Parental request for familial carrier testing in early childhood: The genetic counseling perspective.

Professional guidelines generally caution against carrier testing in minors, though prior research indicates parents request and providers sometimes facilitate testing for unaffected siblings of a child affected by a genetic disorder. We investigated the perspectives of genetic counselors in North America regarding carrier testing prior to adolescence. Practicing genetic counselors (n = 177) responded to an electronic survey assessing their willingness to facilitate testing in four hypothetical scenarios and their evaluation of parental motivations. Participants did not find parental arguments for testing persuasive, and most were unwilling to facilitate carrier testing in children. A significant interaction effect indicated the presence of nonactionable carrier-associated health risks in adulthood made participants significantly less hesitant when the mode of inheritance was X-linked. Participants considered parental motivations that center the child's interests as significantly more persuasive. This study suggests genetic counselors are resistant to carrier testing for familial disorders in young children and tend to align with current guidelines, yet they recognize nuance in various cases. Further investigation into this topic is warranted to support genetic counselors facing these requests as the ethics of pediatric carrier testing continues to be debated.

Clinical and molecular spectrum of thymidine kinase 2-related mtDNA maintenance defect.

Mitochondrial DNA maintenance (mtDNA) defects have a wide range of causes, each with a set of phenotypes that overlap with many other neurological or muscular diseases. Clinicians face the challenge of narrowing down a long list of differential diagnosis when encountered with non-specific neuromuscular symptoms. Biallelic pathogenic variants in the Thymidine Kinase 2 (TK2) gene cause a myopathic form of mitochondrial DNA maintenance defect. Since the first description in 2001, there have been 71 patients reported with 42 unique pathogenic variants. Here we are reporting 11 new cases with 5 novel pathogenic variants. We describe and analyze a total of 82 cases with 47 unique TK2 pathogenic variants in effort to formulate a comprehensive molecular and clinical spectrum of TK2-related mtDNA maintenance disorders.

Outcomes of Trabecular Metal-backed glenoid components in anatomic total shoulder arthroplasty.

BACKGROUND: As glenoid failure is one of the primary causes of failure of anatomic total shoulder arthroplasty (TSA), Trabecular Metal-backed glenoid components have become popular. This study reports implant survival and clinical outcomes of patients who received a Trabecular Metal-backed glenoid component during primary anatomic TSA. METHODS: Patients who underwent TSA with a Trabecular Metal-backed glenoid component by a single surgeon were identified and reviewed for clinical, radiographic, and patient-reported outcome measures with a minimum of 2 years' follow-up. RESULTS: Of 47 patients identified, radiographic and clinical follow-up was available on 36 patients (77%). Average age was 66.36 years (range, 50-85 years), and the average follow-up 41 months (range, 24-66 months). Three patients showed signs of osteolysis, 4 had radiographic evidence of metal debris, and 1 patient had a catastrophic failure after a fall. Of the 47 TSAs, 5 (11%) were revised to a reverse TSA for subscapularis failure and pain. Visual analog scale for pain scores improved by an average of 4.4. At final follow-up, the average Single Assessment Numeric Evaluation score was 72.4; Penn satisfaction score, 7.5; Penn score, 70.35; and American Shoulder and Elbow Surgeons score, 69.23. Outcome scores were similar in the 7 patients with osteolysis or metal debris compared to those without. CONCLUSION: Trabecular Metal-backed glenoids had a 25% rate of radiographic metal debris and osteolysis at a minimum 2-year follow-up in this series with one catastrophic failure. This implant should be used with caution, and patients followed closely.

Loss of SYNJ1 dual phosphatase activity leads to early onset refractory seizures and progressive neurological decline.

SYNJ1 encodes a polyphosphoinositide phosphatase, synaptojanin 1, which contains two consecutive phosphatase domains and plays a prominent role in synaptic vesicle dynamics. Autosomal recessive inherited variants in SYNJ1 have previously been associated with two different neurological diseases: a recurrent homozygous missense variant (p.Arg258Gln) that abolishes Sac1 phosphatase activity was identified in three independent families with early onset parkinsonism, whereas a homozygous nonsense variant (p.Arg136*) causing a severe decrease of mRNA transcript was found in a single patient with intractable epilepsy and tau pathology. We performed whole exome or genome sequencing in three independent sib pairs with early onset refractory seizures and progressive neurological decline, and identified novel segregating recessive SYNJ1 defects. A homozygous missense variant resulting in an amino acid substitution (p.Tyr888Cys) was found to impair, but not abolish, the dual phosphatase activity of SYNJ1, whereas three premature stop variants (homozygote p.Trp843* and compound heterozygote p.Gln647Argfs*6/p.Ser1122Thrfs*3) almost completely abolished mRNA transcript production. A genetic follow-up screening in a large cohort of 543 patients with a wide phenotypical range of epilepsies and intellectual disability revealed no additional pathogenic variants, showing that SYNJ1 deficiency is rare and probably linked to a specific phenotype. While variants leading to early onset parkinsonism selectively abolish Sac1 function, our results provide evidence that a critical reduction of the dual phosphatase activity of SYNJ1 underlies a severe disorder with neonatal refractory epilepsy and a neurodegenerative disease course. These findings further expand the clinical spectrum of synaptic dysregulation in patients with severe epilepsy, and emphasize the importance of this biological pathway in seizure pathophysiology.

The incidence and effect of fatty atrophy, positive tangent sign, and rotator cuff tears on outcomes after total shoulder arthroplasty.

BACKGROUND: Treatment choices for total shoulder arthroplasty (TSA) in the absence of full-thickness rotator cuff tears (RCTs) are not clearly defined in current literature. This study investigated the prevalence and effect of preoperative partial-thickness RCTs and muscular degenerative changes on postoperative outcomes after TSA. METHODS: Medical records and magnetic resonance imaging studies were reviewed for patients who underwent TSA for primary glenohumeral osteoarthritis with minimum 2-year follow-up to determine preoperative tear classification, Goutallier grade, and supraspinatus tangent sign. Postoperative pain on the visual analog scale, range of motion, and patient outcomes scores were obtained to correlate preoperative RCT status, Goutallier grading, tangent sign, and postoperative outcomes. Patients with full-thickness RCT on preoperative magnetic resonance imaging were excluded. RESULTS: Forty-five patients met all inclusion criteria (average age, 65 ± 10 years; average follow-up, 43 months). Of the patients undergoing TSA, 40% had a significant (>50% thickness) partial RCT. Grade 3 to 4 Goutallier changes were noted in 22% of all patients, and 13% demonstrated grade 3 to 4 changes in the context of no tear. Positive tangent sign was present in 7% of all patients. The preoperative Goutallier grade of the infraspinatus was significantly negatively correlated with postoperative forward elevation (P = .02) and external rotation (P = .05), but rotator cuff pathology, including tear status, Goutallier grade, and the presence of a tangent sign, did not correlate with postoperative functional outcome scores. CONCLUSIONS: Even in the absence of a full-thickness RCT, rotator cuff atrophy, fatty infiltration, and partial thickness tearing are common findings. Although postoperative range of motion is correlated to Goutallier changes of the infraspinatus, rotator cuff pathology is not correlated to outcomes after TSA; therefore, one may proceed with TSA without concern of their effect on postoperative outcomes.

Resilience correlates with outcomes after total shoulder arthroplasty.

BACKGROUND: Resilience, characterized by an ability to bounce back or recover from stress, is increasingly recognized as a psychometric property affecting many outcomes' domains including quality of life, suicide risk in active-duty military personnel, and recovery in cancer patients. This study examines the correlation between resilience, as measured by the Brief Resilience Scale (BRS), and traditional outcome scores including the American Shoulder and Elbow Surgeons (ASES), Single Assessment Numeric Evaluation (SANE), and Penn scores in patients undergoing total shoulder arthroplasty (TSA). METHODS: Seventy patients undergoing primary anatomic TSA were followed up for a minimum of 2 years (mean, 30 ± 3 months). Patients were stratified into groups a priori, based on deviation from the mean of the BRS score, into low-resilience (LR), normal-resilience (NR), and high-resilience (HR) patients, and outcome scores were calculated for each group. RESULTS: Postoperative BRS scores significantly correlated with ASES, Penn, and SANE scores (r = 0.41-0.44, P < .004 for all scores). When we evaluated patients based on resilience group, the LR group had a Penn score that was 34 points lower than that in the HR group. Likewise, the LR group had a SANE score that averaged 40 points lower than that in the HR group (SANE score of 53 points in LR group and 92 points in HR group, P = .05). When we evaluated ASES subscores, it appeared that the pain subscale was responsible for most of the difference between the LR and HR groups (29 points and 48 points [out of 50 points], respectively; P = .03). CONCLUSIONS: Resilience is a major predictor of postoperative outcomes after TSA. Patients who are classified as having LR have outcome scores that are 30 to 40 points lower on traditional outcome scales than patients with HR.

Liposomal bupivacaine versus indwelling interscalene nerve block for postoperative pain control in shoulder arthroplasty: a prospective randomized controlled trial.

BACKGROUND: Pain management strategies following shoulder arthroplasty vary significantly. Liposomal bupivacaine (LB) is an extended-release delivery of a phospholipid bilayer encapsulating bupivacaine that can result in drug delivery up to 72 hours. Prior studies in lower extremity surgery demonstrated efficacy of LB in comparison to a single-shot peripheral nerve block; however, no study has investigated LB in a total shoulder arthroplasty population. Therefore, this study compared LB vs. an indwelling interscalene nerve block (IINB). METHODS: This is a prospective, randomized study of 83 consecutive shoulder arthroplasty patients; 36 patients received LB and a "bridge" of 30 mL of 0.5% bupivacaine, and 47 patients received an IINB. Postoperative visual analog scale pain levels, opiate consumption measured with oral morphine equivalents, length of hospital stay, and postoperative complications were recorded. Continuous variables were compared using an analysis of variance with significance set at P < .05. RESULTS: Visual analog scale pain scores were statistically higher in the LB cohort immediately postoperatively in the postanesthesia care unit (7.25 vs. 1.91; P = .000) as well as for the remainder of postoperative day 0 (4.99 vs. 3.20; P = .005) but not for the remainder of admission. Opiate consumption was significantly higher among the LB cohort in the postanesthesia care unit (31.79 vs. 7.47; P = .000), on postoperative day 0 (32.64 vs. 15.04; P = .000), and for the total hospital admission (189.50 vs. 91.70, P = .000). Complication numbers and length of stay were not statistically different. CONCLUSION: Use of an IINB provides superior pain management in the immediate postoperative setting as demonstrated by decreased narcotic medication consumption and lower subjective pain scores.

Pediatric Pharyngeal IgD-positive Monoclonal Plasmacytoid and Plasma Cell Neoplasm.

Pediatric neoplasm with monoclonal proliferation of lymphoplasmacytoid lymphocytes and plasma cells is exceedingly rare and has essentially never been reported in immunocompetent children. Here, we report a previously healthy 13-year-old girl with a pharyngeal mass and enlarged cervical lymph nodes. The pharyngeal mass was composed of CD138, CD79a, MUM-1, IgD, CD20, PAX-5, CD43, λ-restricted monoclonal plasmacytoid, and plasma cells. Scattered CD20, PAX-5 B cells were present in the background. The patient was treated as localized non-Hodgkin lymphoma (stage II) with cyclophosphamide, doxorubicin, vincristine, and prednisone and is in complete remission at 17 months from the last chemotherapy.

Response to BMP4 signalling during ES cell differentiation defines intermediates of the ectoderm lineage.

The formation and differentiation of multipotent precursors underlies the generation of cell diversity during mammalian development. Recognition and analysis of these transient cell populations has been hampered by technical difficulties in accessing them in vivo. In vitro model systems, based on the differentiation of embryonic stem (ES) cells, provide an alternative means of identifying and characterizing these populations. Using a previously established mouse ES-cell-based system that recapitulates the development of the ectoderm lineage we have identified a transient population that is consistent with definitive ectoderm. This previously unidentified progenitor occurs as a temporally discrete population during ES cell differentiation, and differs from the preceding and succeeding populations in gene expression and differentiation potential, with the unique ability to form surface ectoderm in response to BMP4 signalling.

Dental outcomes for children receiving asfotase alfa for hypophosphatasia.

INTRODUCTION: Hypophosphatasia, a genetic disease impeding development of teeth and bones, is associated with premature exfoliation of primary teeth. Hypophosphatasia is caused by mutations in the ALPL gene, which encodes the tissue non-specific form of alkaline phosphatase. Asfotase alfa (Strensiq®) is a human recombinant bone-targeted alkaline phosphatase. OBJECTIVES: To review development and exfoliation patterns of primary/permanent teeth in a cohort of patients with hypophosphatasia enrolled in an open-label clinical trial of enzyme replacement therapy (ERT) with asfotase alfa. METHODS: Data were collected from existing study files of a cohort of patients ≤5 years of age with infantile hypophosphatasia. Children were recruited at the Winnipeg site of a global clinical trial and were treated with ERT. Dental information, including the exfoliation/eruption patterns, were recorded at each visit. RESULTS: Eleven children (7 females, 4 males) participated. Participants enrolled as infants (5 infants; mean age 3.0 ± 2.3 months) prematurely lost significantly fewer teeth to hypophosphatasia than patients recruited as preschoolers (6 preschoolers; mean age 52.5 ± 11.3 months), who started on asfotase alfa at a later age. Conclusion The oral health of children with early onset infantile hypophosphatasia may be improved with early and continued administration of ERT, compared to institution of therapy later in childhood.

"We have been magnified for years - Now you are under the microscope!": Co-researchers with Learning Disabilities Created an Online Survey to Challenge Public Understanding of Learning Disabilities.

Public attitudes towards learning disabilities (LDs) are generally reported as positive, inclusive and empathetic. However, these findings do not reflect the lived experiences of people with LDs. To shed light on this disparity, a team of co-researchers with LDs created the first online survey to challenge public understanding of LDs, asking questions in ways that are important to them and represent how they see themselves. Here, we describe and evaluate the process of creating an accessible survey platform and an online survey in a research team consisting of academic and non-academic professionals with and without LDs or autism. Through this inclusive research process, the co-designed survey met the expectations of the co-researchers and was well-received by the initial survey respondents. We reflect on the co-researchers' perspectives following the study completion, and consider the difficulties and advantages we encountered deploying such approaches and their potential implications on future survey data analysis.

Education Milestones for Newly Diagnosed Pediatric, Adolescent, and Young Adult Cancer Patients: A Quality Improvement Initiative.

The diagnosis of cancer in a child, adolescent, or young adult is an emotionally overwhelming time. To improve the quality of education and support provided to patients and caregivers with a new cancer diagnosis, we executed a quality improvement initiative to (a) define key education milestones for the delivery of essential education during the first 2 months following diagnosis and (b) to define role accountability within the multidisciplinary team for delivery of content and execution of tasks. To develop education milestones, we (a) identified educational content from review of the literature, (b) determined the sequence of content delivery through qualitative interviews with patients and caregivers, and (c) developed education milestones by evaluation of existing workflows. To develop task lists, we (a) determined which multidisciplinary team member was best suited to deliver specific content and (b) defined discrete tasks required to execute education milestones. Key content topics and preferred sequence are as follows: Emotional Adjustment to Diagnosis, When and How to Call the Doctor, Medication Management, Practical Needs, Line Care, and Access to Nontherapeutic Clinical Trials. Eight education milestones were defined across the initial 2 months following cancer diagnosis. The education milestones are paired with task lists. The education milestones and task lists guide the execution of complex education across a multidisciplinary service line in an emotionally challenging time. Early information focuses on essential content, role responsibility is clearly defined, and psychosocial support services are purposefully and iteratively integrated into care during the initial weeks following a cancer diagnosis.

Immuno-Isolating Dual Poly(ethylene glycol) Capsule Prevents Cancer Cells from Spreading Following Mouse Ovarian Tissue Auto-Transplantation.

For female cancer survivors, premature ovarian insufficiency (POI) is a common complication of anticancer treatments. Ovarian tissue cryopreservation before treatment, followed by auto-transplantation after remission is a promising option to restore fertility and ovarian endocrine function. However, auto-transplantation is associated with the risk of re-introducing malignant cells harbored in the stroma of the ovarian autograft. To mitigate this risk, we investigated in this pilot study whether an immuno-isolating dual-layered poly(ethylene glycol)(PEG) capsule can retain cancer cells, while supporting folliculogenesis. The dual PEG capsule loaded with 1000 4T1 cancer cells retained 100% of the encapsulated cells in vitro for 21 days of culture. However, a greater cell load of 10,000 cells/capsule led to capsule failure and cells' release. To assess the ability of the capsule to retain cancer cells, prevent metastasis, and support folliculogenesis in vivo we co-encapsulated cancer cells with ovarian tissue in the dual PEG capsule and implanted subcutaneously in mice. Control mice implanted with 2000 non-encapsulated cancer cells had tumors formed within 14 days and metastasis to the lungs. In contrast, no tumor mass formation or metastasis to the lungs was observed in mice with the same number of cancer cells encapsulated in the capsule. Our findings suggest that the immuno-isolating capsule may prevent the escape of the malignant cells potentially harbored in ovarian allografts and, in the future, improve the safety of ovarian tissue auto-transplantation in female cancer survivors.

High Tibial Osteotomy Performed With All-PEEK Implants Demonstrates Similar Outcomes but Less Hardware Removal at Minimum 2-Year Follow-up Compared With Metal Plates.

BACKGROUND: High tibial osteotomy (HTO) is a valuable treatment option in the high-demand patient with chondral damage and an altered mechanical axis. Traditional opening wedge HTO performed with metal plates has several limitations, including hardware irritation, obscuration of detail on magnetic resonance imaging, and complexity of revision surgery. Recently, an all-polyetheretherketone (PEEK) HTO implant was introduced, but no studies to date have evaluated the performance of this implant with minimum 2-year outcomes compared with a traditional metal plate. PURPOSE: To compare patient outcomes and complications of HTO performed using a traditional metal plate with those performed using an all-PEEK implant. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: All patients who underwent HTO by a single surgeon with a minimum 2-year follow-up over a 4-year period were identified. Medical records were reviewed for patient demographics, concomitant procedures, implant used, type and degree of correction, complications, reoperations, and failures. Recorded patient outcomes included EuroQol-5 dimensions (EQ-5D), resiliency, Single Assessment Numeric Evaluation (SANE), Tegner activity level scale, International Knee Documentation Committee (IKDC), and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores. HTO performed using a traditional metal plate served as the control group. Statistical analysis was performed using the Student t test for continuous variables and chi-square analysis for nonparametric data, with P < .05 considered significant. RESULTS: A total of 41 patients (21 in the all-PEEK group, 20 in the control group) were identified with greater than 2-year follow-up. The mean patient age was 44 years, and there were no differences between the groups with regard to demographics, degree of correction, or concomitant procedures. In addition, no significant differences were found for any of the patient-reported outcomes. Complications (10% vs 15%, respectively; P = .59), failures (10% vs 5%, respectively; P = .58), and reoperations (10% vs 30%, respectively; P = .10) were similar for the all-PEEK and control groups. However, the all-PEEK group did not have any hardware removal, while 4 patients in the control group underwent hardware removal (P = .03). CONCLUSION: This study suggests that an all-PEEK implant may be safely used with comparable outcomes and complication rates to the traditional method but with less need for hardware removal.

TNF-alpha induces transient resistance to Fas-induced apoptosis in eosinophilic acute myeloid leukemia cells.

Tumor necrosis factor alpha (TNF-alpha) has been recognized as an activator of nuclear factor kappaB (NF-kappaB), a factor implicated in the protection of many cell types from apoptosis. We and others have presented evidence to suggest that Fas-induced apoptosis may be an important aspect of the resolution of inflammation, and that delayed resolution of inflammation may be directly associated with NF-kappaB-dependent resistance to Fas. Because TNF-alpha activates NF-kappaB in many cell types including inflammatory cells such as eosinophils, we examined effects of TNF-alpha signaling on the Fas-mediated killing of an eosinophilic cell line AML14. While agonist anti-Fas (CH11) treatment induced apoptosis in AML14 cells, no significant cell death occurred in response to TNF-alpha alone. Electrophoretic mobility shift assay (EMSA) revealed that TNF-alpha induced NF-kappaB transactivation in AML14 cells in a time- and dose-dependent fashion, and subsequent supershift assays indicated that the translocated NF-kappaB was the heterodimer p65 (RelA)/p50. Pre-treatment of cells with TNF-alpha dramatically decreased the CH11-induced cell death in a transient fashion, accompanied by suppression of activation of caspase-8 and caspase-3 activation. Inhibition of NF-kappaB transactivation by inhibitors, BAY 11-7085 and parthenolide, reversed the suppression of Fas-mediated apoptosis by TNF-alpha. Furthermore, TNF-alpha up-regulated X-linked inhibitor of apoptosis protein (XIAP) transiently and XIAP levels were correlated with the temporal pattern of TNF-alpha protection against Fas-mediated apoptosis. This finding suggested that TNF-alpha may contribute to the prolonged survival of inflammatory cells by suppression of Fas-mediated apoptosis, the process involved with NF-kappaB transactivation, anti-apoptotic XIAP up-regulation and caspase suppression.

Early-life exposures predicting onset and resolution of childhood overweight or obesity.

OBJECTIVES: To determine which of multiple early-life exposures predict onset or resolution of overweight/obesity during a 9-year period. METHODS: Design: longitudinal cohort from three harmonised community-based cohorts enriched for overweight and obesity. Early-life exposures: child-gestational age; delivery; birth weight; breast feeding; solids introduction; baseline body mass index (BMI); waist circumference; diet; activity; global, physical and psychosocial health. Mother-baseline BMI; education; age; neighbourhood disadvantage; concern for child's weight. Outcome: change in BMI category. Analyses: adjusted logistic regression. RESULTS: On average, the 363 children (57% retention) were 6 and 15 years old at baseline and follow-up. Children were classified as 'never' overweight/obese (38%), 'resolving' overweight/obese (15%), 'becoming' overweight/obese (8%) or 'always' overweight/obese (39%). Compared with 'never overweight/obese' children, odds of 'becoming overweight/obese' were greater with higher child (OR 2.33, 95% CI 1.02 to 5.29) and maternal BMI (OR 1.18, CI 1.07 to 1.31), and lower with higher maternal education (OR 0.09, CI 0.02 to 0.34). Compared with 'always overweight/obese' children, odds of 'resolving overweight/obese' were lower with higher maternal BMI (OR 0.87, CI 0.78 to 0.97), and higher with better child physical health (OR 1.06, CI 1.02 to 1.10) and higher maternal age (OR 1.11, CI 1.01 to 1.22) and education (OR 4.07, CI 1.02 to 16.19). CONCLUSIONS: Readily available baseline information (child/maternal BMI, maternal age, education and child health) were the strongest predictors of both onset and resolution of overweight/obesity between the primary school and adolescent years. Perinatal, breastfeeding and lifestyle exposures were not strongly predictive. Results could stimulate development of algorithms identifying children most in need of targeted prevention or treatment.

The development of counselling psychology in Ireland.

This paper discusses the distinctive nature of the specialism of counselling psychology and outlines the development of the discipline in Ireland in the context of international developments and its recognition as a professional branch of applied psychology. Today, counselling psychologists are employed in varied clinical and non-clinical settings including health and mental health services (statutory, private and voluntary sector) along with education, forensic, justice, industry and private practices. Counselling psychologist is the primary professional identity of many practising psychologists in Ireland and the Psychological Society of Ireland's Division of Counselling Psychology is the main affiliation of at least 179 members. With its focus on facilitating personal and interpersonal functioning across the life span and its emphasis on the therapeutic process, the specialism continues to bridge the disciplines of psychology, counselling and psychotherapy. In this article, some of the challenges still faced by counselling psychology are explored as it navigates its way through the changing landscape of further development and evolution.

Fas resistance of leukemic eosinophils is due to activation of NF-kappa B by Fas ligation.

TNF family receptors can lead to the activation of NF-kappaB and this can be a prosurvival signal in some cells. Although activation of NF-kappaB by ligation of Fas (CD95/Apo-1), a member of the TNFR family, has been observed in a few studies, Fas-mediated NF-kappaB activation has not previously been shown to protect cells from apoptosis. We examined the Fas-induced NF-kappaB activation and its antiapoptotic effects in a leukemic eosinophil cell line, AML14.3D10, an AML14 subline resistant to Fas-mediated apoptosis. EMSA and supershift assays showed that agonist anti-Fas (CH11) induced nuclear translocation of NF-kappaB heterodimer p65(RelA)/p50 in these cells in both a time- and dose-dependent fashion. The influence of NF-kappaB on the induction of apoptosis was studied using pharmacological proteasome inhibitors and an inhibitor of IkappaBalpha phosphorylation to block IkappaBalpha dissociation and degradation. These inhibitors at least partially inhibited NF-kappaB activation and augmented CH11-induced cell death. Stable transfection and overexpression of IkappaBalpha in 3D10 cells inhibited CH11-induced NF-kappaB activation and completely abrogated Fas resistance. Increases in caspase-8 and caspase-3 cleavage induced by CH11 and in consequent apoptotic killing were observed in these cells. Furthermore, while Fas-stimulation of resistant control 3D10 cells led to increases in the antiapoptotic proteins cellular inhibitor of apoptosis protein-1 and X-linked inhibitor of apoptosis protein, Fas-induced apoptosis in IkappaBalpha-overexpressing cells led to the down-modulation of both of these proteins, as well as that of the Bcl-2 family protein, Bcl-x(L). These data suggest that the resistance of these leukemic eosinophils to Fas-mediated killing is due to induced NF-kappaB activation.