Dual effect of ATP on glucose-induced insulin secretion in HIT-T15 cells.

OBJECTIVES: : The study investigated the dual effect of purinergic nucleotides on the secretion of insulin from pancreatic beta cells. METHODS: : The level of insulin secretion in HIT-T15 cells of static incubation was measured using a radioimmunoassay. RESULTS: : The adenine nucleotides reduced the level of glucose-induced insulin secretion in a concentration-dependent manner, and the relative potency order (IC50; muM) was BzATP (6.9) > ATP (20.4) >/= alpha, beta-methylene ATP (23.3) >/= 2-methylthio-ATP (24.9). Suramin and PPADS (200 muM), which are blockers of the purinergic receptors, had a little influence on the activity of ATP. However, the inhibitory effect of ATP was reversed by preincubation with oxidized ATP (200 muM), which is a P2X7 antagonist. The level of insulin secretion in these preincubated cells exposed to the purinergic nucleotides increased in the following order: ATP > alpha, beta-methylene ATP >/= 2-methylthio-ATP. A pretreatment with foskolin and PDBu (100 nM) potentiated the increasing effect of ATP on insulin secretion. The Western blotting showed the expression of P2X7 and P2Y11 receptors. CONCLUSIONS: : Purinergic stimulation has inhibitory activity on glucose-dependent insulin secretion through the activation of the P2X7 receptor, whereas it has enhancing effect through the activation of the P2Y11 receptor in HIT-T15 cells.

[Trends of doctoral dissertations in nursing science: focused on studies submitted since 2000].

PURPOSE: The purpose of this study was to identify the characteristics of doctoral dissertations in nursing science submitted since 2000. METHOD: Three-hundred and five dissertations of six schools of nursing published from 2000 to 2006 in Korea were analyzed with the categories of philosophy, method, body of knowledge, research design, and nursing domain. RESULT: In philosophy, 82% of all dissertations were identified as scientific realism, 15% were relativism, and 3% were practicism. Two-hundred and fifty dissertations (82%) were divided into a quantitative methodology and 55 dissertations (18%) were qualitative methodology. Specifically, 45% were experimental, 23% methodological, 13% survey and 17% qualitative designed researches. Prescriptive knowledge was created in 47% of dissertations, explanatory knowledge in 29%, and descriptive knowledge in 24%. Over 50% of all research was studied with a community-based population. In the nursing domain, dissertations of the practice domain were highest (48.2%). CONCLUSION: Dissertations since 2000 were markedly different from the characteristics of the previous studies (1982-1999) in the increase of situation-related, prescriptive and community-based population studies. A picture of current nursing science identified in this study may provide a future guideline for the doctoral education for nursing.

Calcium mobilization by activation of M(3)/M(5) muscarinic receptors in the human retinoblastoma.

Activation of muscarinic acetylcholine receptors (mAChR) is one of the most important signal transduction pathways in the human body. In this study, we investigated the role of mAChR activation in relation to its subtypes in human retinoblastoma cell-lines (WERI-Rb-1) using Ca(2+) measurement, real-time PCR, and Western Blot techniques. Acetylcholine (ACh) produced prominent [Ca(2+)](i) transients in a repeated manner in WERI-Rb-1 cells. The maximal amplitude of the [Ca(2+)](i) transient was almost completely suppressed by 97.3 +/- 0.8% after atropine (1 microM) pretreatment. Similar suppressions were noted after pretreatments with thapsigargin (1 microM), an ER Ca(2+)-ATPase (SERCA) inhibitor, whereas the ACh-induced [Ca(2+)](i) transient was not affected even in the absence of extracellular calcium. U-73122 (1 microM), a PLC inhibitor, and xestospongin C (2 microM), an IP(3)-receptor antagonist, elicited 11.5 +/- 2.9% and 17.8 +/- 1.9% suppressions, respectively. The 50% inhibitory concentration of (IC(50)) values for blockade of a 100 microM ACh response by pirenzepine and 4-DAMP were 315.8 and 9.1 nM, respectively. Moreover, both M(3) and M(5) mAChRs were prominent in quantitative real-time-PCR. Taken together, the M(3)/M(5) subtypes appear to be the major contributor, leading to intracellular calcium mobilization from the internal store via an IP(3)-dependent pathway in the undifferentiated retinoblastoma cells.

An alpha3beta4 subunit combination acts as a major functional nicotinic acetylcholine receptor in male rat pelvic ganglion neurons.

We identified major subunits of the nicotinic acetylcholine receptor (nAChR) involved in excitatory postsynaptic potential and intracellular Ca(2+) ([Ca(2+)]i) increase in the major pelvic ganglion (MPG) neurons of the male rat. ACh elicited fast inward currents in both sympathetic and parasympathetic MPG neurons. Mecamylamine, a selective antagonist for alpha3beta4 nAChR, potently inhibited the ACh-induced currents in sympathetic and parasympathetic neurons (IC(50); 0.53 and 0.22 microM, respectively). Furthermore, alpha-conotoxin AuIB (10 microM), a new selective antagonist for alpha3beta4 nAChR, blocked more than 80% of the ACh-induced currents in MPG neurons. Conversely, alpha-bungarotoxin, alpha-methyllycaconitine, and dihydro-beta-erythroidine, known as blockers of the alpha7 or alpha4beta2, did not show selective blocking effects on MPG neurons. ACh transiently increased [Ca(2+)]i which was subsequently abolished in the extracellular Ca(2+)-free environment. Simultaneous recording of [Ca(2+)]i and ionic currents revealed that ACh increased [Ca(2+)]i under the conditions of the voltage-clamped (at -80 mV) state, and this resulted from the influx through nAChR itself. ACh-induced [Ca(2+)]i increase was blocked by mecamylamine (10 microM), but was not affected by atropine (1 microM). RT-PCR analysis showed that, among subunits of nAChR, alpha3 and beta4 were predominantly expressed in MPG. We suggest that activation of alpha3 and beta4 nAChR subunits in MPG neurons induce fast inward currents and [Ca(2+)]i increase, possibly mediating a major role in pelvic autonomic synaptic transmission.

[Trends of nursing science inquiry in doctoral dissertations].

PURPOSE: The purpose of this study was to identify the theoretical characteristics and direction of inquiry in the discipline of nursing by analyzing doctoral dissertations. METHOD: The materials used in this study were 277 doctoral dissertations from five universities in Korea. The framework for the study was derived from Kim's(1993) alternative linkage among philosophy, theory, and method in nursing science. RESULT: Of the 277 dissertations it was found that there were 13 types of linkages out of a possible 54 types. Most of the dissertations (128 of 277) were done within the linkage of realism/etic/quantitative/explanatory knowledge type. Of the 218 dissertations within scientific realism, 42 were within relativism, and 17 within practicism. There were 134 dissertations of the explanatory knowledge type, 112 descriptive ones, and 31 prescriptive ones. Studies done within the etic quantitative methodology included 209 dissertations and within the emic perspective, 43 with qualitative methodology, and 7 with quantitative. CONCLUSION: The results show that it is necessary to develop more alternative linkages for nursing practice and this will lead to expanding nursing knowledge.

[The effect of somatosensory stimulation on recovery of the integrity of the somatosensory pathway after brain damage].

PURPOSE: The purpose of this study was to determine the effect of a 3-week somatosensory stimulation program on the integrity of the somatosensory pathway of patients with brain damage. METHOD: The sample consisted of two groups of patients with brain damage matched by Glasgow Coma Scale (GCS) scores and age: 8 patients with a mean age of 56.75 years who were treated with somatosensory stimulation, and 8 patients with a mean age of 58.88 years, who were not treated with sensory intervention program. A repeated measures matched-control group design was used to assess functional recovery of the brain. The instrument used in this study was SSEP (somatosensory evoked potentials), a neurophysiological parameter, for the integrity of the somatosensory pathway. RESULTS: The hypothesis that patients with brain damage who were treated with the somatosensory stimulation program will show higher SSEP wave form scores than the non-treatment group was supported (3rd week.: U=13.000, p=.014). Additional repeated measures analysis showed that there were no significant differences in recovery trends between the groups (F=1.945, p=.159). CONCLUSION: This study demonstrates that a somatosensory stimulation program is effective in promoting recovery of the integrity of the somatosensory pathway of patients with brain damage.

[The relationships of treatment side effects, family support, and quality of life in patient with cancer].

PURPOSE: The study was done to identify the relationship of treatment side effects, family support, and quality of life in patients with cancer, and factors influencing quality of life. METHOD: A convenience sample of 106 patients who were receiving cancer treatment at W hospital were interviewed using the Side Effects scale by Hur, Family Support scale by Kang, and QOL scale by Ro. RESULT: Results indicate that women experienced more severe side effects than men. There was a negative relationship between side effects and quality of life, and a positive relationship between family support and quality of life. The most bothersome side effects were changes in taste and appetite, followed by general weakness and fatigue. Side effects such as loss of hair, nausea, dizziness, numbness, pins and needles in fingers and toes, and dry mouth were also experienced. General weakness and family support were analysed as to whether they were factors influencing quality of life. CONCLUSION: The results revealed that relieving general weakness should be given high priority in nursing interventions for patients undergoing cancer treatment. In addition, nursing programs should be developed that can reinforce family support.