However, the neural and molecular mechanisms involved in memory f

However, the neural and molecular mechanisms involved in memory facilitation by ICSS are not known. Here, we investigated the influence of ICSS treatment on hippocampal gene expression in order to identify potential signaling pathways and cellular processes involved in ICSS-mediated cognitive improvements. Immunohistochemistry studies demonstrated that ICSS caused a rapid induction of c-Fos expression in hippocampal cornu ammonis (CA) 3 and dentatus gyrus areas. Moreover, using microarray or quantitative real-time polymerase chain reaction (PCR) analysis, we showed that ICSS modulates the expression of 62 hippocampal genes shortly Selleckchem GSK126 after training. Most of the proteins encoded by these genes, such as calmodulin-dependent-phosphodiesterase

1 A (Pde1a), are part of signal transduction machineries or are related to antiapoptosis, as heat shock 70 kDa protein 1A (Hspa1a). Importantly, 10 of the regulated genes have been previously related with learning and memory or neural plasticity, including the cocaine and amphetamine-regulated transcript (Cart), adenylate cyclase activating polypeptide 1 (Adcyap1), serum/glucocorticoid regulated kinase (Sgk), Ret proto-oncogene (Ret), and Fos. The fact that the Fos gene was differentially expressed in our microarray experiments validated our findings from our immunohistochemical

studies mentioned above. In addition, using quantitative real-time PCR, we confirmed the observed expression https://www.selleckchem.com/products/lcl161.html changes for several of the genes identified by our microarray analyses. Our results suggest that ICSS may facilitate all learning and memory by regulation of multiple signaling pathways in the hippocampus that may promote neuroplasticity. (C) 2009 IBRO. Published by

Elsevier Ltd. All rights reserved.”
“The Picornaviridae family comprises a diverse group of small RNA viruses that cause a variety of human and animal diseases. Some of these viruses are known to induce cleavage of components of the innate immune system and to inhibit steps in the interferon pathway that lead to the production of type I interferon. There has been no study of the effect of picornaviral infection on the events that occur after interferons have been produced. To determine whether members of the Enterovirus genus can antagonize the antiviral activity of interferon-stimulated genes (ISGs), we pretreated cells with alpha interferon (IFN-alpha) and then infected the cells with poliovirus type 1, 2, or 3; enterovirus type 70; or human rhinovirus type 16. We found that these viruses were able to replicate in IFN-alpha-pretreated cells but that replication of vesicular stomatitis virus, a Rhabdovirus, and encephalomyocarditis virus (EMCV), a picornavirus of the Cardiovirus genus, was completely inhibited. Although EMCV is sensitive to IFN-alpha, coinfection of cells with poliovirus and EMCV leads to EMCV replication in IFN-alpha-pretreated cells.

On the basis of this intimate association with other cell organel

On the basis of this intimate association with other cell organelles and the morphometric analysis performed, we suggest that the mobilization of lipid bodies is likely mediated not only by glyoxysomes but also by other catabolic pathways involving the interaction of lipid bodies with either protein storage vacuoles or small Golgi vesicles.”
“Background: Limbic circuitry, especially the anterior cingulate gyrus, has been implicated in the see more pathophysiology and cognitive changes of schizophrenia. Previous diffusion tensor imaging studies have demonstrated that the integrity of the anterior cingulum (AC) is abnormal in schizophrenia. However, the relationship between the abnormal

AC tract integrity and the pathophysiology of schizophrenia has not been fully studied. Methods: We performed a voxelwise group comparison of white matter fractional ARS-1620 nmr anisotropy (FA) by using tract-based spatial statistics in 9 patients with schizophrenia and 9 matched controls. We then measured FA specifically in the AC by using a tract-specific measurement. The latency and amplitude of the mismatch negativity (MMN) were also evaluated in all subjects. Results: In patients with schizophrenia, tract-based

spatial statistics showed a reduction in FA in broad white matter areas, including the bilateral AC, compared with controls. Tract-specific measurements confirmed the specific reduction of FA in the region of the bilateral find more AC. The decreased FA in the AC was correlated with prolonged MMN latency in the patient group. Conclusion: Our study of AC structure and electrophysiological changes in schizophrenia suggest that the disruption of limbic-cortical structural networks may be part of the neural basis underlying the changes in MMN in schizophrenia. (C) 2013 S. Karger AG, Basel”
“Objective: Patients with juxtarenal, pararenal, or thoracoabdominal aneurysms require complex

surgical open repair, which is associated with increased mortality and morbidity. The “”chimney graft”" or “”snorkel”" technique has evolved as a potential alternative to fenestrated and side-branched endografts. The purpose of this study is to review all published reports on chimney graft (CG) technique involving visceral vessels and investigate the safety and efficacy of the technique.

Methods: Studies were included in the present review if visceral revascularization during endovascular treatment of aortic pathologies was achieved via a CG implantation. Reports on the chimney technique for aortic arch branches revascularization were excluded. A multiple electronic health database search was performed on all articles published until April 2011.

Results: The electronic literature search yielded 15 reports that fulfilled the inclusion criteria. A total of 93 patients (81.3% male; mean age, 71.9 +/- 0.9 years) were analyzed. In 77.

Taken together, these studies suggest that the nature of perceptu

Taken together, these studies suggest that the nature of perceptual input on which we commonly rely strongly affects the organization of our mental processes. We also review recent neuroimaging studies on the neural correlates of sensory perception and mental imagery in visually impaired individuals that have cast light on the plastic functional reorganization mechanisms associated with visual deprivation. (c) 2008 Elsevier Ltd. All rights reserved.”
“In the study of numerical and arithmetical abilities, there is compelling evidence demonstrating that number and space representations are connected to one another. Historically the first source I-BET151 of support came more than a century ago,

when Galton’s investigations on mental imagery suggested that the internal representation of numbers may evoke a stable, linear space. In the past few decades, empirical evidence lent further support to the hypothesis that numerical representation is spatially coded into a non-verbal ‘mental number line’, buy Erastin which in turn lead to considering this representation as the core of number meaning. Visuo-spatial processing is intuitively involved

in various aspects of number processing and calculation: For instance, the meaning of a digit in a multi-digit number is coded following spatial information, given its association to its relative position within the number; similarly, to solve a complex written multiplication one has to know the correct location of the intermediate results. In this review behavioral, neuropsychological, and neuroimaging data concerning the close relationship between numerical abilities and visuo-spatial processes are considered. (c) 2008 Elsevier Ltd. All rights reserved.”
“It is shown that visuo-spatial working memory is better characterized as processes operating

on sensory information (visual appearance) and on spatial location (environmental coordinates) in a distributed IPI-549 network than as unitary slave system. Results from passive (short-term) and active memory tasks (imagery) disclose the properties (capacity, content) and the components of this network. The prefrontal cortex is a control structure (dorsal prefers active, ventral passive tasks) and it contributes to spatial memory by a prospective spatial code (eye movements). Visual appearance (including dynamic aspects) is represented as features and object files (bound features) within content-specific areas in the ventral occipital cortex. Spatial coordinates are represented in the parietal cortex (modality-unspecific), when used in spatio-temporal tasks (Corsi) they are closely related to attention. Imagery of objects activates occipito-temporal structures, spatial transformations and mental rotation the parietal cortex (specifically the intraparietal sulcus). Perception, working memory, and imagery use the same neural network.

Altogether, these findings underscore the potential therapeutic a

Altogether, these findings underscore the potential therapeutic application of NO donors and subtoxic chemotherapeutic drugs in the treatment of advanced colon cancer resistant to conventional chemotherapeutic agents. Published by Elsevier Inc.”
“We have described a new compound (trans-[RuCl([15]ane N(4))NO](2+)), which in vitro releases NO by the action of a reducing agent such as catecholamines. We investigated the effect

of this NO donor in lowering the mean arterial pressure (MAP) in severe and moderate renal hypertensive 2K-1C rats. MAP was measured before and after intravenous in bolus injection of the compound in conscious 2K-1C and normotensive (2K) rats. In the hypertensive rats (basal 196.70 +/- 8.70 mmHg, n=5), the MAP was reduced CHIR-99021 ic50 in -34.25

+/- 13.50 mmHg(P < 0.05) 6 h after administration Cl-amidine in vitro of 10 mmol/L/Kg of the compound in bolus. In normotensive rats the compound had no effect. We have also studied the effect of the injection of 0.1 mmol/L/Kg in normotensive (basal 118.20 +/- 11.25 mmHg, n = 4), moderate (basal 160.90 +/- 2.30 mmHg, n = 6), and severe hypertensive rats (basal 202.46 +/- 16.74 mmHg, n = 6). The compound at the dose of 0.1 mmol/L/Kg did not have effect (P> 0.05) on MAP of normotensive and moderate hypertensive rats. However, in the severe hypertensive rats (basal 202.46 +/- 16.70 mmHg, n = 6) there was a significant reduction on the MAP of -28.64 +/- 12.45 mmHg. The NO donor reduced the MAP of all hypertensive rats in the dose of 10 mmol/L/Kg and in the severe hypertensive www.selleck.cn/products/mk-4827-niraparib-tosylate.html rats at the dose of 0.1 mmol/L/Kg. The compound was not cytotoxic to the rat aortic vascular smooth muscle cells in the concentration of 0.1 mmol/LKg that produced the maximum relaxation. (C) 2008 Elsevier Inc. All rights reserved.”
“Nitric oxide metabolites (NOx) in serum, and alveolar

concentration of NO (CA(NO)), are markers of inflammation and alveolitis, respectively, in systemic sclerosis (SSc). We prospectively evaluated the usefulness of both NOx and CANO to assess lung involvement and skin fibrosis in SSc. Serum NOx, and CANO measured by two different methods, namely the two-compartment (2CM) and the “”trumpet”" models (TM), were concomitantly assessed in 65 patients with SSc and 17 healthy controls. Whilst serum NOx remained comparable between groups, CANO were significantly higher in SSc patients (n = 65, 6.7 ppb; 4.8-9.7 and 5.9 ppb; 3.9-8.9) as compared with controls (n = 17, 3.0 ppb; 2.0-3.8 and 1.8 ppb; 1.1-2.9, p < 0.001, p < 0.001) using the 2CM and the TM, respectively). CANO from SSc patients with interstitial lung disease (ILD) (n = 26, 8.6 ppb; 6.5-10.9 and 8.5 ppb; 5.9-10.7) or pulmonary arterial hypertension (n = 12, 7.3 ppb; 6.5-10.4 and 6.9 ppb; 5.4-9.

Binding affinity for [(3)H] WIN55,212-2 was increased in brain me

Binding affinity for [(3)H] WIN55,212-2 was increased in brain membranes from PKC epsilon(-/-) mice compared with PKC epsilon(+/+) mice. There was no difference in binding of the inverse agonist [(3)H] SR141716A. In addition, repeated administration of WIN55,212-2 produced greater analgesic and thermal tolerance in PKC epsilon(-/-) mice compared with PKC epsilon(+/+) mice. These results indicate that PKCe selectively regulates behavioral sensitivity, CB1 receptor binding and tolerance to WIN55,212-2.

Neuropsychopharmacology (2009) 34, 1733-1742; doi:10.1038/npp.2008.230; published online 21 January 2009″
“Tobacco addiction is a chronic disorder that is characterized by a negative

affective state upon smoking cessation and relapse after periods of abstinence. Previous research has shown that an increased central release www.selleckchem.com/products/sbi-0206965.html of corticotropin-releasing factor (CRF) at least partly mediates the deficit in brain reward function associated with nicotine withdrawal in rats. The aim of these studies was to investigate the role of CRF in the central nucleus of the amygdala (CeA), the lateral bed nucleus of the stria terminalis (BNST), and the nucleus accumbens shell (Nacc shell) in the deficit in brain reward function associated with precipitated nicotine withdrawal. The intracranial self-stimulation procedure was used to assess the negative selleck kinase inhibitor affective Roscovitine cell line aspects of nicotine withdrawal. Elevations in brain reward thresholds are indicative of a deficit in brain reward function. In all experiments, the nicotinic receptor antagonist mecamylamine (3 mg/kg) elevated the brain reward thresholds of the nicotine-dependent rats (9 mg/kg per day of nicotine salt) and did not affect the brain reward thresholds of the saline-treated control rats. The administration of the nonspecific CRF1/2 receptor antagonist D-Phe CRF((12-41)) into the CeA and the Nacc

shell prevented the mecamylamine-induced elevations in brain reward thresholds in the nicotine-dependent rats. Blockade of CRF1/2 receptors in the lateral BNST did not prevent the mecamylamine-induced elevations in brain reward thresholds in the nicotine-dependent rats. These studies indicate that the negative emotional state associated with precipitated nicotine withdrawal is at least partly mediated by an increased release of CRF in the CeA and the Nacc shell. Neuropsychopharmacology (2009) 34, 1743-1752; doi:10.1038/npp.2008.231; published online 14 January 2009″
“Schizophrenia symptoms can be segregated into positive, negative and cognitive, which exhibit differential sensitivity to drug treatments. Accumulating evidence points to efficacy of alpha 7 nicotinic receptor (nAChR) agonists for cognitive deficits in schizophrenia but their activity against positive symptoms is thought to be minimal.

The social relevance of our findings and a possible explanation b

The social relevance of our findings and a possible explanation based upon neuroscience are discussed. (C) check details 2010 Elsevier Ireland Ltd. All rights reserved.”
“Reports suggest that Bacillus spp. can be used to increase plant growth and resistance to disease, but the molecular mechanisms underlying the interaction between Bacillus spp. and plant is not completely understood. In the present study, to clarify these underlying mechanisms, the interaction between Bacillus cereus and rice was investigated using two-dimensional gel electrophoresis. Through comparative analysis,

a total of 31 differentially expressed proteins were obtained upon B.cereus NMSL88 treatment, including 22 proteins that were up-regulated and nine that were down-regulated. These data indicated that certain proteins involved in plant growth and development were up-regulated, such as xyloglucan endotransglycosylase. Interestingly, proteins involved in defence were also up-regulated, including peroxidases, glutathione S-transferases and kinases. Thus, proteins associated with disease resistance characteristics were induced in the plants after exposure to B.cereus NMSL88. In addition, several proteins involved in protein and lipid metabolism showed significant changes in expression. Significance and Impact of the Study The present study is the first report to reveal the molecular mechanisms involved in rice seedlings in response

to inoculation with Bacillus cereus at the level of proteome. The results demonstrated that B.cereus NMSL88 can up-regulate the expression of proteins related to plant growth and defence, and lead to 5-Fluoracil concentration enhanced plant growth and disease resistance.”
“Recent evidence suggests that normal-range paranoid ideation may be particularly likely to develop in individuals disposed

to both social anxiety and perceptual anomalies. This study was designed to test the hypothesis that among college students in an LXH254 cell line unselected sample, social anxiety and experience of perceptual anomalies would not only each independently predict the experience of self-reported paranoid ideation, but would also interact to predict paranoid patterns of thought. A diverse sample of 644 students completed a large battery of self-report measures, as well as the five-factor Paranoia/Suspiciousness Questionnaire (PSQ). We conducted hierarchical multiple regression analyses predicting scores on each PSQ factor from responses on measures of social anxiety, perceptual aberration, and the interaction between the two constructs. Current general negative affect was covaried in all analyses. We found that both social anxiety and perceptual aberrations, along with negative affect, predicted multiple dimensions of paranoia as measured by the PSQ; the two constructs did not, however, interact significantly to predict any dimensions. Our findings suggest that perceptual aberration and anxiety may contribute to normal-range paranoid ideation in an additive rather than an interactive manner.

Externalization of these entities is followed by release of the R

Externalization of these entities is followed by release of the RNA genome (uncoating), leaving an empty (80S) particle. The antigen-binding fragment (Fab) of a monospecific peptide 1 (P1) antibody, which was raised against a peptide corresponding to amino-terminal residues 24 to 40 of VP1, was utilized to track the location of the amino terminus

of VP1 in the 135S and 80S states of poliovirus particles via cryogenic electron microscopy (cryo-EM) and three-dimensional image reconstruction. On 135S, P1 Fabs bind to a prominent feature on the external surface known as the “”propeller tip.”" In contrast, our initial 80S-P1 reconstruction showed P1 Fabs also binding to a second site, at least 50 angstrom distant, at the icosahedral 2-fold axes. Further analysis showed that the overall population of 80S-P1 particles consisted of three kinds Pifithrin-�� ic50 of capsids: those with P1 Fabs bound only at the propeller tips, P1 Fabs bound only at the 2-fold axes, or P1 Fabs simultaneously

bound at both positions. Our results indicate that, in 80S particles, a significant fraction of VP1 can deviate from icosahedral symmetry. SCH772984 order Hence, this portion of VP1 does not change conformation synchronously when switching from the 135S state. These conclusions are compatible with previous observations of multiple conformations of the 80S state and suggest that movement of the amino terminus of VP1 has a role in uncoating. Similar deviations from icosahedral symmetry may be biologically significant during other viral transitions.”
“Attempts to improve cognitive function in patients with brain disorders have become the focus of intensive research efforts. A recent LY3039478 purchase emerging trend is the use of so-called cognitive enhancers by healthy individuals. Here, we consider some of the effects – positive and negative that current drugs have in neurological conditions and healthy people. We conclude that, to date, experimental and clinical studies have

demonstrated relatively modest overall effects, most probably because of substantial variability in response both across and within individuals. We discuss biological factors that might account for such variability and highlight the need to improve testing methods and to extend our understanding of how drugs modulate specific cognitive processes at the systems or network level.”
“Background (+/-)3,4-Methylenedioxymethamphetamine (MDMA, “”ecstasy”") is a recreational drug and brain serotonin (5-HT) neurotoxin. Under certain conditions, MDMA can also damage brain dopamine (DA) neurons, at least in rodents. Human MDMA users have been found to have reduced brain 5-HT transporter (SERT) density and cognitive deficits, although it is not known whether these are related.

All patients surviving to discharge experienced either complete (

All patients surviving to discharge experienced either complete (n = 9) or incomplete (n = 2) neurologic recovery. At mean follow-up of 49 months, 7 of 9 patients currently alive continued CRT0066101 concentration to exhibit complete, sustained neurologic recovery.

Conclusion: Spinal cord ischemia after TEVAR is an uncommon, but important complication. Preoperative renal insufficiency was identified as a risk factor for the development of SCI. Early detection and treatment of SCI with blood pressure augmentation alone

or in combination with CSF drainage was effective in most patients, with the majority achieving complete, long-term neurologic recovery. (J Vase Surg 2011;54:677-84.)”
“Somatotropin-release inhibitory factor (SRIF) is a major regulator of pituitary function, mostly inhibiting hormone secretion and to a lesser extent pituitary cell growth. Five SRIF receptor subtypes (SSTR1-5) are ubiquitously expressed G-protein coupled receptors. In the pituitary, SSTR1, 2, 3 and 5 are expressed, with SSTR2 and SSTR5 predominating. As new SRIF analogs have recently been introduced for

treatment JPH203 cell line of pituitary disease, we evaluate the current knowledge of cell-specific pituitary SRIF receptor signaling and highlight areas of future research for comprehensive understanding of these mechanisms. Elucidating pituitary SRIF receptor signaling enables understanding of pituitary hormone secretion and cell growth, and also encourages future therapeutic development for pituitary disorders.”
“Bone morphogenetic proteins (BMPs) are involved not only in osteogenesis but also in chondrogenesis. They play an important role in the development and maintenance of the intervertebral disk (IVD). For this reason, an increasing amount of research has been performed to examine the buy HKI-272 relationship between BMPs and degenerative disk disease (DDD). Moreover,

researchers are examining the safe use of BMPs as a potential treatment for diskogenic back pain. We performed a literature search using databases from the US National Library of Medicine and the National Institutes of Health to identify studies relating BMPs to DDD. According to in vitro and in vivo studies in different animal and human IVDs, BMP-2 and BMP-7 are upregulated with aging and with induced disk injury; this represents an anabolic response. Direct administration of BMP-2 to IVD cells results in increased production of components of the extracellular matrix. Upregulation of the BMP pathway via other agents, namely simvastatin and LIM mineralization protein-1, has resulted in similar outcomes. Adenoviruses loaded with BMPs, transfected either directly to IVD cells or via articular chondrocytic vectors, also resulted in reversal of the typical findings in DDD. We conclude that the use of BMPs to treat DDD has a promising future. Further studies are indicated to determine optimal delivery and efficacy in humans.


“This study examined age differences in performance monito


“This study examined age differences in performance monitoring during learning of a stimulus-response association task. At the beginning of the learning process, amplitudes of the response-locked error-related negativity (ERN or Ne) and correct response-related negativity (CRN) did not differ in both age groups. With advanced learning the response ERN/Ne increased and the CRN decreased in younger adults, but did not dissociate in older adults. Feedback ERN amplitudes decreased with learning in both age groups and were reduced in older relative to younger adults.

Results indicate that performance monitoring became error specific this website with advanced learning in younger adults, but not in older adults. This might be due to weak representations of stimulus-response mappings in older adults as they learned worse. The decrease of the feedback ERN with learning and aging might suggest a decline of attention paid to negative feedback.”
“Astrocytes in the somatosensory ventrobasal (VB) thalamus of rats respond to glutamatergic synaptic input with metabotropic glutamate receptor (mGluR) mediated intracellular calcium ([Ca2+](i)) elevations. Astrocytes in the VB

thalamus also release the gliotransmitter (GT) glutamate in a Ca2+-dependent manner. The tripartite find more synapse hypothesis posits that astrocytic [Ca2+](i) elevations resulting from synaptic input releases gliotransmitters that then feedback to modify the synapse. Understanding the dynamics of this process and the conditions under which it occurs are therefore important steps in elucidating the potential roles

and impact of GT release in particular brain activities. In this study, we investigated the relationship between VB thalamus afferent synaptic input and astrocytic glutamate release EPZ015666 order by recording N-methyl-D-aspartate (NMDA) receptor-mediated slow inward currents (SICs) elicited in neighboring neurons. We found that Lemniscal or cortical afferent stimulation, which can elicit astrocytic [Ca2+](i) elevations, do not typically result in the generation of SICs in thalamocortical (TC) neurons. Rather, we find that the spontaneous emergence of SICs is largely resistant to acute afferent input. The frequency of SICs, however, is correlated to long-lasting afferent activity. In contrast to short-term stimulus-evoked GT release effects reported in other brain areas, astrocytes in the VB thalamus do not express a straightforward input-output relationship for SIC generation but exhibit integrative characteristics. (C) 2012 IBRO. Published by Elsevier Ltd. All rights reserved.”
“Gene density and orientation of genes in eukaryotes seem to be correlated with the replication origin and the mutation rate is greater in late replicating regions; however, the reason for these patterns is unknown.

This interaction leads to conformational rearrangements in gp120

This interaction leads to conformational rearrangements in gp120 forming or revealing CD4 induced (CD4i) epitopes which are critical for the subsequent recognition of the co-receptor required for viral entry. The

CD4-bound state of gp120 has been considered a potential immunogen for HIV-1 vaccine development. Here we report on an alternative means to induce gp120 into the CD4i conformation.

Results: Combinatorial phage display peptide libraries were screened against HIV-1 gp120 and short (14aa) peptides were selected that bind the viral envelope and allosterically induce the CD4i conformation. The lead peptide was subsequently systematically optimized for higher affinity as well as more efficient inductive activity. The peptide: gp120 complex was scrutinized with a panel of neutralizing anti-gp120 monoclonal antibodies and CD4 itself, illustrating that peptide binding does not interfere with or obscure the CD4 binding site.

Conclusions: Two apoptosis inhibitor click here surfaces of gp120 are considered targets for the development of cross neutralizing antibodies against HIV-1; the CD4 binding site and CD4i epitopes. By implementing novel peptides that allosterically induce the CD4i epitopes we have generated a viral envelope that presents both of these surfaces simultaneously.”
“Background: Following mucosal human immunodeficiency virus

type 1 (HIV-1) transmission, type 1 interferons (IFNs) are rapidly induced at sites of initial virus replication in the mucosa and draining lymph nodes. However, the role played by IFN-stimulated antiviral activity in restricting HIV-1 replication during the initial stages of infection is not clear. We hypothesized AZD1480 in vitro that if type 1 IFNs exert selective pressure on HIV-1 replication in the earliest stages of infection, the founder viruses that succeed in establishing systemic infection would be more IFN-resistant than viruses replicating during chronic infection, when type 1 IFNs are produced at much lower levels. To address this hypothesis, the relative resistance of virus isolates

derived from HIV-1-infected individuals during acute and chronic infection to control by type 1 IFNs was analysed.

Results: The replication of plasma virus isolates generated from subjects acutely infected with HIV-1 and molecularly cloned founder HIV-1 strains could be reduced but not fully suppressed by type 1 IFNs in vitro. The mean IC50 value for IFNa2 (22 U/ml) was lower than that for IFN beta (346 U/ml), although at maximally-inhibitory concentrations both IFN subtypes inhibited virus replication to similar extents. Individual virus isolates exhibited differential susceptibility to inhibition by IFNa2 and IFN beta, likely reflecting variation in resistance to differentially up-regulated IFN-stimulated genes. Virus isolates from subjects acutely infected with HIV-1 were significantly more resistant to in vitro control by IFNa than virus isolates generated from the same individuals during chronic, asymptomatic infection.