Exploring the Role of Traumatic Event Exposure in Tobacco Dependence Treatment Outcomes Among African Americans

African Americans are more likely to die from tobacco-related diseases and less likely to quit smoking than their white counterparts. Evidence of greater prevalence of posttraumatic stress disorder (PTSD) among African Americans underscores the importance of studying the effects of traumatic event exposure on tobacco dependence treatment outcomes in this group. In this secondary analysis of data from a previously completed randomized control trial, we examined the effects of traumatic event exposure (e.g., serious accident) on tobacco dependence treatment outcomes, as well its moderating effects on the effectiveness of an adapted smoking cessation treatment, in a sample (n = 169) of African American smokers in New York City. Traumatic event exposure did not have a significant impact on tobacco treatment outcomes and did not moderate the relationship between treatment type and outcomes in this sample. While results may be driven by unique sample characteristics, they may also indicate that an average level of traumatic event exposure does not significantly impact tobacco treatment outcomes among African Americans. Future research should examine the effects of higher levels of traumatic event exposure on treatment outcomes, as well as investigating the factors underlying trauma-exposed individuals' difficulties with reducing/quitting smoking in a larger, more diverse African American sample.

The MOBILISE study: utilisation of ambulatory pumps in the inpatient setting to administer continuous antibiotic infusions-a randomised controlled trial

In the inpatient setting, antibiotics are generally administered via bedside pumps with multiple daily dosing. Utilisation of a continuous antibiotic infusion (CAI) instead might have patient and nursing satisfaction, workflow efficiencies and infection control benefits. We aimed to study the utilisation of CAI in the inpatient setting for routine antibiotic administration. Patients receiving a peripherally inserted central venous catheter (PICC) for antibiotic administration were screened for the study. The patients were randomised to either (1) standard pump and intermittent antibiotic administration (IAA) or (2) CAI via an ambulatory pump. An accelerometer placed on the ankle was used to assess patient activity. Nursing and patient satisfaction surveys were also carried out. Forty patients met the study criteria for enrolment with 21 patients being enrolled in the CAI arm of the study. One hundred and five days of accelerometer recordings were available for analysis. The geometric mean activity was 45 min/day in the standard arm and 64 min/day in the CAI arm. This represented a 42% (95% CI: -14 to 133%, p = 0.16) difference in activity between the two groups. Nursing staff reported that they spent less time throughout their shift attending the antibiotic line or pump in patients who were in the CAI arm of the study (p < 0.001). In addition, patients in this arm of the study were more likely to recommend this method of administration of antibiotics to a family member (p =0.0001). The MOBILISE study showed nursing and patient satisfaction when CAI were utilised in the inpatient setting. A statistically non-significant difference in mobility was seen. The trial was registered (28/03/2018) with the Australia New Zealand Clinical Trials Registry (ACTRN12618000452291).

Opsin co-expression in Limulus photoreceptors: differential regulation by light and a circadian clock

A long-standing concept in vision science has held that a single photoreceptor expresses a single type of opsin, the protein component of visual pigment. However, the number of examples in the literature of photoreceptors from vertebrates and invertebrates that break this rule is increasing. Here, we describe a newly discovered Limulus opsin, Limulus opsin5, which is significantly different from previously characterized Limulus opsins, opsins1 and 2. We show that opsin5 is co-expressed with opsins1 and 2 in Limulus lateral and ventral eye photoreceptors and provide the first evidence that the expression of co-expressed opsins can be differentially regulated. We show that the relative levels of opsin5 and opsin1 and 2 in the rhabdom change with a diurnal rhythm and that their relative levels are also influenced by the animal's central circadian clock. An analysis of the sequence of opsin5 suggests it is sensitive to visible light (400-700 nm) but that its spectral properties may be different from that of opsins1 and 2. Changes in the relative levels of these opsins may underlie some of the dramatic day-night changes in Limulus photoreceptor function and may produce a diurnal change in their spectral sensitivity.

Cyclic AMP: a mitogenic signal for Swiss 3T3 cells

Addition of cholera toxin (100 ng/ml) to quiescent cultures of Swiss 3T3 cells acts synergistically with serum (2-4%), insulin, phorbol esters, epidermal growth factor, and fibroblast-derived growth factor to stimulate DNA synthesis. In the presence of insulin, cholera toxin caused a dose-dependent increase in cumulative [3H]thymidine incorporation into acid-insoluble material and in the intracellular cyclic AMP (cAMP) level. The dose--response curves for the two processes were similar. Furthermore, addition of 1-methyl-3-isobutylxanthine (15--500 microM) or of 4-(3-butoxy-4-methoxybenzyl)-2-imidazolidinone (5--100 microM), both of which are potent inhibitors of cyclic nucleotide phosphodiesterase which are potent inhibitors of cyclic nucleotide phosphodiesterase activity, stimulated DNA synthesis and increased cAMP levels in Swiss 3T3 cells. These compounds strikingly potentiated the effect of cholera toxin on DNA synthesis and on cAMP levels. When quiescent Swiss 3T3 cells were exposed to cholera toxin (100 ng/ml) and insulin at 10 micrograms/ml (4- to 7-fold increase in cAMP level) or to these agents and 1-methyl-3-isobutyl xanthine at 50 microM (35-fold increase in cAMP level), DNA synthesis began after a lag of 16 hr. These results indicate that cAMP acts as a mitogenic signal for Swiss 3T3 cells and differ from the widely held view that cyclic AMP inhibits the proliferation of fibroblast cells.

Melittin stimulates Na entry, Na-K pump activity and DNA synthesis in quiescent cultures of mouse cells

Melittin, an amphipatic polypeptide, increases several fold the activity of Na-K pump in quiescent Swiss 3T3 cells. As with other growth factors, melittin increases the activity of the pump by increasing Na entry into the cell. In contrast, other early responses are not elicited by the toxin. At concentrations that promote ion fluxes, melittin stimulates DNA synthesis in quiescent mouse cells acting synergistically with insulin, epidermal growth factor and with the growth factor released by SV40 BHK cells. In contrast, melittin does not interact synergistically with either phorbol esters of vasopressin. The cellular effects of melittin are consistent with the proposal that ion fluxes signal the initiation of mitogenesis in quiescent cells.

Antitubulin agents enhance the stimulation of DNA synthesis by polypeptide growth factors in 3T3 mouse fibroblasts

Colchicine and other antitubulin agents markedly enhanced the stimulation of DNA synthesis by combinations of various growth factors such as epidermal growth factor, insulin, fibroblast-derived growth factor, and vasopressin in serum-free cultures of several quiescent 3T3 mouse fibroblast cell lines. Enhancing effects were observed based on continuous incorporation of [3H]thymidine into DNA as well as by autoradiographic labeling of cell nuclei. The concentration of colchicine and podophyllotoxin required to produce half-maximal enhancement of DNA synthesis stimulated by epidermal growth factor and insulin was 25-50 nM. Lumicolchicine did not produce enhancing effects. The disassembly of microtubules resulting from the action of colchicine, Colcemid, and vinblastine did not inhibit the stimulation of DNA synthesis in quiescent Swiss 3T3 fibroblasts by fetal bovine serum. We conclude that the cytoplasmic microtubule network in 3T3 mouse fibroblasts does not exert a positive regulatory function in the initiation of DNA synthesis but rather can produce a constraint on the initial action of the peptide growth factors in serum-free media.

Vasopressin stimulation of mouse 3T3 cell growth

Vasopressin is shown to be a potent mitogen for Swiss 3T3 cells. The hormone (1--10 ng/ml) causes a striking shift of the dose--response curve for the effect of serum on thymidine incorporation by cultures of 3T3 cells arrested in the G1/G0 phase of the cell cycle. In the absence of added serum, the effect of vasopressin on DNA synthesis is greatly potentiated by insulin, epidermal growth factor, and a factor isolated from medium conditioned by simian virus 40-infected baby hamster kidney cells. The mitogenic effect of vasopressin is dependent on time and hormone concentration. In the presence of insulin, the half-maximal effect elicited by the peptide is obtained at 0.6 ng/ml. [Arg]Vasopressin and [Lys]vasopressin are equally potent. The vasopressins are 10(3)-fold more potent than oxytocin. In the presence of a low (2.5%) concentration of serum, vasopressins stimulate cell proliferation.

Glycolysis in quiescent cultures of 3T3 cells. Stimulation by serum, epidermal growth factor, and insulin in intact cells and persistence of the stimulation after cell homogenization

Addition of serum to quiescent cultures of 3T3 cells rapidly increases lactic acid formation and subsequently stimulates cell division. The stimulation of lactic acid production is seen at high, saturating concentrations of extra-cellular glucose. It is dependent on the time of exposure and on the dose of serum and is not blocked by the addition of cycloheximide, puromycin, or actinomycin D. In contrast, serum only marginally affects glycolysis by rapidly growing 3T6 or SV40-3T3 cells. In addition to serum, epidermal growth factor (0.1 to 10 ng/ml) and insulin (10 to 500 ng/ml) cause a striking stimulation of glycolysis in quiescent 3T3 cells. Neither exogenous cyclic nucleotides nor ouabain effect the glycolytic response, but the presence of Ca2+ markedly influences the activation of glycolysis by epidermal growth factor and by insulin. A novel finding in this study is that homogenates prepared from quiescent cells treated with serum, epidermal growth factor, or insulin show increased glycolysis as compared with homogenates from nonstimulated cultures. This finding will allow further experimental analysis of the cause of increased glycolysis in rapidly proliferating cells.