Long-term bone marrow cultures provide access to early lymphoid progenitors

Long-term bone marrow cultures provide defined systems for studying and manipulating hematopoietic progenitors. Myeloid bone marrow cultures harbor early lymphoid progenitors; however, the nature and phenotype of these progenitors has not been investigated. Phenotypic and molecular markers associated with lymphopoiesis were used to characterize the lymphoid population maintained in these cultures. Cells within myeloid cultures expressed genes associated with lymphopoiesis but did not express the B cell-specific lambda5 gene. Flow cytometry demonstrated that cultures lacked cells expressing markers associated with B cell development. Furthermore, rearrangements of immunoglobulin heavy chain diversity (D) and joining (J(H)) gene segments were not detected in the myeloid cultures suggesting that these conditions support early B cell progenitors. Transferring myeloid cultures to conditions optimal for lymphopoiesis resulted in B cell development that temporally recapitulated events in the bone marrow. We also demonstrate that these lymphoid progenitors are targets for retroviral transduction. This study suggests that long-term cultures provide a useful system to access early lymphoid progenitors and study the events that regulate their differentiation.     

School outcomes of sexual minority youth in the United States: evidence from a national study

Using data from the Add Health Study, the first nationally representative study of adolescents in the U.S. to include information on same-sex romantic attraction, we examine school outcomes (school troubles, attitudes, and performance) of same-sex attracted youth within the context of four relational domains: family, teacher, social, and peer. Results indicate that each domain plays a role in the negative attitudes about school held by these sexual minority youth. However, sexual minority youths' feelings about their teachers play an important role in explaining school troubles.     

Phase II Study of Intravenous Doxil® in Malignant Pleural Mesothelioma

Twenty-four patients with pleural mesotheliomareceived 50 mg/m² of Doxil® every four weeks.At follow-up, the disease had stabilized in 43% percent ofpatients and had progressed in 57%. No objective responses wereobserved. Estimated median survival of all patients was 37 weeks.Major toxicities were erythrodysesthesia of hands and feet andmyelosuppression. No cardiac toxicity was observed. We concludedthat Doxil® at this dosage and schedule is inactiveagainst pleural mesothelioma.     

Evidence for an antigen-driven humoral immune response in medullary ductal breast cancer.

A minority of breast cancers is characterized by lymphoplasmacytic infiltrates that have been correlated with improved patient survivals. The association of improved prognosis with plasmacytic infiltrates has been classically linked with the rare medullary carcinoma subtype but is also evident in the smaller infiltrated fraction of the more abundant nonmedullary (not otherwise specified) tumors. It is our hypothesis that these plasma cell (PC) infiltrates represent a host humoral response driven by one or more tumor-derived neoantigens. As the index study group, two primary medullary carcinoma tumors were examined. Immunophenotyping confirmed a large number of IgG PCs in contradistinction to normal breast, which typically contains a lesser number of mainly IgA isotypes. IgG heavy and light chains were expressed as combinatorial phage Fab libraries. VH and VL sequences showed a preponderance of clonal groups in both patients, as identified by germ-line gene usage and junctional mutation patterns. Panning of phage Fab libraries against purified antigens excluded Her2/neu and p53 as the eliciting antigen, and failure of clonal enrichment by cell panning suggested that the neoantigen was not membrane expressed or was expressed at low levels. Cognate, original VH+VL pairs were obtained by single cell PCR of tumor PCs, which showed overlap with the pooled IgG libraries. Tumor-derived IgG V genes exhibited mutational patterns that were consistent with antigenic selection and affinity maturation. Where examined, IgG1 was the predominant isotype, consistent with a T-dependent (i.e., protein) antigen. From these data, we infer that the breast tumor PC infiltrates of the medullary carcinoma subtype are compatible with an autogenic tumor neoantigen-driven humoral immune response.     

Milacemide increases 5-hydroxytryptamine and dopamine levels in rat brain--possible mechanisms of milacemide antimyoclonic property in the p,p'-DDT-induced myoclonus

Milacemide, a glycine prodrug that is able to enter the brain readily, has been shown to have an antimyoclonic property in the p,p'-DDT-induced myoclonus syndrome. Milacemide increased regional 5-HT and dopamine and decreased 5-HIAA, DOPAC and HVA levels in naive rats. In p,p'-DDT-treated rats, 5-HT levels were unchanged at the time the rats experienced spontaneous myoclonus in all brain regions except in the striatum, where it increased. 5-HIAA levels increased but did not reach significant levels except in the striatum. Dopamine, DOPAC, HVA and norepinephrine were unchanged. When rats were treated concurrently with both p,p'-DDT and milacemide, regional 5-HT levels were increased and NE levels in the brainstem and cerebellum decreased. Depletion of brain serotonin by pretreatment with PCPA or with 5,7-DHT, or blocking 5-HT receptors with different 5-HT antagonists, failed to eliminate the antimyoclonic property of milacemide. This antimyoclonic effect of milacemide may be mediated through other mechanisms besides its ability to increase brain 5-HT levels. Possible mechanisms to be considered are its antiepileptic property, and its ability to increase brain glycine levels. Milacemide may have potential for therapeutic trials in patients with myoclonus.     

Synthesis of 3H, 14C and 2H4 labelled SCH 211803

[³H]SCH 211803, at a specific activity of 1.56 Ci/mmol, was prepared by direct exchange with tritiated water and platinum metal. [²H₄]SCH 211803 was prepared from [²H]formaldehyde in a seven step synthesis in 10% yield. [¹⁴C]SCH 211803 was prepared from N‐benzyl‐4‐hydroxy[2‐¹⁴C]piperidine in a four‐step synthesis in 35% radiochemical yield. Additionally a high specific activity batch of [³H]SCH 211803 was prepared by Ru(Ph₃P)₃Cl₂ catalysed exchange with 90 at% tritiated water to a specific activity of 35 Ci/mmol. Copyright © 2007 John Wiley & Sons, Ltd.