósseos/química , Substitutos Ósseos/farmacologia , Fluoretos/química , Fluoretos/farmacologia , Poliésteres/química , Poliésteres/farmacologia , Ovinos
17.
AIDS ; 9(6): 547-53, 1995 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-7662191

RESUMO

OBJECTIVE: To study the V beta T-cell repertoire in peripheral blood lymphocytes (PBL) during acute HIV syndrome by using several anti-V beta monoclonal antibodies (MAb) and to analyse its functionality by stimulating PBL with superantigens (SAg) such as Staphylococcus aureus enterotoxins. METHODS: Cytofluorimetric analysis of V beta T-cell-receptor expression was performed on PBL from eight patients with symptomatic, acute HIV-1 primary infection, showing a dramatic decrease of CD4+ PBL accompanied by a marked increase in activated/memory CD8+ T cells, and on 12 age- and sex-matched healthy controls. PBL were then isolated, stimulated with different SAg, anti-CD3 MAb or phytohaemagglutinin and cultured for 3 days. PBL capability to progress through cell cycle was studied by the classic cytofluorimetric method of bromodeoxyuridine incorporation and DNA staining with propidium iodide. RESULTS: Despite the presence of a few expansions of some V beta families among CD8+ T lymphocytes, no gross alterations in T-cell repertoire were present in patients with acute HIV syndrome. Its functionality was maintained overall, as PBL responsiveness to SAg was well preserved. Interestingly, all CD8+ T cells, although bearing different V beta T-cell receptors, expressed marked signs of activation, i.e., CD45R0, CD38 and major histocompatibility complex class II molecules, and also high amounts of CD11a and CD18. CONCLUSIONS: Our data suggest, at least in the early phases and in the acute form of the infection, that HIV is not likely to act as a SAg. However, further studies are needed to analyse other sites, such as lymph nodes, where HIV could exert other, significant effects, and to study the expression of other V beta families than those investigated here.


Assuntos
Síndrome da Imunodeficiência Adquirida/imunologia , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , HIV-1/imunologia , Receptores de Antígenos de Linfócitos T alfa-beta/imunologia , Doença Aguda , Adulto , Relação CD4-CD8 , Feminino , Antígenos HLA-DR/imunologia , Humanos , Região Variável de Imunoglobulina/imunologia , Imunofenotipagem , Ativação Linfocitária , Masculino , Superantígenos/imunologia
18.
Mech Ageing Dev ; 102(1): 15-23, 1998 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-9663788

RESUMO

Neutral endopeptidase-24.11 (NEP, EC 3.4.24.11) is a cell surface Zn metallopeptidase that hydrolyzes bioactive regulatory peptides. Using a spectrofluorimetric procedure, we assessed NEP activity in plasma membranes of normal human skin and lung fibroblasts. We found a considerable increase in NEP activity during fetal-to-adult transition. Adult skin fibroblasts from an old donor exhibited significantly higher levels of NEP activity than cells from young donors. Interestingly, however, the NEP activity of fibroblasts from a centenarian donor was similar to that of cells from young donors. Increased levels of NEP activity were also found in in vitro aged lung fibroblasts. Finally, adrenocorticotropin hormone (ACTH (1-24)), a regulatory peptide that can be cleaved by NEP, provoked an increase in enzymic activity in fetal and young adult donor fibroblasts and a decrease in this activity in fibroblasts from adult and old donors. This finding suggests that ageing may affect NEP activity.


Assuntos
Fibroblastos/citologia , Fibroblastos/enzimologia , Neprilisina/metabolismo , Adulto , Idoso , Divisão Celular , Células Cultivadas , Senescência Celular/efeitos dos fármacos , Senescência Celular/fisiologia , Criança , Cosintropina/farmacologia , Feto , Fibroblastos/efeitos dos fármacos , Glicopeptídeos/farmacologia , Humanos , Pulmão/citologia , Pulmão/efeitos dos fármacos , Pulmão/enzimologia , Neprilisina/antagonistas & inibidores , Neprilisina/efeitos dos fármacos , Inibidores de Proteases/farmacologia , Pele/citologia , Pele/efeitos dos fármacos , Pele/enzimologia
19.
Mech Ageing Dev ; 86(3): 173-95, 1996 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-8733112

RESUMO

CD4+ and CD8+ peripheral blood T lymphocytes show mutually exclusive expression of CD45RA or CD45R0, two isoforms of the common leukocyte antigen that seem to recognize so-called virgin/unprimed and memory/activated T cells. The expression of these isoforms has been studied by three colour cytofluorimetric analysis on CD4+ or CD8+ peripheral blood CD3+ cells from 22 healthy centenarians, analyzed in a context of 202 healthy donors 0-110 years old. An age-related unbalance of virgin and memory cells was found between CD4+ and CD8+ subsets. As expected, at birgh 95-99% of the CD3+ lymphocytes expressed the CD45RA isoform. A rapid increase of CD45R0+ cells was observed in the first 2-3 decades of life, this phenomenon being much more pronounced on CD4+ cells. Subsequently, the increase of the 'memory' compartment was much less rapid, so that in centenarians a consistent reservoire of CD45RA+ among CD4+ cells was still present (about 20%). In these exceptional individuals the percentage of CD45RA+ cells among CD8+ T lymphocytes was even higher (about 50%), and only slightly lower than that of young donors (about 55-60%). Thus, the main changes occurred at a different rate in CD4+ (about 20%). In these exceptional individuals the percentage of CD45RA+ cells among CD8+ T lymphocytes was even higher (about 50%), and only slightly lower than that of young donors (about 55-60%). Thus, the main changes occurred at a different rate in CD4+ and in CD8+ T cells, at an age of between 0 and 30 years, when the thymus is still functionally active. Interestingly, no difference in the usage of CD45 isoforms was observed within T cells bearing four different V beta-T cell receptor (TCR). The significance of this age-related unbalance is unknown. However, the presence of a great number of CD45RA+ T lymphocytes within the CD4+ and the CD8+ T cell subsets even in the peripheral blood of centenarians poses the problem of their origin (thymus? extrathymic sites?), of their functional role and of their lifespan. Moreover, the data on centenarians suggest that they may represent a very selected population where a slowing of immunosenescence occurs.


Assuntos
Envelhecimento/imunologia , Envelhecimento/metabolismo , Linfócitos T CD4-Positivos/metabolismo , Linfócitos T CD8-Positivos/metabolismo , Memória Imunológica , Antígenos Comuns de Leucócito/metabolismo , Adolescente , Adulto , Distribuição por Idade , Idoso , Idoso de 80 Anos ou mais , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Criança , Pré-Escolar , Feminino , Humanos , Imuno-Histoquímica , Lactente , Recém-Nascido , Antígenos Comuns de Leucócito/imunologia , Masculino , Pessoa de Meia-Idade
20.
Eur J Cancer ; 33(4): 669-75, 1997 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-9274452

RESUMO

The effect of spermine (Sp), a natural polycationic amine, on cisplatin (CDDP) sensitivity and accumulation of a human ovarian CDDP-sensitive cell line (2008) and its resistant variant (C13*) was investigated. Survival was also studied. The C13* cells were approximately 20-fold resistant to CDDP, yet were found to be just as sensitive to Sp as 2008 cells. When Sp was concurrently added with CDDP to the colony-forming assay, the IC50 dose was approximately 3-fold lower than that of CDDP alone. This decrease was the result of a synergistic interaction, as assessed by median effect analysis. The incubation of cells with the approximate IC50 dose of Sp for 1-8 h indicated that this synergism could be due to stimulation of CDDP accumulation, showing maximal uptake after 4 h of Sp exposure. This stimulation may be the result of a modulation of cellular membrane permeability by Sp, as assessed by the accumulation of [3H]mannitol. Exposure to Sp concentrations active on CDDP uptake also significantly increased [3H]mannitol accumulation in both cell lines. The triamine spermidine (Spd) did not significantly affect either the sensitivity of the two cell lines or CDDP and [3H]mannitol accumulation. These results suggest that Sp is a positive modulator of CDDP uptake, and thus of its cytotoxicity, even in resistant cells, where the phenotype is partly due to a CDDP accumulation defect.


Assuntos
Antineoplásicos/metabolismo , Cisplatino/metabolismo , Neoplasias Ovarianas/metabolismo , Espermina/farmacologia , Antineoplásicos/uso terapêutico , Permeabilidade da Membrana Celular , Cisplatino/uso terapêutico , Resistencia a Medicamentos Antineoplásicos , Sinergismo Farmacológico , Feminino , Humanos , Manitol/metabolismo , Neoplasias Ovarianas/tratamento farmacológico , Poliaminas/metabolismo , Células Tumorais Cultivadas , Ensaio Tumoral de Célula-Tronco
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