1,721,966 research outputs found
Tests for mitochondrial function and DNA: potentials and pitfalls
No full textIn the past few years, mitochondria have been carefully studied to ascertain whether and how in patients affected by HIV antiretroviral therapy is able to alter their functionality and exert a toxic effect on immune cells, as well as on cells present in other districts. Recent findings. A variety of in-vivo and ex-vivo models have been developed to investigate the functionality of mitochondria and DNA during a variety of physiopathological situations, including HIV infection and its treatment. Numerous technologies are available to study at the single-cell or at the single-organelle level a variety of parameters, such as membrane potential, the activity of respiratory chain enzymes, and DNA content or its sequence. As far as in-vitro studies are concerned, a substantial homogeneity of data exists, and several changes in different mitochondrial parameters have been described that depend upon the drug used, the cell model and the parameter investigated. On the other hand, different results have been reported on biological material collected from HIV-positive patients and immediately analysed. Ex-vivo studies showed that changes in mitochondrial DNA content or in the functionality of the organelle exist in some tissues or cells, but not in others. Summary. One of the possible causes of the discrepancies is the technologies used to investigate mitochondria, and this paper summarizes some of the pros and cons of the main methods used to study mitochondrial function or DNA
Discontinuation of maintenance therapy for cryptococcal meningitis in HIV-1-infected persons receiving highly active antiretroviral therapy
No full textBackground. Little is known on whether HIV-infected persons with cryptococcal meningitis can discontinue maintenance therapy following HAART-induced immune-reconstitution. The present study is a longitudinal multicentre observational study which aims to determine the incidence of relapses of cryptococcal meningitis among persons undergoing HAART. Methods. The study was conducted by reviewing the clinical charts of HIV-positive adults who had ever attended, as consecutive outpatients, 10 hospital-based infectious-disease clinics located throughout Italy. We included all of the persons who had recovered from at least one episode of cryptococcal meningitis, and who were currently undergoing HAART. The study group consisted of those persons who had discontinued maintenance therapy for cryptococcal meningitis; the, control group consisted of those persons who were still undergoing maintenance therapy. Of the 45 study participants, 24 had discontinued maintenance therapy and 21 had continued. At the time of discontinuation, for the discontinuing participants, the mean CD4 cell count was 113.5 cells/mL, although 12 (50.0%) of them had less than 100 cells/mL; the mean plasma viral load was 2.48 log10 copies/mL; and 12 of them (50.0%) were seropositive for cryptococcal antigen. Results. At the end of the observation period, for the discontinuing participants, the mean CD4 count was 330 cells/mL (compared to 240 cells/mL for the continuing participants); the mean plasma viral load was 2.34 log10 copies/mL (compared to <1.90 log10 copies/mL for the continuing participants); and 2 of the discontinuing participants were seropositive for cryptococcal antigen (compared to 13 continuing participants) (p<0.01). After a mean observation time of 27.5 months for the discontinuing participants (57.9 person-years), no relapse of cryptococcal meningitis was observed or even suspected. Conclusions. This study suggests that persons receiving HAART could consider safety discontinuing maintenance therapy for cryptococcal meningitis, as has been previously described for other opportunistic infections
Senescence and immune system: The example of centenarians
No full textHealthy centenarians are the best example of successful ageing, as they have escaped the major age-associated diseases, and most of them are in good mental and physical condition. In this review, it is discussed how the study of their immune systems reveals that several immune parameters are still well conserved, suggesting that a complex remodelling of most immune parameters occurs with age, rather than a unidirectional deterioration
Erratum: ACTH-like molecules in gastropod molluscs: A possible role in ancestral immune response and stress (Proceedings of the Royal Society of London - Biological Sciences (1991) B 245 (215-218))
No full textKinetic control in healthy volunteers of low molecular weight heparin antithrombotic activity
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Exposure to low-frequency pulsed electromagnetic fields increases mitogen- induced lymphocyte proliferation in Down’s syndrome
No full textWe previously reported that exposure of human mitogen-stimulated peripheral blood lymphocytes (PBL) to extremely low frequency pulsed electromagnetic fields (PEMFs) could restore the defective proliferative capability of PBL from aged subjects. The effects of exposure to PEMFs were studied in PBL from 25 patients with Down’s syndrome (DS), a syndrome of premature aging characterized by precocious immune system derangement, including age-related defective PBL proliferative capability. PBL were stimulated with different doses of phytohemagglutinin, and cell proliferation was assessed by measuring the incorporation of tritiated thymidine. After PEMF-exposure, a significant increase in cell proliferation was observed in cells from DS children and young adults, but it was much more evident in PBL from relatively aged DS patients. The age-related effect of PEMFs on DS lymphocytes demonstrates that age must be considered a major variable when studies on DS are performed, and confirms that DS must be regarded as a syndrome of accelerated aging. (Aging 3: 241–246, 1991) © 1991, Editrice Kurtis s.r.l.. All rights reserved
Flow cytometric analysis of mitochondrial membrane potential using JC-1
No full textChanges in membrane potential have long been known to represent early activation events. This unit presents very recent developments in both fluorescent probes and functional applications and demonstrates the use of the JC-1 probe for measuring mitochondrial membrane potential by flow cytometry. A valuable component of this measurement system is the possibility of making quantitative measurements of changes in membrane potential
Caloric restriction modulates aging rate and sensitivity to oxygen free radical damage in rats
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