Nurse anesthetist students' experiences of peer learning in clinical education - A qualitative study.

BACKGROUND: As part of an interprofessional operating team, nurse anesthetists need to be skilled in collaboration, problem solving, attentiveness, independent decision-making and knowledge of anesthesiology nursing. Factors that are vital for nurse anesthetist students' future profession. The educational model peer learning, characterized by collaboration and learning through social interaction between individuals, may support nurse anesthetist students' development in such skills. AIM: The aim of the study was to explore nurse anesthetist students' perceptions of their experiences of peer learning as an educational model during their clinical education in a Swedish context. METHODS: The approach was a qualitative descriptive design. Seven nurse anesthetist students from four different universities were interviewed individually using a semi-structured interview guide. The data were analyzed with content analysis. RESULTS: Three generic categories revealed a description of the phenomenon: Increased independence, Holistic view and Expansive learning process. A main category brought together the content of the generic categories and shows the overall finding of the study: Peer learning promotes nurse anesthetist students' personal and professional development. CONCLUSION: Peer learning as an educational model during nurse anesthetist students' clinical education might facilitate preparation for their coming profession.

Vitamin D deficiency at the Arctic Circle - a study in food-allergic adolescents and controls.

AIM: At the extremes of latitude, UVB intensity is insufficient for adequate vitamin D synthesis in winter. Fatty fish, vitamin D enriched milk, margarine and eggs are main dietary sources of vitamin D. Their elimination may increase the risk of vitamin D deficiency. The aim was to assess vitamin D status in food-allergic adolescents eliminating milk, egg and/or fish compared with adolescents on normal diets. METHODS: In winter, vitamin D intake was assessed by a food frequency questionnaire in 20 food-allergic adolescents and 42 controls in the population-based Obstructive Lung Disease In Northern Sweden (OLIN) cohort studies. Vitamin D supplementation was queried. Serum 25-hydroxyvitamin D [S-25(OH)D] and S-parathormone (S-PTH) levels were determined. RESULTS: Mean (SD) dietary vitamin D intake was 7.9 (3.6) µg/day in allergic adolescents and 7.8 (3.4) in controls (p > 0.05). Mean (SD) S-25(OH)D levels in supplement consumers were 44 (18) nmol/L compared with 35 (10) in non-consumers (p = 0.03). S-25(OH)D and S-PTH levels were similar in food-allergic adolescents and controls (p > 0.05). Eighty-two percentage had deficient S-25(OH)D levels <50 nmol/L, and none reached levels >75 nmol/L. CONCLUSION: Vitamin D deficiency was as common in food-allergic adolescents as in controls although the vitamin D intake met national recommendations. Large-scale studies on the prevalence of vitamin D deficiency in this region are needed.

Effects of nicotine, its metabolites and tobacco extracts on human platelet function in vitro.

Cigarette smoking is a leading cause of cardiovascular disease. The cardiovascular effects of smoking are probably multifactorial, including effects on platelets. Previous reports investigating the effects of nicotine and tobacco on platelet function are inconsistent. The present study investigated in vitro effects of nicotine, its major metabolites, tobacco extracts and extract of tobacco-free snuff on human platelets. None of the metabolites cotinine, cotinine-N-oxide, nicotine-1'-N-oxide or trans-3'-hydroxycotinine (0.1-10 µM) affected platelet aggregation or P-selectin expression. Nicotine (10 µM) weakly increased platelet aggregation, whereas trans-3'-hydroxycotinine (0.1 µM) and nicotine-1'-N-oxide (1-10 µM) weakly inhibited adhesion to fibrinogen. To elucidate the influence of other tobacco compounds, we investigated the impact of moist tobacco and smoke extracts on platelet function. Filtered extracts of oral snuff, cigarette smoke and tobacco free snuff inhibited platelet adhesion concentration-dependently. The inhibitory effects of tobacco extracts on platelet adhesion were independent of nicotine content and the nitric-oxide-pathway and not mediated through a platelet-nicotine-receptor. Taken together, tobacco extracts inhibit platelet activation during short-term in vitro challenge. As only limited effects of nicotine and nicotine metabolites were seen, the tobacco-induced platelet inhibition are likely induced by other compounds present in tobacco and tobacco free snuff.

Effects of cocoa extract and dark chocolate on angiotensin-converting enzyme and nitric oxide in human endothelial cells and healthy volunteers--a nutrigenomics perspective.

Evidence suggests that cocoa from the bean of Theobroma cacao L. has beneficial effects on cardiovascular disease. The aim of this study was to investigate if cocoa extract and dark chocolate influence angiotensin-converting enzyme (ACE) and nitric oxide (NO) in human endothelial cells (in vitro) and in healthy volunteers (in vivo). ACE activity was analyzed with a commercial radioenzymatic assay and measured in human endothelial cells from umbilical veins (HUVEC) after 10 minutes of incubation with cocoa extract. NO was measured after 24 hours of incubation. ACE activity and NO were measured at baseline and after 30, 60, and 180 minutes in 16 healthy volunteers after a single intake of 75 g of dark chocolate containing 72% cocoa. Significant inhibition of ACE activity (P < 0.01) and significant increase of NO (P < 0.001) were seen in HUVEC. In the study subjects, a significant inhibition of ACE activity (mean 18%) 3 hours after intake of dark chocolate was seen, but no significant change in NO was seen. According to ACE genotype, significant inhibition of ACE activity was seen after 3 hours in individuals with genotype insertion/insertion and deletion/deletion (mean 21% and 28%, respectively). Data suggest that intake of dark chocolate containing high amount of cocoa inhibits ACE activity in vitro and in vivo.

Effects of green tea, black tea and Rooibos tea on angiotensin-converting enzyme and nitric oxide in healthy volunteers.

OBJECTIVE: Tea has been reported to reduce cardiovascular mortality, but the underlying mechanisms are largely unknown. The aim of the current project was to investigate the effect of green tea (Japanese Sencha), black tea (Indian Assam B.O.P.) and Rooibos tea (South Africa) on angiotensin-converting enzyme (ACE) and nitric oxide (NO). DESIGN: Seventeen healthy volunteers received a single oral dose of 400 ml green tea, black tea or Rooibos tea in a randomized, three-phase, crossover study. ACE activity and NO concentration were measured (at 0, 30, 60 and 180 min) in all phases. ACE activity was analysed by means of a commercial radioenzymatic assay. Nitrite was analysed as a marker of NO concentration. In addition, ACE genotype was determined using a PCR method. RESULTS: Oral intake of a single dose of Rooibos tea significantly inhibited ACE activity after 30 min (P < 0.01) and after 60 min (P < 0.05). A significant inhibition of ACE activity was seen with green tea for the ACE II genotype 30 min after intake of the tea (P < 0.05) and for the ACE ID genotype 60 min after intake (P < 0.05). A significant inhibition of ACE activity was also seen with Rooibos tea for the ACE II genotype 60 min after intake (P < 0.05). No significant effect on NO concentration was seen. CONCLUSIONS: These results suggest that green tea and Rooibos tea may have cardiovascular effects through inhibition of ACE activity.

Horse chestnut extract contracts bovine vessels and affects human platelet aggregation through 5-HT(2A) receptors: an in vitro study.

Extract from seeds and bark of horse chestnut (Aesculus hippocastanum L) is used as an herbal medicine against chronic venous insufficiency. The effect and mechanism of action on veins, arteries, and platelets are not fully understood. The aim of this study was to investigate the effects and mechanisms of action of horse chestnut on the contraction of bovine mesenteric veins and arteries, and human platelet aggregation. Contraction studies showed that horse chestnut extract dose-dependently contracted both veins and arteries, with the veins being the most sensitive. Contraction of both veins and arteries were significantly inhibited by the 5-HT(2A) receptor antagonist ketanserin. No effect on contraction was seen with the cyclooxygenase inhibitor indomethacin, the alpha(1) receptor antagonist prazosin or the angiotensin AT(1) receptor antagonist saralasin neither in veins nor arteries. ADP-induced human platelet aggregation was significantly reduced by horse chestnut. A further reduction was seen with the extract in the presence of ketanserin. In conclusion, horse chestnut contraction of both veins and arteries is, at least partly, mediated through 5-HT(2A) receptors. Human platelet aggregation is reduced by horse chestnut. The clinical importance of these findings concerning clinical use, possible adverse effects, and drug interactions remains to be investigated.

Effect of Vaccinium myrtillus and its polyphenols on angiotensin-converting enzyme activity in human endothelial cells.

This study investigates if the connection between Vaccinium myrtillus and angiotensin-converting enzyme (ACE) might be an explanation of the pharmacological effects on circulation. Cultured endothelial cells from human umbilical veins were incubated with bilberry 25E extract. The main anthocyanidins combined in myrtillin chloride and separately in cyanidin, delphinidin, and malvidin, respectively, were examined concerning their effects on ACE. After 10 min of incubation with bilberry 25E, a significant, dose-dependent inhibition of ACE activity was seen, and after incubation with myrtillin chloride a significant inhibition was seen. No effect was seen with the anthocyanidins. The effect seems to be dependent on this specific mixture of anthocyanins in the bilberry. V. myrtillus may thus have the potential to prevent and protect against cardiovascular diseases.

Panax ginseng induces anterograde transport of pigment organelles in Xenopus melanophores.

Melanophores from Xenopus laevis are pigmented cells, capable of quick colour changes through cyclic adenosine 3':5'-monophosphate (cAMP) coordinated transport of their intracellular pigment granules, melanosomes. In this study we use the melanophore cell line to evaluate the effects of Panax ginseng extract G115 on organelle transport. Absorbance readings of melanophore-coated microplates, Correlate-EIA direct cAMP enzyme immunoassay kit, and western blot were used to measure the melanosome movement and changes in intracellular signalling. We show that Panax ginseng induces a fast concentration-dependent anterograde transport of the melanosomes. No significant increase in the cAMP level was seen and pre-incubation of melanophores with the protein kinase C (PKC) inhibitor EGF-R Fragment 651-658 (M-EGF) only partly decreased the ginseng-induced dispersion. We also demonstrate that Panax ginseng, endothelin-3 (ET-3) and alpha-melanocyte stimulating hormone (MSH) stimulate an activation of mitogen activated protein kinase (MAPK). Pre-incubation with M-EGF decreased the MAPK activity induced by ET-3 and MSH, but again only marginally affected the response of Panax ginseng. Thus, in melanophores we suggest that Panax ginseng stimulates an anterograde transport of pigment organelles via a non-cAMP and mainly PKC-independent pathway.

Tea flavanols inhibit angiotensin-converting enzyme activity and increase nitric oxide production in human endothelial cells.

A diversity of pharmacological effects on the cardiovascular system have been reported for Camellia sinensis: antioxidative, antiproliferative and anti-angiogenic activity, and nitric oxide synthase activation. The purpose of this study was to investigate if the connection between tea and angiotensin-converting enzyme (ACE) and nitric oxide (NO) might be an explanation of the pharmacological effects of tea on the cardiovascular system. Cultured endothelial cells from human umbilical veins (HUVEC) were incubated with extracts of Japanese Sencha (green tea), Indian Assam Broken Orange Pekoe (black tea) and Rooibos tea, respectively. The main flavanols and purine alkaloids in green and black tea were examined for their effects on ACE and NO. After incubation with green tea, black tea and Rooibos tea for 10 min, a significant and dose-dependent inhibition of ACE activity in HUVEC was seen with the green tea and the black tea. No significant effect on ACE was seen with the Rooibos tea. After 10-min incubation with (-)-epicatechin, (-)-epigallocatechin, (-)-epicatechingallate and (-)-epigallocatechingallate, a dose-dependent inhibition of ACE activity in HUVEC was seen for all four tea catechins. After 24-h incubation, a significantly increased dose-dependent effect on NO production in HUVEC was seen for the green tea, the black tea and the Rooibos tea. After 24-h incubation with (-)-epicatechin, (-)-epigallocatechin, (-)-epicatechingallate and (-)-epigallocatechingallate, a dose-dependent increased NO production in HUVEC was seen. In conclusion, tea extracts from C. sinensis may have the potential to prevent and protect against cardiovascular disease.

Effect of Panax ginseng extract (G115) on angiotensin-converting enzyme (ACE) activity and nitric oxide (NO) production.

This study investigates the effects of the Panax ginseng (Araliaceae) extract G115 on angiotensin-converting enzyme (ACE) activity and nitric oxide (NO) in cultured human endothelial cells from umbilical veins (HUVEC) and bovine mesenteric arteries (BMA). In HUVEC, ACE activity was significantly reduced after 10 min incubation with aqueous extract of ginseng 5.0 and 10 mg/ml. This effect was additative with the inhibition of the traditional ACE inhibitor enalaprilat. No effect was seen on NO production from the cells. Angiotensin I-induced contraction of BMA was significantly attenuated by 0.1 and 0.5 mg/ml ginseng, while no endothelium-dependent or -independent relaxation was seen. In conclusion, extract of Panax ginseng (G115) inhibits ACE activity, but does not affect NO production in HUVEC and BMA.