HES1 inhibits cycling of hematopoietic progenitor cells via DNA binding

Notch signaling is implicated in stem cell self-renewal, differentiation, and other developmental processes, and the Drosophila hairy and enhancer of split (HES) 1 basic helix-loop-helix protein is a major downstream effector in the Notch pathway. We found that HES1 was expressed at high levels in the hematopoietic stem cell (HSC)-enriched CD34+/[CD38/Lin](- /low) subpopulation but at low levels in more mature progenitor cell populations. When CD34+ cells were cultured for 1 week, the level of HES1 remained high in the CD34+ subset that had remained quiescent during ex vivo culture but was reduced in CD34+ cells that had divided. To investigate the effects of HES1 in human and mouse hematopoietic stem-progenitor cells (HSPCs), we constructed conditional lentiviral vectors (lentivectors) to introduce transgenes encoding either wild-type HES1 or a mutant lacking the DNA-binding domain (BHES1). We found that lentivector-mediated HES1 expression in CD34+ cells inhibited cell cycling in vitro and cell expansion in vivo, associated with upregulation of the cell cycle inhibitor p21(cip1/Waf1) (p21). The HES1 DNA-binding domain was required for these actions. HES1 did not induce programmed cell death or alter differentiation in HSPCs, and while short-term repopulating activity was reduced in HES1-transduced mouse and human cells, long-term reconstituting HSC function was preserved. Our data characterize the complex, cell context-dependent actions of HES1 as a major downstream Notch signaling regulator of HSPC function.     

Mismatched hemagglutinin and neuraminidase specificities in recent human H3N2 influenza viruses

The hemagglutinin (HA) of influenza viruses initiates infection by binding to sialic acid on the cell surface via alpha2,6 (human) or alpha2,3 (avian) linkage. The influenza neuraminidase (NA) can cleave both alpha2,3- and alpha2,6-linked sialic acids, but all influenza NAs have a marked preference for the non-human alpha2,3 linkage. Recent H3N2 influenza viruses have lost the ability to agglutinate chicken red blood cells. To determine if changes in HA specificity or affinity correlate with NA specificity or activity, we examined red cell binding and elution of a series of H3N2 viruses. We found that the NA activity of many influenza viruses does not release binding by their HA. In some egg-adapted strains, lack of elution correlates with low levels of viral NA activity, and these elute rapidly when bacterial NA is added. However, a Fujian-like virus, A/Oklahoma/323/03, does not elute by its own NA or with Vibrio cholerae sialidase, and it binds to red cells pre-treated with V. cholerae sialidase. It elutes after addition of the broad specificity Micromonospora viridifaciens sialidase. Human glycophorin inhibits A/Oklahoma/323/03 hemagglutination 6-fold better than fetuin. We conclude that specific forms of sialic acid are used as receptor by recent human H3N2 influenza viruses, perhaps involving branched alpha2,6 sialic acid or alpha2,8 sialic acid structures on O-linked carbohydrates. The virus itself has no O-linked glycans, so even though the NA is not able to cleave receptors on cells, the viruses will not self-aggregate. It will be important to monitor efficacy of neuraminidase inhibitors in case there are NA-resistant receptors in the human respiratory tract that allow the viruses to be less dependent on NA activity.     

Busulfan/melphalan/antithymocyte globulin followed by unrelated donor cord blood transplantation for treatment of infant leukemia and leukemia in young children: the Cord Blood Transplantation study (COBLT) experience.

A non-total body irradiation-containing preparative regimen was studied in young children (<4 years old) undergoing unrelated donor cord blood transplantation as part of the Cord Blood Transplantation trial for the treatment of acute lymphoblastic leukemia (n = 14), acute myeloid leukemia (n = 13), undifferentiated leukemia (n = 1), juvenile myelomonocytic leukemia (n = 2), and myelodysplastic syndromes (n = 2). Donor/recipient HLA matching based on low-/intermediate-resolution molecular typing for HLA-A and -B and high-resolution HLA-DRB1 typing was 5/6 or 6/6 (n = 21) or 4/6 (n = 11). The preparative therapy consisted of busulfan, melphalan, and antithymocyte globulin, with cyclosporine and corticosteroids for graft-versus-host disease (GVHD) prophylaxis. The median age was 1.6 years (range, 0.5-3.9 years), and the median weight was 10.5 kg (range, 5.8-19.5 kg). Cord blood grafts contained a median of 10.7 x 10 7 nucleated cells per kilogram (range, 4.6-29.2) and 2.6 x 10(5) CD34+ cells per kilogram (range, 0.7-8.3). The cumulative incidence (CINC) of neutrophil recovery (absolute neutrophil count >500/microL) at day 42 was 0.59 (95% confidence interval [CI], 0.44-0.78) at a median of 31 days (range, 23-55 days). The CINC and Kaplan-Meier estimates of platelet engraftment at day 180 were 0.53 (95% CI, 0.34-0.69) and 0.82 (95% CI, 0.61-1.00), respectively. CINC estimates of grade III/IV acute GVHD at day 100 and chronic GVHD at 1 year were 0.25 (95% CI, 0.09-0.41) and 0.26 (95% CI, 0.09-0.44), respectively. The CINC estimate of relapse was 0.31 (95% CI, 0.16-0.47) at 2 years. With a median follow-up of 27.8 months (range, 23.4-46.7 months), the probability of survival at 1 year was 0.47 (95% CI, 0.30-0.64). A preparative regimen containing a busulfan/melphalan/antithymocyte globulin preparative regimen is well tolerated in the setting of unrelated donor cord blood transplantation for childhood leukemia and can serve as a platform preparative regimen for intensifying host immunosuppression and antileukemic therapy to allow for improved engraftment and improved relapse-free survival.     

Substance use and perceived symptom improvement among patients with bipolar disorder and substance dependence

BACKGROUND: Bipolar disorder (BPD) is the Axis I disorder with the highest risk for coexisting substance use disorder. One explanation for this phenomenon is the 'self-medication hypothesis', which states that some patients experience improvement in psychiatric symptoms as a result of substance use. We thus investigated reasons for substance use and perceived substance-induced improvement in BPD symptoms among patients with current BPD and substance dependence. METHODS: A total of 45 patients received six monthly assessments; 21 also received integrated group therapy (IGT), focusing simultaneously on BPD and substance dependence, while 24 did not receive IGT. Patients reported at intake their current reasons for initiating substance use (including BPD symptoms) and the effects of substance use on those symptoms. RESULTS: Nearly all patients initiated substance use because of at least one BPD symptom, especially depression (77.8%) and racing thoughts (57.8%); most (66.7%) reported improvement in at least one BPD symptom as a result of substance use. Among patients reporting substance-induced improvement in BPD symptoms, those receiving IGT reported fewer days of drug use over the 6-month study period than those not receiving IGT; this difference was not significant among patients without substance-induced improvement in BPD symptoms. LIMITATIONS: The study is limited by its small sample size and by the potential inaccuracy of self-reports regarding the effects of substance use on mood. CONCLUSIONS: Substance dependent patients who report that substance use improves their BPD symptoms may benefit from treatment that focuses simultaneously on both disorders.     

Should genetic testing for BRCA1/2 be permitted for minors? Opinions of BRCA mutation carriers and their adult offspring

Although professional guidelines recommend against testing minors for adult-onset genetic conditions, the genetic testing of minors for BRCA1/2 alterations has been debated in the literature. To better understand the opinions of BRCA mutation carriers regarding the genetic testing of minors and the cognitive and affective processes underlying these opinions, we interviewed BRCA mutation carriers and their adult offspring who had learned of their parent's BRCA mutation. Semi-structured interviews were conducted with 53 parents and 22 offspring. In response to a closed-ended question, 52% (n = 39) of participants were opposed to the testing of minors. Responses to an open-ended question indicate that many participants (24%, n = 18) feel that testing could be permitted for some minor offspring. Psychological risks and the insufficient maturity of minors were frequent concerns of participants opposed to testing minors. The potential to impact health behaviors was frequently cited as a reason to support the genetic testing of minors. These preliminary results suggest that many BRCA mutation carriers and their adult offspring have concerns about, or are opposed to the genetic testing of minors. However, a significant minority in our study would support testing minors. Greater support for testing among offspring could indicate increasing requests for early genetic diagnosis. Further research is necessary to explore the risks and benefits of providing genetic testing to minors for adult-onset hereditary cancer syndromes in order to inform clinical practice and public policy and to ensure optimal psychosocial and medical outcomes for all members in families at risk for genetically determined disease.     

Large platelet aggregates in endoscopic ultrasound‐guided fine‐needle aspiration of the pancreas and peripancreatic region: A clue for the diagnosis of intrapancreatic or accessory spleen

Intrapancreatic and intraabdominal accessory spleens (IPIASs) are rarely encountered in endoscopic ultrasound‐guided fine‐needle aspiration (EUS‐FNA) biopsies. However, as incidentally discovered IPIAS can mimic a benign or malignant pancreatic neoplasm on imaging studies, a definitive diagnosis made by EUS‐FNA can avert an unnecessary surgical intervention or additional radiologic follow‐up. We report five cases of intrapancreatic splenules and one case of accessory spleen (AS) in which a definitive diagnosis was made on EUS‐FNA. Previously recognized FNA cytomorphologic features of splenic tissue, including ASs and splenosis, are endothelial cells and polymorphous lymphocytes admixed with neutrophils, eosinophils, plasma cells, histiocytes, and lymphoglandular bodies. We describe the additional finding of abundant large platelet aggregates as another distinguishing feature of splenic tissue on FNA. In all six cases, large platelet aggregates were identified along with polymorphous lymphoid cells, lymphoglandular bodies, loose aggregates of endothelial cells and scattered or aggregated bland spindle cells. A review of 10 consecutive cases of EUS‐FNA‐sampled benign intraabdominal lymph nodes showed that the presence of large platelet aggregates, three‐dimensional aggregates of lymphoid cells and of bland slender spindle cells and the absence of follicular germinal cell components (tingible body macrophages and lymphohistiocytic aggregates) are useful in differentiating IPIASs from reactive lymph nodes. Immunoperoxidase stains were useful to confirm a suspected IPIASs by showing CD31‐positive acellular flocculent material, consistent with large platelet aggregates and a rich CD8‐positive endothelial cell network between CD45‐positive lymphoid cells and CD68‐positive histiocytes in all six cases. Diagn. Cytopathol. 2013;41:661–672. © 2013 Wiley Periodicals, Inc.