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Although it is widely known that various pharmaceuticals affect the methylome, the knowledge of the effects from anesthesia is limited, and nearly nonexistent regarding the effects of obstetric anesthesia on the newborn child. Using sequencing based-methylation data and a reference-based statistical deconvolution approach we performed methylome-wide association studies (MWAS) of neonatal whole blood, and for each cell-type specifically, to detect methylation variations that are associated with the pain relief administered to the mother during delivery. Significant findings were replicated in a different dataset and followed-up with gene ontology analysis to pinpoint biological functions of potential relevance to these neonatal methylation alterations. The MWAS analyses detected methylome-wide significant (q<0.1) alterations in the newborn for laughing gas in granulocytes (two CpGs, p<5.50x10-9, q = 0.067), and for pudendal block in monocytes (five CpGs across three loci, p<1.51 x10-8, q = 0.073). Suggestively significant findings (p<1.00x10-6) were detected for both treatments for bulk and all cell-types, and replication analyses showed consistent significant enrichment (odds ratios ranging 3.47–39.02; p<4.00×10−4) for each treatment, suggesting our results are robust. In contrast, we did not observe any overlap across treatments, suggesting that the treatments are associated with different alterations of the neonatal blood methylome. Gene ontology analyses of the replicating suggestively significant results indicated functions related to, for example, cell differentiation, intracellular membrane-bound organelles and calcium transport. In conclusion, for the first time, we investigated and detected effect of obstetric pain-relief on the blood methylome in the newborn child. The observed differences suggest that anesthetic treatment, such as laughing gas or pudendal block, may alter the neonatal methylome in a cell-type specific manner. Some of the observed alterations are part of gene ontology terms that previously have been suggested in relation to anesthetic treatment, supporting its potential role also in obstetric anesthesia. [ABSTRACT FROM AUTHOR]

Background: The WHO recommended 1200mg/day of fluconazole (FCZ) in the induction phase of cryptococcal meningitis (CM) in HIV prior to 2018 in regions where amphotericin-B (AMB) was unavailable. A 2-stage AMB-controlled, dose-escalation study to determine the maximum tolerated dose and the safety/efficacy of an induction-consolidation strategy of higher doses FCZ (1200mg-2000mg/day), adjusted for weight and renal function (eGFR)in adults with CM was undertaken. Methods: In Stage-1, three induction doses of FCZ (1200mg/day, 1600mg/day and 2000mg/day) were tested in sequential cohortsand compared with AMB in a 3:1 ratio. A particular dose was not tested in Stage 2 if there were significant predetermined safety or efficacy concerns. In Stage-2, the 1200mg dose was excluded per protocol because of increased mortality, and participants were randomised to 1600mg, 2000mg FCZ or AMB in a 1:1:1 ratio. Findings: One hundred and sixty eight participants were enrolled with 48, 50, and 48 in the AMB, 1600mg and 2000mg cohorts. The Kaplan Meier proportion for mortality (90% CI) at 10 and 24 weeks for AMB was 17% (10, 29) and 24% (15, 37), compared to 20% (12, 32) and 30% (20, 43) for 1600mg, and 33% (23, 46) and 38% (27, 51) for 2000mg/day FCZ. With the exception of a higher incidence of gastrointestinal side effects in the 2000mg cohort, both induction doses of FCZ were safe and well tolerated. There were no life-threatening changes in electrocardiogram QTc which were similar across all doses of FCZ and AMB. The median (IQR) change in log10 cryptoccal colony forming units (CFU) from week 0 to week 2 was -8(-4.1,-1.9) for AMB; -2.5(-4.0, -1.4) for 1600mg FCZ and -8 (-3.2, -1.0) for 2000mg FCZ. The proportion (90% CI) CSF CM negative at 10 weeks was 81%(71,90) for AMB; 56%(45,69) for 1600mg FCZ and 60%(49,73) for 2000mg FCZ. Interpretation: Induction phase weight and renal-adjusted doses of 1600mg and 2000mg/day FCZ for CM were safe and well tolerated except for increased GI side effects in the 2000mg/day dose, and had similar times to achieve CSF sterilization, but took significantly longer than AMB. The WHO recommended 1200mg FCZ was associated with a high mortality. While not statistically significant, mortality was numerically lower in the AMB compared to 1600mg and 2000mg FCZ These data make a case for a phase 3 study of higher doses of FZC. [ABSTRACT FROM AUTHOR]

The impaired host defense system in HIV infection impacts the oral and gastrointestinal microbiota and associated opportunistic infections. Antiretroviral treatment is predicted to partially restore host defenses and decrease the oral manifestation of HIV/AIDS. Well-designed longitudinal studies are needed to better understand the interactions of soluble host defense proteins with bacteria and virus in HIV/AIDS. "Crosstalk" was designed as a longitudinal study of host responses along the gastrointestinal (GI) tract and interactions between defense molecules and bacteria in HIV infection and subsequent therapy.The clinical core formed the infrastructure for the study of the interactions between the proteome, microbiome and innate immune system. The core recruited and retained study subjects, scheduled visits, obtained demographic and medical data, assessed oral health status, collected samples, and guided analysis of the hypotheses. This manuscript presents a well-designed clinical core that may serve as a model for studies that combine clinical and laboratory data.Crosstalk was a case-control longitudinal clinical study an initial planned enrollment of 170 subjects. HIV+ antiretroviral naïve subjects were followed for 9 visits over 96 weeks and HIV uninfected subjects for 3 visits over 24 weeks. Clinical prevalence of oral mucosal lesions, dental caries and periodontal disease were assessed.During the study, 116 subjects (47 HIV+, 69 HIV-) were enrolled. Cohorts of HIV+ and HIV- were demographically similar except for a larger proportion of women in the HIV- group. The most prevalent oral mucosal lesions were oral candidiasis and hairy leukoplakia in the HIV+ group.The clinical core was essential to enable the links between clinical and laboratory data. The study aims to determine specific differences between oral and GI tissues that account for unique patterns of opportunistic infections and to delineate the differences in their susceptibility to infection by HIV and their responses post-HAART.

Expression of the gastrin-releasing peptide receptor (GRPR) in prostate cancer suggests that this receptor can be used as a potential molecular target to visualize and treat these tumors. We have previously investigated an antagonist analog of bombesin (D-Phe-Gln-Trp-Ala-Val-Gly-His-Sta-Leu-NH2, RM26) conjugated to 1,4,7-triazacyclononane-N,N',N''-triacetic acid (NOTA) via a diethylene glycol (PEG2) spacer (NOTA-P2-RM26) labeled with (68)Ga and (111)In. We found that this conjugate has favorable properties for in vivo imaging of GRPR-expression. The focus of this study was to develop a (18)F-labelled PET agent to visualize GRPR. NOTA-P2-RM26 was labeled with (18)F using aluminum-fluoride chelation. Stability, in vitro binding specificity and cellular processing tests were performed. The inhibition efficiency (IC50) of the [(nat)F]AlF-NOTA-P2-RM26 was compared to that of the (nat)Ga-loaded peptide using (125)I-Tyr(4)-BBN as the displacement radioligand. The pharmacokinetics and in vivo binding specificity of the compound were studied. NOTA-P2-RM26 was labeled with (18)F within 1 h (60-65% decay corrected radiochemical yield, 55 GBq/µmol). The radiopeptide was stable in murine serum and showed high specific binding to PC-3 cells. [(nat)F]AlF-NOTA-P2-RM26 showed a low nanomolar inhibition efficiency (IC50=4.4±0.8 nM). The internalization rate of the tracer was low. Less than 14% of the cell-bound radioactivity was internalized after 4 h. The biodistribution of [(18)F]AlF-NOTA-P2-RM26 demonstrated rapid blood clearance, low liver uptake and low kidney retention. The tumor uptake at 3 h p.i. was 5.5±0.7 %ID/g, and the tumor-to-blood, -muscle and -bone ratios were 87±42, 159±47, 38±16, respectively. The uptake in tumors, pancreas and other GRPR-expressing organs was significantly reduced when excess amount of non-labeled peptide was co-injected. The low uptake in bone suggests a high in vivo stability of the Al-F bond. High contrast PET image was obtained 3 h p.i. The initial biological results suggest that [(18)F]AlF-NOTA-P2-RM26 is a promising candidate for PET imaging of GRPR in vivo.

Background: Youth have residual thymic tissue and potentially greater capacity for immune reconstitution than adults after initiation of combination antiretroviral therapy (cART). However, youth face behavioral and psychosocial challenges that may make them more likely than adults to delay ART initiation and less likely to attain similar CD4 outcomes after initiating cART. This study compared CD4 outcomes over time following cART initiation between ART-naïve non-perinatally HIV-infected (nPHIV) youth (13–24 years-old) and adults (≥25–44 years-old). Methods: Retrospective analysis of ART-naïve nPHIV individuals 13–44 years-old, who initiated their first cART between 2008 and 2011 at clinical sites in the HIV Research Network. A linear mixed model was used to assess the association between CD4 levels after cART initiation and age (13–24, 25–34, 35–44 years), accounting for random variation within participants and between sites, and adjusting for key variables including gender, race/ethnicity, viral load, gaps in care (defined as > 365 days between CD4 tests), and CD4 levels prior to cART initiation (baseline CD4). Results: Among 2,595 individuals (435 youth; 2,160 adults), the median follow-up after cART initiation was 179 weeks (IQR 92–249). Baseline CD4 was higher for youth (320 cells/mm3) than for ages 25–34 (293) or 35–44 (258). At 239 weeks after cART initiation, median unadjusted CD4 was higher for youth than adults (576 vs. 539 and 476 cells/mm3, respectively), but this difference was not significant when baseline CD4 was controlled. Compared to those with baseline CD4 ≤200 cells/mm3, individuals with baseline CD4 of 201–500 and >500 cells/mm3 had greater predicted CD4 levels: 390, 607, and 831, respectively. Additionally, having no gaps in care and higher viral load were associated with better CD4 outcomes. Conclusions: Despite having residual thymic tissue, youth attain similar, not superior, CD4 gains as adults. Early ART initiation with minimal delay is as essential to optimizing outcomes for youth as it is for their adult counterparts. [ABSTRACT FROM AUTHOR]

Objective: Many studies include oral HIV-related endpoints that may be diagnosed by non-oral-health specialists (non-OHS) like nurses or physicians. Our objective was to assess the accuracy of clinical diagnoses of HIV-related oral lesions made by non-OHS compared to diagnoses made by OHS. Methods: A5254, a cross-sectional study conducted by the Oral HIV/AIDS Research Alliance within the AIDS Clinical Trial Group, enrolled HIV-1-infected adults participants from six clinical trial units (CTU) in the US (San Francisco, New York, Chapel Hill, Cleveland, Atlanta) and Haiti. CTU examiners (non-OHS) received standardized training on how to perform an oral examination and make clinical diagnoses of specific oral disease endpoints. Diagnoses by calibrated non-OHS were compared to those made by calibrated OHS, and sensitivity and specificity computed. Results: Among 324 participants, the majority were black (73%), men (66%), and the median CD4+ cell count 138 cells/mm3. The overall frequency of oral mucosal disease diagnosed by OHS was 43% in US sites, and 90% in Haiti. Oral candidiasis (OC) was detected in 153 (47%) by OHS, with erythematous candidiasis (EC) the most common type (39%) followed by pseudomembranous candidiasis (PC; 26%). The highest prevalence of OC (79%) was among participants in Haiti, and among those with CD4+ cell count ≤ 200 cells/mm3 and HIV-1 RNA > 1000 copies/mL (71%). The sensitivity and specificity of OC diagnoses by non-OHS were 90% and 92% (for EC: 81% and 94%; PC: 82% and 95%). Sensitivity and specificity were also high for KS (87% and 94%, respectively), but sensitivity was < 60% for HL and oral warts in all sites combined. The Candida culture confirmation of OC clinical diagnoses (as defined by ≥ 1 colony forming unit per mL of oral/throat rinse) was ≥ 93% for both PC and EC. Conclusion: Trained non-OHS showed high accuracy of clinical diagnoses of OC in comparison with OHS, suggesting their usefulness in studies in resource-poor settings, but detection of less common lesions may require OHS. [ABSTRACT FROM AUTHOR]

The incidence of breast cancer is increasing in the Western world and there is an urgent need for studies of the mechanisms of sex steroids in order to develop novel preventive strategies. Diet modifications may be among the means for breast cancer prevention. Angiogenesis, key in tumor progression, is regulated by the balance between pro- and anti-angiogenic factors, which are controlled in the extracellular space. Sampling of these molecules at their bioactive compartment is therefore needed. The aims of this study were to explore if tamoxifen, one of the most used anti-estrogen treatments for breast cancer affected some of the most important endogenous angiogenesis regulators, vascular endothelial growth factor (VEGF), angiogenin, and endostatin in normal breast tissue in vivo and if a diet supplementation with flaxseed had similar effects as tamoxifen in the breast. Microdialysis was used for in situ sampling of extracellular proteins in normal breast tissue of women before and after six weeks of tamoxifen treatment or before and after addition of 25 g/day of ground flaxseed to the diet or in control women. We show significant correlations between estradiol and levels of VEGF, angiogenin, and endostatin in vivo, which was verified in ex vivo breast tissue culture. Moreover, tamoxifen decreased the levels of VEGF and angiogenin in the breast whereas endostatin increased significantly. Flaxseed did not alter VEGF or angiogenin levels but similar to tamoxifen the levels of endostatin increased significantly. We conclude that one of the mechanisms of tamoxifen in normal breast tissue include tipping of the angiogenic balance into an anti-angiogenic state and that flaxseed has limited effects on the pro-angiogenic factors whereas the anti-angiogenic endostatin may be modified by diet. Further studies of diet modifications for breast cancer prevention are warranted. [ABSTRACT FROM AUTHOR]

BackgroundThe WHO recommended 1200mg/day of fluconazole (FCZ) in the induction phase of cryptococcal meningitis (CM) in HIV prior to 2018 in regions where amphotericin-B (AMB) was unavailable. A 2-stage AMB-controlled, dose-escalation study to determine the maximum tolerated dose and the safety/efficacy of an induction-consolidation strategy of higher doses FCZ (1200mg-2000mg/day), adjusted for weight and renal function (eGFR)in adults with CM was undertaken.MethodsIn Stage-1, three induction doses of FCZ (1200mg/day, 1600mg/day and 2000mg/day) were tested in sequential cohortsand compared with AMB in a 3:1 ratio. A particular dose was not tested in Stage 2 if there were significant predetermined safety or efficacy concerns. In Stage-2, the 1200mg dose was excluded per protocol because of increased mortality, and participants were randomised to 1600mg, 2000mg FCZ or AMB in a 1:1:1 ratio.FindingsOne hundred and sixty eight participants were enrolled with 48, 50, and 48 in the AMB, 1600mg and 2000mg cohorts. The Kaplan Meier proportion for mortality (90% CI) at 10 and 24 weeks for AMB was 17% (10, 29) and 24% (15, 37), compared to 20% (12, 32) and 30% (20, 43) for 1600mg, and 33% (23, 46) and 38% (27, 51) for 2000mg/day FCZ. With the exception of a higher incidence of gastrointestinal side effects in the 2000mg cohort, both induction doses of FCZ were safe and well tolerated. There were no life-threatening changes in electrocardiogram QTc which were similar across all doses of FCZ and AMB. The median (IQR) change in log10 cryptoccal colony forming units (CFU) from week 0 to week 2 was -8(-4.1,-1.9) for AMB; -2.5(-4.0, -1.4) for 1600mg FCZ and -8 (-3.2, -1.0) for 2000mg FCZ. The proportion (90% CI) CSF CM negative at 10 weeks was 81%(71,90) for AMB; 56%(45,69) for 1600mg FCZ and 60%(49,73) for 2000mg FCZ.InterpretationInduction phase weight and renal-adjusted doses of 1600mg and 2000mg/day FCZ for CM were safe and well tolerated except for increased GI side effects in the 2000mg/day dose, and had similar times to achieve CSF sterilization, but took significantly longer than AMB. The WHO recommended 1200mg FCZ was associated with a high mortality. While not statistically significant, mortality was numerically lower in the AMB compared to 1600mg and 2000mg FCZ These data make a case for a phase 3 study of higher doses of FZC.

Learning how to gain rewards (approach learning) and avoid punishments (avoidance learning) is fundamental for everyday life. While individual differences in approach and avoidance learning styles have been related to genetics and aging, the contribution of personality factors, such as traits, remains undetermined. Moreover, little is known about the computational mechanisms mediating differences in learning styles. Here, we used a probabilistic selection task with positive and negative feedbacks, in combination with computational modelling, to show that individuals displaying better approach (vs. avoidance) learning scored higher on measures of approach (vs. avoidance) trait motivation, but, paradoxically, also displayed reduced learning speed following positive (vs. negative) outcomes. These data suggest that learning different types of information depend on associated reward values and internal motivational drives, possibly determined by personality traits.

BACKGROUND:Prothymosin α (ProTα) (isoform 2: iso2) is a widely distributed, small acidic protein with intracellular and extracellular-associated functions. Recently, we identified two new ProTα variants with potent anti-HIV activity from CD8+ T cells and cervicovaginal lavage. The first is a splice variant of the ProTα gene known as isoB and the second is the product of ProTα pseudogene 7 (p7). Similarly to iso2, the anti-HIV activity of both variants is mediated by type I IFN. Here we tested whether the immunomodulatory activity of isoB and p7 are also TLR4 dependent and determined their kinetic of release in response to HIV-1 infection. METHODS:Type I, type III, TNF-α and IL-6 mRNA inducing activity was determined in macrophages from wild type and TLR4 knockout mice treated with recombinant ProTα variants. Supernatants from mock and HIV infected cells were analyzed by mass spectrometry in positive and negative modes for the presence of ProTα variants. In silico structural and functional analysis of ProTα variants were performed. RESULTS:We show that both isoB and p7 upregulate IFN-β, IFN-λ1, IL-6, TNF-α and RANTES mRNAs in primary human macrophages. The potent stimulation of IFN-β by the recombinant ProTα variants in human macrophages is dependent on the TLR4 pathway, whereas the induction of TNF-α and IL-6 may also occur independently of TLR4, suggesting the interaction of ProTα variants with other signaling molecules/receptors. In silico analyses confirmed that the novel isoB and p7 variants are intrinsically disordered proteins, which lack the NLS and mass spectrometry showed release of ProTα variants within minutes post HIV-1 infection. These features are consistent with the function of ProTα variants as damage associate molecular patterns (DAMPs). CONCLUSIONS:Our findings indicate that ProTα variants strongly inhibit viral replication mainly, but not exclusively, through TLR4 signaling and that they are released within minutes of viral infection suggesting that they may function as DAMPs.

BackgroundWe previously suggested that abnormal sleep behaviors, i.e., as found in parasomnias, may often be the expression of increased activity of the reward system during sleep. Because nightmares and sleepwalking predominate during REM and NREM sleep respectively, we tested here whether exploratory excitability, a waking personality trait reflecting high activity within the mesolimbic dopaminergic (ML-DA) system, may be associated with specific changes in REM and NREM sleep patterns in these two sleep disorders.MethodsTwenty-four unmedicated patients with parasomnia (12 with chronic sleepwalking and 12 with idiopathic nightmares) and no psychiatric comorbidities were studied. Each patient spent one night of sleep monitored by polysomnography. The Temperament and Character Inventory (TCI) was administered to all patients and healthy controls from the Geneva population (n = 293).ResultsSleepwalkers were more anxious than patients with idiopathic nightmares (Spielberger Trait anxiety/STAI-T), but the patient groups did not differ on any personality dimension as estimated by the TCI. Compared to controls, parasomnia patients (sleepwalkers together with patients with idiopathic nightmares) scored higher on the Novelty Seeking (NS) TCI scale and in particular on the exploratory excitability/curiosity (NS1) subscale, and lower on the Self-directedness (SD) TCI scale, suggesting a general increase in reward sensitivity and impulsivity. Furthermore, parasomnia patients tended to worry about social separation persistently, as indicated by greater anticipatory worry (HA1) and dependence on social attachment (RD3). Moreover, exploratory excitability (NS1) correlated positively with the severity of parasomnia (i.e., the frequency of self-reported occurrences of nightmares and sleepwalking), and with time spent in REM sleep in patients with nightmares.ConclusionsThese results suggest that patients with parasomnia might share common waking personality traits associated to reward-related brain functions. They also provide further support to the notion that reward-seeking networks are active during human sleep.

Many studies include oral HIV-related endpoints that may be diagnosed by non-oral-health specialists (non-OHS) like nurses or physicians. Our objective was to assess the accuracy of clinical diagnoses of HIV-related oral lesions made by non-OHS compared to diagnoses made by OHS.A5254, a cross-sectional study conducted by the Oral HIV/AIDS Research Alliance within the AIDS Clinical Trial Group, enrolled HIV-1-infected adults participants from six clinical trial units (CTU) in the US (San Francisco, New York, Chapel Hill, Cleveland, Atlanta) and Haiti. CTU examiners (non-OHS) received standardized training on how to perform an oral examination and make clinical diagnoses of specific oral disease endpoints. Diagnoses by calibrated non-OHS were compared to those made by calibrated OHS, and sensitivity and specificity computed.Among 324 participants, the majority were black (73%), men (66%), and the median CD4+ cell count 138 cells/mm(3). The overall frequency of oral mucosal disease diagnosed by OHS was 43% in US sites, and 90% in Haiti. Oral candidiasis (OC) was detected in 153 (47%) by OHS, with erythematous candidiasis (EC) the most common type (39%) followed by pseudomembranous candidiasis (PC; 26%). The highest prevalence of OC (79%) was among participants in Haiti, and among those with CD4+ cell count ≤ 200 cells/mm(3) and HIV-1 RNA > 1000 copies/mL (71%). The sensitivity and specificity of OC diagnoses by non-OHS were 90% and 92% (for EC: 81% and 94%; PC: 82% and 95%). Sensitivity and specificity were also high for KS (87% and 94%, respectively), but sensitivity was < 60% for HL and oral warts in all sites combined. The Candida culture confirmation of OC clinical diagnoses (as defined by ≥ 1 colony forming unit per mL of oral/throat rinse) was ≥ 93% for both PC and EC.Trained non-OHS showed high accuracy of clinical diagnoses of OC in comparison with OHS, suggesting their usefulness in studies in resource-poor settings, but detection of less common lesions may require OHS.

Methyl-binding domain (MBD) enrichment followed by deep sequencing (MBD-seq), is a robust and cost efficient approach for methylome-wide association studies (MWAS). MBD-seq has been demonstrated to be capable of identifying differentially methylated regions, detecting previously reported robust associations and producing findings that replicate with other technologies such as targeted pyrosequencing of bisulfite converted DNA. There are several kits commercially available that can be used for MBD enrichment. Our previous work has involved MethylMiner (Life Technologies, Foster City, CA, USA) that we chose after careful investigation of its properties. However, in a recent evaluation of five commercially available MBD-enrichment kits the performance of the MethylMiner was deemed poor. Given our positive experience with MethylMiner, we were surprised by this report. In an attempt to reproduce these findings we here have performed a direct comparison of MethylMiner with MethylCap (Diagenode Inc, Denville, NJ, USA), the best performing kit in that study. We find that both MethylMiner and MethylCap are two well performing MBD-enrichment kits. However, MethylMiner shows somewhat better enrichment efficiency and lower levels of background "noise". In addition, for the purpose of MWAS where we want to investigate the majority of CpGs, we find MethylMiner to be superior as it allows tailoring the enrichment to the regions where most CpGs are located. Using targeted bisulfite sequencing we confirmed that sites where methylation was detected by either MethylMiner or by MethylCap indeed were methylated.

Only a subset of patients will typically respond to any given prescribed drug. The time it takes clinicians to declare a treatment ineffective leaves the patient in an impaired state and at unnecessary risk for adverse drug effects. Thus, diagnostic tests robustly predicting the most effective and safe medication for each patient prior to starting pharmacotherapy would have tremendous clinical value. In this article, we evaluated the use of genetic markers to estimate ancestry as a predictive component of such diagnostic tests. We first estimated each patient's unique mosaic of ancestral backgrounds using genome-wide SNP data collected in the Clinical Antipsychotic Trials of Intervention Effectiveness (CATIE) (n = 765) and the Sequenced Treatment Alternatives to Relieve Depression (STAR*D) (n = 1892). Next, we performed multiple regression analyses to estimate the predictive power of these ancestral dimensions. For 136/89 treatment-outcome combinations tested in CATIE/STAR*D, results indicated 1.67/1.84 times higher median test statistics than expected under the null hypothesis assuming no predictive power (p

In motor learning, training a task B can disrupt improvements of performance of a previously learned task A, indicating that learning needs consolidation. An influential study suggested that this is the case also for visual perceptual learning. Using the same paradigm, we failed to reproduce these results. Further experiments with bisection stimuli also showed no retrograde disruption from task B on task A. Hence, for the tasks tested here, perceptual learning does not suffer from retrograde interference.