2,925 research outputs found
Retinoic acid induces the differentiation of B cell hybridomas from patients with common variable immunodeficiency.
Human-human B cell hybridomas constructed from B lymphocytes of common variable immunodeficiency (CVI) patients and the nonsecreting cell line WIL2/729 HF consistently secrete low levels of Ig and appear to retain a defect characteristic of the CVI patient's B cells. We assessed the differentiative capacity of retinoic acid (RA) on these hybridomas, as well as on hybridomas constructed from normal B cells and from patients with selective IgA deficiency. RA at concentrations varying between 10(-5) and 10(-9) M augmented IgM secretion 4-20-fold from four of four CVI hybridomas tested, but did not affect Ig secretion from normal or IgA-deficiency hybridomas. In support of this elevated Ig secretion, RA enhanced the de novo synthesis of biosynthetically labeled light (kappa) and heavy (mu) Ig (up to 4- and 15-fold, respectively) in the CVI hybridoma line JK32.1. The increase in IgM synthesis/secretion could not be accounted for by RA-induced alteration in the cell cycle. In inducing this increase in IgM production, RA was found to affect two aspects of Ig gene expression: (a) the steady-state levels of heavy and light chain mRNAs were enhanced, and (b) the processing of mu heavy chain transcripts to the secreted mRNA form became favored over the membrane mRNA form. We also show that expression of Leu-17 (CD38), a surface marker that is re-expressed in the late pre-plasma stage of B cell development, was increased by RA from less than 20% to greater than 90% of the total cell population, with a concomitant 4-10-fold augmentation in the mean fluorescence intensity. Changes in both Leu-17 expression and de novo Ig synthesis were prominent by 24 h, but could be observed as early as 8 h after induction. Taken together, our study demonstrates that RA affects a marked alteration in the differentiated state of the CVI hybridoma clones. This finding suggests that retinoids can enhance the functional capabilities of B cells with defects in maturation and support further studies to evaluate their clinical potential in CVI
Matter Radii of \u3csup\u3e29-35\u3c/sup\u3eMg
We have computed matter radii for the ground states of 29–35Mg for a variety of reasonable assumptions about the structure of the relevant states. For cases in which the dominant configuration is generally agreed, our computed radii are in good agreement with experimental ones. For cases in which the dominant configuration is unknown or ambiguous, comparisons between the calculated and experimental Rm do not allow a decision as to the preferred configuration
Excited states of \u3csup\u3e19\u3c/sup\u3eMg
We have calculated energies of the first two excited states of 19Mg by using a model that was previously successful for the ground state. Computed excitation energies are 1.12 and 1.54 MeV for (3/2−) and (5/2−), respectively—somewhat in disagreement with values of 1.38 and 2.14 MeV from a recent experiment
Mass of \u3csup\u3e18\u3c/sup\u3eMg(g.s.)
We use a potential model, together with spectroscopic factors from a combination of weak coupling and a shell-model calculation, to compute the mass of the ground state of 18Mg, considered as a mirror of 18C. The result is E2p=3.87(10)MeV
Predictions for the first two positive-parity states of \u3csup\u3e13\u3c/sup\u3eF
We have used a potential model, together with information from 13Be, to compute expected energies and widths for the first two positive-parity states of 13F. Results are (all in MeV) Ep = 2.30 and 4.94 (or 5.26), width ∼0.6 and 0.3 (or 0.4), for 1/2+ and 5/2+, respectively
Continuum three-body decays of \u3csup\u3e9\u3c/sup\u3eBe(5/2\u3csup\u3e−\u3c/sup\u3e)
We describe and discuss various three-body decay mechanisms for 9Be(5/2−). We find that its decay to n+ 8Be(2+) is a small fraction of the total decay
Uptake of HIV testing among 15–19-year-old adolescents in Zambia
Adolescent HIV testing rates remain low with many unaware of their status. We explored factors associated with HIV testing uptake among adolescents aged 15–19 years using data from the Zambian Demographic Health Survey 2013–2014. The sample consisted of 7030 adolescents of which 42% reported ever testing for HIV. We found that as the age of a respondent increased so did their odds of testing (aOR = 1.26; 1.21–1.32); females had higher odds of testing than males (aOR = 1.719; 1.53–1.92); those with secondary or higher education (aOR = 3.64; 2.23–5.96) and those with primary education (aOR=1.97; 1.21–3.19) had higher odds of testing than those with no education; those who were formerly married or living with a partner (aOR =  4.99; 2.32–10.75) and those who were currently married or living with a partner (aOR = 4.76; 3.65–6.21) had higher odds of testing than those who were never married or lived with a partner; as the age at first sexual intercourse increased so did the odds of testing (aOR = 1.07; 1.06–1.08); and as HIV knowledge increased so did the odds of testing (aOR = 1.13; 1.06–1.19). The data points to population level social determinants that may be targeted to increase testing among adolescents
School, Supervision and Adolescent-Sensitive Clinic Care: Combination Social Protection and Reduced Unprotected Sex Among HIV-Positive Adolescents in South Africa
Social protection can reduce HIV-risk behavior in general adolescent populations, but evidence among HIV-positive adolescents is limited. This study quantitatively tests whether social protection is associated with reduced unprotected sex among 1060 ART-eligible adolescents from 53 government facilities in South Africa. Potential social protection included nine 'cash/cash-in-kind' and 'care' provisions. Analyses tested interactive/additive effects using logistic regressions and marginal effects models, controlling for covariates. 18 % of all HIV-positive adolescents and 28 % of girls reported unprotected sex. Lower rates of unprotected sex were associated with access to school (OR 0.52 95 % CI 0.33-0.82 p = 0.005), parental supervision (OR 0.54 95 % CI 0.33-0.90 p = 0.019), and adolescent-sensitive clinic care (OR 0.43 95 % CI 0.25-0.73 p = 0.002). Gender moderated the effect of adolescent-sensitive clinic care. Combination social protection had additive effects amongst girls: without any provisions 49 % reported unprotected sex; with 1-2 provisions 13-38 %; and with all provisions 9 %. Combination social protection has the potential to promote safer sex among HIV-positive adolescents, particularly girls
In the Interests of clients or commerce? Legal aid, supply, demand, and 'ethical indeterminacy' in criminal defence work
As a professional, a lawyer's first duty is to serve the client's best interests, before simple monetary gain. In criminal defence work, this duty has been questioned in the debate about the causes of growth in legal aid spending: is it driven by lawyers (suppliers) inducing unnecessary demand for their services or are they merely responding to increased demand? Research reported here found clear evidence of a change in the handling of cases in response to new payment structures, though in ways unexpected by the policy's proponents. The paper develops the concept of 'ethical indeterminacy' as a way of understanding how defence lawyers seek to reconcile the interests of commerce and clients. Ethical indeterminacy suggests that where different courses of action could each be said to benefit the client, the lawyer will tend to advise the client to decide in the lawyer's own interests. Ethical indeterminacy is mediated by a range of competing conceptions of 'quality' and 'need'. The paper goes on to question the very distinction between 'supply' and 'demand' in the provision of legal services
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