Phenotypic characterization and prognostic impact of circulating γδ and αβ T‐cells in metastatic malignant melanoma

Human T cells carrying γδ T‐cell receptors (TCRs) represent a minor population relative to those with αβ TCRs. There has been much interest recently in the possibility of using these γδ T‐cells in cancer therapy because they can kill tumor cells in vitro in an MHC‐unrestricted manner, and possess potential regulatory capability and antigen‐presenting capacity. The presence of γδ T‐cells in late‐stage melanoma patients and their relationship with survival has not been extensively explored, although relatively lower percentages of total γδ T‐cells and Vδ2+ cells have been reported. Here, we present a detailed analysis of associations of γδ T‐cell subsets and differentiation stages with survival in Stage IV patients, compared with CD4+ and CD8+ αβ T‐cells. We found an increased Vδ1:Vδ2‐ratio and a decreased CD4:CD8‐ratio in patients compared to healthy controls, on the basis both of relative frequencies and absolute cell counts per μL blood. Nonetheless, Kaplan–Meier analyses showed that a higher than median frequency of Vδ1+ cells was negatively associated with survival, whereas there were no positive or negative associations with frequencies of Vδ2+ cells. Correlations of cell differentiation status with survival revealed a negative association of early‐differentiated Vδ1+ T cells with survival, both on the basis of relative frequencies and absolute counts. There was also a positive correlation between the frequencies of early‐differentiated CD8+ αβ T‐cells and survival. Our findings suggest peripheral blood frequencies of Vδ1+ T‐cells as a potential prognostic marker in melanoma. The mechanisms by which higher abundance of Vδ1+ cells are associated with poorer survival require determination.     

Ca(2+) exchange with troponin C and cardiac muscle dynamics

Controversy abounds in the cardiac muscle literature over the rate-limiting steps of cardiac muscle contraction and relaxation. However, the idea of a single biochemical mechanism being the all-inclusive rate-limiting step for cardiac muscle contraction and relaxation may be oversimplified. There is ample evidence that Ca(2+) concentration and dynamics, intrinsic cross-bridge properties, and even troponin C (TnC) Ca(2+) binding and dissociation can all modulate the mechanical events of cardiac muscle contraction and relaxation. However, TnC has generally been thought to play no role in influencing cardiac muscle dynamics due to the idea that Ca(2+) exchange with TnC is very rapid. This definitely is the case for isolated TnC, but not for the more sophisticated biochemical systems of reconstituted thin filaments and myofibrils. This review will discuss the biochemical influences on Ca(2+) exchange with TnC and their physiological implications.     

Auxin acts as a local morphogenetic trigger to specify lateral root founder cells

Plants exhibit an exceptional adaptability to different environmental conditions. To a large extent, this adaptability depends on their ability to initiate and form new organs throughout their entire postembryonic life. Plant shoot and root systems unceasingly branch and form axillary shoots or lateral roots, respectively. The first event in the formation of a new organ is specification of founder cells. Several plant hormones, prominent among them auxin, have been implicated in the acquisition of founder cell identity by differentiated cells, but the mechanisms underlying this process are largely elusive. Here, we show that auxin and its local accumulation in root pericycle cells is a necessary and sufficient signal to respecify these cells into lateral root founder cells. Analysis of the alf4-1 mutant suggests that specification of founder cells and the subsequent activation of cell division leading to primordium formation represent two genetically separable events. Time-lapse experiments show that the activation of an auxin response is the earliest detectable event in founder cell specification. Accordingly, local activation of auxin response correlates absolutely with the acquisition of founder cell identity and precedes the actual formation of a lateral root primordium through patterned cell division. Local production and subsequent accumulation of auxin in single pericycle cells induced by Cre-Lox-based activation of auxin synthesis converts them into founder cells. Thus, auxin is the local instructive signal that is sufficient for acquisition of founder cell identity and can be considered a morphogenetic trigger in postembryonic plant organogenesis.     

Current approaches to the management of early active diffuse scleroderma skin disease

Skin sclerosis is a clinical hallmark of systemic sclerosis (SSc) and provides a means to classify and evaluate patients. In the diffuse cutaneous subset, skin involvement is often extensive and warrants direct therapy. Currently, broad spectrum immunosuppressive strategies are used, but more targeted specific approaches are now emerging. This article reviews the evidence for efficacy of current treatment approaches and future developments for managing skin disease in early diffuse cutaneous SSc.     

Inhibition of metoprolol metabolism and potentiation of its effects by paroxetine in routinely treated patients with acute myocardial infarction (AMI)

Objective To investigate the influence of paroxetine on metoprolol concentrations and its effect in patients treated for acute myocardial infarction (AMI) who are routinely given paroxetine as a co-treatment of depression. Methods We recruited 17 depressed AMI patients who received metoprolol as a routine part of their therapy (mean dose 75 ± 39 mg/day). Patients were genotyped for CYP2D6 *3, *4 and gene duplication. Metoprolol and α-hydroxy-metoprolol were analyzed in plasma 0, 2, 6 and 12 h post-dose. Heart rates (HR) at rest were registered after each sampling. Paroxetine 20 mg daily was then administered, and all measurements were repeated on day 8. Results All patients were genotypically extensive metabolizers (EMs) (nine with *1/*1 and eight with *1/*3 or *4). Following the administration of paroxetine, mean metoprolol areas under the concentration–time curve (AUC) increased (1064 ± 1213 to 4476 ± 2821 nM × h/mg per kg, P = 0.0001), while metabolite AUCs decreased (1492 ± 872 to 348 ± 279 n M × h/mg per kg, P < 0.0001), with an increase of metabolic ratios (MR) (0.9 ± 1.3 to 26 ± 29; P < 0.0001). Mean HRs were significantly lower after the study week at each time point. Mean area under the HR versus time curve (AUEC) decreased (835 ± 88 to 728 ± 84 beats × h/min; P = 0.0007). Metoprolol AUCs correlated with patients’ AUECs at the baseline (Spearman r  = −0.64, P < 0.01), but not on the eighth day of the study. A reduction of metoprolol dose was required in two patients due to excessive bradycardia and severe orthostatic hypotension. No other adverse effects of the drugs were identified. Conclusion A pronounced inhibition of metoprolol metabolism by paroxetine was observed in AMI patients, but without serious adverse effects. We suggest, however, that the metoprolol dose is controlled upon initiation and withdrawal of paroxetine.     

Synthesis and antiprotozoal activity of cationic 2-phenylbenzofurans

A series of cationically substituted 2-phenylbenzofurans 1- 49 have been synthesized, and their in vitro antiprotozoal properties against Trypanosoma brucei rhodesiense, Plasmodium falciparum, and Leishmania donovani, as well as cytotoxicity against mammalian cells, have been evaluated. Eight dications exhibited antitrypanosomal activities comparable to that of pentamidine and melarsoprol. Twenty-six compounds were more active than pentamidine, and seven dications demonstrated increased activities against P. falciparum than artemisinin. Five congeners were more active against L. donovani than pentamidine. Introduction of methoxy or hydroxy groups in the 7- and/or 2'-position afforded derivatives that were highly selective against T. b. rhodesiense, P. falciparum, and L. donovani. Fourteen 2-phenylbenzofurans displayed excellent in vivo efficacies in the acute mouse model of trypanosomiasis, curing 3/4 or 4/4 animals at 4 x 5 mg/kg. Diamidine 1 and di( N-isopropyl)amidine 45, administered at 4 x 1 mg/kg, exhibited potency comparable to that of melarsoprol, providing 3/4 and 2/4 cures, respectively.     

The organophosphate-induced acute-phase response is characterized by synthesis of alpha 1-acid glycoprotein that exhibits an immunomodulatory effect

The organophosphorus compounds soman and paraoxon induce the acute-phase (AP) response. All phases of the AP response, from macrophage activation and stimulation of glucocorticoid secretion to AP protein expression appear to be under the control of similar molecular mechanisms to those during the turpentine-induced AP response. The AP protein content in the circulation 24 h after either soman, paraoxon or turpentine administration was injury-specific. Both soman and paraoxon poisoning were characterized by significantly increased synthesis of alpha(1)-acid glycoprotein (AGP) that displayed an immunomodulatory effect in vitro. This result suggests that after organophosphate poisoning AGP participates in vivo in a negative feedback mechanism that prevents over-activity of the immune system.