Improving Children's Behavior in Seven Sessions: A Randomized Controlled Trial of Parent-Child Care (PC-CARE) for Children Aged 2-10 Years.

Parent-Child Care (PC-CARE) is a brief intervention for children with externalizing behaviors designed to address issues with their access to and retention in treatment. A growing evidence base of open trials and comparison studies support PC-CARE's benefits, but no randomized controlled trials (RCTs) of its effectiveness exist. The current study presents the first RCT of PC-CARE, a 7-session dyadic parenting intervention (trial number removed for blind review). Participants included a racially/ethnically diverse sample of 49 children (29% female) aged 2-10 years and their caregivers. Participants were randomly assigned to PC-CARE or waitlist control. Families participating in PC-CARE showed greater reductions in children's externalizing behaviors, improvements in children's adaptive skills, declines in parental stress, and increases in parents' positive communication skills, compared to families on the waitlist. The results of this first RCT of PC-CARE support the effectiveness of this brief intervention in improving children's behaviors.

Isolation housing elevates amphetamine seeking independent of nucleus accumbens glutamate receptor adaptations.

Overdose death rates caused by psychostimulants have increased by 22.3% annually from 2008 to 2017. Cue-evoked drug craving progressively increases and contributes to perpetual relapse. Preclinical models have determined that glutamate receptor plasticity within the nucleus accumbens (NAc) drives amplified cue-evoked drug seeking after prolonged abstinence (>40 days). Isolated condition (IC) rearing increases cocaine and amphetamine (AMP) self-administration and cue-induced reinstatement. We tested the hypothesis that housing in the IC will augment AMP seeking after short and prolonged abstinence from AMP self-administration when compared with rats reared in the enrichment condition (EC). EC and IC male rats acquired stable AMP or SAL self-administration and were tested in a cue-induced AMP-seeking test after 1 and 40 days of abstinence. After the seeking test, the whole NAc was extracted and prepared for western blot analysis. Results indicate that IC rats had more active lever presses during a brief extinction interval and during the cue-induced seeking test. After 40 days of abstinence, IC rats had more active lever presses than EC rats during the cue-induced seeking test. Western blots indicated that the expression ratio between GluA1:mGlur5 was reduced only in IC-AMP-trained rats and the ratio between GluA1:mGlur1 was positively correlated with AMP seeking after prolonged abstinence in IC-AMP rats. These results indicate that IC housing engenders a vulnerable phenotype prone to persistent AMP seeking. The behavioural momentum of this vulnerable phenotype is further revealed when AMP-associated cues are presented following prolonged abstinence.

FGF, BMP, and RA signaling are sufficient for the induction of complete limb regeneration from non-regenerating wounds on Ambystoma mexicanum limbs.

Some organisms, such as the Mexican axolotl, have the capacity to regenerate complicated biological structures throughout their lives. Which molecular pathways are sufficient to induce a complete endogenous regenerative response in injured tissue is an important question that remains unanswered. Using a gain-of-function regeneration assay, known as the Accessory Limb Model (ALM), we and others have begun to identify the molecular underpinnings of the three essential requirements for limb regeneration; wounding, neurotrophic signaling, and the induction of pattern from cells that retain positional memory. We have previously shown that treatment of Mexican axolotls with exogenous retinoic acid (RA) is sufficient to induce the formation of complete limb structures from blastemas that were generated by deviating a nerve bundle into an anterior-located wound site on the limb. Here we show that these ectopic structures are capable of regenerating and inducing new pattern to form when grafted into new anterior-located wounds. We additionally found that the expression of Alx4 decreases, and Shh expression increases in these anterior located blastemas, but not in the mature anterior tissues, supporting the hypothesis that RA treatment posteriorizes blastema tissue. Based on these and previous observations, we used the ALM assay to test the hypothesis that a complete regenerative response can be generated by treating anterior-located superficial limb wounds with a specific combination of growth factors at defined developmental stages. Our data shows that limb wounds that are first treated with a combination of FGF-2, FGF-8, and BMP-2, followed by RA treatment of the resultant mid-bud stage blastema, will result in the generation of limbs with complete proximal/distal and anterior/posterior limb axes. Thus, the minimal signaling requirements from the nerve and a positional disparity are achieved with the application of this specific combination of signaling molecules.

In vitro and in vivo characterization of an interleukin-15 antagonist peptide by metabolic stability, 99m Tc-labeling, and biological activity assays.

Interleukin (IL)-15 is an inflammatory cytokine that constitutes a validated therapeutic target in some immunopathologies, including rheumatoid arthritis (RA). Previously, we identified an IL-15 antagonist peptide named [K6T]P8, with potential therapeutic application in RA. In the current work, the metabolic stability of this peptide in synovial fluids from RA patients was studied. Moreover, [K6T]P8 peptide was labeled with 99m Tc to investigate its stability in human plasma and its biodistribution pattern in healthy rats. The biological activity of [K6T]P8 peptide and its dimer was evaluated in CTLL-2 cells, using 3 different additives to improve the solubility of these peptides. The half-life of [K6T]P8 in human synovial fluid was 5.88 ± 1.73 minutes, and the major chemical modifications included peptide dimerization, cysteinylation, and methionine oxidation. Radiolabeling of [K6T]P8 with 99m Tc showed a yield of approximately 99.8%. The 99m Tc-labeled peptide was stable in a 30-fold molar excess of cysteine and in human plasma, displaying a low affinity to plasma proteins. Preliminary biodistribution studies in healthy Wistar rats suggested a slow elimination of the peptide through the renal and hepatic pathways. Although citric acid, sucrose, and Tween 80 enhanced the solubility of [K6T]P8 peptide and its dimer, only the sucrose did not interfere with the in vitro proliferation assay used to assess their biological activity. The results here presented, reinforce nonclinical characterization of the [K6T]P8 peptide, a potential agent for the treatment of RA and other diseases associated with IL-15 overexpression.

Comparison of maternal beliefs about causes of autism spectrum disorder and association with utilization of services and treatments.

BACKGROUND: This study aimed to describe parental perceptions of the causes of autism spectrum disorder (ASD) in an ethnically diverse sample and explore whether these perceptions relate to treatment choices. METHODS: The sample consisted of White (n = 224), Hispanic (n = 85), and Asian (n = 21) mothers of a child with ASD. A mixed methods approach was used in this secondary analysis focusing on parental perceptions about the causes of ASD and the relationship of these to utilization of services and treatment. RESULTS: Environmental and genetic factors were most often believed to be the cause or one of the causes of ASD by mothers across all ethnic groups studied. Asian mothers were more likely to cite multiple causes. Environmental causes were associated with receiving 20 or more hours of autism-related services per week, whereas belief in environmental exposures and vaccines and medications as causes were associated with complementary-alternative medicine (CAM) use. CONCLUSION: Our findings suggest that ethnic differences in autism causal beliefs and treatment choices may exist. Future research should be conducted to specifically confirm the findings, to understand parental motivation behind their service and treatment choices, and to gain more insight into the types, usage, and sources of CAM treatments. Clinicians can use parental autism causal beliefs in discussions about treatment recommendations.

The effect of targeted and tailored patient depression engagement interventions on patient-physician discussion of suicidal thoughts: a randomized control trial.

BACKGROUND: Despite improvements in the diagnosis and treatment of depression, primary care provider (PCP) discussion regarding suicidal thoughts among patients with depressive symptoms remains low. OBJECTIVE: To determine whether a targeted depression public service announcement (PSA) video or an individually tailored interactive multimedia computer program (IMCP) leads to increased primary care provider (PCP) discussion of suicidal thoughts in patients with elevated risk for clinical depression when compared to an attention control. DESIGN: Randomized control trial at five different healthcare systems in Northern California; two academic, two Veterans Affairs (VA), and one group-model health maintenance organization (HMO). PARTICIPANTS: Eight-hundred sixty-seven participants, with mean age 51.7; 43.9% women, 43.4% from a racial/ethnic minority group. INTERVENTION: The PSA was targeted to gender and socio-economic status, and designed to encourage patients to seek depression care or request information regarding depression. The IMCP was an individually tailored interactive health message designed to activate patients to discuss possible depressive symptoms. The attention control was a sleep hygiene video. MAIN MEASURES: Clinician reported discussion of suicidal thoughts. Analyses were stratified by depressive symptom level (Patient Health Questionnaire [PHQ-9] score < 9 [mild or lower] versus ≥ 10 [at least moderate]). KEY RESULTS: Among patients with a PHQ-9 score ≥ 10, PCP discussion of suicidal thoughts was significantly higher in the IMCP group than in the control group (adjusted odds ratio = 2.33, 95% confidence interval = 1.5, 5.10, p = 0.03). There were no significant effects of either intervention on PCP discussion of suicidal thoughts among patients with a PHQ-9 score < 9. CONCLUSIONS: Exposure of patients with at least moderate depressive symptoms to an individually tailored intervention designed to increase patient engagement in depression care led to increased PCP discussion of suicidal thoughts.

Biological sex modulates the efficacy of 2,5-dimethoxy-4-iodoamphetamine (DOI) to mitigate fentanyl demand.

BACKGROUND: Overdose deaths remain high for opioid use disorder, emphasizing the need to pursue innovative therapeutics. Classic psychedelic drugs that engage many monoamine receptors mitigate opioid use. Here, we tested the hypothesis that the preferential serotonin 5-HT2AR agonist, 2,5-dimethoxy-4-iodoamphetamine (DOI) could reduce the demand for fentanyl in a preclinical model of fentanyl self-administration. METHODS: Male and female Sprague-Dawley rats (n = 25-29) were implanted with indwelling jugular catheters and allowed to self-administer fentanyl (3.2µg/kg/infusion). Rats progressed to a novel low price twice within-session threshold procedure where rats sampled the lowest price twice before decreasing the dose of fentanyl by a » log every 10minutes across 11 doses. Once stable, rats were pretreated with saline or DOI (0.01, 0.03, 1mg/kg). Fentanyl consumption was analyzed using an exponentiated demand function to extract the dependent variables, Q0 and α. RESULTS: Male and female rats acquired fentanyl self-administration in the lowest price twice within-session threshold procedure. DOI dose-dependently altered fentanyl intake such that 5-HT2AR activation decreased Q0 in female rats but increased Q0 in male rats. For demand elasticity, DOI increased α in male rats but did not alter α in female rats. DOI did not alter inactive lever presses or latency. CONCLUSION: DOI reduces consumption at minimally constrained costs but did not affect the reinforcement value of fentanyl in female rats. Alternatively, DOI significantly reduced the reinforcement value of fentanyl in male rats. Biological sex alters the therapeutic efficacy of DOI and 5-HT2AR activation sex-dependently alters opioid reinforcement.

Early Estrogen Replacement Therapy Attenuates Cardiac Dysfunction Caused by Aging and Ovariectomy in Female Wistar Rats.

BACKGROUND: Cardiovascular diseases (CVDs) are the leading cause of women's mortality, linked to aging and reduced estrogen during menopause. Estrogen replacement therapy (ERT) is suggested for CVDs prevention. Yet, its timing initiation remains contentious. Thus, we aimed to evaluate the effect of early and late estrogen therapy on cardiac function and lipid metabolism in ovariectomized old female Wistar rats. METHODS: Fifty randomized female Wistar rats were included in 5 groups (n = 10, 18 months old): (1) Sham, (2) 10 weeks post ovariectomy (Ovx-10 w), (3) 10 weeks post Ovx + early estrogen replacement therapy (Ovx 10 w-early ERT), (4) 20 weeks post Ovx (Ovx-20 w) and (5) Ovx 20 w-late ERT. Three days (early ERT) or 10 weeks (late ERT) after surgery 17-ß estradiol was given (5 µg/kg/day), and 10 weeks after the start of ERT, we assessed cardiac function by echocardiography, electrocardiography, and cardiac catheterization. Estradiol, cholesterol, triglyceride (TG), high-density lipoprotein (HDL) and low-density lipoprotein (LDL) levels were determined. Cardiac histology was performed with Masson's staining. RESULTS: Ovariectomy (Ovx) increases left ventricle internal systolic diameter (0.4 vs 0.3 cm, *p = 0.020) and decreases shortening fraction (40 vs 54 %, *p = 0.030) regardless of therapy. ERT prevents the increase in left ventricle mass after 10 weeks post-Ovx and the ejection fractionreduction after 20 weeks. Lower P wave amplitudes (18.8 vs 24.2 ms, *p = 0.013) were found in the Ovx-20 w group. A longer duration of the QRS complex after 20 weeks post-Ovx with and without ERT was found (32.5 and 32.1 vs 28.3 ms, *p = 0.003; *p = 0.007). Diastolic blood pressure was higher 20 weeks post-Ovx (86 vs 76 mmHg, *p = 0.047), regardless of ERT. The left ventricle (LV) -dP/dt was decreased in Ovx groups without ERT (-750 vs -1320 mmHg, *p = 0.034). An increase in LV collagen deposition was found in the Ovx 10 w group vs Sham (9.58 vs 4.54 %, *p = 0.028). Early ERT avoids the increase in body weight, cholesterol and LDL caused by Ovx. CONCLUSIONS: Ovariectomy causes time-dependent alterations in lipid metabolism, morphology, electrical activity, and heart contractile function. Early but not late ERT prevents some of these effects.

A lack of living donor renal transplantation for Asian children represents an opportunity to improve pediatric healthcare.

INTRODUCTION: The relationship between pediatric primary care practitioners and families provides an early opportunity to address ethnic/racial pediatric subspecialty health care disparities. Living donor pediatric renal transplantation is safe and more effective than deceased donor renal transplantation. The purpose of this study is to identify groups of children who may be less likely to receive living donor renal transplantation, as the first step in assisting pediatric clinicians to increase living donor renal transplantation. METHOD: We employed a retrospective cohort design. We analyzed data from the medical records of 80 children receiving renal transplantation over 20 years in a large pediatric medical center. RESULTS: The proportions of children receiving a living donor renal allograft differed by ethnicity/race (P = .04). Specifically, children of Asian ethnicity/ race were significantly less likely than children of White ethnicity/race to receive a living donor renal allograft (P = .01). There were no significant differences in age at transplantation or wait time for deceased donor transplantation. DISCUSSION: We discuss the possible reasons for the discrepancy and potential directions for family-centered pediatric practice, policy, and research to address this potential pediatric healthcare disparity.

COVID-19's Still-Urgent Lessons of Structural Inequality and Child Health in the United States.

COVID-19's lessons on structural inequality should have been painful and embarrassing to all of us. These daily experiences of an unacceptable status quo among US children are still with us in a post-COVID America. Addressing the multi-sectoral factors that undermine the nation...s health should remain urgent priorities for all health professionals.

Ghrelin receptor antagonist JMV2959 blunts cocaine and oxycodone drug-seeking, but not self-administration, in male rats.

The drug overdose crisis has spawned serious health consequences, including the increased incidence of substance use disorders (SUDs), conditions manifested by escalating medical and psychological impairments. While medication management is a key adjunct in SUD treatment, this crisis has crystallized the need to develop additional therapeutics to facilitate extended recovery from SUDs. The "hunger hormone" ghrelin acts by binding to the growth hormone secretagogue receptor 1α (GHS1αR) to control homeostatic and hedonic aspects of food intake and has been implicated in the mechanisms underlying SUDs. Preclinical studies indicate that GHS1αR antagonists and inverse agonists suppress reward-related signaling associated with cocaine and opioids. In the present study, we found that the GHS1αR antagonist JMV2959 was efficacious to suppress both cue-reinforced cocaine and oxycodone drug-seeking, but not cocaine or oxycodone self-administration in male Sprague-Dawley rats. These data suggest a role of the ghrelin-GHS1αR axis in mediating overlapping reward-related aspects of cocaine and oxycodone and premises the possibility that a GHS1αR antagonist may be a valuable therapeutic strategy for relapse vulnerability in SUDs.

Social Needs and Acculturation as Predictors of Emotional Problems and Perceived Stress Among Latinx Mothers with Low Income.

Associations between household social needs, acculturation, and emotional health remain understudied, particularly among Latinx mothers. We analyzed baseline survey data from 455 Latinx mothers in a previous study. Using multinomial regression, we examined whether emotional problems and perceived stress were associated with household social needs and acculturation. Almost half the sample reported four or more household social needs. Social needs cumulatively and independently predicted increased odds of frequent emotional problems or perceived stress. Lower acculturation predicted lower odds of frequent emotional problems. There is increased risk for emotional problems and stress in low-income Latinx mothers who experience high social need. Integrated social service and mental health care models may be one way to improve health outcomes. More research is needed to understand how clinical settings can leverage unique cultural protective factors to address the social and emotional health needs of Latinx mothers.

Household Social Needs, Emotional Functioning, and Stress in Low-Income Latinx Children and their Mothers.

Latinx families may be particularly vulnerable to emotional dysfunction, due to higher rates of economic hardship and complex social influences in this population. Little is known about the impact of environmental stressors such as unmet social needs and maternal stress on the emotional health of Latinx children from low-income families. We conducted secondary analyses using survey and biomarker data from 432 Latinx children and mothers collected in a separate study. We used binomial and multinomial logistic regression to test if household social needs, or maternal perceived stress or hair cortisol concentration (HCC), predicted child measures of emotional functioning or child HCC, independent of relevant sociodemographic factors. Approximately 40% of children in the sample had symptoms consistent with emotional dysfunction, and over 37% of households reported five or more social needs. High perceived maternal stress predicted higher odds of child emotional dysfunction (OR = 2.15; 95% CI [1.14, 4.04]; p = 0.01), and high maternal HCC was positively associated with high child HCC (OR = 10.60; 95% CI [4.20, 26.74]; p < 0.01). Most individual household social needs, as well as the level of household social need, were not independently associated with child emotional dysfunction or child HCC. Our findings begin to define a framework for understanding emotional health, stress, and resilience when caring for Latinx children and mothers living with high levels of social need, and the need for integrated mental health and social needs screening and interventions in settings that serve this population.

A mobile addiction service for community-based overdose prevention.

Mainstays of opioid overdose prevention include medications for opioid use disorder (e.g., methadone or buprenorphine) and naloxone distribution. Inadequate access to buprenorphine limits its uptake, especially in communities of color, and people with opioid use disorders encounter multiple barriers to obtaining necessary medications including insurance, transportation, and consistent availability of telephones. UMass Memorial Medical Center and our community partners sought to alleviate these barriers to treatment through the deployment of a mobile addiction service, called the Road to Care. Using this approach, multidisciplinary and interprofessional providers deliver holistic addiction care by centering our patients' needs with respect to scheduling, location, and convenience. This program also extends access to buprenorphine and naloxone among people experiencing homelessness. Additional systemic and individualized barriers encountered are identified, as well as potential solutions for future mobile addiction service utilization. Over a two-year period, we have cared for 1,121 individuals who have accessed our mobile addiction service in over 4,567 encounters. We prescribed buprenorphine/naloxone (Suboxone®) to 330 individuals (29.4% of all patients). We have distributed nearly 250 naloxone kits directly on-site or and more than 300 kits via prescriptions to local pharmacies. To date, 74 naloxone rescue attempts have been reported back to us. We have demonstrated that a community-based mobile addiction service, anchored within a major medical center, can provide high-volume and high-quality overdose prevention services that facilitate engagement with additional treatment. Our experience is described as a case study below.

Discovery of Novel Oleamide Analogues as Brain-Penetrant Positive Allosteric Serotonin 5-HT2C Receptor and Dual 5-HT2C/5-HT2A Receptor Modulators.

The serotonin 5-HT2A receptor (5-HT2AR) and 5-HT2CR localize to the brain and share overlapping signal transduction facets that contribute to their roles in cognition, mood, learning, and memory. Achieving selective targeting of these receptors is challenged by the similarity in their 5-HT orthosteric binding pockets. A fragment-based discovery approach was employed to design and synthesize novel oleamide analogues as selective 5-HT2CR or dual 5-HT2CR/5-HT2AR positive allosteric modulators (PAMs). Compound 13 (JPC0323) exhibited on-target properties, acceptable plasma exposure and brain penetration, as well as negligible displacement to orthosteric sites of ∼50 GPCRs and transporters. Furthermore, compound 13 suppressed novelty-induced locomotor activity in a 5-HT2CR-dependent manner, suggesting 5-HT2CR PAM, but not 5-HT2AR, activity at the level of the whole organism at the employed doses of 13. We discovered new selective 5-HT2CR PAMs and first-in-class 5-HT2CR/5-HT2AR dual PAMs that broaden the pharmacological toolbox to explore the biology of these vital receptors.

Feeling labeled, judged, lectured, and rejected by family and friends over depression: cautionary results for primary care clinicians from a multi-centered, qualitative study.

BACKGROUND: Family and friends may help patients seek out and engage in depression care. However, patients' social networks can also undermine depression treatment and recovery. In an effort to improve depression care in primary care settings, we sought to identify, categorize, and alert primary care clinicians to depression-related messages that patients hear from friends and family that patients perceive as unhelpful or detrimental. METHODS: We conducted 15 focus groups in 3 cities. Participants (n = 116) with a personal history or knowledge of depression responded to open-ended questions about depression, including self-perceived barriers to care-seeking. Focus group conversations were audio-recorded and analyzed using iterative qualitative analysis. RESULTS: Four themes emerged related to negatively-received depression messages delivered by family and friends. Specifically, participants perceived these messages as making them feel labeled, judged, lectured to, and rejected by family and friends when discussing depression. Some participants also expressed their interpretation of their families' motivations for delivering the messages and described how hearing these messages affected depression care. CONCLUSIONS: The richness of our results reflects the complexity of communication within depression sufferers' social networks around this stigmatized issue. To leverage patients' social support networks effectively in depression care, primary care clinicians should be aware of both the potentially beneficial and detrimental aspects of social support. Specifically, clinicians should consider using open-ended queries into patients' experiences with discussing depression with family and friends as an initial step in the process. An open-ended approach may avoid future emotional trauma or stigmatization and assist patients in overcoming self-imposed barriers to depression discussion, symptom disclosure, treatment adherence and follow-up care.

ST-Elevation Myocardial Infarction With Occluded Culprit Coronary Artery in a Young Patient Recovered From Mild COVID-19: A Case Report.

ST-elevation myocardial infarction (STEMI) is a cardiovascular emergency that requires an early reperfusion strategy to reduce mortality and hemodynamic, mechanical, and electrical complications. STEMI is more frequent in men older than 40 years with well-known cardiovascular risk factors such as hypertension, diabetes mellitus, dyslipidemia, and smoking. The coronavirus disease 2019 (COVID-19) changed this reality worldwide due to the fact that STEMI cases associated with severe forms of COVID-19 began to be reported, which generally affected the older adult population; in contrast, there is still limited data on young healthy patients recovering from mild COVID-19. The exact mechanism behind the association remains unclear. We present a case of a healthy 29-year-old man with a history of mild COVID-19, diagnosed by reverse-transcription polymerase chain reaction 20 days before his admission with inferior STEMI. Coronary angiography revealed an occluded mid-right coronary artery, and he was successfully treated with a drug-eluting stent. The patient evolved favorably and was discharged on the fifth day of hospitalization.

Automated Systems for Calculating Arteriovenous Ratio in Retinographies: A Scoping Review.

There is evidence of an association between hypertension and retinal arteriolar narrowing. Manual measurement of retinal vessels comes with additional variability, which can be eliminated using automated software. This scoping review aims to summarize research on automated retinal vessel analysis systems. Searches were performed on Medline, Scopus, and Cochrane to find studies examining automated systems for the diagnosis of retinal vascular alterations caused by hypertension using the following keywords: diagnosis; diagnostic screening programs; image processing, computer-assisted; artificial intelligence; electronic data processing; hypertensive retinopathy; hypertension; retinal vessels; arteriovenous ratio and retinal image analysis. The searches generated 433 articles. Of these, 25 articles published from 2010 to 2022 were included in the review. The retinographies analyzed were extracted from international databases and real scenarios. Automated systems to detect alterations in the retinal vasculature are being introduced into clinical practice for diagnosis in ophthalmology and other medical specialties due to the association of such changes with various diseases. These systems make the classification of hypertensive retinopathy and cardiovascular risk more reliable. They also make it possible for diagnosis to be performed in primary care, thus optimizing ophthalmological visits.

An Experimental Analysis of the High-Cycle Fatigue Fracture of H13 Hot Forging Tool Steels.

In this study, the axial fatigue behaviour of hot forging tool steels at room temperature was investigated. Fatigue tests were performed on two steels within the same H13 specification. The fatigue tests were carried out in the high-cycle fatigue domain under normal conditions. These tests were also performed on specimens in contact with a corrosive medium, applying stress values that led to the high-cycle fatigue domain under normal conditions for the sake of comparison. Both materials showed similar fatigue strengths when they were tested under normal conditions. In contrast, corrosion fatigue lives were much lower than in normal tests and differed significantly between the two steels. Crack initiation was triggered by microstructural and surface defects in the normal tests, whereas the formation of corrosion pits caused crack initiation in the corrosion fatigue tests. Moreover, a fracture surface analysis revealed dissimilar crack propagation areas between both steels, which suggested that both steels had different fracture toughness. These results were in line with the differences observed between the carbide and grain sizes of both of the material microstructures.