Distribution of tuberculosis in migrant children and young people in Europe: a retrospective database analysis of European data.

OBJECTIVE: The burden of tuberculosis (TB) in migrant children and young people (CYP) is commonly overlooked, despite the increasing incidence of TB in migrant populations in the European region. This study aimed to examine the distribution and disease characteristics of TB among migrant and native-born CYP through analysis of data from the European Centre for Disease Prevention and Control (ECDC) surveillance system (TESSy). STUDY DESIGN: Retrospective database analysis. METHODS: A retrospective database analysis was conducted on all CYP TB cases (0-17 years) reported to TESSy (1995-2017), exploring distribution, site of TB, and presence of MDR-TB using multivariate analysis in R statistical software. RESULTS: Of the 73,176 CYP TB cases reported in the EU/EFTA (1995-2017), 24.4% (n = 17,879) occurred in migrant CYP and 75.6% (n = 55,297) occurred in native-born CYP. Migrant CYP were more likely (P < 0.001) to have pulmonary TB (OR: 1.90; 95% CI: 1.74-2.09) and unsuccessful treatment outcomes (OR: 2.05; 95% CI: 1.74-2.40) compared to native-born CYP. The proportion of extrapulmonary TB, compared to pulmonary TB across total CYP cases was higher than the existing evidence base. CONCLUSIONS: Overall, there were significant differences in the site of TB and treatment outcomes between migrant and native-born CYP. To improve outcomes, TB screening and detection practices should focus on facilitating care in migrant CYP. However, to better understand the implications of these findings on broader TB control, TB among CYP should be addressed more frequently in reports and research.

Sustainable Development Goals' health-related indicators for Brazil and Ecuador: an analysis for the period of 1990-2019.

OBJECTIVE: This article aims to analyse the evolution of 40 Sustainable Development Goals' (SDGs) health-related indicators in Brazil and Ecuador from 1990 to 2019. STUDY DESIGN: Epidemiological study of long-term trends in 40 SDGs' health-related indicators for Brazil and Ecuador from 1990 to 2019, using estimates from the Global Burden of Disease Study. METHODS: Forty SDGs' health-related indicators and an index from 1990 to 2017 for Brazil and Ecuador, and their projections up to 2030 were extracted from the Institute for Health Metrics and Evaluation's Global Burden of Disease website and analysed. The percent annual change (PC) between 1990 and 2019 was calculated for both countries. RESULTS: Both countries have made progress on child stunting (Brazil: PC = -38%; Ecuador: PC = -43%) and child wasting prevalences (Brazil: PC = -42%; Ecuador: PC = -41%), percent of vaccine coverage (Brazil: PC = +215%; Ecuador: PC = +175%), under-5 (Brazil: PC = -75%; Ecuador: PC = -60%) and neonatal mortality rates (Brazil: PC = -69%; Ecuador: PC = -51%), health worker density per 1000 population (Brazil: PC = +153%; Ecuador: PC = +175%), reduction of neglected diseases prevalences (Brazil: PC = -40%; Ecuador: PC = -58%), tuberculosis (Brazil: PC = -27%; Ecuador: PC = -55%) and malaria incidences (Brazil: PC = -97%; Ecuador: PC = -100%), water, sanitation and hygiene mortality rates (Brazil and Ecuador: PC = -89%). However, both countries did not show sufficient improvement in maternal mortality ratio to meet SDGs targets (Brazil: PC = -37%; Ecuador: PC = -40%). Worsening of indicators were found for violence, such as non-intimate partner violence for both countries (Brazil: PC = +26%; Ecuador: PC = +18%) and suicide mortality rate for Ecuador (PC = +66%), child overweight indicator for Brazil (PC = -67%), disaster mortality rates (Brazil: PC = +100%; Ecuador: PC = +325%) and alcohol consumption (Brazil: PC = +46%; Ecuador: PC = +35%). CONCLUSIONS: Significant improvements are necessary in both countries requiring the strengthening of health and other policies, particularly concerning the prevention and management of violence and alcohol consumption, and preparedness for dealing with environmental disasters.

Efficacy of ixekizumab compared to etanercept and placebo in patients with moderate-to-severe plaque psoriasis and non-pustular palmoplantar involvement: results from three phase 3 trials (UNCOVER-1, UNCOVER-2 and UNCOVER-3).

BACKGROUND: Palmoplantar psoriasis has significant physical and emotional impact on patients and can be difficult to treat. OBJECTIVE: To evaluate the efficacy of ixekizumab in the treatment of patients with moderate-to-severe plaque psoriasis and moderate-to-severe non-pustular palmoplantar involvement. METHODS: In three phase 3, double-blind, placebo-controlled trials, patients with moderate-to-severe non-pustular plaque psoriasis [UNCOVER-1 (N = 1296), UNCOVER-2 (N = 1224), UNCOVER-3 (N = 1346)] were randomized to subcutaneous 80 mg ixekizumab every 2 or 4 weeks (Q2W, Q4W), after a 160-mg starting dose, or placebo through week 12. Additional UNCOVER-2 and UNCOVER-3 cohorts were randomized to 50 mg etanercept biweekly. Patients entering the open-label long-term extension (UNCOVER-3) received ixekizumab Q4W weeks 12-60. Moderate-to-severe palmoplantar involvement was defined as Palmoplantar Psoriasis Area and Severity Index (PPASI) ≥8. RESULTS: Twenty-eight percent of UNCOVER-1, UNCOVER-2 and UNCOVER-3 patients had baseline palmoplantar involvement (PPASI ≥0, n = 1092) and 9.1% (n = 350) had moderate-to-severe involvement, with mean baseline PPASI ~20, PASI ~24, and most (>60%) had static Physician's Global Assessment ≥4. Higher percentages of patients treated with ixekizumab vs. placebo or etanercept achieved PPASI 50 (approximately 80% vs. 32.9%, 67.8%; ixekizumab, placebo, etanercept, respectively) and PPASI 75 (approximately 70% vs. 18.8%, 44.1%; ixekizumab, placebo, etanercept, respectively) at week 12 (all P < 0.05). PPASI 100 was achieved by higher percentages of ixekizumab-treated patients vs. placebo (approximately 50% vs. 8.2%, P < 0.001) and ixekizumab Q2W-treated patients vs. etanercept (51.8% vs. 32.2%, P < 0.05). Outcomes were maintained or improved in patients continuing on ixekizumab Q4W through week 60. Differences between ixekizumab and placebo or etanercept were statistically significant as early as week 1. CONCLUSION: In a subpopulation analysis of patients from phase 3 trials with moderate-to-severe non-pustular palmoplantar involvement and moderate-to-severe plaque psoriasis, ixekizumab treatment resulted in greater and more rapid improvements than placebo and etanercept at week 12; improvements were sustained with continued treatment.

Risk factors associated with resistance to HIV testing among transwomen in Brazil.

Transwomen are a high-risk population for HIV/AIDS worldwide. However, many transwomen do not test for HIV. This study aimed to identify factors associated with resistance to HIV testing among transwomen in Fortaleza/CE. A cross-sectional study was conducted between August and December 2008 with a sample of 304 transwomen recruited through respondent-driven sampling. Data analysis utilized Respondent-Driven Sampling Analysis Tool and SPSS 11.0. Univariate, bivariate, and multivariate analyses examined risk factors associated with resistance to HIV testing. Less than 18 years of age (OR = 4.221; CI = 2.419-7.364), sexual debut before 10 years of age (OR = 6.760; CI = 2.996-15.256), using illegal drugs during sex (OR = 2.384; CI = 1.310-4.339), experience of discrimination (OR = 3.962; CI = 1.540-10.195) and a belief that the test results were not confidential (OR = 3.763; CI = 2.118-6.688) are independently associated with resistance to testing. Intersectoral and targeted strategies aimed at encouraging the adoption of safer sexual behaviors and testing for HIV among transwomen are required.

Signal transduction: the nuclear target.

Fos and jun heterodimers activate the transcription of genes containing an AP-1 site. The activity of Fos and Jun proteins is regulated by post-translational modification. The activity of the rel/NF-kappa family of transcriptional factors is regulated by their sequestration in the cytoplasm in association with the inhibitor protein, I kappa B. An ankyrin repeat motif in I kappa B proteins is required for their direct association with rel/NF-kappa B.

Direct evidence of sex and a hypothesis about meiosis in Symbiodiniaceae.

Dinoflagellates in the family Symbiodiniaceae are obligate endosymbionts of diverse marine invertebrates, including corals, and impact the capacity of their hosts to respond to climate change-driven ocean warming. Understanding the conditions under which increased genetic variation in Symbiodiniaceae arises via sexual recombination can support efforts to evolve thermal tolerance in these symbionts and ultimately mitigate coral bleaching, the breakdown of the coral-Symbiodiniaceae partnership under stress. However, direct observations of meiosis in Symbiodiniaceae have not been reported, despite various lines of indirect evidence that it occurs. We present the first cytological evidence of sex in Symbiodiniaceae based on nuclear DNA content and morphology using Image Flow Cytometry, Cell Sorting and Confocal Microscopy. We show the Symbiodiniaceae species, Cladocopium latusorum, undergoes gamete conjugation, zygote formation, and meiosis within a dominant reef-building coral in situ. On average, sex was detected in 1.5% of the cells analyzed (N = 10,000-40,000 cells observed per sample in a total of 20 samples obtained from 3 Pocillopora colonies). We hypothesize that meiosis follows a two-step process described in other dinoflagellates, in which diploid zygotes form dyads during meiosis I, and triads and tetrads as final products of meiosis II. This study sets the stage for investigating environmental triggers of Symbiodiniaceae sexuality and can accelerate the assisted evolution of a key coral symbiont in order to combat reef degradation.

High rate of autonomic neuropathy in Cornelia de Lange Syndrome.

BACKGROUND: Cornelia de Lange Syndrome (CdLS) is a rare congenital disorder characterized by typical facial features, growth failure, limb abnormalities, and gastroesophageal dysfunction that may be caused by mutations in several genes that disrupt gene regulation early in development. Symptoms in individuals with CdLS suggest that the peripheral nervous system (PNS) is involved, yet there is little direct evidence. METHOD: Somatic nervous system was evaluated by conventional motor and sensory nerve conduction studies and autonomic nervous system by heart rate variability, sympathetic skin response and sudomotor testing. CdLS Clinical Score and genetic studies were also obtained. RESULTS: Sympathetic skin response and sudomotor test were pathological in 35% and 34% of the individuals with CdLS, respectively. Nevertheless, normal values in large fiber nerve function studies. CONCLUSIONS: Autonomic nervous system (ANS) dysfunction is found in many individuals with Cornelia de Lange Syndrome, and could be related to premature aging.

Clinical responses observed with imatinib or sorafenib in melanoma patients expressing mutations in KIT.

BACKGROUND: Mutations in KIT are more frequent in specific melanoma subtypes, and response to KIT inhibition is likely to depend on the identified mutation. METHODS: A total of 32 patients with metastatic acral or mucosal melanoma were screened for mutations in KIT exons 11, 13 and 17. RESULTS: KIT mutations were found in 38% of mucosal and in 6% of acral melanomas. Three patients were treated with imatinib and one with sorafenib. All four patients responded to treatment, but three have since progressed within the brain. CONCLUSION: The observed clinical responses support further investigation of KIT inhibitors in metastatic melanoma, selected according to KIT mutation status.

The role of spatial dynamics in the stability, resilience, and productivity of an estuarine fish population.

Understanding mechanisms that support long-term persistence of populations and sustainability of productive fisheries is a priority in fisheries management. Complex spatial structure within populations is increasingly viewed as a result of a plastic behavioral response that can have consequences for the dynamics of a population. We incorporated spatial structure and environmental forcing into a population model to examine the consequences for population stability (coefficient of variation of spawning-stock biomass), resilience (time to recover from disturbance), and productivity (spawning-stock biomass). White perch (Morone americana) served as a model species that exhibits simultaneous occurrence of migratory and resident groups within a population. We evaluated the role that contingents (behavioral groups within populations that exhibit divergent life histories) play in mitigating population responses to unfavorable environmental conditions. We used age-structured models that incorporated contingent-specific vital rates to simulate population dynamics of white perch in a sub-estuary of Chesapeake Bay, USA. The dynamics of the population were most sensitive to the proportion of individuals within each contingent and to a lesser degree to the level of correlation in recruitment between contingents in their responses to the environment. Increased representation of the dispersive contingent within populations resulted in increased productivity and resilience, but decreased stability. Empirical evidence from the Patuxent River white perch population was consistent with these findings. A high negative correlation in resident and dispersive contingent recruitment dynamics resulted in increased productivity and stability, with little effect on resilience. With high positive correlation between contingent recruitments, the model showed similar responses in population productivity and resilience, but decreased stability. Because contingent structure involves differing patterns of nursery habitat use, spatial management that conserves sets of habitats rather than the single most productive nursery habitat would be expected to contribute to long-term population stability.

Growth factors regulate transin gene expression by c-fos-dependent and c-fos-independent pathways.

The rapid induction of the proto-oncogene c-fos by growth factors and other bioactive agents, and the recent evidence that the c-fos protein (Fos) is associated with transcriptional complexes, suggests that Fos may represent an integral part of an intracellular messenger pathway that triggers changes in gene expression and ultimately phenotypic alterations. This report examines the role of c-fos in growth factor stimulation of transin, a matrix-degrading secreted metalloproteinase. Platelet-derived growth factor (PDGF) stimulation of transin RNA was blocked by a selective reduction in Fos synthesis with antisense c-fos mRNA, whereas epidermal growth factor (EGF) stimulation of transin occurred despite an equivalent inhibition of Fos levels. The stimulatory effect of both PDGF and EGF on transin transcription involved factors recognizing the sequence TGAGTCA, which is found in the transin promoter and is reported to be a binding site for the transcriptional factor Jun/AP-1 and for associated Fos and Fos-related complexes. Thus both Fos-dependent and Fos-independent pathways exist for growth factor regulation of gene expression, and both effects may be mediated through the same cis-acting transcription element.

The Scottish Audit of Surgical Mortality: a review of areas of concern related to anaesthesia over 10 years.

The Scottish Audit of Surgical Mortality is a voluntary, peer reviewed, critical event analysis of patients who die under the care of consultant surgeons in acute hospitals in Scotland. The anaesthetic contribution to surgical mortality over a 10-year period from 1996 was reviewed. The total number of deaths was 44 230 or 1.5% of all admissions. Forty thousand, eight hundred and ninety-six deaths (92%) were audited. Deaths after elective surgery declined over 10 years. Over 80% of deaths followed emergency admission. The number of deaths where an anaesthetist was present was 16 981 or 0.6% of all admissions. Anaesthetic areas of concern were identified in 8% of deaths. Of these, 43% were related to pre-operative assessment. Anaesthesia also played a part in a further 18% of deaths where decision making was shared with the surgical team. Of these, 41% were related to access to critical care. A further 24% related to communication failures, principally when the operation should not have been done or was unnecessary.

Adaptive genetic variation underlies biocomplexity of Atlantic Cod in the Gulf of Maine and on Georges Bank.

Atlantic cod (Gadus morhua) populations in the Gulf of Maine (GoM) are at a fraction of their historical abundance, creating economic hardships for fishermen and putting at risk the genetic diversity of the remaining populations. An understanding of the biocomplexity among GoM populations will allow for adaptive genetic diversity to be conserved to maximize the evolutionary potential and resilience of the fishery in a rapidly changing environment. We used restriction-site-associated DNA sequencing (RADseq) to characterize the population structure and adaptive genetic diversity of five spawning aggregations from the western GoM and Georges Bank. We also analyzed cod caught in the eastern GoM, an under-sampled area where spawning aggregations have been extirpated. Using 3,128 single nucleotide polymorphisms (SNPs), we confirmed the existence of three genetically separable spawning groups: (1) winter spawning cod from the western GoM, (2) spring spawning cod, also from the western GoM, and (3) Georges Bank cod. Non-spawning cod from the eastern GoM could not be decisively linked to either of the three spawning groups and may represent a unique component of the resource, a mixed sample, or cod from other unsampled source populations. The genetic differentiation among the three major spawning groups was primarily driven by loci putatively under selection, particularly loci in regions known to contain genomic inversions on linkage groups (LG) 7 and 12. These LGs have been found to be linked to thermal regime in cod across the Atlantic, and so it is possible that variation in timing of spawning in western GoM cod has resulted in temperature-driven adaptive divergence. This complex population structure and adaptive genetic differentiation could be crucial to ensuring the long-term productivity and resilience of the cod fishery, and so it should be considered in future management plans.

Nucleophosmin is a novel Bax chaperone that regulates apoptotic cell death.

The proapoptotic B-cell lymphoma-2 family protein Bax is a key regulatory point in the intrinsic apoptotic pathway. However, the factors controlling the process of Bax activation and translocation to mitochondria have yet to be fully identified and characterized. We performed affinity chromatography using peptides corresponding to the mitochondrial-targeting region of Bax, which is normally sequestered within the inactive structure. The molecular chaperone nucleophosmin was identified as a novel Bax-binding protein by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Reciprocal co-immunoprecipitation and proximity assays confirmed the Bax-nucleophosmin protein-protein interaction and verified that nucleophosmin only bound to activated conformationally altered Bax. Confocal microscopy in a cell-based apoptosis model, demonstrated that nucleophosmin translocation from nucleolus to cytosol preceded Bax movement. Specific knockdown of nucleophosmin expression using RNAi attenuated apoptosis as measured by mitochondrial cytochrome c release and activation of the caspase cascade. In a mouse model of ischaemic stroke, subcellular fractionation studies verified that nucleophosmin translocation occurred within 3 h, at a time before Bax translocation but after Bax conformational changes have occurred. Thus, we have elucidated a novel molecular mechanism whereby Bax becomes activated and translocates to the mitochondria to orchestrate mitochondrial dysfunction and apoptotic cell death, which opens new avenues for therapeutic intervention.

Late dislocation after total hip arthroplasty.

OBJECTIVES: Instability after total hip arthroplasty is a troublesome complication. It commonly occurs in the first 3 postoperative months, but the risk continues over time. There are numerous treatment options, but they have relatively unpredictable outcomes. Numerous factors have been associated with dislocation, but research has mainly focused on the surgical ones. Epidemiological factors remain the subject of much debate. We aimed to establish the incidence of dislocation over time. METHODS: The Scottish National arthroplasty non-voluntary registry is based on SMR01 records (Scottish Morbidity Record) data. We analyzed the Scottish National Arthroplasty Project to find patients' dislocation rates. RESULTS: There were 62,175 total hip arthroplasties performed from April 1989 to March 2004 with an annual incidence of dislocation of 0.9%. We found no increase in the rate of dislocation after 2 years. CONCLUSIONS: It appears there is no late increase in dislocation rate. LEVEL OF EVIDENCE: Prognostic study, level II-1 (prospective study).

Epidermal growth factor stimulation of stromelysin mRNA in rat fibroblasts requires induction of proto-oncogenes c-fos and c-jun and activation of protein kinase C.

Stromelysin (transin) is a secreted metalloprotease that is transcriptionally induced by a variety of growth factors and oncogenes. We examined the necessity of specific secondary (protein kinase C) and tertiary (c-fos and c-jun protein products) messengers in the transactivation of stromelysin gene expression by epidermal growth factor (EGF). Rat-1 fibroblasts exposed to antisense c-fos DNA or RNA demonstrated that c-fos expression was necessary for complete EGF induction of stromelysin expression. Similar results demonstrating the necessity of c-jun protein in the EGF induction of stromelysin were obtained. We also demonstrated that protein kinase C activation is required for the EGF induction of stromelysin, since phorbol ester desensitization of C kinase proteins abolished the ability of EGF to induce stromelysin mRNA, protein, and promoter activity. In reconstitution experiments, neither c-fos, c-jun, nor C kinase activation alone induced significant stromelysin expression. Overexpression of c-fos and c-jun was able to induce stromelysin to a level similar to that of the growth factor, and stimulation of protein kinase C activity augmented this induction. The data suggest that the EGF induction of stromelysin in rat fibroblasts procedes through a pathway involving c-fos, c-jun, and protein kinase C.

Nuclear factor-kappaB (NF-kappaB) regulates proliferation and branching in mouse mammary epithelium.

The nuclear factor-kappaB (NF-kappaB) family of transcription factors has been shown to regulate proliferation in several cell types. Although recent studies have demonstrated aberrant expression or activity of NF-kappaB in human breast cancer cell lines and tumors, little is known regarding the precise role of NF-kappaB in normal proliferation and development of the mammary epithelium. We investigated the function of NF-kappaB during murine early postnatal mammary gland development by observing the consequences of increased NF-kappaB activity in mouse mammary epithelium lacking the gene encoding IkappaBalpha, a major inhibitor of NF-kappaB. Mammary tissue containing epithelium from inhibitor kappaBalpha (IkappaBalpha)-deficient female donors was transplanted into the gland-free mammary stroma of wild-type mice, resulting in an increase in lateral ductal branching and pervasive intraductal hyperplasia. A two- to threefold increase in epithelial cell number was observed in IkappaBalpha-deficient epithelium compared with controls. Epithelial cell proliferation was strikingly increased in IkappaBalpha-deficient epithelium, and no alteration in apoptosis was detected. The extracellular matrix adjacent to IkappaBalpha-deficient epithelium was reduced. Consistent with in vivo data, a fourfold increase in epithelial branching was also observed in purified IkappaBalpha-deficient primary epithelial cells in three-dimensional culture. These data demonstrate that NF-kappaB positively regulates mammary epithelial proliferation, branching, and functions in maintenance of normal epithelial architecture during early postnatal development.

A GH receptor antisense oligonucleotide inhibits hepatic GH receptor expression, IGF-I production and body weight gain in normal mice.

Diabetic retinopathy and acromegaly are diseases associated with excess action of GH and its effector IGF-I, and there is a need for improved therapies. We have designed an optimised 2'-O-(2-methoxyethyl)-modified phosphorothioate oligodeoxynucleotide, ATL 227446, and demonstrated its ability to suppress GH receptor mRNA in vitro. Subcutaneous injections of ATL 227446 reduced GH receptor mRNA levels, GH binding activity and serum IGF-I levels in mice after seven days of dosing. The reduction in serum IGF-I could be sustained for over ten weeks of dosing at therapeutically relevant levels, during which there was also a significant decrease in body weight gain in antisense-treated mice relative to saline and mismatch control-treated mice. The findings indicate that administration of an antisense oligonucleotide to the GH receptor may be applicable to human diseases in which suppression of GH action provides therapeutic benefit.

Enhanced in vitro lysis of human ovarian carcinomas with activated peripheral blood lymphocytes and bifunctional immune heteroaggregates.

Heteroaggregated monoclonal antibodies (HA) comprised of an anti-CD3 and an anti-tumor associated antigen (TAA) antibody were evaluated for their ability to lyse fresh human ovarian cancer cells. HAs were able to significantly enhance the in vitro lysis of fresh ovarian tumor cells by in vitro activated peripheral blood lymphocytes (PBLs). HAs did not increase tumor lysis using fresh PBLs or PBLs cultured overnight in vitro. HA efficacy required both anti-CD3 and anti-TAA antibodies to be present in the same molecule, implying that physical bridging between the effector and target cell by the HA may be a requirement for their activity in cell lysis. The presence of anti-CD3 antibody in the PBL cultures enhanced cell growth and did not block the efficacy of the anti-CD3 containing HAs. The frequent expression of multiple TAAs in human ovarian cancers and the ability to recruit cytotoxic T-cell activity with HAs in vitro give promise to the future of this form of immunotherapy in the clinical setting.

Effects of social housing condition on the response of the Shionogi mouse mammary carcinoma (SC115) to chemotherapy.

In the present study, we demonstrate that social housing conditions significantly alter the response of the transplantable androgen-responsive Shionogi mouse mammary tumor (SC115) to chemotherapy. Mice were reared either in groups (G) or as individuals (I). Immediately following tumor cell or vehicle injection, mice were rehoused from group to individual (GI) or from individual to group (IG) conditions. A combination of Adriamycin (4 mg/kg) and cyclophosphamide (61.5 mg/kg), in a series of three i.p. injections 7 days apart, was initiated when mean tumor weights of mice within a housing condition (GI or IG) reached 1 g. Survival probability was significantly greater in mice in the IG housing condition compared to those in the GI housing condition (47% versus 19%, respectively). Additionally, the median survival time following the initiation of chemotherapy was greater for mice in the IG than for mice in the GI condition (24.5 days versus 15.0 days, respectively). These findings suggest that a psychosocial stressor, social housing condition, can significantly influence chemotherapeutic efficacy.

Nuclear factor-kappaB/Rel is apoptogenic in cytokine withdrawal-induced programmed cell death.

In the complex microenvironment where they evolve, developing cells undergo rapid programmed cell death (PCD) when cytokines that support them become limiting. The transcriptional mechanisms of cytokine-withdrawal apoptosis are poorly understood. In this report, we used early B-lymphocyte tissue culture and transgenic cells to demonstrate that nuclear factor-kappaB (NF-kappaB) promotes apoptosis during cytokine withdrawal-induced PCD. In the progenitor B lymphocyte model FL5.12, whereas NF-kappaB has an antiapoptotic function in response to tumor necrosis factor-alpha, cytokine withdrawal causes nuclear translocation of NF-kappaB/cRel, where it is apoptogenic. Inhibition of NF-kappaB activation delays cytokine withdrawal-induced PCD in both FL5.12 and transgenic early B cells. Additionally, reconstituting a bone marrow microenvironment ex vivo abrogates the differential apoptotic pattern between control and transgenic early B cells.