Prototypical innate immune mechanism hijacked by leukemia-initiating mutant stem cells for selective advantage and immune evasion in Ptpn11-associated juvenile myelomonocytic leukemia.

Juvenile myelomonocytic leukemia (JMML), a clonal hematologic malignancy, originates from mutated hematopoietic stem cells (HSCs). The mechanism sustaining the persistence of mutant stem cells, leading to leukemia development, remains elusive. In this study, we conducted comprehensive examination of gene expression profiles, transcriptional factor regulons, and cell compositions/interactions throughout various stages of tumor cell development in Ptpn11 mutation-associated JMML. Our analyses revealed that leukemia-initiating Ptpn11 E76K/+ mutant stem cells exhibited de novo activation of the myeloid transcriptional program and aberrant developmental trajectories. These mutant stem cells displayed significantly elevated expression of innate immunity-associated anti-microbial peptides and pro-inflammatory proteins, particularly S100a9 and S100a8. Biological experiments confirmed that S100a9/S100a8 conferred a selective advantage to the leukemia-initiating cells through autocrine effects and facilitated immune evasion by recruiting and promoting immune suppressive myeloid-derived suppressor cells (MDSCs) in the microenvironment. Importantly, pharmacological inhibition of S100a9/S100a8 signaling effectively impeded leukemia development from Ptpn11 E76K/+ mutant stem cells. These findings collectively suggest that JMML tumor-initiating cells exploit evolutionarily conserved innate immune and inflammatory mechanisms to establish clonal dominance.

The Growth of Problematic Media Use Over Early Childhood: Associations with Long-Term Social and Emotional Outcomes.

Problematic media use (PMU) tends to be related to significant social, emotional, and behavioral problems throughout life. Little research, however, has examined the development of PMU during early childhood, where media habits begin to form. The current longitudinal study examines the growth of PMU across early childhood (between 2.5 and 5.5 years of age) with a focus on predictors and outcomes (social, emotional, and parenting) of the intercept and slope of PMU over time. Participants (N = 269 children and their parents; 4.9% Asian American, 8.2% Black, 21% Hispanic or Latino, 63% White, 7% Mixed or Other race) completed questionnaires assessing PMU, media parenting, parental warmth and connection, and child social and emotional problems. Results indicated slight overall increases in PMU from ages 2.5 to 5.5. Emotional reactivity, aggression, and overall TV time predicted initial levels of PMU. Additionally, initial levels of PMU were related to social and emotional problems four years later. An increasing trajectory of PMU was associated with later aggression in childhood, even when controlling for initial levels of aggression. Implications for parents and prevention efforts aimed at reducing PMU are discussed.

Mothers' and fathers' depressive symptoms across four years postpartum: An examination of between- and bidirectional within-person relations.

BACKGROUND: Both mothers and fathers are at risk for experiencing postpartum depressive symptoms shortly after the birth of a child. Previous studies suggest mothers' and fathers' depressive symptoms to be interrelated. This study examined bidirectional relations between mothers' and fathers' depressive symptoms across four years postpartum. METHODS: Longitudinal data for this study were collected across five waves from 485 mothers and 359 fathers of infants when infants were on average 6 months-old until children were 54 months-old (1-year lags). Mothers and fathers reported on their depressive symptoms using the Center for the Epidemiological Studies Short Depression Scale (CES-D 10). A random intercept cross-lagged panel model (RICLPM) was specified to examine the bidirectional relations between mothers' and fathers' depressive symptoms over time. RESULTS: At the between-person level, mothers' and fathers' depressive symptoms were positively associated. At the within-person level, unique carry-over effects were found for mothers and fathers in that when reporting higher depressive symptoms than their trait levels, they were more likely to report higher depressive symptoms one year later. Moreover, intermittent cross-lagged effects were observed from mothers' depressive symptoms to fathers' depressive symptoms during toddlerhood. LIMITATIONS: The sample was not racially or structurally diverse thereby limiting the generalizations of the findings. CONCLUSIONS: After the birth of a child, mothers and fathers are at risk for experiencing chronic depressive symptoms which can have implications for individual, couple and child health. Mothers' depressive symptoms are related to fathers' depressive symptoms over time.

Links between parent-child conversations about emotions and changes in children's emotion knowledge across early childhood.

This study examined different sources of emotion socialization. Children (N = 256, 115 girls, 129 boys, 12 child gender not reported) and parents (62% White, 9% Black, 19% Hispanic, 3% Asian American, and 7% "Other") were recruited from Denver, Colorado. In waves 1 (Mage = 2.45 years, SD = 0.26) and 2 (Mage = 3.51 years, SD = 0.26), parents and children discussed wordless images of children experiencing an emotion (e.g., sad after dropping ice cream). Children's emotion knowledge was assessed at waves 2 and 3 (Mage = 4.48 years, SD = 0.26). Structural equation modeling found concurrent and prospective relations between parents' questions, parents' emotion talk, children's emotion talk, and children's emotion knowledge, highlighting the multidimensional nature of early emotion socialization.

"Oh no! What happened?" an investigation of parent-child conversations about self-conscious emotions.

Parents play an important role in socializing children's emotion understanding. Previous research shows that parents emphasize different aspects of emotion contexts depending on the discrete emotion. However, there is limited research on how parents and children discuss self-conscious emotions, such as embarrassment, guilt, and shame, and what socialization practices parents employ to elicit children's talk about these emotions. In this study, children (N = 166, 78 females, 88 males) ages 2-3 years (M = 2.46, SD = 0.26) and their parents (65.5% White, 10.2% Black, 17.5% Hispanic, 2.4% Asian American, and 5.4% other) from a large city in the Western United States discussed a wordless storybook depicting different female and male characters experiencing self-conscious emotions (embarrassment, guilt, shame, awe, and pride). Parents' and children's emotion talk and parents' questions were coded from their conversations about each emotion scenario and subsequently analyzed by discrete emotion, child gender, and the depicted character's gender. Parents and children differentially focused on different aspects of each self-conscious emotion as a function of discrete emotion and picture gender, and elements of children's talk about self-conscious emotions were related to children's expressive language and age. Additionally, parents' emotion talk and questions about emotions were directly related to children's emotion talk, even after controlling for children's age, expressive language, and parental education. Taken together, these findings suggest that parent-child emotion conversations may be one context that facilitates the development of children's understanding of self-conscious emotions. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Parenting measurement, normativeness, and associations with child outcomes: Comparing evidence from four non-Western cultures.

This study compared parenting across four non-Western cultures to test cross-cultural commonality and specificity principles in three aspects: measurement properties, parenting normativeness, and their associations with child outcomes. Both mothers and fathers (N = 1509 dyads) with preschool-aged children (M = 5.00 years; 48% girls) from urban areas of four countries (Malaysia, N = 372; China, N = 441; Turkey, N = 402; and Japan, N = 294) reported on four parenting constructs (authoritative, authoritarian, group harmony socialization, and intrusive control) and their sub-dimensions using modified culturally relevant measures. Teachers reported on children's internalizing, externalizing, and prosocial behaviors. The commonality principle was supported by two sets of findings: (1) full measurement invariance was established for most parenting constructs and sub-dimensions, except that intrusive control only reached partial scalar invariance, and (2) no variations were found in associations between parenting and any child outcomes across cultures or parent gender at the construct level for all four parenting constructs and at the sub-dimensional level for authoritarian and intrusive control sub-dimensions. The specificity principle was supported by the other two sets of findings: (1) cross-cultural differences in parenting normativeness did not follow the pattern of economic development but yielded culture-specific patterns, and (2) at the sub-dimensional level, the authoritative parenting and group harmony socialization sub-dimensions were differently associated with child outcomes across cultures and/or parent gender. The findings suggested that examining specific dimensions rather than broad parenting constructs is necessary to reflect cultural specificities and nuances. Our study provided a culturally-invariant instrument and a three-step guide for future parenting research to examine cross-cultural commonalities/specificities. RESEARCH HIGHLIGHTS: This is the first study to use an instrument with measurement invariance across multiple non-Western cultures to examine the commonality and specificity principles in parenting. Measurement invariance was achieved across cultures for authoritative and authoritarian parenting, group harmony socialization, intrusive control, and their sub-dimensions, supporting the commonality principle. Cross-cultural differences in parenting normativeness did not follow the pattern of economic development but yielded culture-specific patterns, supporting the specificity principle. Both commonalities and specificities were manifested in associations between parenting and child outcomes across cultures.

"Katerina gets mad": Infants' physiological and behavioral responses to co-viewing educational, self-regulatory media.

A growing body of research has focused on the physiological impact of media on older children and adolescents. Less research has been focused on the potential physiological impact of media on infants and younger children, especially media designed to be age appropriate and educational in content. In this study, we examined respiratory sinus arrhythmia (RSA) in infants (N = 269, Mage  = 17.13 months) while they co-viewed an educational video clip that modeled emotion regulation and contrasted their physiological response to an unoccupied baseline and a frustration paradigm (arm-restraint). Given parent reports showing the calming effect of educational media viewing in young children, we anticipated that a similar pattern of calming would be observed physiologically in infants. Results showed that relative to baseline, most infants demonstrated an increase in RSA while co-viewing, suggesting greater parasympathetic (regulatory) activation consistent with behavioral calming. However, infants who demonstrated vagal withdrawal during co-viewing (decrease in RSA) were more likely to have parents who used a tablet to help infants go to sleep at night. Vagal withdrawal was also associated with increased levels of negative affect observed during the co-viewing task. Findings are discussed in relation to the contextual effect of co-viewing age-appropriate, educational media on children's physiological responses.

Development of mother-infant co-regulation: The role of infant vagal tone and temperament at 6, 9, and 12 months of age.

Using Porges' (2011) Polyvagal Theory as a backdrop, this study examined whether changes in parasympathetic functioning, as indexed by baseline measures of cardiac vagal tone at 6, 9, and 12 months of age, were linked to changes in infants' (N = 101) dyadic co-regulation over these same time points. Mothers and infants were observed at each time point during a 15-minute unstructured free-play and co-regulated patterns of interactions were coded using the Revised Relational Coding System (Fogel et al., 2003). Analyses were carried out using multi-process growth curve modeling to examine baseline measurements (intercepts) and changes (slopes) in vagal tone, co-regulation as well as mothers' report of infant temperament. Findings demonstrate links between infants' vagal tone and changes in mother-infant co-regulation. Specifically, increasing levels of cardiac vagal tone was related to increases in symmetrical but decreases in unilateral patterns of co-regulation over time. These findings suggest that changes in the autonomic nervous system likely undergird infants' improving capacity to engage in more mutually sustained patterns of co-regulation.

Abdominal and perineal hernia rates following vertical rectus abdominis myocutaneous (VRAM) flap reconstruction - a supraregional experience.

BACKGROUND: Vertical rectus abdominis myocutaneous (VRAM) flap has proven to be a robust reconstruction method following radical pelvic surgery. Radical pelvic surgery is associated with high morbidity due to pelvic complications and non-healing perineal wounds, as a result of non-collapsible pelvic dead space and pre-operative adjuvant radiotherapy insult. VRAM flap reconstruction addresses both issues by obliterating the dead space and introducing healthy non-radiated tissue. However, flap reconstruction complications can include donor site hernias (abdominal wall), perineal hernias, and flap-specific complications. This study aimed to evaluate the abdominal and perineal hernia rates as well as radiological evidence of flap vascularity post-operatively. METHODS: We conducted a retrospective analysis of patients who underwent a VRAM flap reconstruction following radical pelvic surgery at Christchurch hospital over a 10-year period. We identified the presence of donor site hernias (abdominal wall hernias), perineal hernias, and flap vascularity on post-operative radiological imaging performed within 48 months. RESULTS: Seventy-seven patients underwent a VRAM flap reconstruction of which 60 patients met the inclusion requirements for the study (mean age was 60.3 years [range 26-89]; 31 were male and 29 were female). Eighteen patients underwent an APR and 42 underwent a partial or a complete pelvic exenteration and the majority of them (75.0%) were for rectal cancers. Available imaging was on average 21.6 months post-operatively (IQR 11.8-31.3 months). The donor site hernia rate was 16.7%, and the perineal hernia rate was 3.3%. VRAM flap appeared to have DIEA flow in 98.3% of the patients. CONCLUSION: VRAM flap reconstruction of complex pelvic defects remains a robust method of choice in complex pelvic reconstruction with little morbidity.

Attachment Issues: A Case Report of a Promising Sternal Implantation with 3D-printed Polyethylene.

Sternal reconstruction is beneficial for chest wall stability, respiratory function, and cosmetics, with no superior prosthesis or method thus far identified. We present a case of sternal reconstruction in a patient 6 years post sternal removal using a 3D-printed, patient-specific, polyethylene prosthesis with reasonable short-term outcomes. We believe a polyethylene prosthesis shows advantages over other materials and is worth further investigation, providing a technique for attaching said prosthesis to the native tissues is established.

Lipophilic Conjugates of Drugs: A Tool to Improve Drug Pharmacokinetic and Therapeutic Profiles.

Lipophilic conjugates (LCs) of small molecule drugs have been used widely in clinical and pre-clinical studies to achieve a number of pharmacokinetic and therapeutic benefits. For example, lipophilic derivatives of drugs are employed in several long acting injectable products to provide sustained drug exposure for hormone replacement therapy and to treat conditions such as neuropsychiatric diseases. LCs can also be used to modulate drug metabolism, and to enhance drug permeation across membranes, either by increasing lipophilicity to enhance passive diffusion or by increasing protein-mediated active transport. Furthermore, such conjugation strategies have been employed to promote drug association with endogenous macromolecular carriers (e.g. albumin and lipoproteins), and this in turn results in altered drug distribution and pharmacokinetic profiles, where the changes can be 'general' (e.g. prolonged plasma half-life) or 'specific' (e.g. enhanced delivery to specific tissues in parallel with the macromolecular carriers). Another utility of LCs is to enhance the encapsulation of drugs within engineered nanoscale drug delivery systems, in order to best take advantage of the targeting and pharmacokinetic benefits of nanomedicines. The current review provides a summary of the mechanisms by which lipophilic conjugates, including in combination with delivery vehicles, can be used to control drug delivery, distribution and therapeutic profiles. The article is structured into sections which highlight a specific benefit of LCs and then demonstrate this benefit with case studies. The review attempts to provide a toolbox to assist researchers to design and optimise drug candidates, including consideration of drug-formulation compatibility.

Associations between brain and behavioral processing of facial expressions of emotion and sensory reactivity in young children.

The ability to decode and accurately identify information from facial emotions may advantage young children socially. This capacity to decode emotional information may likewise be influenced by individual differences in children's temperament. This study investigated whether sensory reactivity and perceptual awareness, two dimensions of temperament, as well as children's ability to accurately label emotions relates to the neural processing of emotional content in faces. Event related potentials (ERPs) of 4 to 6 year-old children (N  = 119) were elicited from static displays of anger, happy, fearful, sad, and neutral emotion faces. Children, as a group, exhibited differential early (N290) and mid-latency (P400) event-related potentials (ERPs) in response to facial expressions of emotion. Individual differences in children's sensory reactivity were associated with enhanced P400 amplitudes to neutral, sad, and fearful faces. In a separate task, children were asked to provide an emotional label for the same images. Interestingly, children less accurately labeled the same neutral, sad, and fearful faces, suggesting that, contrary to previous work showing enhanced attentional processing to threatening cues (i.e., fear), children higher in sensory reactivity may deploy more attentional resources when decoding ambiguous emotional cues.

Early life trauma: An exploratory study of effects on OXTR and NR3C1 gene expression and nurturing self-efficacy in mothers of infants.

BACKGROUND: In animals, adverse early experience alters oxytocinergic and glucocorticoid activity and maternal behavior in adulthood. This preliminary study explored associations among childhood trauma (loss of a parent or sexual abuse in childhood), maternal self-efficacy, and leukocyte gene expression (mRNA) of oxytocin and glucocorticoid receptors (OXTR and NR3C1) in mothers of infants. METHODS: 62 mothers (20 with early life trauma) with healthy 3-month old infants reported maternal self-efficacy, depression, infant temperament, and overall social support; the effects of early trauma on these measures were assessed. Of these, 35 mothers (14 with early trauma) underwent blood draws after 2 infant feeding times; their OXTR and NR3C1 mRNA was compared to a control group of 25 no-infant women without early trauma, and also was examined for associations with self-efficacy. RESULTS: OXTR mRNA was increased in mothers of infants versus no-infant controls (p < 0.0003), and mothers with greatest prior maternal experience had higher OXTR than those with less experience (0-2 vs. 3+ older children, p < 0.033). Mothers with early trauma and less maternal experience had lower OXTR mRNA than no-trauma mothers (p < 0.029) and lower NR3C1 mRNA than controls (p < 0.004). Mothers with depression also had lower NR3C1 than other mothers (p < 0.003) but did not differ in OXTR. Mothers with early trauma also reported their support network to be less helpful and more upsetting and unpredictable than other mothers (p < 0.035-p < 0.005). Regarding maternal behavior, in mothers with early trauma, helpful support networks increased self-reported nurturing self-efficacy when babies were not fussy but decreased it with fussy babies (p < 0.05). Support was unrelated to self-efficacy in no-trauma mothers. Similarly, among mothers with low OXTR or NR3C1 (-1SD, most having early trauma and lower maternal experience), greater support was associated with lower self-efficacy (p < 0.05), while mothers with high OXTR or NR3C1 (+1SD) tended to have higher self-efficacy with greater support. CONCLUSIONS: These preliminary findings need confirmation in a larger sample but suggest that childhood trauma influences maternal behavior and both OXTR and NR3C1 pathways in mothers of infants, and that both depression and prior maternal experience may be other important factors. Effects on maternal behavior appear to require more complex modeling.

Behavioral and Neural Foundations of Multisensory Face-Voice Perception in Infancy.

In this article, we describe behavioral and neurophysiological evidence for infants' multimodal face-voice perception. We argue that the behavioral development of face-voice perception, like multimodal perception more broadly, is consistent with the intersensory redundancy hypothesis (IRH). Furthermore, we highlight that several recently observed features of the neural responses in infants converge with the behavioral predictions of the intersensory redundancy hypothesis. Finally, we discuss the potential benefits of combining brain and behavioral measures to study multisensory processing, as well as some applications of this work for atypical development.

Relational congruence facilitates neural mapping of spatial and temporal magnitudes in preverbal infants.

Mental representations of space, time, and number are fundamental to our understanding of the world around us. It should come as no surprise that representations of each are functional early in human development, appear to share a common format, and may be maintained by overlapping cortical structures. The consequences of these similarities for early learning and behavior are poorly understood. We investigated this issue by assessing neurophysiological processing of audio-visual temporal and spatial magnitude pairs using event-related potentials (ERPs) with young infants. We observed differential early processing and later enhanced attentional processing for pairings of spatial and temporal magnitudes that were relationally congruent (short visual character paired with a short auditory tone or long visual character paired with a long auditory tone) compared to the same stimuli paired in a relationally incongruent manner (short visual character with the long auditory tone or long visual character with a short tone). Unlike previous studies, these results were not dependent on a redundancy of information between the senses or an alignment of congruent magnitude properties within a single sense modality. Rather, these results demonstrate that mental representations of space and time interact to bias learning before formal instruction or the acquisition of spatial language.

Neural signatures of face-voice synchrony in 5-month-old human infants.

Infants' unitary perception of their multisensory world, including learning from people (faces and speech), hinges on temporal synchrony. Despite its importance, relatively little work has investigated the brain processes involved in infants' perception of temporal synchrony. In two experiments, we examined event-related brain potentials (ERPs) to asynchronous and synchronous audio-visual speech in infants. Both experiments showed the early auditory P2 was greater for the synchronously presented pairings and later attentional processing (Nc) was greater for asynchronous pairings. In addition, dynamic stimuli used in Experiment 2 produced a greater early visual response (N1) to the asynchronous condition and an enhanced memory-related slow wave (PSW) later for the synchronous condition. These results suggest that, like adults, auditory-visual integration for young infants begins early during sensory processing rather than later during higher-level cognitive processing. However, unlike adults, infants' brain responses may be biased towards synchrony. Furthermore, effects of attentional and memory processing confirm interpretations of behavioral looking patterns suggesting infants find synchrony more familiar.

Alcohol-related emergency department attendances: is preloading a risk factor? Cross-sectional survey.

INTRODUCTION: 'Preloading' is a phenomenon where people drink alcohol at a private residence before going out. We aimed to identify whether preloading is a risk factor for alcohol-related emergency department attendance. We also wanted to identify where people became injured or unwell. METHODS: We conducted a cross-sectional, anonymous, survey at peak drinking times in our emergency department. We interviewed adult patients who presented to our emergency department with an alcohol-related presentation over an 8-week period. RESULTS: We approached 1,079 patients. One hundred sixty-one had suffered an alcohol-related problem while out drinking; 27% of women and 14% of men had their first drink at home. There was no particular presentation or age group that was associated with preloading. Seventy percent of patients stated that they had drunk most of their alcohol at a public place; 76% of patients suffered their alcohol-related problem at a site different from where they had drunk most of their alcohol or where they had had their first drink. CONCLUSION: Preloading is more common in women than men. Preloading is common in alcohol-related emergency department attendances. The proportions of patients preloading in this study are lower than in other studies conducted in different environments. Preloading is not a risk factor for alcohol-related emergency department attendance. Polices to reduce alcohol-related harm should continue to focus on bars, nightclubs and pubs.

Visual stimulation enhances auditory processing in 3-month-old infants and adults.

Behavioral work demonstrates human infants are sensitive to a host of intersensory properties and this sensitivity promotes early learning and memory. However, little is known regarding the neural basis of this ability in infants. Using event-related potentials (ERPs) with infants and adults, we show that during passive viewing auditory evoked brain responses are increased with the presence of simultaneous visual stimulation. Results converge with previous adult neuroimaging studies, single-cell recordings in nonhuman animals, and behavioral studies with human infants to provide evidence for an elevated status of multisensory stimulation in infancy. Furthermore, these results may provide a neural marker of multisensory audio-visual processing in infants that can be used to test developmental theories of how information is integrated across the senses to form a unitary perception of the world.

Racial differences in serum prostate-specific antigen (PSA) doubling time, histopathological variables and long-term PSA recurrence between African-American and white American men undergoing radical prostatectomy for clinically localized prostate cancer.

OBJECTIVE: To determine if there are significant differences in biochemical characteristics, biopsy variables, histopathological data, and rates of prostate-specific antigen (PSA) recurrence between African-American (AA) and white American (WA) men undergoing radical prostatectomy (RP), as AA men are twice as likely to die from prostate cancer than their white counterparts. PATIENTS AND METHODS: We established a cohort of 1058 patients (402 AA, 646 WA) who had RP and were followed for PSA recurrence. Age, race, serum PSA, biopsy Gleason score, clinical stage, pathological stage, and PSA recurrence data were available for the cohort. The chi-square test of proportions and t-tests were used to assess basic associations with race, and log-rank tests and Cox regression models for time to PSA recurrence. Forward stepwise variable selection was used to assess the effect on the risk of PSA recurrence for race, adjusted by the other variables added one at a time. RESULTS: The AA men had higher baseline PSA levels, more high-grade prostatic intraepithelial neoplasia (HGPIN) in the biopsy, and more HGPIN in the pathology specimen than WA men. The AA men also had a shorter mean (sd) PSA doubling time before RP, at 4.2 (4.7) vs 5.2 (5.9) years. However, race was not an independent predictor of PSA recurrence (P = 0.225). Important predictors for PSA recurrence in a multivariable model were biopsy HGPIN (P < 0.014), unilateral vs bilateral cancer (P < 0.006), pathology Gleason score and positive margin status (both P < 0.001). CONCLUSIONS: This study indicates that while there are racial differences in baseline serum PSA and incidence of HGPIN, race is not an independent risk factor for PSA recurrence. Rather, other variables such as pathology Gleason score, bilateral cancers, HGPIN and margin positivity are independently associated with PSA recurrence. The PSA doubling time after recurrence may also be important, leading to the increased mortality of AA men with prostate cancer.

Optimization and evaluation of surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF MS) with reversed-phase protein arrays for protein profiling.

Surface-enhanced laser desorption/ionization (SELDI) time-of-flight mass spectrometry with protein arrays has facilitated the discovery of disease-specific protein profiles in serum. Such results raise hopes that protein profiles may become a powerful diagnostic tool. To this end, reliable and reproducible protein profiles need to be generated from many samples, accurate mass peak heights are necessary, and the experimental variation of the profiles must be known. We adapted the entire processing of protein arrays to a robotics system, thus improving the intra-assay coefficients of variation (CVs) from 45.1% to 27.8% (p<0.001). In addition, we assessed up to 16 technical replicates, and demonstrated that analysis of 2-4 replicates significantly increases the reliability of the protein profiles. A recent report on limited long-term reproducibility seemed to concord with our initial inter-assay CVs, which varied widely and reached up to 56.7%. However, we discovered that the inter-assay CV is strongly dependent on the drying time before application of the matrix molecule. Therefore, we devised a standardized drying process and demonstrated that our optimized SELDI procedure generates reliable and long-term reproducible protein profiles with CVs ranging from 25.7% to 32.6%, depending on the signal-to-noise ratio threshold used.