Micro-opioid receptor preferentially inhibits oxytocin release from neurohypophysial terminals by blocking R-type Ca2+ channels

Oxytocin release from neurophypophysial terminals is particularly sensitive to inhibition by the micro-opioid receptor agonist, DAMGO. Because the R-type component of the neurophypophysial terminal Ca2+ current (ICa) mediates exclusively oxytocin release, we hypothesised that micro-opioids could preferentially inhibit oxytocin release by blocking this channel subtype. Whole-terminal recordings showed that DAMGO and the R-type selective blocker SNX-482 inhibit a similar ICa component. Measurements of [Ca2+]i levels and oxytocin release confirmed that the effects of DAMGO and SNX-482 are not additive. Finally, isolation of the R-type component and its associated rise in [Ca2+]i and oxytocin release allowed us to demonstrate the selective inhibition by DAMGO of this channel subtype. Thus, micro-opioid agonists modulate specifically oxytocin release in neurophypophysial terminals by selectively targeting R-type Ca2+ channels. Modulation of Ca2+ channel subtypes could be a general mechanism for drugs of abuse to regulate the release of specific neurotransmitters at central nervous system synapses.     

Caring for children and adolescents with cancer: the intrathecal chemotherapy phase

This study aims to explore the experiences of children and adolescents with cancer during the intrathecal chemotherapy phase, by means of a qualitative approach. Empirical data were collected on the basis of semi-structured interviews. Study participants were eleven children/adolescents who received intrathecal chemotherapy, between 07 and 16 years old, from both genders, attended at a hospital school in the interior of S?o Paulo State, Brazil. Results converged towards the following issues: intrathecal routine; fear, pain and relief fantasies and strategies. This study gave access to important information with a view to caring for children/adolescents during the intrathecal chemotherapy phase, which is considered as one of the most stressing situations. With respect to nursing implications, we identified the vital nature of information for children/adolescents with cancer since this makes it possible to minimize uncertainties and negative feelings and makes them collaborate and participate in treatment.     

Restenosis rates following bifurcation stenting with sirolimus-eluting stents for de novo narrowings

The percutaneous treatment of coronary bifurcation stenoses is hampered by an increased rate of subsequent restenosis. The present study reports on the outcomes of a consecutive series of 58 patients with 65 de novo bifurcation stenoses treated with sirolimus-eluting stent implantation in both the main vessel and side branch. At 6 months, the incidence of major adverse cardiac events was 10.3% (1 death and 5 target lesion revascularizations) with no episodes of acute myocardial infarction or stent thrombosis.     

Kinins and cytokines in plasma and cerebrospinal fluid of patients with neuropsychiatric lupus

OBJECTIVE: To evaluate the kinin system components and selected cytokines in plasma and cerebrospinal fluid (CSF) of patients with neuropsychiatric lupus (NPL). METHODS: We studied 29 women with active NPL and 29 healthy women matched to patients for age. Low (LKg) and high molecular weight kininogen (HKg) and cytokine concentrations [interleukin 1beta (IL-1beta), IL-6, IL-8, IL-10, and tumor necrosis factor-a (TNF-a)] were determined by ELISA. The activities of tissue kallikrein, plasma prekallikrein, and kininase II were assayed by their action on selective substrates. RESULTS: Compared to controls, patients with NPL presented increased plasma and CSF levels of LKg, HKg, and prekallikrein, increased activity of tissue kallikrein and kininase II, and increased levels of IL-6, IL-10, and TNF-a (p < 0.001 each comparison). IL-1beta levels were increased in patient plasma (p < 0.001), whereas plasma IL-8 levels did not differ from controls. IL-1beta and IL-8 were not detected in CSF of patients or controls. CONCLUSION: The increased levels of kininogen fractions, kallikreins, and kininase II in patient plasma and CSF indicate overactivity of the kinin system, suggesting intense kinin production. Since kinins may induce the production of proinflammatory cytokines including IL-1beta, IL-6, and TNF-a, these findings support the participation of kinins and cytokines in the acute manifestations of NPL. Most of the variables evaluated in patients' CSF increased proportionally in relation to plasma levels. In contrast, the activity of tissue kallikrein in patient CSF increased out of proportion to plasma levels, appearing to be locally synthesized in response to brain involvement.     

A comparison of physical activity in men and women with cardiac disease: do gender roles complicate recovery?

Fifty-four male and twenty-six female married cardiac patients were studied for five months post-hospital discharge. Participants completed activity diaries for three days at 5, 10, 15, and 20 weeks. Reported activities were converted to METs. Patients increased activity across the five-month study period. Patients also tended to engage in higher levels of activity in the morning hours. Men and women did not differ in average total METs expended. Comparisons for specific activities indicated that women consistently expended more energy on domestic responsibilities, such as cleaning and laundry. Men engaged more in repairs, yardwork and carrying, but these activities were performed sporadically and involved low METs requirements. The concentrated domestic activity assumed by women early in recovery may pose a risk of complications.     

Effects of soy phytoestrogens genistein and daidzein on breast cancer growth

OBJECTIVE: To determine whether genistein and daidzein, the major phytoestrogens in soy, can stimulate breast cancer growth. DATA SYNTHESIS: Systematic search through primary English-language literature on MEDLINE (1966-January 2001), EMBASE (1982-January 2001) and Current Contents (1998-January 2001). DATA SOURCES: Genistein and daidzein at low concentrations were found to stimulate breast tumor growth in in vitro and in vivo animal studies, and antagonize the antitumor effect of tamoxifen in vitro. At high concentrations, genistein inhibited tumor growth and enhanced the effect of tamoxifen in vitro. CONCLUSIONS: Genistein and daidzein may stimulate existing breast tumor growth and antagonize the effects of tamoxifen. Women with current or past breast cancer should be aware of the risks of potential tumor growth when taking soy products.