The p38 mitogen-activated protein kinase cascade is not required for the stimulation of insulin secretion from rat islets of Langerhans.

The expression of the p38 subfamily of mitogen-activated protein kinases (MAPKs) was examined in rat islets of Langerhans and pancreatic beta-cell lines, and its involvement in the regulation of insulin secretion was investigated. Rat islets and several rodent beta-cell lines were shown to express p38 MAPK by Western blotting. The cellular stress agents sodium arsenite and hyperosmotic sorbitol significantly stimulated p38 MAPK activity, as did the tyrosine phosphatase inhibitor sodium pervanadate and the serine/threonine phosphatase inhibitor okadaic acid. Increases in p38 MAPK activity were not consistently correlated with increases in insulin secretion, and the dissociation between p38 MAPK activity and the regulation of insulin secretion was further demonstrated in studies using the specific p38 MAPK inhibitor SB203580, which was without significant effect on the stimulation of insulin secretion by glucose, 4beta phorbol myristate acetate and forskolin. These studies indicate that although p38 MAPK is expressed in pancreatic beta-cells and can be activated pharmacologically, its activity can be dissociated from the exocytotic release of insulin from rat islets of Langerhans.

Promoting nurses' positive attitudes toward cancer prevention/screening.

BACKGROUND: From 1991 to 1994, a special projects grant to teach nurses cancer prevention/screening theory and clinical skills was developed, implemented, and evaluated. Approximately 60 nurses in Colorado rural settings attended five two-day training sessions over a 20-month period. Attitudes, constructive or destructive, regarding specific behaviors lead to intentions to perform those behaviors and have an important impact on cancer-related nursing practice. METHODS: Two cancer-related attitude scales, Cancer Prevention/Early Detection Attitude Inventory and Fanslow Cancer Attitudes Scale, were administered prior to the first training session, following the final session, and at six-month follow-up. Data reflecting program impact on nursing practice were obtained from follow-up self-assessment of confidence in implementing new knowledge and skills. RESULTS: Significant differences in pre- and post-training attitude scores and fairly high-level confidence ratings suggest that these nurses will continue to use their cancer prevention and detection skills in practice. CONCLUSION: Documentation of practice activities to date has been impressive.

Glucose-stimulated insulin secretion from rat islets of Langerhans is independent of mitogen-activated protein kinase activation.

The role played by mitogen-activated protein kinases (MAPKs) in the regulation of insulin secretion from adult rat islets of Langerhans was investigated by examining the effects of glucose, forskolin and 4beta phorbol myristate acetate (PMA) on islet MAPK activity and by measuring insulin secretion from islets in response to these agonists after inhibition of MAPK by PD 098059 (PD). Glucose (20mM) had a small (<2-fold) stimulatory effect on MAPK activity in isolated islets, and this was potentiated by forskolin (10 microM) and PMA (500nM), which also significantly stimulated MAPK activity at 2mM glucose. Pretreatment of islets with 50 microM PD inhibited MAPK activity, but had no effect on secretory responses to glucose, forskolin and PMA. These results suggest that although MAPK may be activated by insulin secretagogues in adult rodent islets, this can be dissociated from the exocytotic release of insulin.

Utilizing narrative inquiry to evaluate a nursing doctorate program professional residency.

Because the University of Colorado (CU) School of Nursing Nursing Doctorate (ND) Program initiated an innovative nursing educational reform, emerging program evaluation challenges were addressed to ensure successful implementation and program quality. The study's purpose was to evaluate the effectiveness of the ND professional clinical residency (fourth and final year) from the students' perspectives. Therefore, this evaluation was exploratory and inductive to focus on the primary questions: "How does one become an ND nurse during the residency?" (process) and "What is an ND nurse?" (outcome). Additionally, an explanation of how interactive processes affected residency experiences was addressed. The narrative inquiry framework made available a special access to the human experiences of time, order, and change during the residency process. Ten students in the first CU ND Program residency participated. Narrative data for qualitative analysis were obtained from students' monthly written vignettes and verbal sharing of their clinical experiences during conferences. Vignette formats directed students to describe significant residency experiences and share reflections on the events. One finding suggested that students' formative progression through the residency occurred in four phases similar to cognitive development theories. Additional findings confirmed students' growth toward and summative attainment of ND outcome behaviors, including holistic clinical proficiency, client advocacy, and promotion of professional growth for colleagues.

Identification and localisation of a type IV cytosolic phospholipase A2 in rat pancreatic beta-cells.

The liberation of arachidonic acid (AA), by phospholipase A2 (PLA2), is the rate-limiting step in a number of cell signalling pathways. In the pancreatic beta-cell, AA itself is thought to participate in the regulation of insulin secretion. Recently a Ca(2+)-sensitive, AA-selective cytosolic PLA2 (type IV cPLA2) has been isolated from the human monocyte U937 cell line. Although the DNA sequence of this enzyme implies a molecular weight of 85 kDa, the protein migrates with a molecular weight of 100-110 kDa on SDS-PAGE. In many cell types, cPLA2s which are reactive towards antibodies raised against the type IV cPLA2 have been shown to hydrolyse AA from membrane glycerophospholipids. Using a polyclonal antibody raised against a recombinant form of type IV cPLA2, we have detected an immunoreactive protein with a molecular weight of 93.5 kDa in rat islets of Langerhans. Furthermore, we have detected similar immunoreactive proteins in insulin-secreting beta-cell lines and have shown co-expression of type IV cPLA2 immunoreactivity and insulin immunoreactivity in rat pancreatic beta-cells. Under non-stimulatory conditions the 93.5 kDa immuno-reactive protein detected in rat islets of Langerhans was located predominantly in the cytosolic fraction. We have shown that immunoprecipitation of the rat immunoreactive protein from rat islet homogenates significantly decreases the total dithiothreitol/beta-mercaptoethanol-insensitive PLA2 activity by 56.4 +/- 7%. This provides further evidence that the immunoreactive rat protein is a type IV cPLA2 and is responsible for a large component of the PLA2 activity in rat islets of Langerhans. It is possible that, in the rat beta-cell, type IV cPLA2 couples the increase in intracellular Ca2+, brought about by insulin secretagogues, to the liberation of AA and the subsequent release of insulin.

Evaluating a pediatric pain management research utilization program.

Research-based pain assessment and management innovations are not fully utilized in clinical nursing practice. Thus children continue to suffer despite strategies that could eliminate or significantly reduce their pain. An educational program was developed and implemented to integrate state-of-the-art pain assessment and management strategies into the clinical practice of pediatric nurses. This article reports on evaluation of the research utilization process during development and implementation of the program. The program included formal classes, development of instruments for pain assessment and documentation, ongoing consultation on pain management strategies, and designation of a unit-based staff nurse liaison. Findings illuminated the process through which nursing staff on one unit came to learn about new ideas, try those ideas in their clinical practice, re-invent certain strategies to better meet their needs, and, ultimately, to adopt innovations deemed helpful in their work.

Insulin secretion from islets of GK rats is not impaired after energy generating steps.

Insulin secretory responses of intact and electrically permeabilised islets of Goto-Kakizaki (GK) rats, a novel model of non-insulin dependent diabetes mellitus, and Wistar (control) rats were compared to investigate the mechanism of the impairment of insulin secretion from pancreatic islets of GK rats. Insulin secretion from intact islets in response to glucose, glyceraldehyde, succinate monomethylester and tetramethyl p-phenylenediamine, which reduces cytochrome c directly, was significantly impaired in GK rats compared to control rats (P < 0.05, P < 0.01, P < 0.05 and P < 0.05, respectively). However, Ca(2+)-induced insulin release from electrically permeabilised islets of GK rats was higher than that of control rats. Moreover, insulin secretion from intact islets in response to 50 mM KCl, which depolarises islet cells, was not impaired in GK rats. These results indicate that insulin secretion from islets of GK rats is not impaired after energy generating steps of metabolism.

Protein phosphorylation in the regulation of insulin secretion: the use of site-directed inhibitory peptides in electrically permeabilised islets of Langerhans.

We have used electrically permeabilised rat islets of Langerhans to investigate the role of protein phosphorylation in the regulation of insulin secretion using pseudosubstrate inhibitory peptides for cyclic AMP-dependent protein kinase (PKA) and for protein kinase C (PKC). The protein kinase inhibitor (PKI) peptide, PKI(6-22), completely inhibited the effects of cyclic AMP on islet PKA activity in vitro, on endogenous protein phosphorylation and on insulin secretion. This peptide had no significant effect on islet PKC activity in vitro, on Ca(2+)-induced protein phosphorylation and on secretory responses to Ca2+ or to the PKC activator, 4 beta-phorbol myristate acetate (PMA). The PKC pseudosubstrate inhibitory peptide, PKC(19-36), caused a marked inhibition of islet PKC activity in vitro and inhibite PMA-induced insulin secretion without affecting secretory responses to cyclic AMP and Ca2+. These results demonstrate that PKA- and PKC-induced protein phosphorylation is obligatory for cyclic AMP- and PMA-stimulated insulin secretion, respectively, and suggest that there is little "crosstalk" between the response elements of the secretory pathways to the different second messengers, at least after the generation of the messengers within the beta-cells.

Severity-adjusted differences in hospital utilization by gender.

Gender-based differences in hospital use may result from biological differences or may suggest problems of access to health services and quality of care. We hypothesized that there should be no difference in hospital care between men and women, given the same diagnosis. Hospitalizations were characterized by severity of illness, as this may indicate the timeliness of hospital care. Hospitalizations may be too late (with higher severity of illness) resulting in long stays and high costs, or too early (with lower severity of illness) resulting in care that could be given in alternative treatment settings. Three abdominal conditions were examined which could be misdiagnosed or confused with other diseases involving the female reproductive system: appendicitis, diverticulitis, and cholecystitis. The National Hospital Discharge Survey (NHDS) was used for analysis. Disease staging was used to assign a severity of illness indicator, ranging from stage 1 (conditions with no complications) to stage 3 (multiple site involvement, poor prognosis). For each disease, the percentage of discharges and the age-adjusted discharge rate per 1000 population was examined by stage of illness and gender. For appendectomy, there was a significantly greater percentage of men at stage 1 (lower severity) compared to women (73% versus 67%). For diverticular disease, women had higher proportions of stage 2/3 discharges than men for both medical and surgical hospitalizations. For cholecystitis, women had a greater percentage of hospitalizations at stage 1 than men, notably for surgical treatment (63% compared with 38%), although more men were admitted at stage 2 for both medical and surgical treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Regulation of insulin secretion: the role of second messengers.

This review summarises briefly studies performed in the last 5-6 years concerning the role of second messengers in the regulation of insulin secretion, using intact and electrically permeabilized rat islets of Langerhans. It is concluded that cyclic AMP (through protein kinase A), calcium (through calcium-calmodulin dependent protein kinases) and diacylglycerol (through protein kinase C) may be important second messengers in modulating the effects of specific secretagogues on insulin release. However, recent studies strongly suggest that neither protein kinase A nor protein kinase C are directly involved in the regulation of insulin secretion by glucose. The possible involvement of other second messengers, nitric oxide and arachidonic acid, in the regulation of secretion is also briefly reviewed.

Natural/alternative health care practices used by women with chronic pain: findings from a grounded theory research study.

Findings from a grounded theory research study provide insights into making health care practices more beneficial for the needs and concerns of women with chronic pain. This article focuses on how healthy women advantageously used natural/alternative health care and pain management practices. The "healthiest" women primarily used self-care with a wide, holistic range of natural/alternative modalities.

Isoflurane inhibits insulin secretion from isolated rat pancreatic islets of Langerhans.

We have investigated the effects of isoflurane on insulin secretion in vitro from rat isolated islets of Langerhans and found a significant, dose-related and reversible inhibition of insulin secretion. Isoflurane 2% decreased insulin secretion stimulated by glucose 20 mmol litre-1 to basal, nonstimulated values. In other studies to identify the stage in the stimulus secretion pathway for insulin at which the anaesthetic may exert an inhibitory action, we have stimulated insulin release using glyceraldehyde and a phorbol ester. Insulin secretion induced by these secretagogues was also blocked by isoflurane. This suggests that the inhibitory effect of the anaesthetic agent may be at a site distal to stimulation of insulin secretion by glyceraldehyde and phorbol esters.

Staurosporine inhibits protein kinases activated by Ca2+ and cyclic AMP in addition to inhibiting protein kinase C in rat islets of Langerhans.

Staurosporine has been used in several studies to investigate the role of protein kinase C (PKC) in secretory responses of islets of Langerhans to insulin secretagogues. We have assessed the effect of staurosporine on: [i] islet PKC activity in vitro; [ii] the stimulation of insulin secretion by nutrient secretagogues and [iii] the stimulation of protein phosphorylation and insulin secretion in electrically permeabilised islets. All experiments were carried out on rat isolated islets of Langerhans, either intact or permeabilised by high voltage discharge (3.4 kV/cm). The activity of PKC partially purified from rat islets was inhibited by staurosporine (1.6-400 nM) in a concentration-dependent manner. Staurosporine also inhibited insulin secretion stimulated by both glucose and glyceraldehyde, with maximal effects at 50 nM. After prolonged exposure of islets to the tumour-promoting phorbol ester, 4 beta phorbol myristate acetate (4 beta PMA), a procedure which depletes islet PKC activity, staurosporine still inhibited both glucose- and glyceraldehyde-stimulated insulin release. In electrically permeabilised islets, staurosporine inhibited both Ca(2+)- and cyclic AMP-stimulated protein phosphorylation and insulin secretion. These results suggest that staurosporine should not be used as a selective inhibitor of PKC in rat islets.

The mechanism of arachidonic acid-induced insulin secretion from rat islets of Langerhans.

The stimulation of rat pancreatic islets by glucose leads both to the secretion of insulin, and the production of arachidonic acid (AA). We have previously shown that exogenous AA can stimulate insulin secretion and that this secretion was not dependent upon extracellular Ca2+ nor upon the activation of protein kinase C. We have now demonstrated that AA-induced insulin secretion was a saturable and reversible process. AA-stimulated insulin secretion was slow in onset from intact islets but immediate from electrically permeabilized islets. In permeabilized islets AA-induced insulin secretion was not dependent on changes in intracellular Ca2+ or ATP and was not inhibited by noradrenaline. These results suggest that AA affects insulin secretion at a late stage in the exocytotic process.

Arachidonic acid-induced insulin secretion from rat islets of Langerhans is not mediated by protein phosphorylation.

Arachidonic acid (AA) stimulated protein phosphorylation in electrically permeabilised islets, most notably of an islet protein of approximate molecular weight 18 kDa. This protein did not appear to be a substrate for cAMP-dependent protein kinase. The AA-induced protein phosphorylation was mediated by unmetabolised AA since the lipoxygenase inhibitor, nordihydroguaretic acid (NDGA), or the cyclooxygenase inhibitor, indomethacin, did not significantly reduce AA-induced phosphorylation. Although saturated fatty acids did not stimulate phosphorylation of islet proteins, a number of cis-unsaturated fatty acids, other than AA, induced 32P incorporation into an 18 kDa protein. However, some fatty acids which stimulated protein phosphorylation had no effect on insulin secretion in experiments where AA clearly stimulated insulin secretion. AA stimulated protein kinase C (PKC) activity extracted from islets but several fatty acids which induced protein phosphorylation had no significant effect on PKC activity in vitro. 50 nM staurosporine had no effect on AA-induced protein phosphorylation but this concentration of staurosporine markedly inhibited PKC activity. 200 nM staurosporine caused complete inhibition of the AA-induced phosphorylation without having any effect on AA-induced insulin secretion. These results suggest that AA and some other fatty acids can promote 32P incorporation into islet proteins, independently of PKC activation, and that AA-induced phosphorylation is not required for insulin secretory responses to AA.

Effects of midazolam on insulin secretion from isolated rat pancreatic islets of Langerhans.

Isolated, cultured rat pancreatic islets of Langerhans were incubated in medium containing glucose 2 or 20 mmol litre-1 and with glucose supplemented with midazolam 10, 100 or 1000 ng ml-1. Glucose 20 mmol litre-1 with the addition of noradrenaline 10 mumol litre-1 was used as a control. In contrast with noradrenaline, midazolam did not inhibit glucose-induced insulin secretion. Noradrenaline 10 mumol litre-1 inhibited secretion to basal values in response to glucose 20 mmol litre-1 (P < 0.001).