Role of scaffolds in MAP kinase pathway specificity revealed by custom design of pathway-dedicated signaling proteins

BACKGROUND

Signal transduction pathways with shared components must be insulated from each other to avoid the inappropriate activation of multiple pathways by a single stimulus. Scaffold proteins are thought to contribute to this specificity by binding select substrates.

RESULTS

We have studied the ability of scaffold proteins to influence signaling by the yeast kinase Ste11, a MAPKKK molecule that participates in three distinct MAP kinase pathways: mating, filamentation, and HOG. We used protein fusions to force Ste11 to associate preferentially with a subset of its possible binding partners in vivo, including Ste5, Ste7, and Pbs2. Signaling became confined to a particular pathway when Ste11 was covalently attached to these scaffolds or substrates. This pathway bias was conferred upon both stimulus-activated and constitutively active forms of Ste11. We also used membrane-targeted derivatives of the mating pathway scaffold, Ste5, to show that stimulus-independent signaling initiated by this scaffold remained pathway specific. Finally, we demonstrate that loss of pathway insulation has a negative physiological consequence, as nonspecific activation of both the HOG and mating pathways interfered with proper execution of the mating pathway.

CONCLUSIONS

The signaling properties of these kinase fusions support a model in which scaffold proteins dictate substrate choice and promote pathway specificity by presenting preferred substrates in high local concentration. Furthermore, insulation is inherent to scaffold-mediated signaling and does not require that signaling be initiated by pathway-specific stimuli or activator proteins. Our results give insight into the mechanisms and physiological importance of pathway insulation and provide a foundation for the design of customized signaling proteins.

Feasibility of a music intervention protocol for patients receiving mechanical ventilatory support

CONTEXT

Music has been found to be an effective nonpharmacologic adjunct for managing anxiety and promoting relaxation in limited trials of critically ill patients receiving mechanical ventilation. No data are available to determine the effect of the intervention over repeated trials or to determine whether patients or staff will use music intervention independently.

OBJECTIVE

To test the feasibility of a patient-initiated music intervention protocol over a 3-day trial and to discern the associated barriers to adherence by study participants and nursing staff.

DESIGN

Descriptive pilot study.

SETTING

Two adult critical care units contained in 1 university-affiliated tertiary care center in the urban Midwest.

PATIENTS

Five alert, critically ill adults receiving mechanical ventilatory support.

INTERVENTION

Patient-selected music listening via audiotapes and head-phones with frequency and length of session determined by each patient.

MAIN OUTCOME MEASURES

Anxiety, heart rate, respiratory rate, blood pressure, and identified barriers to protocol adherence.

RESULTS

Subjects averaged 2 self-initiated music interventions (mode = 3; range = 1-5) and listened for an average of 67.8 minutes per session (SD 34.3; mode = 50; range = 25-120 minutes). Barriers to this intervention included inaccessibility of the equipment and lack of knowledge and experience of the nursing staff. Due to missing data, physiological measures were not interpretable.

CONCLUSIONS

Patient-initiated music is a feasible intervention protocol: subjects were able to request music independently and nursing staff were cooperative. Findings will be used in future studies to refine the protocol and attendant measures to implement music intervention in the critical care setting and to develop detailed staff education materials.

A psychosocial approach to arson--a case controlled study of female offenders

Few studies of arsonists have focused specifically on females, many of whom have historically avoided prosecution. This study examines demographic details, psychopathology and personality characteristics of female arsonists and violent offenders in custody and compares them with an age matched group of comparison females. A significantly greater number of arsonists admitted to a history of deliberate self-harm and to sexual abuse as a child. The results emphasize the degree of psychosocial disadvantage in female arsonists and fit the model of displaced aggression in that female arsonists in this study are found to be less assertive and may displace their aggression onto property due to their inability to confront people directly. This channelling of aggression may be seen as an attempt to influence their environment and improve their self-esteem where other means have failed. Many of the findings match those of a previous study of male Special Hospital arsonists and indicate the need for larger studies within prison and hospital settings. Based on the potential areas for clinical intervention, prospective treatment studies of arsonists offer exciting implications in terms of risk management and may begin to address the needs of this severely disadvantaged group.

Emerging role of the pediatric nurse practitioner in acute care

The pediatric nurse practitioner role in the tertiary setting is one of several emerging roles gaining recognition in the various groups of advanced practice nursing programs today. The advanced practice nurse (APN) who is a pediatric nurse practitioner (PNP) in an acute care setting helps to provide cost-effective, quality patient care for critically and chronically ill children who are in these settings. The foundation of advanced practice nursing in this role incorporates the general role expectations of advanced nursing preparation, including case management, clinical pathway development, consultation and education, research, and collaboration, with the specific knowledge and skills of the pediatric nurse practitioner to function effectively with sick children in the acute care areas.

A randomized clinical trial of exercise and spinal manipulation for patients with chronic neck pain

STUDY DESIGN

A randomized, parallel-group, single-blinded clinical trial was performed. After a 1-week baseline period, patients were randomized to 11 weeks of therapy, with posttreatment follow-up assessment 3, 6, and 12 months later.

OBJECTIVES

To compare the relative efficacy of rehabilitative neck exercise and spinal manipulation for the management of patients with chronic neck pain.

SUMMARY OF BACKGROUND DATA

Mechanical neck pain is a common condition associated with substantial morbidity and cost. Relatively little is known about the efficacy of spinal manipulation and exercise for chronic neck pain. Also, the combination of both therapies has yet to be explored.

METHODS

Altogether, 191 patients with chronic mechanical neck pain were randomized to receive 20 sessions of spinal manipulation combined with rehabilitative neck exercise (spinal manipulation with exercise), MedX rehabilitative neck exercise, or spinal manipulation alone. The main outcome measures were patient-rated neck pain, neck disability, functional health status (as measured by Short Form-36 [SF-36]), global improvement, satisfaction with care, and medication use. Range of motion, muscle strength, and muscle endurance were assessed by examiners blinded to patients' treatment assignment.

RESULTS

Clinical and demographic characteristics were similar among groups at baseline. A total of 93% of the patients completed the intervention phase. The response rate for the 12-month follow-up period was 84%. Except for patient satisfaction, where spinal manipulative therapy and exercise were superior to spinal manipulation with (P = 0.03), the group differences in patient-rated outcomes after 11 weeks of treatment were not statistically significant (P = 0.13). However, the spinal manipulative therapy and exercise group showed greater gains in all measures of strength, endurance, and range of motion than the spinal manipulation group (P < 0.05). The spinal manipulation with exercise group also demonstrated more improvement in flexion endurance and in flexion and rotation strength than the MedX group (P < 0.03). The MedX exercise group had larger gains in extension strength and flexion-extension range of motion than the spinal manipulation group (P < 0.05). During the follow-up year, a greater improvement in patient-rated outcomes were observed for spinal manipulation with exercise and for MedX exercise than for spinal manipulation alone (P = 0.01). Both exercise groups showed very similar levels of improvement in patient-rated outcomes, although the spinal manipulation and exercise group reported greater satisfaction with care (P < 0.01).

CONCLUSIONS

For chronic neck pain, the use of strengthening exercise, whether in combination with spinal manipulation or in the form of a high-technology MedX program, appears to be more beneficial to patients with chronic neck pain than the use of spinal manipulation alone. The effect of low-technology exercise or spinal manipulative therapy alone, as compared with no treatment or placebo, and the optimal dose and relative cost effectiveness of these therapies, need to be evaluated in future studies.

Asg7p-Ste3p inhibition of pheromone signaling: regulation of the zygotic transition to vegetative growth

The inappropriate expression of the a-factor pheromone receptor (Ste3p) in the MATa cell leads to a striking inhibition of the yeast pheromone response, the result of a functional interaction between Ste3p and some MATa-specific protein. The present work identifies this protein as Asg7p. Normally, expression of Ste3p and Asg7p is limited to distinct haploid mating types, Ste3p to MATalpha cells and Asg7p to MATa cells. Artificial coexpression of the two in the same cell, either a or alpha, leads to dramatic inhibition of the pheromone response. Ste3p-Asg7p coexpression also perturbs the membrane trafficking of Ste3p: Ste3p turnover is slowed, a result of an Asg7p-mediated retardation of the secretory delivery of the newly synthesized receptor to the plasma membrane. However, in the absence of ectopic Ste3p expression, the asg7Delta mutation is without consequence either for pheromone signaling or overall mating efficiency of a cells. Indeed, the sole phenotype that can be assigned to MATa asg7Delta cells is observed following zygotic fusion to its alpha mating partner. Though formed at wild-type efficiency, zygotes from these pairings are morphologically abnormal. The pattern of growth is deranged: emergence of the first mitotic bud is delayed, and, in its place, growth is apparently diverted into a novel structure superficially resembling the polarized mating projection characteristic of haploid cells responding to pheromone. Together these results suggest a mechanism in which, following the zygotic fusion event, Ste3p and Asg7p gain access to one another and together act to repress the pheromone response, promoting the transition of the new diploid cell to vegetative growth.

Exhaled nitric oxide levels correlate with measures of disease control in asthma

BACKGROUND

Asthma guidelines emphasize maintaining disease control. However, objective measures of asthma disease control are lacking.

OBJECTIVE

We sought to examine the relationship between exhaled nitric oxide (NO) levels and measures of asthma disease control versus asthma disease severity.

METHODS

We performed a cross-sectional study of 100 patients (age range, 7-80 years) with asthma. We administered a questionnaire to identify characteristics of asthma, performed spirometric testing before and after administration of a bronchodilator, and measured exhaled NO levels in all participants.

RESULTS

Exhaled NO was significantly correlated with the following markers of asthma disease control: asthma symptoms within the past 2 weeks (P =.02), dyspnea score (P =. 02), daily use of rescue medications (P =.01), and reversibility of airflow obstruction (P =.02). Exhaled NO levels were not correlated with the following markers of asthma disease severity: history of respiratory failure (P =.20), health care use (P =.08), fixed airflow obstruction (P =.91), or a validated asthma severity score (P =.19). Markers with relevance to both disease control and severity showed either a weak correlation (FEV(1) and FEV(1) percent predicted) or no correlation (controller drug use) with exhaled NO.

CONCLUSION

We conclude that exhaled NO levels are correlated predominantly with markers of asthma control rather than asthma severity. Monitoring of exhaled NO may be useful in outpatient asthma management.

Class II correction in patients treated with class II elastics and with fixed functional appliances: a comparative study

The aim of the present study was to evaluate quantitatively the skeletal and dental changes contributing to Class II corrections in subjects treated with Class II elastics (Begg technique) compared with subjects treated with fixed functional appliances (Herbst appliance). Thirty-six male patients with Class II, Division 1 malocclusions whose treatment had not included extraction were investigated. Eighteen were treated with the Begg technique, and eighteen were treated with Herbst appliance for an average period of 1.3 and 0.5 years, respectively. Lateral radiographs in habitual occlusion were taken at the start of treatment and 12 months afterwards. In the Begg group, the maxilla moved forward 1 mm more than in the Herbst group, and the mandible moved 1 mm more in the Herbst group than in the Begg group. The skeletal improvement in the Herbst group exceeded the changes in the Begg group by, on average, 2.0 mm (P <.01). The overjet reduction in the Begg group was larger (2.1 mm; P <.01) than in the Herbst group, mostly because of dental movements. The skeletal part of the overjet reduction was 4% in the Begg group compared with 51% in the Herbst group. The molar correction was similar in both groups, but in the Begg group, the skeletal improvement was 10%, compared with 66% in the Herbst group. The overbite correction and the increase in the anterior lower facial height and in the NSL/ML angle were larger in the Begg group (P <.05). The conclusions of this study were that the changes contributing to the Class II corrections in Begg and Herbst therapy were skeletal and dental. The skeletal changes were, however, larger in the Herbst-treated group. On the other hand, favorable and unfavorable vertical changes were more pronounced in the group treated with Class II elastics.

Achieving a credible health and safety approach to increasing seat belt use among African Americans

African American youth are 60 percent less likely than children from other racial or ethnic backgrounds to be buckled up. Seat belt use among African American males has largely remained stagnant while that for other groups has increased. Overall, African Americans buckle up less often than other racial or ethnic populations. Seat belt use is a preventive health care action within public health. Clearly, a credible health and safety message is not being communicated effectively to African American communities. This paper proposes a number of possible solutions, including: recognition of the role that health care providers play in shaping patient or consumer attitudes and subsequent behavior in terms of prevention of disease and injury, educating physicians and health care providers to routinely recommend seat belt use especially for children, culturally appropriate educational safety programs, an improved relationship between law enforcement and communities, and zero tolerance for nonuse of seat belts.

Sarcoidosis of the scalp: a case series and review of the literature

Sarcoidosis of the scalp is a rare manifestation of cutaneous sarcoidosis. We report 4 cases, all in African-American women with systemic sarcoidosis. A review of the English-language literature reveals only 24 reported cases, most in African-American women with systemic involvement and other cutaneous lesions. Scalp sarcoidosis may exhibit variable morphologies and therefore must be kept in the differential diagnosis of plaques or nodules of the scalp as well as both cicatricial and noncicatricial alopecia.

Signaling and circuitry of multiple MAPK pathways revealed by a matrix of global gene expression profiles

Genome-wide transcript profiling was used to monitor signal transduction during yeast pheromone response. Genetic manipulations allowed analysis of changes in gene expression underlying pheromone signaling, cell cycle control, and polarized morphogenesis. A two-dimensional hierarchical clustered matrix, covering 383 of the most highly regulated genes, was constructed from 46 diverse experimental conditions. Diagnostic subsets of coexpressed genes reflected signaling activity, cross talk, and overlap of multiple mitogen-activated protein kinase (MAPK) pathways. Analysis of the profiles specified by two different MAPKs-Fus3p and Kss1p-revealed functional overlap of the filamentous growth and mating responses. Global transcript analysis reflects biological responses associated with the activation and perturbation of signal transduction pathways.

Evaluation of the effects of brushing on the removal of dental plaque

The ability of three different toothpaste abrasive systems--sodium bicarbonate, hydrated silica, and dicalcium phosphate--to remove dental plaque has been examined. A total of 34 volunteers participated in an independent, double-blind, crossover clinical investigation that compared the amount and percentage of plaque removed with a single brushing with Arm & Hammer Dental Care (sodium bicarbonate), Crest Regular Toothpaste (hydrated silica), and Colgate Regular Toothpaste (dicalcium phosphate) after 48 hours of limited oral hygiene. All three dentifrices removed from 58% to 68% of plaque, but the percentage removed after brushing with Arm & Hammer Dental Care was significantly greater than with either Crest (p = 0.0001) or Colgate (p = 0.0002) during a controlled, 1-minute toothbrushing. The mean amount of plaque removed with Arm & Hammer Dental Care was also significantly greater than that with Crest or Colgate (p = 0.0002 and p = 0.0004, respectively). These results indicate that the abrasive system in Arm & Hammer Dental Care was the most efficient in removing plaque and improving oral hygiene. In the second half of the study, Arm & Hammer Dental Care was compared with Arm & Hammer Peroxicare and Mentadent toothpaste in 45 subjects. All three dentifrices removed from 57% to 70% of the plaque, with Arm & Hammer Dental Care removing significantly more than Mentadent (p = 0.007).

Restorative exercise for clinical low back pain. A prospective two-center study with 1-year follow-up

STUDY DESIGN

A comparison of treatment of 412 patients with chronic back pain at two separate centers using the same treatment protocols and outcome measures. Outcome was defined by specific strength testing; Short Form-36 scores at intake, discharge, and 1-year follow-up; self-appraisal of improvement at discharge and in a 1-year follow-up; and reuse of health care services after discharge.

OBJECTIVES

To investigate the efficacy of standardized treatment methods using isolated lumbar strength testing and strengthening based on progressive protocols using specific equipment. Comparison of results should clarify the effect of the treatment center versus the efficacy of standardized protocols.

SUMMARY OF BACKGROUND DATA

There has been little support in the scientific literature for exercise programs based on standardized protocols. The use of specialized equipment to achieve intense specific exercise also has been poorly supported. Overall health benefit has not often been related to specific improvement in strength.

METHODS

More than 400 individuals with chronic back pain were evaluated at the initiation of treatment, discharge, and 1 year after discharge. Measures of efficacy were based on Short Form-36 scores, self-appraisal of improvement, and reuse of health care services after discharge. Study participants were patients with chronic back pain consecutively referred to each treatment site and underwritten by a variety of payers, including workers' compensation, Medicare, and private insurance.

RESULTS

Overall response during the course of the program and at 1-year follow-up was similar between the two centers. Similar proportions of participants at each site demonstrated improvement in SF-36 scores, self-appraisal of improvement, and reuse of health care services.

CONCLUSIONS

Standardized protocols using specific strength and measurement equipment can achieve similar benefits at different sites.

Overjet reduction and molar correction in fixed appliance treatment of class II, division 1, malocclusions: sagittal and vertical components

The purpose of this study was to quantitatively evaluate skeletal and dental changes contributing to Class II correction in patients treated with the Begg technique. The sample consisted of 18 male subjects with Class II, division 1, malocclusions treated with fixed appliances (Begg technique, nonextraction) for an average period of 1.3 years (standard deviation, 0.24 years). Lateral radiographs in habitual occlusion taken at 6 months before the start of treatment, at the start of treatment, and 6, 12, and 18 months after the start of treatment were analyzed. During the control period, normal sagittal and vertical growth changes occurred. In the initial treatment period (0 to 6 months), the overjet reduction (6.6 mm; P <. 001) and the molar correction (2.2 mm; P <.001) were obtained mainly by dental movements. The overbite was reduced by 4.1 mm (P <.001). The NSL/ML and NL/ML angles increased by 1.5 degrees (P <.05) and 1. 4 degrees (P <.01), respectively, and the anterior lower facial height increased by 3.1 mm (P <.001). During the second period of treatment (6 to 12 months), the molar correction continued to improve, and the anterior lower facial height continued to increase. During the third period (12 to 18 months), a small relapse in overjet and overbite was noted, but the anterior lower facial height continued to increase. During the total treatment period (0 to 18 months), the overjet reduction and molar correction were 5.8 mm (P <. 001) and 3.0 mm (P <.001), respectively. Mandibular growth exceeded maxillary growth by 1.1 mm (P <.01). The overbite correction and the increase in anterior lower facial height were 3.0 mm (P <.001) and 5. 0 mm (P <.001), respectively. The NSL/ML angle increased 1.0 degrees (P <.05). The conclusions were that the changes contributing to the Class II correction were mostly dental. Vertically, the net effects of treatment were an increase in the mandibular plane angle and in lower anterior facial height.

The relationship between medical students' academic achievement and patterns of initial postgraduate placement

PURPOSE

To explore the relationship between various levels of academic achievement and the spectrum of initial specialty placements for graduates.

METHOD

The authors studied the initial specialty placements of all 1984-1994 graduates of the University of Kentucky College of Medicine. Statistical analyses were used to determine the nature and strength of the relationships between initial specialty selection and students' achievement indicators and changes in that relationship over time.

RESULTS

Students tended to aggregate across time into discernible levels of achievement. The relationships between academic achievement levels and initial specialty placements were highly variable.

CONCLUSION

Although students with higher levels of achievement had broader choices available to them, graduates at every level of achievement entered a wide variety of specialties. Thus, the authors believe that academic achievement should not be used to the exclusion of other performance characteristics in determining how students and residencies should be matched.

Similar Müller-Lyer effects from operant and comparison response modes

A one-sided (monopole) version of the Müller-Lyer was used to assess the effect of response mode on the metric distortion associated with the illusion. Two different response modes were tested for comparability. The Operant Mode required the judgment of stimulus span to be indicated by marking a dot on the test page. The Comparison Mode required judgment of equality of two adjoining prepositioned spans. The perceptual effects with the comparison procedure are known to consist of underestimation of spans which are bounded by concave fin-sets and over-estimation of spans which are bounded by convex fin-sets. The question is whether the motor demands of the operant task produce an additional source of metric bias. Analysis indicate a very high correlation of judgments for the two modes of testing. Also, data with either mode of responding closely fit a linear model of the effect, and the model provides comparable index values for the concave and convex versions. These results should mitigate concern about potential motor bias from the operant method and encourage its use as a more efficient procedure for assessing metric distortion.

The structure and function of endoscope channels: the inside story

The GIA who has knowledge of channels in the flexible endoscope can avoid the need for repairs due to channel blockage and will be able to achieve the best possible instrument care. This paper provides a detailed description of the channels of the working endoscope, including location, access and functional interrelation-ships, to help make cleaning, disinfecting and troubleshooting a logical process. Diagrams are included to clarify the descriptions.

Evaluating the decay gradient for collinearity bias with lateral displacement from the axis of induction

The misperception of alignment which is found in many geometric illusions can be quantified using relatively simple stimulus configurations. Perceived collinearity of one segment (designated as the test segment) is biased by a second segment (designated as the induction segment), with the size of effect being a function of the relative angle between the two segments. The process can be described as angular induction. The strength of bias is greatest when the induction segment is centered at the tip of the test segment. Tong and Weintraub have reported that lateral displacement from the tip, i.e., at right angles to the axis of the induction segment, produces a sharp drop in the strength of effect. This decline is described as a "decay gradient" for the angular induction. One experiment replicates and provides better quantification of this "decay gradient". Two other experiments examine the decay gradient using a pair of induction segments, one on each side of the tip of the test segment. Displacement of the segments (either in the same direction or in opposite directions) produces substantially the same gradient of effect. Therefore, previous evidence of "tandem boosting" of effect for segment pairs does not depend on collinearity among the stimulus components. Finally, a fourth experiment finds that an induction segment which is at a fixed position and orientation differentially affects the influence of a variable induction segment. At some angles the influence of the variable segment is augmented, and at others it is suppressed. These findings are discussed in a neuroreductionist context, and a simple model for angular induction is presented.