Continued Presence (continued + presence)

Distribution by Scientific Domains


Selected Abstracts


Myosin localization during meiosis I of crane-fly spermatocytes gives indications about its role in division

CYTOSKELETON, Issue 2 2003
Rosalind V. Silverman-Gavrila
Abstract We showed previously that in crane-fly spermatocytes myosin is required for tubulin flux [Silverman-Gavrila and Forer, 2000a: J Cell Sci 113:597,609], and for normal anaphase chromosome movement and contractile ring contraction [Silverman-Gavrila and Forer, 2001: Cell Motil Cytoskeleton 50:180,197]. Neither the identity nor the distribution of myosin(s) were known. In the present work, we used immunofluorescence and confocal microscopy to study myosin during meiosis-I of crane-fly spermatocytes compared to tubulin, actin, and skeletor, a spindle matrix protein, in order to further understand how myosin might function during cell division. Antibodies to myosin II regulatory light chain and myosin II heavy chain gave similar staining patterns, both dependent on stage: myosin is associated with nuclei, asters, centrosomes, chromosomes, spindle microtubules, midbody microtubules, and contractile rings. Myosin and actin colocalization along kinetochore fibers from prometaphase to anaphase are consistent with suggestions that acto-myosin forces in these stages propel kinetochore fibres poleward and trigger tubulin flux in kinetochore fibres, contributing in this way to poleward chromosome movement. Myosin and actin colocalization at the cell equator in cytokinesis, similar to studies in other cells [e.g., Fujiwara and Pollard, 1978: J Cell Biol 77:182,195], supports a role of actin-myosin interactions in contractile ring function. Myosin and skeletor colocalization in prometaphase spindles is consistent with a role of these proteins in spindle formation. After microtubules or actin were disrupted, myosin remained in spindles and contractile rings, suggesting that the presence of myosin in these structures does not require the continued presence of microtubules or actin. BDM (2,3 butanedione, 2 monoxime) treatment that inhibits chromosome movement and cytokinesis also altered myosin distributions in anaphase spindles and contractile rings, consistent with the physiological effects, suggesting also that myosin needs to be active in order to be properly distributed. Cell Motil. Cytoskeleton 55:97,113, 2003. © 2003 Wiley-Liss, Inc. [source]


Organizational Challenges and Strategic Responses of Retail TNCs in Post-WTO-Entry China

ECONOMIC GEOGRAPHY, Issue 1 2009
Wance Tacconelli
abstract In the context of a market characterized by the enduring legacy of socialism through governmental ownership of retail businesses, the continued presence of domestic retailers, and increasing levels of competition, this article examines the organizational challenges faced by, and the strategic responses adopted by, a group of leading food and general merchandise retail transnational corporations (TNCs) in developing networks of stores in the post-WTO-entry Chinese market. On the basis of extensive interview-based fieldwork conducted in China from 2006 to 2008, the article details the attempts of these retail TNCs to embed their operations in Chinese logistics and supply networks, real estate markets, and consumer cultures,three dimensions that are fundamental to the achievement of market competitiveness by the retail TNCs. The article illustrates how this process of territorial embeddedness presents major challenges for the retail TNCs and how their strategic responses vary substantially, indicating different routes to the achievement of organizational legitimacy in China. The article concludes by offering an analysis of the various strategic responses of the retail TNCs and by suggesting some future research propositions on the globalization of the retail industry. [source]


Glycolipid-activated NKT cells support the induction of persistent plasma cell responses and antibody titers

EUROPEAN JOURNAL OF IMMUNOLOGY, Issue 4 2008
Scott Devera
Abstract NKT cell activation with CD1d-binding glycolipid ,-galactosylceramide (,-GC) enhances antibody responses to co-administered T-dependent antigen. The efficacy of ,-GC relative to other CD1d-binding glycolipids and adjuvants is not known. There is little information on how NKT cells affect antibody production beyond initial booster-stimulated recall responses. We therefore tested the hypothesis that ,-GC stimulates induction of plasma cells and antibody responses as effectively as Th1- and Th2-skewing variants of ,-GC and several other adjuvants. C57BL/6 and CD1d,/, mice were immunized with nitrophenol-conjugated keyhole limpet hemocyanin (NP-KLH) plus ,-GC or NP-KLH plus adjuvants before administration of an NP-KLH booster and assessing antibody responses and plasma cell frequency. ,-GC boosted long-term antibody responses as efficiently as all other agents tested and induced plasma cells that were detected in bone marrow 13,weeks after immunization. We then determined whether NKT cells were required in the presence of other adjuvants. CD1d,/, mice had a reduced induction of plasma cells in response to NP-KLH/Alum as compared to C57BL/6 mice. However, NKT cells were not required for the continued presence of those cells that were induced. Although NKT cells are capable of inducing persistent plasma cell responses, they may not play a major role in supporting longevity post-induction. [source]


An FGF-responsive astrocyte precursor isolated from the neonatal forebrain

GLIA, Issue 6 2009
Grace Lin
Abstract Gliogenesis in the mammalian CNS continues after birth, with astrocytes being generated well into the first two postnatal weeks. In this study, we have isolated an A2B5+ astrocyte precursor (APC) from the postnatal rat forebrain, which is capable of differentiating into mature astrocytes in serum-free medium without further trophic support. Exposure to basic fibroblast growth factor (bFGF) selectively induces the APCs to proliferate, forming clusters of vimentin+ cells, which, within 2 weeks, differentiate into GFAP+ astrocytes. While bFGF functions as a potent mitogen, neither is it necessary to induce or maintain astrocyte differentiation, nor is it capable of maintaining the precursors in an immature, proliferative state. APCs exit the cell cycle and differentiate, even in the continued presence of fibroblast growth factor alone or in combination with other mitogenic factors such as platelet-derived growth factor. Under the culture conditions used, it was not possible to cause the astrocytes to re-enter cell cycle. After transplantation into the neonatal forebrain, APCs differentiated exclusively into astrocytes, regardless of brain region. Initially distributed widely within the forebrain, the precursors are most greatly concentrated within the subventricular zone (SVZ) and subcortical white matter, where they are maintained throughout postnatal development. APCs can be isolated from the SVZ and white matter of animals as late as 4 weeks after birth. © 2008 Wiley-Liss, Inc. [source]


Astrocyte-derived factors modulate the inhibitory effect of ethanol on dendritic development

GLIA, Issue 4 2002
Penelope A. Yanni
Abstract Numerous studies in vivo and in vitro have demonstrated that ethanol disrupts neuromorphogenesis. However, it has not been determined what role, if any, is played by non-neuronal cells in mediating this effect. We recently reported that ethanol inhibits dendritic development in low-density cultures of fetal rat hippocampal pyramidal neurons (Yanni and Lindsley, 2000: Dev Brain Res 120:233,243). In this culture system, cortical astrocytes precondition neuronal culture media for 2 days before the addition of neurons, which then develop on a separate substrate in coculture with the astrocytes. To determine whether astrocyte response to ethanol mediates the effects of ethanol on neurons, the present study compared dendritic development of neurons after 6 days in medium containing 400 mg/dl ethanol in coculture with live astrocytes and in conditioned medium from astrocytes that were never exposed to ethanol. The same experiment was also performed with and without ethanol present during astrocyte preconditioning of the medium. The effects of ethanol differed depending on when it was added to the cultures relative to addition of newly dissociated neurons. However, the effects of ethanol were not related to whether neurons were cocultured with live astrocytes. When astrocytes preconditioned the medium normally, ethanol added at plating inhibited dendritic development of neurons regardless of whether they were maintained in coculture with live astrocytes or in conditioned medium. In surprising contrast, the presence of ethanol during astrocyte preconditioning of the media had a growth promoting effect on subsequent dendrite development despite the continued presence of ethanol in the medium. Thus, astrocytes release soluble factors in response to ethanol that can protect neurons from the inhibitory effects of ethanol on dendritic growth, but the timing of neuronal exposure to these factors, or their concentration, may influence their activity. GLIA 38:292,302, 2002. © 2002 Wiley-Liss, Inc. [source]


The development of effector and memory T cells in cutaneous leishmaniasis: the implications for vaccine development

IMMUNOLOGICAL REVIEWS, Issue 1 2004
Phillip Scott
Summary:,Leishmania major infections induce the development of a CD4+ T-helper 1 (Th1) response that not only controls the primary infection but also results in life-long immunity to reinfection. How that immunity is maintained is unknown, although because of the existence of infection-induced immunity, there has been an assumption that the development of a vaccine against leishmaniasis would be relatively easy. This has turned out not to be the case. One problem has been the finding that a large part of the immunity induced by a primary infection depends upon the presence of persistent parasites. Nevertheless, there are ample situations where immunologic memory persists without the continued presence of antigen, providing the prospect that a non-live vaccine for leishmaniasis can be developed. To do so will require an understanding of the events involved in the development of an effective protective T-cell response and, more importantly, an understanding of how to maintain that response. Here, we review work from our laboratory, describing how Th1 cells develop in L. major -infected mice, the nature of the memory T cells that provide protection to reinfection, and how that information may be utilized in the development of vaccines. [source]


Disruption of an exotic mutualism can improve management of an invasive plant: varroa mite, honeybees and biological control of Scotch broom Cytisus scoparius in New Zealand

JOURNAL OF APPLIED ECOLOGY, Issue 2 2010
Quentin Paynter
Summary 1.,A seed-feeding biocontrol agent Bruchidius villosus was released in New Zealand (NZ) to control the invasive European shrub, broom Cytisus scoparius, in 1988 but it was subsequently considered unable to destroy sufficient seed to suppress broom populations. We hypothesized that an invasive mite Varroa destructor, which has caused honeybee decline in NZ, may cause pollinator limitation, so that the additional impact of B. villosus might now reach thresholds for population suppression. 2.,We performed manipulative pollination treatments and broad-scale surveys of pollination, seed rain and seed destruction by B. villosus to investigate how pollinator limitation and biocontrol interact throughout the NZ range of broom. 3.,The effect of reduced pollination in combination with seed-destruction was explored using a population model parameterized for NZ populations. 4.,Broom seed rain ranged from 59 to 21 416 seeds m,2 from 2004 to 2008, and was closely correlated with visitation frequency of honeybees and bumblebees. Infestation of broom seeds by B. villosus is expected to eventually reach 73% (the average rate observed at the localities adjacent to early release sites). 5.,The model demonstrated that 73% seed destruction, combined with an absence of honeybee pollination, could cause broom extinction at many sites and, where broom persists, reduce the intensity of treatment required to control broom by conventional means. 6.,Nevertheless, seed rain was predicted to be sufficient to maintain broom invasions over many sites in NZ, even in the presence of the varroa mite and B. villosus, largely due to the continued presence of commercial beehives that are treated for varroa mite infestation. 7.,Synthesis and applications. Reduced pollination through absence of honeybees can reduce broom seed set to levels at which biocontrol can be more effective. To capitalize on the impact of the varroa mite on feral honeybees, improved management of commercial beehives (for example, withdrawal of licences for beekeepers to locate hives on Department of Conservation land) could be used as part of a successful integrated broom management programme at many sites in NZ. [source]


Effect of time of year on the development of immature stages of the Large Pine Weevil (Hylobius abietis L.) in stumps of Sitka spruce (Picea sitchensis Carr.) and influence of felling date on their growth, density and distribution

JOURNAL OF APPLIED ENTOMOLOGY, Issue 3 2004
R. Moore
Abstract:, The time of year and time of felling of a commercial stand of Sitka spruce (Picea sitchensis Carr.) were both shown to influence the spatial distribution and development of the large pine weevil, Hylobius abietis (L). Stump and root systems were excavated over a 5-month period in 1997, between 18 and 27 months after felling, and all immature H. abietis removed. On a site with a 6-month spread of felling dates in 1995, mean larval weights in 1997 were higher in stumps from earlier fellings, but H. abietis numbers were higher in stumps from later fellings. This appeared to be due to the continued presence of older, heavier larvae, laid as eggs in 1995, in stumps from earlier fellings, combined with a greater concentration of oviposition having occurred in 1996 in the fresher stumps of later fellings. Pupae were first found in excavated stumps on 12 June 1997 and adults on 29 July 1997. Emergence of the ,new generation' of adult weevils commenced on 7 August 1997. On average, 25% of H. abietis adults emerged in autumn 1997, 41% in 1998 and 34% in 1999. First emergence (1997) was proportionally higher in the areas felled earlier in 1995 than those felled later that year. However, the opposite was found for third emergence (1999) where emergence was greater for stumps created later in 1995. Larger stumps contained greater densities of H. abietis. Total ,potential' emergence was estimated to be between 46400 and 170825 H. abietis/ha. However, emergence traps indicated that only 40,80% managed to complete their development and emerge successfully. It is suggested that within-season felling date may be one of the most important factors affecting larval development, distribution and abundance; as well as subsequent damage levels associated with adult feeding. Consequently, knowledge of felling date could be crucial to developing methods of integrated forest management for this major forest pest. [source]


Behavior of Nonselective Cation Channels and Large-Conductance Ca2+ -Activated K+ Channels Induced by Dynamic Changes in Membrane Stretch in Cultured Smooth Muscle Cells of Human Coronary Artery

JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 1 2003
PH.D., SHENG-NAN WU M.D.
Stretch-Activated Ion Channels. Introduction: The effects of membrane stretch on ion channels were investigated in cultured smooth muscle cells of human coronary artery. Methods and Results: In the cell-attached configuration, membrane stretch with negative pressure induced two types of stretch-activated (SA) ion channels: a nonselective cation channel and a large-conductance Ca2+ -activated K+ (BKCa) channel. The single-channel conductances of SA cation and BKCa channels were 26 and 203 pS, respectively. To elucidate the mechanism of activation of these SA channels and to minimize mechanical disruption, a sinusoidal change in pipette pressure was applied to the on-cell membrane patch. During dynamic changes in pipette pressure, increases in SA cation channel activity was found to coincide with increases in BKCa channel activity. In the continued presence of cyclic stretch, the activity of SA cation channels gradually diminished. However, after termination of cyclic stretch, BKCa channel activity was greatly enhanced, but the activity of SA cation channels disappeared. Conclusion: This study is the first to demonstrate that the behavior of SA cation and BKCa channels in coronary smooth muscle cells is differentially susceptible to dynamic changes in membrane tension. [source]


Fibroblast growth factor-9 inhibits astrocyte differentiation of adult mouse neural progenitor cells

JOURNAL OF NEUROSCIENCE RESEARCH, Issue 10 2009
Maggie Lum
Abstract Fibroblast growth factor-9 (FGF9) is expressed in the CNS and is reported to be a mitogen for glial cells, to promote neuronal survival, and to retard oligodendrocyte differentiation. Here we examined the effects of FGF9 on the differentiation, survival, and proliferation of adult neural progenitor cells derived from the adult mouse subventricular zone. FGF9 by itself induced neurosphere proliferation, but its effects were modest compared with those of epidermal growth factor and FGF2. When neurospheres were dissociated and plated for differentiation, FGF9 increased total cell number over time in a dose-dependent manner. Ki67 immunostaining and bromodeoxyuridine incorporation indicated that this was at least partially due to the continued presence of proliferative nestin-positive neural progenitor cells and ,III tubulin-positive neuronal precursors. FGF9 also promoted cell survival as indicated by a decreased number of TUNEL-positive cells over time. Assessment of differentiation showed that FGF9 increased neuron generation that reflected the increase in total cell number; however, the percentage of progenitor cells differentiating into neurons was slightly decreased. FGF9 had a modest effect on oligodendrocyte generation, although it appeared to slow the maturation of oligodenrocytes at higher concentrations. The most marked effect on differentiation was an almost total lack of glial fibrillary acidic protein (GFAP)-positive astrocytes up to 7 days following FGF9 addition, indicating that astrocyte differentiation was strongly inhibited. Total inhibition required prolonged treatment, although a 1-hr pulse was sufficient for partial inhibition, and bone morphogenic protein-4 could partially overcome the FGF9 inhibition of astrocyte differentiation. FGF9 therefore has multiple effects on adult neural precursor cell function, enhancing neuronal precursor proliferation and specifically inhibiting GFAP expression. © 2009 Wiley-Liss, Inc. [source]


Molecular Evidence for Persistence of Anaplasma phagocytophilum in the Absence of Clinical Abnormalities in Horses after Recovery from Acute Experimental Infection

JOURNAL OF VETERINARY INTERNAL MEDICINE, Issue 3 2009
P. Franzén
Background: Anaplasma phagocytophilum infects several mammalian species, and can persist in sheep, dogs, and calves. However, whether this organism persists in horses or induces long-term clinical abnormalities is not known. Objectives: To evaluate whether A. phagocytophilum can persist in horses and to document clinical findings for 3 months after complete recovery from acute disease. Animals: Five clinically normal adult horses that had recovered spontaneously from experimentally induced acute disease caused by a Swedish equine isolate of A. phagocytophilum. Methods: Horses were monitored for up to 129 days post inoculation (PI) by daily clinical examination and at least alternate day blood sampling for evidence of A. phagocytophilum on polymerase chain reaction (PCR) and blood smears. All horses were euthanized and underwent postmortem examination. Results: All horses were periodically PCR positive after recovery from acute infection. Before day 66 PI 2 horses were persistently PCR negative whereas 3 horses were intermittently PCR positive. Subsequently, 4 of 5 horses were intermittently PCR positive, particularly after stress mimicking interventions. One animal was positive immediately before postmortem examination. Clinical abnormalities related to persistence of anaplasma were not observed. No specific changes were found at postmortem examination, and all sampled tissues from all horses were negative on PCR for A. phagocytophilum. Conclusions and Clinical Importance: Infection with A. phagocytophilum can persist in the horse for at least 129 days. However, the continued presence of the organism is not associated with detectable clinical or pathological abnormalities. [source]


The gut, immunoregulation and micro-organisms from man's evolutionary past

NUTRITION BULLETIN, Issue 2 2010
G. A. W. Rook
Summary Man has moved rapidly from the hunter-gatherer environment to the living conditions of the rich industrialised countries. The hygiene hypothesis suggests that the resulting changed and reduced pattern of exposure to certain critical micro-organisms, mostly derived from mud, animals and faeces, has led to disordered regulation of the immune system and, hence, to increases in chronic inflammatory disorders such as allergies, inflammatory bowel diseases and autoimmunity. Epidemiology, backed up by laboratory models, indicates that the relevant organisms are those that have very long associations with the mammalian immune system, traceable back to the Palaeolithic or earlier. Often, these organisms have been present as commensals (notably in the intestinal microbiota), environmental ,pseudocommensals', sub-clinical infections or asymptomatic carrier states, and the mammalian immune system is in a state of ,evolved dependence' on their continued presence. Several of these ,Old Friends', often operating primarily in the gut, act as modulators of dendritic cells and T cells, leading to the establishment of immunoregulatory circuits. Clinical trials are in progress to test living helminths (Trichuris suis and Necator americanus) in allergies, inflammatory bowel disease and multiple sclerosis. We can anticipate rapid increases in the use of these and other organisms or their components in novel types of therapy with applications in several branches of medicine. Probiotics tested in clinical trials targeting chronic inflammatory disorders have so far given unconvincing results, but if strains for these indications are selected on the basis of their ability to induce immunoregulation, and not merely imposed by companies that have intellectual property rights, we can anticipate rapid progress. [source]


DICHOTOMY OF CORTICAL PAIN PROCESSING

PAIN MEDICINE, Issue 2 2002
Article first published online: 4 JUL 200
Jahangir Maleki, Rollin M. Gallagher, Pain Medicine and Rehabilitation Center, MCP/Hahnemann School of Medicine Introduction: Functional MRI and PET studies of cortical pain processing indicate segregated pain pathways above the thalamus. Although experimental pain may result in multiple areas of altered cortical activity, it is postulated that thalamic pain fibers known as the lateral system, projecting to sensory cortex, serve to localize pain, whereas medial pathways projecting to limbic cortex, process affective aspects of pain. Case Study: A 27 y/o female, with left upper extremity pain and severe allodynia from Complex Regional Pain Syndrome, Type I (CRPS I / RSD), after receiving intra-pleural bupivacaine blocks developed an ipsilateral focal-onset secondary generalized tonic clonic seizure. This was followed by one hour of post-ictal confusion. Simultaneously she developed a dense left-sided motor and sensory deficit (Todd's palsy) with a motor deficit resolving in one day whereas a sensory deficit lasted 2 days. Throughout the duration of the sensory deficit she denied any left arm pain, although she continued to report the same intensity of pain, but now localized to her epigastric region. Interestingly, despite the lack of sensory perception on the left side, palpation of her left arm resulted in increased epigastric pain and suffering. Discussion: This case indicates a bifurcation of the pain pathway between the thalamus and cortex. Due to focal seizure activity, the sensory cortex (i.e. lateral system) was transiently rendered dysfunctional, during which time the continued presence of pain and allodynia without appropriate localization likely resulted from pain conduction, from the thalamus to functional limbic structures such as Cingulum (i.e. via the medial fibre system). Conclusion: This case report strongly supports the hypothesis of medial and lateral pain conducting fibers branching at the level of thalamus with medial sub-serving the emotional aspects of pain by projection to limbic cortex, whereas lateral fibres project to sensory cortex, primarily serving a localizing function. [source]


Priestly Sacrifice in the Hebrew Bible: A Summary of Recent Scholarship and a Narrative Reading

RELIGION COMPASS (ELECTRONIC), Issue 1 2008
David Janzen
The field of Hebrew Bible/Old Testament has come to no consensus on the meaning of sacrifice in ancient Israel. The most influential theory of the meaning of biblical sacrifice, at least in the Priestly Writing (P) of the Pentateuch, is that of Jacob Milgrom. Milgrom argues that the purification sacrifice, as presented by P in Leviticus 1,7, is key to understanding P's sacrificial system, as its blood provided a ritual detergent on the altar for Israel's unintentional sins and impurities, thus permitting the continued presence of God in the sanctuary. Milgrom's theory has recently come under challenge, and a reading of P's narrative throughout the entire Pentateuch, and not only in Leviticus 1,7, shows that, for the Priestly Writing, sacrifice seems to draw Israel's attention to the differences between the divine and human realms, and thus points to Israel's moral failings in relationship to the divine law, as well as to the punishment Israel will suffer for this failure. [source]


Inflammatory cytokine regulation of transgene expression in human fibroblast-like synoviocytes infected with adeno-associated virus

ARTHRITIS & RHEUMATISM, Issue 7 2006
Russell S. Traister
Objective An ideal gene transfer vector for chronic inflammatory diseases such as rheumatoid arthritis (RA) would provide local transgene expression only when the disease is active. To determine whether adeno-associated virus (AAV) possesses this ability, the effects of inflammatory cytokines on transgene expression were evaluated in human RA fibroblast-like synoviocytes (FLS). Methods Human FLS were infected with AAV in the presence or absence of inflammatory cytokines or synovial fluid obtained from patients with RA. Transgene expression was monitored by either enzyme-linked immunosorbent assay or flow cytometry. Transgene messenger RNA (mRNA) was measured by real-time quantitative reverse transcription,polymerase chain reaction. Results Inflammatory cytokines increased transgene expression in FLS by up to 60-fold. Synovial fluid from patients with RA, but not from patients without arthritis, was also able to increase expression in synoviocytes. Protein expression correlated with transgene mRNA levels. The enhanced expression required the continued presence of cytokines because, upon removal, transgene expression returned to baseline levels. Expression could be repeatedly reinduced by reexposure to cytokines. The effect was not promoter specific and was demonstrated to be phosphatidylinositol 3-kinase,dependent. Conclusion These results suggest that expression of a therapeutic transgene can be controlled by the presence of inflammation following AAV gene transfer, making it an attractive vector for chronic inflammatory diseases such as RA. [source]


Immune-mediated control of Chlamydia infection

CELLULAR MICROBIOLOGY, Issue 1 2008
Nadia R. Roan
Summary Infection with the bacterium Chlamydia trachomatis can lead to a variety of diseases, including ectopic pregnancy, infertility and blindness. Exposure of the host to C. trachomatis stimulates multiple innate and adaptive immune effectors that can contribute towards controlling bacterial replication. However, these effectors are often insufficient to resolve the infection and prevent re-infection, and the continued presence of C. trachomatis within the host may induce immune effectors to chronically produce inflammatory cytokines. This may eventually lead to the tissue pathologies associated with the infection. Reducing the incidence and sequelae of infection will ultimately require the development of a C. trachomatis vaccine that can stimulate sterilizing immunity while avoiding immune-mediated pathology. [source]


Immunologic memory in cutaneous leishmaniasis

CELLULAR MICROBIOLOGY, Issue 12 2005
Phillip Scott
Summary Leishmania major infections induce solid immunity to reinfection. Experimental studies in mice indicate that the CD4+ T cells responsible for this immunity include two populations: parasite-dependent T effector cells and parasite-independent central memory T (Tcm) cells. While there currently is no vaccine for leishmaniasis, the existence of a long-lived population of Tcm cells that does not require the continued presence of live parasites suggests that a vaccine that expands these cells might be efficacious. [source]