Disabil Rehabil Assist Technol
May 2018
Purpose: The aim of this review is to analyze haptic sensory substitution technologies for deaf, blind and deaf-blind individuals.
Method: The literature search has been performed in Scopus, PubMed and Google Scholar databases using selected keywords, analyzing studies from 1960s to present. Search on databases for scientific publications has been accompanied by web search for commercial devices.
The integration of polymeric actuators in haptic displays is widespread nowadays, especially in virtual reality and rehabilitation applications. However, we are still far from optimizing the transducer ability in conveying sensory information. Here, we present a vibrotactile actuator characterized by a piezoelectric disk embedded in a polydimethylsiloxane (PDMS) shell.
View Article and Find Full Text PDFDigestive diseases are a major burden for society and healthcare systems, and with an aging population, the importance of their effective management will become critical. Healthcare systems worldwide already struggle to insure quality and affordability of healthcare delivery and this will be a significant challenge in the midterm future. Wireless capsule endoscopy (WCE), introduced in 2000 by Given Imaging Ltd.
View Article and Find Full Text PDFThis paper reviews the state of the art in piezoelectric energy harvesting. It presents the basics of piezoelectricity and discusses materials choice. The work places emphasis on material operating modes and device configurations, from resonant to non-resonant devices and also to rotational solutions.
View Article and Find Full Text PDFObjectives: (i) To generate a new heterodinucleotide (3TCpPMPA) comprising the drugs lamivudine and tenofovir which have been shown to act synergistically and (ii) to protect macrophages from 'de novo' HIV-1-infection through its administration.
Methods: 3TCpPMPA was obtained by coupling the morpholidate derivative of tenofovir with the mono n-tri-butylammonium salt of lamivudine 5'-monophosphate. Stability and metabolism were evaluated in vitro and in vivo in mice.
Objectives: The aim of this study was to investigate the development and progression of phenotypic resistance to the HIV-1-reverse transcriptase (RT) inhibitor lamivudine, and genotypic variations of HIV-1-RT occurring under lamivudine treatment in HIV-1-infected human primary monocytes-macrophages (M/M).
Methods: Cellular passages in the presence of lamivudine were performed every 2 weeks by transferring supernatants of infected M/M to fresh M/M. A fitness assay using wild-type virus and a lamivudine-resistant HIV-1 virus (harbouring the M184V RT mutation) was performed in peripheral blood mononuclear cells.
Given the important role of macrophages in various disorders, the transient and organ specific suppression of their functions may benefit some patients. Until now, liposome-encapsulated bisphosphonate clodronate has been extensively proposed to this end. In this paper, we demonstrate that erythrocytes loaded with clodronate can also be effective in macrophage depletion.
View Article and Find Full Text PDFCurr Top Med Chem
June 2004
Macrophages (M/M) are identified as the second cellular target of HIV and a crucial virus reservoir. M/M are persistently infected cells and not susceptible to the HIV cytophatic effects typical of infected CD4+ T-lymphocytes. HIV replication in M/M is a crucial pathogenetic event during the whole course of the disease.
View Article and Find Full Text PDFThe ability of human immunodeficiency virus (HIV) strains to replicate in human target cells represents a major driving force of the progression of the disease. Despite antiretroviral treatment, HIV overcomes drug pressure by adding new (compensatory) mutations, appearing in a specific and sequential order, that modulate its replication capacity and favour viral escape. In the case of M184V (a mutation involving the catalytic site of HIV reverse transcriptase), no pathways of viral escape have been defined so far; it is thus conceivable that the mutated virus maintains a relatively low replicative capacity.
View Article and Find Full Text PDFObjective of the present study was then to assess the antiviral activity of the protease inhibitor amprenavir in macrophages (M/M), and to compare it with its efficacy in peripheral blood lymphocytes (PBL). M/M were obtained from blood of sero-negative healthy donors and infected with M-tropic HIV-1 strain (HIV-1(Ba-L)). The stabilized infection was assessed by monitoring the HIV-1 p24 gag antigen production in the supernatants of M/M cultures.
View Article and Find Full Text PDFThe role of macrophages in the pathogenesis and progression of human immunodeficiency virus (HIV)-related infection is substantiated by in vitro and in vivo evidence. The unique ability to survive HIV infection and produce viral particles for long periods is postulated. Detailed studies of this phenomenon are lacking.
View Article and Find Full Text PDFCells of macrophage lineage represent a key target of human immunodeficiency virus (HIV) in addition to CD4-lymphocytes. The absolute number of infected macrophages in the body is relatively low compared to CD4-lymphocytes. Nevertheless, the peculiar dynamics of HIV replication in macrophages, their long-term survival after HIV infection, and their ability to spread virus particles to bystander CD4-lymphocytes, make evident their substantial contribution to the pathogenesis of HIV infection.
View Article and Find Full Text PDFJ Biol Regul Homeost Agents
March 2002
The replication of Human Immunodeficiency Virus (HIV) in cells of macrophage lineage represents a key pathogenetic event of the neurological damages typically found during the course of this disease. Macrophages are persistently infected cells and thus not susceptible to the cytophatic effect typical of infected activated CD4-lymphocytes. The resistance of macrophages to HIV infection is at least in part mediated by the autocrine production of the nerve growth factor (NGF), a neurokine able to sustain the survival of some cells of bone marrow origin, including monocyte-derived macrophages.
View Article and Find Full Text PDFInfection of macrophages (M/M) by human immunodeficiency virus (HIV) is a main pathogenetic event leading to neuronal dysfunction and death in patients with AIDS dementia complex. Alteration of viability of neurons and astrocytes occurs in vivo even without their infection, thus it is conceivable that HIV-infected M/M may affect viability of such cells even without direct infection. To assess this hypothesis, we studied the effects of HIV-infected M/M on an astrocytic cell-line lacking CD4-receptor expression.
View Article and Find Full Text PDFJ Biol Regul Homeost Agents
June 2000
The understanding of viral dynamics and appearance of mutations during primary infection could be useful for the design of an efficient therapy. For this reason a cohort of samples from naive primary patients was examined. The results pointed out that only a few secondary mutations in protease gene (having no effect on resistance) were found, while a single mutation conferring resistance to non-nucleosides inhibitors of reverse transcriptase was found both in plasma and cerebrospinal fluid of a patient.
View Article and Find Full Text PDFAntimicrob Agents Chemother
January 2000
The anti-human immunodeficiency virus (HIV) activity of aryloxyphosphoramidate protides of a number of anti-HIV nucleoside analogues was assessed in resting primary monocyte-macrophages (M/M). While 2',3'-dideoxythymidine (d4T), 2',3'-dideoxyadenosine (ddA), and 2',3'-dideoxy-2',3'-didehydroadenosine (d4A) protides showed an anti-HIV activity that was 25- to 625-fold greater than the parent nucleotides d4T, ddA, and d4A, respectively, other aryloxyphosphoramidate protides showed similar or even lower anti-HIV activities than their parent compounds. This variable anti-HIV effect is most likely related to the different dynamics of intracellular nucleoside monophosphate release from the protides.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
November 1999
Nerve growth factor (NGF) is a neurotrophin with the ability to exert specific effects on cells of the immune system. Human monocytes/macrophages (M/M) infected in vitro with HIV type 1 (HIV-1) are able to produce substantial levels of NGF that are associated with enhanced expression of the high-affinity NGF receptor (p140 trkA) on the M/M surface. Treatment of HIV-infected human M/M with anti-NGF Ab blocking the biological activity of NGF leads to a marked decrease of the expression of p140 trkA high-affinity receptor, a concomitant increased expression of p75(NTR) low-affinity receptor for NGF, and the occurrence of apoptotic death of M/M.
View Article and Find Full Text PDFThe activity of three human immunodeficiency virus (HIV) protease inhibitors was investigated in human primary monocytes/macrophages (M/M) chronically infected by HIV-1. Saquinavir, KNI-272, and ritonavir inhibited the replication of HIV-1 in vitro, with EC50s of approximately 0.5-3.
View Article and Find Full Text PDFJ Biol Regul Homeost Agents
October 1998
Macrophages are widely recognized as the second major target of HIV in the body. The cellular characteristics of such resting cells markedly affect the dynamics of virus lifecycle, that is slower but far more prolonged that in lymphocytes. In addition, the limited concentrations of endogenous nucleotide pools in macrophages downregulate the enzymatic activity of reverse transcriptase.
View Article and Find Full Text PDFPurpose: To assess the comparative efficacy of drugs inhibitors of human immunodeficiency virus (HIV) in human macrophages and lymphocytes, and to correlate the results with the clinical outcome.
Materials And Methods: Human primary macrophages and lymphocytes were infected with HIV in the presence of the following HIV inhibitors, all currently in clinical use: zidovudine, stavudine, zalcitabine, didanosine, lamivudine, PMEA, PMPA (all inhibitors of HIV reverse transcriptase), saquinavir and U-75875 (inhibitors of HIV protease).
Results: All reverse transcriptase inhibitors tested showed a markedly higher antiviral activity in macrophages than in lymphocytes.
Several anti-HIV drugs acting on different steps of virus replication were tested in our experimental model of primary monocyte/macrophages; the results were compared with the activity found in lymphocytes. Nucleoside analogues (AZT, ddI, ddC, d4T, PMEA, 3TC etc.) show greater activity in macrophages (M/M) than in lymphocytes.
View Article and Find Full Text PDFRed blood cells (RBC) may act as selective carriers of drugs to macrophages, an important reservoir of viruses such as human immunodeficiency virus (HIV) and herpes simplex virus type 1 (HSV-1). We therefore assessed the incorporation of 9-(2-phosphonylmethoxyethyl)adenine (PMEA), a potent inhibitor of HIV and HSV-1) into RBC, its delivery to macrophages and its activity against HIV or HSV-1. Loading of PMEA in artificially aged opsonized RBC affords significant levels of intracellular PMEA.
View Article and Find Full Text PDFJ Biol Regul Homeost Agents
January 1998
Therapeutical strategies aimed to the maximal inhibition (if not the eradication) of infection by human immunodeficiency virus should take into account the issue of the viral reservoir in the body. Recent data clearly show that latently infected lymphocytes represent a minimal part of the viral reservoir, while the majority of these cells are macrophages (variably differentiated) scattered in the tissues and lymph nodes. Immunologically-sequestred areas, such as the central nervous system, are particularly relevant in view of the different concentrations of antiviral drugs achieved in the organs.
View Article and Find Full Text PDFThe efficacy of 9-(2-phosphonylmethoxyethyl)adenine (PMEA) against the replication of human immunodeficiency virus (HIV) and herpes simplex virus type 1 (HSV-1) and its cellular metabolism were investigated in human primary macrophages from seronegative donors. PMEA potently inhibited the replication of both HIV and HSV-1 in macrophages, with similar EC50 values (0.025 and 0.
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