RESUMO
This is an overview of the biography and scientific accomplishments of Dr. Juri Vasiliev, an outstanding Russian cell biologist. Ju. M. Vasiliev published seminal papers on carcinogenesis and cytoskeleton of normal and cancer cells. He founded a scientific school and mentored many students that are now occupying leading positions in different laboratories throughout the world.
Assuntos
Biologia Celular/história , Amigos , Mentores , História do Século XIX , História do Século XXRESUMO
Atherosclerosis underlies the development of many cardiovascular diseases that continue to hold a leading place among the causes of death in developed countries. The role of activated immune cells in atherosclerosis progression has been convincingly demonstrated, but the mechanism of their action remains poorly investigated. Since atherosclerosis is associated with chronic inflammatory response, involvement of viral and bacterial infections in atherogenesis has been examined. A special place among the infectious agents is held by human herpesviruses as the most common persistent viruses in human population coupled to chronic inflammation during atherosclerosis. We found that activation of cytomegalovirus (CMV, human herpesvirus 5) infection is associated with the emergence of acute coronary syndrome, which is in a good agreement with the data on productive CMV infection published elsewhere. In this review, we discuss the data obtained by us and other researchers regarding the role of cytomegalovirus infection and related potential mechanisms resulting in the expansion of atherosclerotic plaques during ischemic heart disease and stroke, including virus transfer to immune and endothelial cells via extracellular vesicles. In particular, the data presented in the review demonstrate that virus spreading in the vascular wall triggers immune system activation in atherosclerotic plaques and causes endothelial dysfunction. Moreover, productive CMV infection in patients with acute myocardial infarction correlates with the extent of endothelial dysfunction. The mechanisms described by us and other researchers may explain the role of CMV infection in atherosclerosis and development of ischemic heart disease.
Assuntos
Doenças Cardiovasculares/complicações , Infecções por Citomegalovirus/complicações , Animais , Doenças Cardiovasculares/patologia , Doenças Cardiovasculares/virologia , HumanosRESUMO
PURPOSE: to study elucidate association of active cytomegalovirus (CMV) infection with endothelial dysfunction in patients with acute myocardial infarction (AMI). MATERIALS AND METHODS: The study included 42 volunteers without ischemic heart disease (IHD) and 63 patients with AMI. Blood samples for analysis of the deoxyribonucleic acid (DNA) of CMV in plasma by real-time polymerase chain reaction were taken in patients - before coronary angiography, in volunteers - at admission. In addition, in patients with AMI and volunteers without IHD, endothelial function was analyzed using endothelium-dependent vasodilatation (EDVD) test of the brachial artery. RESULTS: We showed that in patients with AMI, the concentration of CMV DNA in plasma was statistically significantly increased when compared with that in volunteers without IHD, which reflects active CMV infection - 1185.7 (0; 3003.0) vs. 0 (0; 910.8) copies of DNA / ml plasma (p=0.011). In comparison with volunteers without IHD, patients with AMI also more often had endothelial dysfunction - 11.5 (7.5, 15.2) % vs. 4.4 (0; 9.6) % of cases (p.
Assuntos
Artéria Braquial/fisiopatologia , Infecções por Citomegalovirus , Endotélio Vascular/fisiopatologia , Infarto do Miocárdio , Idoso , Artéria Braquial/patologia , Angiografia Coronária , Citomegalovirus/genética , Infecções por Citomegalovirus/sangue , Infecções por Citomegalovirus/complicações , Infecções por Citomegalovirus/patologia , Infecções por Citomegalovirus/fisiopatologia , DNA Viral/sangue , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/sangue , Infarto do Miocárdio/complicações , Infarto do Miocárdio/patologia , Infarto do Miocárdio/fisiopatologia , VasodilataçãoRESUMO
The level of proinflammatory markers was assessed in HIV-infected patients that were coinfected with hepatitis C virus (HCV) and had failed to restore the CD4+ T cell counts (immunological nonresponders, INR) during the antiretroviral therapy (ART). Among four patient groups (HIV+HCV- and HIV+HCV+ subjects with the concordant response to ART; HIV+HCV- and HIV+HCV+ subjects that were INR), the greatest systemic inflammation was in the latter group. The maximum difference was between the subjects HIV+HCV-INR and HIV+HCV+ INR: the blood of coinfected patients contained significantly higher concentrations of the IP-10, sCD163, sTNF-RI, and sTNF-RII and of bacterial lipopolysaccharide. Systemic inflammation in HIV/HCV coinfected patients with the discordant response to ART is probably caused by a breach of hepatic barrier for the intestine products.
Assuntos
Antirretrovirais/uso terapêutico , Linfócitos T CD4-Positivos/efeitos dos fármacos , Infecções por HIV/sangue , Hepatite C/sangue , Síndrome de Resposta Inflamatória Sistêmica/sangue , Adulto , Antirretrovirais/efeitos adversos , Linfócitos T CD4-Positivos/imunologia , Coinfecção , Citocinas/sangue , Feminino , Infecções por HIV/complicações , Infecções por HIV/tratamento farmacológico , Hepatite C/complicações , Hepatite C/tratamento farmacológico , Humanos , Lipopolissacarídeos/sangue , Fígado/efeitos dos fármacos , Masculino , Síndrome de Resposta Inflamatória Sistêmica/etiologiaRESUMO
OBJECTIVES: Chronic hepatitis C virus (HCV) and HIV viral infections are characterized by systemic inflammation. Yet the relative levels, drivers and correlates of inflammation in these settings are not well defined. METHODS: Seventy-nine HIV-infected patients who had been receiving antiretroviral therapy (ART) for more than 2 years and who had suppressed plasma HIV levels (< 50 HIV-1 RNA copies/mL) were included in the study. Two patient groups, HCV-positive/HIV-positive and HCV-negative/HIV-positive, and a control group comprised of healthy volunteers (n = 20) were examined. Markers of systemic inflammation [interleukin (IL)-6, interferon gamma-induced protein (IP)-10, soluble tumour necrosis factor receptor-I (sTNF-RI) and sTNF-RII], monocyte/macrophage activation [soluble CD163 (sCD163), soluble CD14 and neopterin], intestinal epithelial barrier loss [intestinal fatty acid binding protein (I-FABP) and lipopolysaccharide (LPS)] and coagulation (d-dimers) were analysed. CD4 naïve T cells and CD4 recent thymic emigrants (RTEs) were enumerated. RESULTS: Plasma levels of IP-10, neopterin and sCD163 were higher in HCV/HIV coinfection than in HIV monoinfection and were positively correlated with indices of hepatic damage [aspartate aminotransferase (AST), alanine aminotransferase (ALT) and the AST to platelet ratio index (APRI)]. Levels of I-FABP were comparably increased in HIV monoinfection and HIV/HCV coinfection but LPS concentrations were highest in HCV/HIV coinfection, suggesting impaired hepatic clearance of LPS. Plasma HCV levels were not related to any inflammatory indices except sCD163. In coinfected subjects, a previously recognized relationship of CD4 naïve T-cell and RTE counts to hepatocellular injury was defined more mechanistically by an inverse relationship to sCD163. CONCLUSIONS: Hepatocellular injury in HCV/HIV coinfection is linked to elevated levels of certain inflammatory cytokines and an apparent failure to clear systemically translocated microbial products. A related decrease in CD4 naïve T cells and RTEs also merits further exploration.
Assuntos
Coinfecção/patologia , Infecções por HIV/complicações , Infecções por HIV/patologia , Hepatite C Crônica/complicações , Hepatite C Crônica/patologia , Inflamação/patologia , Fígado/patologia , Adulto , Biomarcadores/sangue , Citocinas/sangue , Feminino , Humanos , MasculinoRESUMO
Extracellular vesicles (EVs) are released from various cell types and play an important role in intercellular interactions. In our study, we investigated abundance of individual EVs in patients with acute forms of ischemic heart disease. Previously, we developed an approach for individual analysis of EVs conjugated with magnetic nanoparticles (MNPs), which was applied in the current study for analyzing phenotypic composition of EVs (by staining for markers CD31, CD41a, and CD63). EVs were isolated using fluorescently labeled MNPs containing anti-CD31, CD41a, or CD63 antibodies and analyzed by combining fluorescently labeled anti-CD41a and CD63, CD31 and CD63, or CD41a and CD31 antibodies, respectively. EVs were analyzed in 30 individuals: 17 healthy volunteers and 13 patients with acute coronary syndrome (ACS). Six and seven ACS patients were with acute myocardial infarction and unstable angina, respectively. It was found that patients with ACS and healthy volunteers contained a dominant subset of EVs expressing surface CD41a antigen, suggesting that they originated from platelets. In addition, the total number of EVs isolated using either of the surface markers examined in our study was higher in patients with ACS compared to healthy volunteers. The subgroup of patients with acute myocardial infarction was found to contain significantly higher number of blood EVs compared to the control group. Moreover, increased number of EVs in patients with ACS is mainly due to the increased number of EVs in the subset of EVs bearing CD41a. By analyzing individual EVs, we found that plasma of patients with ACS, particularly upon developing of myocardial infarction, contained dominant platelet-derived EVs fraction, which may reflect activation of platelets in such patients.
Assuntos
Síndrome Coronariana Aguda/diagnóstico , Vesículas Extracelulares/metabolismo , Nanopartículas de Magnetita/química , Síndrome Coronariana Aguda/sangue , Idoso , Anticorpos/química , Anticorpos/imunologia , Plaquetas/metabolismo , Estudos de Casos e Controles , Vesículas Extracelulares/química , Feminino , Citometria de Fluxo , Antígenos de Histocompatibilidade Classe I/metabolismo , Humanos , Integrina alfa2/imunologia , Integrina alfa2/metabolismo , Masculino , Pessoa de Meia-Idade , Molécula-1 de Adesão Celular Endotelial a Plaquetas/imunologia , Molécula-1 de Adesão Celular Endotelial a Plaquetas/metabolismoRESUMO
THE AIM OF THE STUDY: to analyze the dynamics of lymphocytic composition of human atherosclerotic plaques in ex vivo culture system. MATERIALS AND METHODS: The study included 15 atherosclerotic plaques obtained from patients who underwent carotid endarterectomy. Plaques were cultured as ring-shaped explants on collagen rafts in culture medium of special composition in CO2 incubator according to the previously developed technique. On day 0, and also on the 4th and 19th days of culture we extracted cells from plaque explants and analyzed B- and T-lymphocytic content of the tissue, as well as the percentage of CD16+ natural killer (NK) cells, using multichromatic flow cytometry. For this purpose we digested the explants with an original enzymatic cocktail, which allows preservation of cell surface markers, and we stained extracted cells with fluorescence-labelled monoclonal antibodies against CD45, CD3, CD19, CD4, CD8, CD16. In addition, we estimated the amount of interleukin 2 (IL-2) and interferon-gamma (IFN-)-producing T-cells by means of flow cytometry. RESULTS: After 4 days of culture the amount of lymphocytes in plaques explants decreased, however live lymphocytes were still preserved (2619.3 [1680.4, 3478.2] cells/100mg tissue). Viable lymphocytes population included T cells (2123.4 [484.9; 3181.2] cells/100 mg tissue), B cells (5.6 [3.4, 27.9] cell/100 mg tissue) and CD16+ NK cells (10.6 [1.8, 23.7] cell/100mg tissue). On the 4th day of culture T cells were presented by CD4+CD8- (797 [475.5, 1000.7] cells/100mg tissue, 37.5 [32.1; 46.3]%) and CD4-CD8+ (686.2 [423.6; 1158.4] cells/100 mg tissue, 45.6 [38.1; 47.9]%) populations. The percentage of CD4+CD8- T cell population decreased compared to the 1st day of culture, and this decrease correlated with the increase in CD4-CD8- T cells content (p<0.05). Additionally, after 4 days of culture we found in tissue explants both CD8+ (17.5[13.3;19.9]%) and CD8- (9.9 [6.4; 14]%) IFN--producing T-cells, however, their percentage, as well as the percentage of IL-2-producing T cells tended to decrease. After 19 days of culture explants of atherosclerotic plaques also contained lymphocytes (2830.1 [2350.3, 5900.2] cells/100mg tissue). Lymphocytes population included T cells (2594.5 [2035.7, 5306.7] cells/100mg tissue), presented by CD4+CD8- (1016.8 [671.2, 2201.7] cells/100mg tissue, 42.3 [34.3; 47.8]%) and CD4-CD8+ (1534.3 [813.8; 2207.2] cells/100mg tissue, 50.8 [45.6; 56.5]%) subsets, B cells (31 [18.3; 64.4] cell/100 mg tissue) and CD16+ NK cells (44.9 [33.4; 138.9] cells/100 mg of tissue). DISCUSSION: An ex vivo model of human atherosclerotic plaque culture that we previously developed enables to preserve viability of various lymphocyte subsets for up to 19 days. We also found that cultured tissue explants retain T cells that can maintain T-helper-1-dependent immune response, which demonstrates inflammation in atherosclerotic plaques. Our results allow to perform experiments on immunological mechanisms of atherogenesis and to develop new approaches for treatment of atherosclerosis, devoted to the suppression of local inflammatory processes in atherosclerotic plaques. CONCLUSIONS: An ex vivo model of human atherosclerotic plaque preserves CD4+CD8- and CD4-CD8+ T cells, B cells, and CD16+ NK cells for a long time. Moreover, after 4 days of culture tissue explants also retain IFN-++ T cells.
Assuntos
Subpopulações de Linfócitos , Placa Aterosclerótica/imunologia , Subpopulações de Linfócitos T , Técnicas de Cultura de Tecidos , Idoso , Feminino , Citometria de Fluxo , Humanos , Masculino , Pessoa de Meia-Idade , Placa Aterosclerótica/patologiaRESUMO
To determine whole-body protein turnover responses to high-protein diets during weight loss, 39 adults (age, 21±1 years; VO2peak, 48±1 ml kg(-1) min(-1); body mass index, 25±1 kg m(2)) were randomized to diets providing protein at the recommend dietary allowance (RDA), 2 × -RDA or 3 × -RDA. A 10-day weight maintenance period preceded a 21-day, 40% energy deficit. Postabsorptive (FASTED) and postprandial (FED) whole-body protein turnover was determined during weight maintenance (day 10) and energy deficit (day 31) using [1-(13)C]leucine. FASTED flux, synthesis and breakdown were lower (P<0.05) for energy deficit than weight maintenance. Protein flux and synthesis were higher (P<0.05) for FED than FASTED. Feeding attenuated (P<0.05) breakdown during weight maintenance but not energy deficit. Oxidation increased (P<0.05) between dietary protein levels and feeding stimulated oxidation, although oxidative responses to feeding were higher (P<0.05) for energy deficit than weight maintenance. FASTED net balance decreased between dietary protein levels, but in the FED state, net balance was lower for 3 × -RDA as compared with RDA and 2 × -RDA (diet-by-state, P<0.05). Consuming dietary protein at levels above the RDA, particularly 3 × -RDA, during short-term weight loss increases protein oxidation with concomitant reductions in net protein balance.
Assuntos
Proteínas Alimentares/administração & dosagem , Proteínas Alimentares/farmacocinética , Ingestão de Energia , Proteínas Musculares/metabolismo , Músculo Esquelético/metabolismo , Redução de Peso , Adulto , Índice de Massa Corporal , Dieta , Exercício Físico , Jejum , Feminino , Humanos , Masculino , Período Pós-PrandialRESUMO
A rapid decline in T-cell counts and the progression to AIDS is often associated with a switch from CCR5-tropic (R5) HIV-1 to CXCR4-tropic (X4) HIV-1 or R5/X4 HIV-1 variants. Experimental infection with R5 HIV-1 causes less T-cell depletion than infection with X4 or R5/X4 variants in T-cell cultures, in ex vivo infected human lymphoid tissue and in SCID/hu mice, despite similar replication levels. Experimental genetic changes in those sequences in gp120 that transform R5 HIV-1 variants into otherwise isogenic X4 viruses make them highly cytopathic. Thus, it is now believed that R5 variants are less cytopathic for T cells than are X4 variants. However, it is not known why CCR5-mediated HIV-1 infection does not lead to a massive CD4+ T-cell depletion, as occurs in CXCR4-mediated HIV-1 infection. Here we demonstrate that R5 HIV-1 isolates are indeed highly cytopathic, but only for CCR5+/CD4+ T cells. Because these cells constitute only a small fraction of CD4+ T cells, their depletion does not substantially change the total CD4+ T-cell count. These results may explain why the clinical stage of HIV disease correlates with viral tropism.
Assuntos
Linfócitos T CD4-Positivos/virologia , HIV-1/fisiologia , Receptores CCR5/metabolismo , Receptores CXCR4/metabolismo , Animais , Efeito Citopatogênico Viral , HIV-1/isolamento & purificação , HIV-1/metabolismo , Humanos , Tecido Linfoide/citologia , Camundongos , Camundongos SCIDRESUMO
Both cellular and humoral immunodeficiency develop in vivo after prolonged infection with HIV-1, but the mechanisms are unclear. Initial infection with HIV-1 is transmitted by macrophage (M)-tropic/non-syncytia-inducing (NSI) viruses, which hyperactivate the immune system, and, in one view, cause immunodeficiency by "exhaustion" of lymphoid tissue. An alternative hypothesis is that immunodeficiency is caused by the replacement of M-tropic viruses by T cell (T)-tropic/syncytia-inducing (SI) viruses, which are known to be highly cytopathic in vitro and emerge late in infected individuals around the time of transition to AIDS (refs. 1, 7-9). To test these two possibilities, we have developed an ex vivo model of humoral immunity to recall antigens using human lymphoid tissue. This tissue supports productive infection with both M- and T-tropic HIV-1 isolates when cultured ex vivo. We found that specific immune responses were enhanced by productive infection of the tissue with M-tropic/NSI HIV-1 isolates, but were blocked by T-tropic/SI HIV-1 isolates. The mechanism involves specific irreversible effect on B-cell activity. Our results support the hypothesis that the phenotype switch to T-tropic viruses is a key determinant of acquired humoral immunodeficiency in patients infected with HIV.
Assuntos
Síndrome da Imunodeficiência Adquirida/etiologia , HIV-1/imunologia , Tonsila Palatina/imunologia , Linfócitos B/imunologia , Técnicas de Cultura , HIV-1/classificação , Humanos , Macrófagos/virologia , Modelos Imunológicos , Tonsila Palatina/virologia , Fenótipo , Linfócitos T/virologiaRESUMO
HIV-1 infects target cells via a receptor complex formed by CD4 and a chemokine receptor, primarily CCR5 or CXCR4 (ref. 1). Commonly, HIV-1 transmission is mediated by CCR5-tropic variants, also designated slow/low, non-syncytia-inducer or macrophage-tropic, which dominate the early stages of HIV-1 infection and frequently persist during the entire course of the disease. In contrast, HIV-1 variants that use CXCR4 are typically detected at the later stages, and are associated with a rapid decline in CD4+ T cells and progression to AIDS (refs. 2,7-11). Disease progression is also associated with the emergence of concurrent infections that may affect the course of HIV disease by unknown mechanisms. A lymphotropic agent frequently reactivated in HIV-infected patients is human herpesvirus 6 (HHV-6), which has been proposed as a cofactor in AIDS progression. Here we show that in human lymphoid tissue ex vivo, HHV-6 affects HIV-1 infection in a coreceptor-dependent manner, suppressing CCR5-tropic but not CXCR4-tropic HIV-1 replication, as shown with both uncloned viral isolates and isogenic molecular chimeras. Furthermore, we demonstrate that HHV-6 increases the production of the CCR5 ligand RANTES ('regulated upon activation, normal T-cell expressed and secreted'), the most potent HIV-inhibitory CC chemokine, and that exogenous RANTES mimics the effects of HHV-6 on HIV-1, providing a mechanism for the selective blockade of CCR5-tropic HIV-1. Our data suggest that HHV-6 may profoundly influence the course of HIV-1 infection.
Assuntos
HIV-1/fisiologia , HIV-1/patogenicidade , Herpesvirus Humano 6/fisiologia , Quimiocina CCL5/biossíntese , Quimiocina CCL5/farmacologia , Técnicas de Cultura , Infecções por HIV/complicações , Infecções por HIV/etiologia , Infecções por HIV/virologia , HIV-1/efeitos dos fármacos , HIV-1/genética , Humanos , Tecido Linfoide/imunologia , Tecido Linfoide/virologia , Receptores CCR5/fisiologia , Receptores CXCR4/fisiologia , Infecções por Roseolovirus/complicações , Infecções por Roseolovirus/etiologia , Infecções por Roseolovirus/virologia , Replicação Viral/efeitos dos fármacosRESUMO
Zika virus (ZIKV) is a flavivirus transmitted by mosquitoes of the genus Aedes, but unlike other flaviviruses, ZIKV can be sexually transmitted by vaginal intercourse. The healthy vaginal pH ranges from 4.0 to 6.0, reaching values of 6.0-7.0 after semen deposition. Here, we report that low extracellular pH values (range 6.2-6.6) dramatically increase ZIKV infection on cell lines of different origin including some derived from the female genital tract and monocyte-derived macrophages. Furthermore, low pH significantly increased ZIKV infection of human ectocervix and endocervix cultured ex-vivo. Enhancement of infection by low pH was also observed using different ZIKV strains and distinct methods to evaluate viral infection, i.e. plaque assays, RT-PCR, flow cytometry, and fluorescence microscopy. Analysis of the mechanisms involved revealed that the enhancement of ZIKV infection induced by low pH was associated with increased binding of the viral particles to the heparan sulphate expressed on the target cell surface. Acidosis represents a critical but generally overlooked feature of the female genital tract, with major implications for sexual transmission diseases. Our results suggest that low vaginal pH might promote male-to-female transmission of ZIKV infection.
Assuntos
Colo do Útero/química , Vagina/química , Infecção por Zika virus/transmissão , Zika virus/patogenicidade , Acidose , Animais , Linhagem Celular , Colo do Útero/virologia , Chlorocebus aethiops , Feminino , Heparitina Sulfato/metabolismo , Humanos , Concentração de Íons de Hidrogênio , Microscopia de Fluorescência , Vagina/virologia , Células Vero , Zika virus/genéticaRESUMO
Initial biologic events that underlie sexual transmission of HIV-1 are poorly understood. To model these events, we exposed human immature Langerhans cells (LCs) within epithelial tissue explants to two primary and two laboratory-adapted HIV-1 isolates. We detected HIV-1(Ba-L) infection in single LCs that spontaneously emigrated from explants by flow cytometry (median of infected LCs = 0.52%, range = 0.08-4.77%). HIV-1-infected LCs downregulated surface CD4 and CD83, whereas MHC class II, CD80, and CD86 were unchanged. For all HIV-1 strains tested, emigrated LCs were critical in establishing high levels of infection (0.1-1 microg HIV-1 p24 per milliliter) in cocultured autologous or allogeneic T cells. HIV-1(Ba-L) (an R5 HIV-1 strain) more efficiently infected LC-T cell cocultures when compared with HIV-1(IIIB) (an X4 HIV-1 strain). Interestingly, pretreatment of explants with either aminooxypentane-RANTES (regulated upon activation, normal T cell expressed and secreted) or cellulose acetate phthalate (potential microbicides) blocked HIV-1 infection of LCs and subsequent T cell infection in a dose-dependent manner. In summary, we document HIV-1 infection in single LCs after exposure to virus within epithelial tissue, demonstrate that relatively low numbers of these cells are capable of inducing high levels of infection in cocultured T cells, and provide a useful explant model for testing of agents designed to block sexual transmission of HIV-1.
Assuntos
Fármacos Anti-HIV/farmacologia , Quimiocina CCL5/análogos & derivados , Células Epiteliais/virologia , Infecções por HIV/transmissão , HIV-1 , Células de Langerhans/virologia , Linfócitos T CD4-Positivos/virologia , Movimento Celular , Quimiocina CCL5/farmacologia , Técnicas de Cocultura , HumanosRESUMO
BACKGROUND: Special Operations Forces (SOF) engage in a variety of military tasks with many producing high energy expenditures, leading to undesired energy deficits and loss of body mass. Therefore, the ability to accurately estimate daily energy requirements would be useful for accurate logistical planning. PURPOSE: Generate a predictive equation estimating energy requirements of SOF. METHODS: Retrospective analysis of data collected from SOF personnel engaged in 12 different SOF training scenarios. Energy expenditure and total body water were determined using the doubly-labeled water technique. Physical activity level was determined as daily energy expenditure divided by resting metabolic rate. Physical activity level was broken into quartiles (0 = mission prep, 1 = common warrior tasks, 2 = battle drills, 3 = specialized intense activity) to generate a physical activity factor (PAF). Regression analysis was used to construct two predictive equations (Model A; body mass and PAF, Model B; fat-free mass and PAF) estimating daily energy expenditures. RESULTS: Average measured energy expenditure during SOF training was 4468 (range: 3700 to 6300) Kcal·d-1. Regression analysis revealed that physical activity level (r = 0.91; P < 0.05) and body mass (r = 0.28; P < 0.05; Model A), or fat-free mass (FFM; r = 0.32; P < 0.05; Model B) were the factors that most highly predicted energy expenditures. Predictive equations coupling PAF with body mass (Model A) and FFM (Model B), were correlated (r = 0.74 and r = 0.76, respectively) and did not differ [mean ± SEM: Model A; 4463 ± 65 Kcal·d- 1, Model B; 4462 ± 61 Kcal·d- 1] from DLW measured energy expenditures. CONCLUSION: By quantifying and grouping SOF training exercises into activity factors, SOF energy requirements can be predicted with reasonable accuracy and these equations used by dietetic/logistical personnel to plan appropriate feeding regimens to meet SOF nutritional requirements across their mission profile.
Assuntos
Metabolismo Energético , Exercício Físico , Militares , Necessidades Nutricionais , Antropometria , Metabolismo Basal , Composição Corporal , Humanos , Análise de Regressão , Estudos RetrospectivosRESUMO
The CC chemokines MIP-1alpha, MIP-1beta, and RANTES suppress replication of certain HIV-1 strains in cultured PBMC and T cell lines by blocking interaction of gp120 with CC chemokine receptor 5 (CCR5). However, the same chemokines can enhance HIV-1 replication in cultured macrophages. The net effect of chemokines on HIV-1 infection in intact lymphoid tissue, the major reservoir of HIV-1 in vivo, is unknown and unpredictable since the tissue contains both T lymphocytes and macrophages. Here we show that exogenous MIP-1alpha, MIP-1beta, and RANTES markedly suppressed replication of CCR5-tropic HIV-1 strains in blocks of human lymphoid tissue infected ex vivo. Moreover, endogenous MIP-1alpha, MIP-1beta, and RANTES were upregulated in tissues infected ex vivo with CXC chemokine receptor 4-tropic but not CCR5-tropic HIV-1. Such an upregulation may contribute to the virus phenotype shift in the course of HIV disease in vivo.
Assuntos
Quimiocinas CC/farmacologia , HIV-1/efeitos dos fármacos , Tecido Linfoide/virologia , Receptores CCR5/efeitos dos fármacos , Quimiocina CCL3 , Quimiocina CCL4 , Quimiocina CCL5/farmacologia , Técnicas de Cultura/métodos , Humanos , Linfonodos/virologia , Proteínas Inflamatórias de Macrófagos/farmacologia , Tonsila Palatina/virologia , Receptores CXCR4/efeitos dos fármacosRESUMO
Many HIV-1 isolates at the late stage of disease are capable of using both CXCR4 and CCR5 in transfected cell lines, and are thus termed dual-tropic. Here we asked whether these dual-tropic variants also use both coreceptors for productive infection in a natural human lymphoid tissue microenvironment, and whether use of a particular coreceptor is associated with viral cytopathicity. We used 3 cloned dual-tropic HIV-1 variants, 89.6 and its chimeras 89-v345.SF and 89-v345.FL, which use both CCR5 and CXCR4 in transfected cell lines. In human lymphoid tissue ex vivo, one variant preferentially used CCR5, another preferentially used CXCR4, and a third appeared to be a true dual-tropic variant. The 2 latter variants severely depleted CD4(+) T cells, whereas cytopathicity of the virus that used CCR5 only in lymphoid tissue was mild and confined to CCR5(+)/CD4(+) T cells. Thus, (a) HIV-1 coreceptor usage in vitro cannot be unconditionally extrapolated to natural microenvironment of human lymphoid tissue; (b) dual-tropic viruses are not homogeneous in their coreceptor usage in lymphoid tissue, but probably comprise a continuum between the 2 polar variants that use CXCR4 or CCR5 exclusively; and (c) cytopathicity toward the general CD4(+) T cell population in lymphoid tissue is associated with the use of CXCR4.
Assuntos
Proteína gp120 do Envelope de HIV/metabolismo , HIV-1/fisiologia , Receptores CCR5/metabolismo , Receptores CXCR4/metabolismo , Receptores de HIV/metabolismo , Fármacos Anti-HIV/farmacologia , Benzilaminas , Relação CD4-CD8 , Linfócitos T CD4-Positivos/virologia , Células Cultivadas , Quimiocina CCL5/farmacologia , Quimiocinas/fisiologia , Técnicas de Cocultura , Ciclamos , Efeito Citopatogênico Viral , Genes env , Proteína do Núcleo p24 do HIV/biossíntese , HIV-1/classificação , HIV-1/genética , HIV-1/patogenicidade , Compostos Heterocíclicos/farmacologia , Humanos , Ativação Linfocitária , Substâncias Macromoleculares , Macrófagos/virologia , Fusão de Membrana , Modelos Biológicos , Especificidade de Órgãos , Tonsila Palatina/citologia , Tonsila Palatina/virologia , Receptores CCR5/efeitos dos fármacos , Receptores CXCR4/efeitos dos fármacos , Subpopulações de Linfócitos T/virologia , Transfecção , VirulênciaRESUMO
Rhesus monkey embryonic stem cells (ESCs) (R366.4), cultured on a three-dimensional (3D) collagen matrix with or without human neonatal foreskin fibroblasts (HPI.1) as feeder cells, or embedded in the collagen matrix, formed complex tubular or spherical gland-like structures and differentiated into phenotypes characteristic of neural, epithelial and endothelial lineages. Here, we analysed the production of endogenous extracellular matrix (ECM) proteins, cell-cell adhesion molecules, cell-surface receptors, lectins and their glycoligands, by differentiating ESCs, forming a micro-environment, a niche, able to positively influence cell behaviour. The expression of some of these molecules was modulated by HPI.1 cells while others were unaffected. We hypothesized that both soluble factors and the niche itself were critical in directing growth and/or differentiation of ESCs in this 3D environment. Creating such an appropriate experimental 3D micro-environment, further modified by ESCs and modulated by exogenous soluble factors, may constitute a template for adequate culture systems in developmental biology studies concerning differentiation of stem cells.
Assuntos
Diferenciação Celular , Embrião de Mamíferos/citologia , Células-Tronco/citologia , Animais , Adesão Celular , Embrião de Mamíferos/metabolismo , Proteínas da Matriz Extracelular/metabolismo , Macaca mulatta , Células-Tronco/metabolismoRESUMO
The relationship between acute coronary syndrome (ACS) and local and systemic inflammation, including accumulation of macrophages in atherosclerotic plaques and upregulation of blood cytokines (e.g., C-reactive protein (CRP)), has been known for more than 100 years. The atherosclerosis-associated inflammatory response has been traditionally considered as an immune system reaction to low-density lipoproteins. At the same time, some data have indicated a potential involvement of cytomegalovirus (CMV) in the activation and progression of atherosclerosis-associated inflammation, leading to ACS. However, these data have been tangential and mainly concerned the relationship between a coronary artery disease (CAD) prognosis and the anti-CMV antibody titer. We assumed that ACS might be associated with CMV reactivation and virus release into the bloodstream. The study's aim was to test this assumption through a comparison of the plasma CMV DNA level in patients with various CAD forms and in healthy subjects. To our knowledge, no similar research has been undertaken yet. A total of 150 subjects (97 CAD patients and 53 healthy subjects) were examined. Real- time polymerase chain reaction (RT-PCR) was used to determine the number of plasma CMV DNA copies. We demonstrated that the number of plasma CMV genome copies in ACS patients was significantly higher than that in healthy subjects (p = 0.01). The CMV genome copy number was correlated with the plasma CRP level (p = 0.002). These findings indicate a potential relationship between CMV activation and atherosclerosis exacerbation that, in turn, leads to the development of unstable angina and acute myocardial infarction. Monitoring of the CMV plasma level in CAD patients may be helpful in the development of new therapeutic approaches to coronary atherosclerosis treatment.
RESUMO
The pH dependence of spreading of normal mouse embryo fibroblasts was investigated. It was shown that, in contrast to DNA synthesis, cell spreading did not depend on intracellular pH in the same pH range. Serum growth factors had no influence on intracellular pH in the suspended cells. Spreading of the fibroblasts on poly-L-lysine-coated coverslips in a serum-free medium did not alter intracellular pH. Cytoplasm alkalynization accompanying the fibroblasts spreading in a medium with serum is suggested to be due to the effect of serum growth factors on the spread cells. The inhibitor of the Na+ H(+)-antiporter, MIBA, and the inhibitor of PKC, staurosporin, as well as the PMA-induced cell depletion of PKC prevented pH increase, but had no effect on the spreading itself. It is concluded that the pH increase observed during fibroblasts spreading in a serum-containing medium is not required for the spreading itself being due to the activation of both the Na+/H(+)-antiporter and PKC.