Impact of guideline adherence and race on asthma control in children

BACKGROUND

Asthma control in African Americans (AA) is considered more difficult to achieve than in Caucasian Americans (CA). The aim of this study was to compare asthma control over time among AA and CA children whose asthma is managed per NAEPP (EPR-3) guidelines.

METHODS

This was a one-year prospective study of children referred by their primary care physicians for better asthma care in a specialty asthma clinic. All children received asthma care per NAEPP guidelines. Results were compared between CA and AA children at baseline and then at three-month intervals for one year.

RESULTS

Of the 345 children, ages 2-17 years (mean = 6.2 ± 4), 220 (63.8%) were CA and 125 (36.2%) were AA. There were no significant differences in demographics other than greater pet ownership in CA families. At baseline, AA children had significantly more visits to the Emergency Department for acute asthma symptoms (mean = 2.3 [Formula: see text] compared to CA (1.4 ± 2.3, P = 0.003). There were no other significant differences in acute care utilization, asthma symptoms (mean days/month), or mean asthma control test (ACT) scores at baseline. Within 3-6 months, in both groups, mean ACT scores, asthma symptoms and acute care utilization significantly improved (P < 0.05 for all) and change over time in both groups was comparable except for a significantly greater decrease in ED visits in AA children compared to CA children (P = 002).

CONCLUSION

Overall, improvement in asthma control during longitudinal assessment was similar between AA and CA children because of  consistent use of NAEPP asthma care guidelines.

Impact of type of health care provider on long term asthma control

OBJECTIVE

Asthma prevalence is high and adherence to asthma guidelines is still less than adequate. The main objective of this study was to determine if there were significant differences in outcome measures if asthma care was provided per guidelines either by physicians (pediatric pulmonologists) or specialty trained advance practice nurses (APNs).

METHODS

This was a three-year, prospective cohort study of children referred by their primary care providers to a tertiary care center for better asthma control. Patients were provided asthma care per NAEPP guidelines including asthma education. Results were compared over time and between patients followed by physicians or APNs. Alpha level of significance was ≤0.05.

RESULTS

The sample included 471 children, ages 2-17 years (mean = 6.4 ± 2.4 years). Physicians and APN's provided asthma care. Of the 471 children enrolled in the study, 176 (37%) were followed for the full three-year study period. At the initial visit, physician group reported more short courses of oral steroids and more unscheduled visits to PCP for acute asthma care in the past 6 months compared to those followed by APNs (<0.05 for all). Among the total cohort and both subgroups, there were significant improvements in mean Asthma Control Test (ACT), acute care need and mean days/month with asthma symptoms over a three-year period (p < 0.05). There was significantly more improvement in use of oral steroids and urgent care visits in physician group (p < 0.05).

CONCLUSION

When asthma guidelines are followed, improvements in asthma control are achieved in children in both the MD and APN groups.

Impact of asthma severity on long-term asthma control

Background: Asthma is a common childhood disease with significant morbidity. Severe asthma accounts for just 4-6% of patients, but this group is more difficult to treat and is responsible for up to 40% of asthma expenses.Objective: The relationship between asthma severity and control is not well characterized. The main objective of this study was to determine impact of asthma severity on asthma control over time.Methods: This was a three year, prospective observational cohort study at a tertiary care children's hospital. Results were compared over time and between patients with severe and non-severe persistent asthma. Intervention included therapy based on severity and control, accompanied by a NAEPP (EPR-3) guidelines based structured asthma education program.Results: The sample included 471 children referred from primary care offices with the diagnosis of persistent asthma, mean age 6.4 ± 2.4 years. Forty-one children (8.7%) had severe persistent asthma and 430 (91.3%) children had non-severe persistent asthma (mild-moderate persistent). Our sample size decreased over the three-year period and the number of patients completing the third year were 176 (38%) and among them 20 (11.4%) had severe asthma. At the initial visit, children with severe persistent asthma had significantly more acute care needs, more daily symptoms, and lower mean Asthma Control Test™ scores compared to children with non-severe persistent asthma. Differences between groups decreased within six months with significant improvements in most indicators persisting throughout three-year follow up in both groups (p < 0.05).Conclusion: Asthma control improves independent of severity if asthma guidelines are followed.

Erratum to: Racial differences in pet ownership in families of children with asthma

In the article by Sheikh SI, et al, "Racial differences in pet ownership in families of children with asthma" in World Journal of Pediatrics 2016;12(3):343-346 (doi: 10.1007/s12519-016-0027-9), the last author's name was incorrectly listed as "Don Hayes". His name should have read "Don Hayes Jr".

Improved quality-of-life of caregivers of children with asthma through guideline-based management

OBJECTIVE

The quality of life (QOL) of caregivers of children with asthma may be related to children's responses to asthma management.

AIM

To evaluate change in QOL over time of caregivers of children with asthma through guideline-based management.

DESIGN

This was a 3-year prospective cohort study of children with asthma referred to our pediatric asthma center. Families completed Pediatric Asthma Caregiver's Quality of Life Questionnaire (PACQLQ), the Asthma Control Test™ (ACT), and reported the number of days/month of albuterol use and wheezing at each clinic visit.

RESULTS

We enrolled 143 children, ages 7-17 years (mean = 10.6 ± 2.9), 56.6% male, 70.6% Caucasian. Patients were managed by the same MD (n = 65,45.5%) or APN (n = 78,54.5%) over time. The mean total PACQLQ significantly increased over the 3-year period (F = 67.418, p < .001). Total scores at the first visit were 4.8 ± 1.6, which improved to 6.1 ± 1 at the 3-month follow-up visit. This improvement was sustained at the 1, 2, and 3-year clinic visits. PACQLQ emotional function (F = 60.798, p < .001) and activity limitation (F = 41.517, p < .001) domains significantly improved as well. PACQLQ scores were significantly associated with improved ACT scores (r = .37 to .47, p < .05), fewer days/month of albuterol use (r = -.25 to -.36., p < .05), and wheezing (r = -.28 to -.33, p < .05). There were no significant differences in PACQLQ, or asthma clinical outcome measures between MD and APN providers.

CONCLUSION

Use of National Asthma Education and Prevention Program (NAEPP) guidelines significantly improved QOL of caregivers of children with asthma and in asthma-related symptoms. Improvements over time were independent of type of providers.

Racial differences in pet ownership in families of children with asthma

BACKGROUND

Exposure to household domestic animals such as cats and dogs in early life may have some role in pathogenesis of asthma. Racial differences exist in the prevalence of asthma. We hypothesized that there may also be racial differences in pet ownership in families with asthma.

METHODS

A cross sectional study was conducted from June 2011 to December 2014 on 823 of 850 (97%) families of children with asthma for pet ownership. Comparisons among racial groups were done using chi square analysis and one-way analysis of variance.

RESULTS

The mean age of the cohort was 6.9±4.4 years. A total of 540 (65.62%) patients were Caucasian, 195 (23.7%) African American, 42 (5.1%) hispanics, and 26 (3.2%) biracial with one Caucasian parent. Pets in the home were reported by 470 (58.5%) households. Significantly fewer African American and hispanic families had pets in the home (26.9% and 44.7%) than biracial and Caucasian families (72% and 69.9%, P<0.001). Likewise, significantly more biracial and Caucasian families were noted to have dogs (52% and 54.4%) or cats (25.4% and 40%) or both cats and dogs (28% and 18%) than African Americans families (20.3%, P<0.001; 7.1%, P<0.001) and (4.6%, P<0.001), respectively.

CONCLUSIONS

Among families with asthmatic children, pet ownership is significantly more likely in Caucasian families compared with African-American and Hispanic families, thus there is a racial diversity in pet ownership among families of children with asthma.

Environmental exposures and family history of asthma

BACKGROUND

Asthma pathogenesis is a complex interaction of genetic, ethnic, environmental and social/life style risk factors.

AIM

The goal of this study was to identify associations, if any, in children with asthma, between environmental risk factors (exposure to second-hand tobacco smoke (STS), pet ownership, race and a family history of asthma.

METHODS

After IRB approval, from June 2011 to December 2014, 823 children with asthma were enrolled in this prospective cross sectional study. At the initial visit, families completed a questionnaire with information on family history of asthma, having a pet at home and exposure to STS by parents at home. Chi square analyses were calculated, with alpha level of significance ≤0.05.

RESULTS

History of asthma in parents, siblings or grandparents was reported by 575 (69.8%) patients including father (n = 154, 17.8%) and mother (n = 235, 26.5%). Children with family history of asthma (n = 575) were significantly more likely to have a pet at home and exposure to STS (n = 347, 60.3% and n = 198, 34.4%, respectively) compared to families without a history of asthma (n = 124, 50%, p = 0.006 and n = 44, 17.7%, p < 0.001, respectively). Similarly, asthmatic children with exposure to STS (n = 241) were significantly more likely to have a pet at home and a family history of asthma (n = 153, 63.5% and n = 197, 81.7%, respectively) compared to children with no STS exposure (n = 315, 55.5%, p = 0.034 and n = 371, 65.3%, p < 0.001 respectively).

CONCLUSIONS

Significantly more asthmatic children with immediate relatives with a history of asthma have a pet at home and experience STS exposure compared to children without relatives with a history of asthma, suggesting association between life style choices/environmental exposures and family history of asthma.

Screening high-risk children for asthma through a community intervention

OBJECTIVE

Many children, particularly those from inner city neighborhoods, have undiagnosed asthma. This study was done to evaluate the effectiveness of an asthma screening, referral and follow-up intervention in an inner city community setting in early identification of children at risk for undiagnosed asthma.

METHODS

A descriptive longitudinal cohort design was used to assess children at baseline and at a 2-year follow-up. Parents of children in a private day school and a church Sunday school (N = 103) completed a validated Asthma Screening Tool at both time periods. Children with asthma and at risk for asthma were referred to a primary care provider (PCP).

RESULTS

At baseline, screening of 103 children, ages 3-17 years (mean=7.7 ± 2.9), were categorized as known asthma diagnosis (n = 22), at-risk for undiagnosed asthma (n = 52) and not at-risk for asthma (n = 29). Sixty-two (60.2%) parents responded to the 2-year follow-up. Referral to PCP was kept by 61.5% from the known asthma group and by 24% of children at-risk for asthma. At 2-year follow-up, among not at-risk group, no one converted to at risk status, but majority of children among known asthma group continued to have uncontrolled asthma symptoms, and very few received daily preventive asthma medications.

CONCLUSIONS

The asthma screening, referral and follow-up intervention for inner city children in a community setting was successful in early identification of patients at-risk for asthma. More education for PCPs on guidelines for diagnosis and management of asthma is needed to decrease childhood asthma morbidity.

Islet autoantibody status in a multi-ethnic UK clinic cohort of children presenting with diabetes

OBJECTIVE

We prospectively determined islet autoantibody status in children presenting with diabetes to a single UK region in relation to ethnicity.

DESIGN

316 (68.0% non-white) children presenting with diabetes between 2006 and 2013 were tested centrally for islet cell autoantibodies (ICA) and glutamic acid decarboxylase autoantibodies (GAD-65) at diagnosis, and if negative for both, tested for insulin autoantibodies (IAA). The assay used to measure GAD-65 autoantibodies changed from an in-house to a standardised ELISA method during the study.

RESULTS

Even with use of the standardised ELISA method, 25.8% of children assigned a diagnosis of type 1 diabetes still tested negative for all three autoantibodies. 30% of children assigned a diagnosis of type 2 diabetes were autoantibody positive, and these had the highest glycated haemoglobin (HbA1c) levels at 12 months follow-up compared with other groups (p value for analysis of variance <0.001), although the sample size was small. Autoantibody positivity was similar between non-white and white children regardless of assay used (60.0% (n=129) vs 56.4% (n=57), χ(2)=0.9, p=0.35), as was mean GAD-65 autoantibody levels, but fewer non-white children had two or more autoantibodies detectable (13% (n=28) vs 27.7% (n=28), χ(2)=12.1, p=0.001).

CONCLUSIONS

Islet autoantibody positivity was associated with a more severe phenotype, as demonstrated by poorer glycaemic control, regardless of assigned diabetes subtype. Positivity did not differ by ethnic group.

Patterns of junctional communication in animal tissues

Gap junctions provide pathways for direct communication between cells in almost all animal tissues. The junctional channels are freely permeable to small ions and molecules but not to macromolecules. A coupled cell population is as a consequence a partial syncytium, within which metabolites, cofactors, small control molecules and inorganic ions can all diffuse freely through the combined cytoplasmic compartment, while intracellular macromolecules remain relatively fixed in space, in the cells where they are synthesized. Little is known about the extent and distribution of these communication compartments in tissues. To further understand their significance, we have mapped the patterns of junctional communication in skin by intracellular injection of the tracer dye Lucifer Yellow. Cells in the dermal layer are widely coupled, with dye spreading through hundreds of cells in a few minutes. Dye spread in the epidermis is much more restricted, passing in the same time into only a few cells. Dermal-epidermal coupling is not normally detected but is occasionally seen in new-born mouse skin when hair follicles are starting to invaginate. Dermal cells are coupled to a band of follicular cells near the base of mature hair follicles, whereas sebaceous glands appear to be coupled units, isolated from surrounding cells.

Autogenous hard palate mucosa: the ideal lower eyelid spacer?

BACKGROUND/AIMS

Raising a displaced lower eyelid frequently involves recession of the lower eyelid retractors with interposition of a "spacer," and several materials for this purpose have been described. This study reviewed the results of autogenous palatal mucosa in the treatment of lower eyelid displacement, including assessment of any donor site morbidity.

METHODS

A retrospective case note review of consecutive patients treated at Moorfields Eye Hospital between 1993 and 1998. All patients underwent insertion of hard palate mucosa between the inferior border of the tarsus and the recessed conjunctiva and lower eyelid retractors. Parameters studied included the underlying diagnosis, measurements of lower lid displacement or retraction, related previous surgery, the experience of the operating surgeon, intraoperative and postoperative complications, surgical outcome, and length of follow up. The main outcome measure was the position of the lower eyelid relative to the globe in primary position of gaze.

RESULTS

102 lower eyelids of 68 patients were included and a satisfactory lid position was achieved in 87/102 (85%), with inadequate lengthening or significant recurrence of displacement occurring in 15 cases. Donor site haemorrhage requiring treatment in the early postoperative period occurred in seven patients (10%).

CONCLUSION

Autogenous hard palate mucosa is an effective eyelid spacer and provides good long term support for the lower eyelid. Donor site complications are the main disadvantage, but may be minimised by attention to meticulous surgical technique and appropriate postoperative management.

Gap junctional communication and connexin expression in cultured olfactory ensheathing cells

The olfactory ensheathing cell (OEC) is a unique glial cell able to support neurite outgrowth in the CNS throughout life. The OEC has been described as having both Schwann cell-like and astrocyte-like characteristics. The purpose of this study was to compare gap junctional communication and connexin (Cx) expression in cultured olfactory ensheathing cells with both astrocytes and Schwann cells to establish which of these two cells types they most closely resemble. We examined the Cx mRNA profile of OECs, astrocytes, and Schwann cells using primers to Cx26, Cx32, Cx37, Cx43, Cx46, and Cx50. All connexins tested except Cx50 were expressed by all three cell types when initially cultured. However, we observed differences in the levels of expression of Cx32 and Cx26 between astrocytes, Schwann cells, and OECs that became pronounced with time. All three cell types show limited and variable gap junctional communication in culture as assessed by the transfer of microinjected Lucifer yellow. OECs had limited coupling compared with Schwann cells and astrocytes, although the extent of the dye spread through OECs was more comparable to that seen with Schwann cells than astrocytes. Thus, OECs display a profile of Cx expression that more closely resembles the Cx expression of Schwann cells rather than astrocytes.

Structure-function studies of an IGF-I analogue that can be chemically cleaved to a two-chain mini-IGF-I

The structure and biological activities of two disulphide isomers of a C-region deletion mutant of insulin-like growth factor-I (IGF-I) which has an Asn--Gly link engineered at the junction of the A- and B-regions were studied before and after chemical cleavage. Circular dichroism (CD) spectra and binding affinity to IGF binding protein 3 (IGFBP3) indicated that the treatment with hydroxylamine did not disrupt the overall tertiary fold of the hormones. Cleavage restored some binding affinity for the IGF-I receptor in both isomers and weakly restored the ability to stimulate incorporation of tritiated thymidine into DNA in NIH 3T3 fibroblasts transfected with the human IGF-I receptor. Cleavage also restored metabolic capacity, as measured by the ability of the isomers to promote lipogenesis in isolated rat adipocytes through the insulin receptor. These results are consistent with the theory that binding of IGF-I to the IGF-I receptor requires a conformational change similar to that involved in insulin binding the insulin receptor. The weak affinity for the IGF-I receptor after cleavage is consistent with the belief that residues in the C-region interact with the IGF-I receptor. This structural difference between insulin and IGF-I gives each a higher binding affinity for its own receptor.

Novel expression and function of peroxisome proliferator-activated receptor gamma (PPARgamma) in human neuroblastoma cells

Peroxisome proliferator-activated receptor gamma (PPAR-gamma) is a member of the nuclear receptor superfamily of ligand-dependent transcription factors that has been shown to play a major role in adipocyte and monocyte/macrophage differentiation. Recent work has also suggested a role for PPARgamma in cell cycle control and/or differentiation of other cell types including breast and lung cancer cells. Using reverse transcription-PCR, we now show for the first time that human neuroblastoma (nb) cells express PPARbeta and -gamma, but not -alpha. Using the LA-N-5 nb cell line, we have determined that the natural PPARgamma ligand 15-deoxy-delta prostaglandin J2, as well as the synthetic PPARgamma agonist GW1929, can stimulate the differentiation of nb cells, as evidenced by the inhibition of cell proliferation, neurite outgrowth, increased acetylcholinesterase activity, and the reduction of N-myc expression. We have also demonstrated that PPARgamma is expressed in primary nb and, furthermore, that the expression of this receptor correlates with the maturational stage of the nb cells. Taken together, these studies have implicated a role for PPARgamma in peripheral nerve cell biology and suggest that the PPARgamma signaling pathway is involved in the regulation of nb cell growth and differentiation.

PPARgamma: observations in the hematopoietic system

Human Peroxisome Proliferator-Activated Receptor gamma (PPARgamma) was originally cloned from a human bone marrow library. What role does this ligand activated transcription factor play in hematopoiesis and the immune system? We note that: a) PPARgamma has potential to interact/interfere or synergize with retinoid biology, b) fatty acids and a prostaglandin have been identified as ligands, and c) lymphocytes, monocytes and neutrophils use fatty acids as a major source of energy production, d) PPARgamma has been shown to oppose TNFalpha and down regulate cytokine production in monocytes. Therefore, we undertook a review of the literature and an expression survey of PPARgamma in a number of major organs and cells involved in the hematopoietic system, for the purpose of building a database towards understanding the role and function of PPARgamma gene regulation in the developing blood and immune systems. PPARgamma is expressed before mesodermal induction in tissue in and around Speymann's organizer in the xenopus blastocyst, in erythroid precursors of blood islands and in the circulation of the day 10.0 murine embryo, in human 19 week fetal liver, in some but not all murine and human bone marrow erythroid, myeloid, and monocytoid progenitors, bone marrow stromal cells and adipocytes, osteoblasts, endothelial cells, some T, and B lymphocytes, monocytes, macrophages, and other monocytic derivatives. It can be found in the cells of Peyer's patches, lymphoid follicles, spleen, and thymus. It is not clear if it is ever or transiently expressed in megakaryocytes, mast cells, or neutrophils. Based on the above data and a review of the literature, PPARgamma seems to play a role during the elicitation of immune responses. We propose PPARgamma may be involved in changes in energy states required during activation and development of many cell types involved, and has additional immunologically relevant effects in erythroid, myeloid, monocytic, T and B lymphocytic, stromal, and endothelial cell function.

Associations between primary care physician satisfaction and self-reported aspects of utilization management

OBJECTIVE

To evaluate the association between physician-reported utilization management (UM) techniques in capitated physician groups and physician satisfaction with capitated care.

STUDY SETTING

1,138 primary care physicians from 89 California capitated physician groups in 1995.

STUDY DESIGN

Eighty percent of physicians (N = 910) responded to a mail survey regarding the UM policies in their groups and their satisfaction with the care they deliver. Physician-reported UM strategies measured included group-mandated preauthorization (number of referrals requiring preauthorization, referral denial rate, and referral turnaround time), group-provided explicit practice guidelines, and group-delivered educational programs regarding capitated care. We also measured two key dimensions of satisfaction with capitated care (multi-item scales): (1) satisfaction with capitated care autonomy and quality, and (2) satisfaction with administrative burden for capitated patients.

EXTRACTION METHODS

We constructed two multivariate linear regression models to examine associations between physician-reported UM strategies and physician satisfaction, controlling for demographic and practice characteristics and adjusting for clustering.

PRINCIPAL FINDINGS

Physician-reported denial rate and turnaround time were significantly negatively associated with capitated care satisfaction. Physicians who reported that their groups provided more guidelines were more satisfied on both dimensions, while physicians who reported that their groups sponsored more educational programs were more satisfied with administrative burden. The number of clinical decisions requiring preauthorization was not significantly associated with either dimension of satisfaction.

CONCLUSIONS

Physicians who reported that their groups used UM methods that directly affected their autonomy (high denial rates and long turnaround times) were less satisfied with care for capitated patients. However, a preauthorization policy for referrals or tests was not, in and of itself, associated with satisfaction. Indirect control mechanisms such as guidelines and education were positively associated with satisfaction.

'Practice professional development plans': general practitioners' perspectives on proposed changes in general practice education

BACKGROUND

The Chief Medical Officer has presented a report proposing a change in general practitioners' education towards a 'Practice Professional Development Plan', which, in principle, is based around formal needs assessment, practice-based learning in areas identified by those involved, and with the potential for multi-professional learning. This aims to replace the present system of a financial allowance earned by attending a certain amount of educational activity.

AIM

To study the opinions of a group of general practitioners attending a course that included workshops that introduced and considered this educational initiative.

METHOD

Semi-structured interviews four weeks after the course.

RESULTS

Educational benefits were clearly seen, while issues such as funding and time will present difficulties in implementation.

CONCLUSIONS

This proposal was seen as an improvement to the existing postgraduate educational allowance system. To maintain enthusiasm, successful introduction will depend on the issues of support and resources.

Comparison of dacryocystography and lacrimal scintigraphy in the diagnosis of functional nasolacrimal duct obstruction

AIM

It appears from the literature that no standardised examination exists for patients with functional nasolacrimal duct obstruction. The role of dacryocystography and lacrimal scintigraphy was compared in the diagnosis and management of these patients.

METHOD

Patients who were clinically diagnosed as having unilateral or bilateral functional nasolacrimal duct obstruction were prospectively entered into the study and data collected over 12 months in Moorfields Eye Hospital and Whipps Cross Hospital, London. All cases had, on separate occasions, a standardised dacryocystogram with delayed erect films and a lacrimal drainage scintigram.

RESULTS

45 lacrimal systems of 32 patients (mean age 62 years; 59% male) fulfilled the inclusion criteria. Abnormalities were detected with dacryocystography in 93% of systems and with lacrimal drainage scintigraphy in 95% of systems. Based on the results of previous quantitative studies, the positive scintigrams were subdivided into those demonstrating prelacrimal sac delay (13%), delay at the lacrimal sac/duct junction (35%), or delay within the duct (47%). Combining the two imaging techniques increased the sensitivity to 98%.

CONCLUSIONS

Both investigations are very sensitive at detecting abnormalities in patients with a clinical diagnosis of functional nasolacrimal duct obstruction. Lacrimal drainage scintigraphy is a slightly more sensitive test, but missed an abnormality detected by dacryocystography in two (4%) systems. A combination of the two techniques gives the highest sensitivity with maximum anatomical and physiological information but, in clinical practice, it is reasonable to perform a dacryocystogram initially and proceed to scintigraphy only if contrast radiography is normal.

Educational portfolios in the assessment of general practice trainers: reliability of assessors

OBJECTIVES

This paper reports a project that assessed a series of portfolios assembled by a cohort of participants attending a course for prospective general practice trainers.

DESIGN

The reliability of judgements about individual 'components', together with an overall global judgement about performance were studied.

SETTING

NHSE South & West, King Alfred's College, Winchester and Institute of Community Studies, Bournemouth University.

SUBJECTS

Eight experienced general practice trainers recruited from around Wessex, which incorporates Hampshire, Dorset, Wiltshire and the Isle of Wight.

RESULTS

The reliability of individual assessor's judgements (i.e. their consistency) was moderate, but inter-rater reliability did not reach a level which could support making a safe summative judgement. The levels of reliability reached were similar to other subjective assessments and perhaps reflected individuality of personal agendas of both the assessed and the assessors, and variations in portfolio structure and content.

CONCLUSIONS

Suggestions for approaches in future are made.

Modelling of the disulphide-swapped isomer of human insulin-like growth factor-1: implications for receptor binding

Insulin-like growth factor-1 (IGF-1) is a serum protein which unexpectedly folds to yield two stable tertiary structures with different disulphide connectivities; native IGF-1 [18-61,6-48,47-52] and IGF-1 swap [18-61,6-47, 48-52]. Here we demonstrate in detail the biological properties of recombinant human native IGF-1 and IGF-1 swap secreted from Saccharomyces cerevisiae. IGF-1 swap had a approximately 30 fold loss in affinity for the IGF-1 receptor overexpressed on BHK cells compared with native IGF-1. The parallel increase in dose required to induce negative cooperativity together with the parallel loss in mitogenicity in NIH 3T3 cells implies that disruption of the IGF-1 receptor binding interaction rather than restriction of a post-binding conformational change is responsible for the reduction in biological activity of IGF-1 swap. Interestingly, the affinity of IGF-1 swap for the insulin receptor was approximately 200 fold lower than that of native IGF-1 indicating that the binding surface complementary to the insulin receptor (or the ability to attain it) is disturbed to a greater extent than that to the IGF-1 receptor. A 1.0 ns high-temperature molecular dynamics study of the local energy landscape of IGF-1 swap resulted in uncoiling of the first A-region alpha-helix and a rearrangement in the relative orientation of the A- and B-regions. The model of IGF-1 swap is structurally homologous to the NMR structure of insulin swap and CD spectra consistent with the model are presented. However, in the model of IGF-1 swap the C-region has filled the space where the first A-region alpha-helix has uncoiled and this may be hindering interaction of Val44 with the second insulin receptor binding pocket.

Experiences and career intentions of general practice registrars from The Netherlands

For some years prospective general practitioners (GPs) from the Netherlands have come to Britain to complete their training. Not all report enjoying their time here, and many leave this country after training. The aim of this study was to examine reasons for coming to Britain, experiences, perceptions and career intentions. The sample consisted of 14 general practice registrars working in their practice year in Southern England. Data were collected through in-depth semistructured interviews and analysed by thematic qualitative analysis. The main reasons for training in this country were easier access, a quicker route to specialization and the quality of training provided. Most had positive professional and personal experiences and saw the British system of training GPs as up to date and supportive of their educational and professional needs. They highlighted some of the positive aspects of the British system, such as the emphasis on teamwork and collaboration with other primary care professionals. They did, however, point out problems and conflicts; for instance, they saw the health care system in Britain as more bureaucratic and as providing unequal access for different groups of the population. Despite their fear of litigation, which they saw as one of the drawbacks for British general practitioners, most looked favourably on the option of staying in or returning to this country if possible. All registrars valued their stay in Britain; however, personal circumstances often dictated a return to Holland. Our findings have implications for manpower planning and recruitment for general practice in both Britain and Holland.

Psychometric properties of the National Eye Institute Visual Function Questionnaire (NEI-VFQ). NEI-VFQ Field Test Investigators

OBJECTIVE

To test the reliability and validity of the 51-item Field Test Version of the National Eye Institute Visual Function Questionnaire (NEI-VFQ) across 5 common chronic eye conditions.

DESIGN

Prospective observational cohort study of persons with 1 of 5 chronic eye diseases who were scheduled for nonurgent visits in ophthalmology practices or had low vision from any cause, and a reference sample of persons without eye disease.

SETTING

Six university-based ophthalmology practices and the National Eye Institute Clinical Center, Bethesda, Md.

PATIENTS

Eligible participants had to have 1 of the following eye conditions: age-related cataracts, age-related macular degeneration, diabetic retinopathy, primary open-angle glaucoma, cytomegalovirus retinitis, or low vision from any cause. Each of the 7 sites also enrolled persons in a reference sample. Reference sample participants had no evidence of underlying eye disease but were scheduled for either screening eye examinations or correction of refractive error. All eligible persons had to be aged 21 years or older, English speaking, and cognitively able to give informed consent and participate in a health status interview.

MEASUREMENTS AND MAIN RESULTS

To provide the data needed to assess the reliability and validity of the 51-item NEI-VFQ, all subjects completed an interview that consisted of the 51-item NEI-VFQ, the Medical Outcomes Study 36-Item Short-Form Health Survey, and at least 1 measure of vision-targeted functional status. Estimates of internal consistency and test-retest reproducibility indicate that the 51-item NEI-VFQ is reliable. Tests of association with other scales and clinical variables support the construct validity of the survey.

CONCLUSIONS

In this cross-sectional study, the 51-item NEI-VFQ seems to be reliable and valid and should be a useful tool for group-level comparisons of vision-targeted, health-related quality of life in clinical research. Additionally, the psychometric properties of the NEI-VFQ were not influenced by the type or severity of the underlying eye disease, suggesting that the measure will provide reproducible and valid data when used across multiple eye conditions.

Cerebellar encephalitis following Epstein-Barr virus infection

A case is described of acute cerebellar symptoms as the presenting features of Epstein-Barr virus (EBV) infection. Cerebellar encephalitis is discussed with particular reference to EBV infection.

The use of nurse practitioners in pediatric institutions

INTRODUCTION

Across the United States nurse practitioners (NPs) are used in widely different ways even when they are employed in similar settings. The purpose of this survey was to describe the use of NPs in pediatric hospitals.

METHOD

A survey was conducted of the chief nurse officers in pediatric hospitals associated with the National Association of Children's Hospitals and Related Institutions. Questions were asked about hiring practices, qualifications, specialties of the NPs employed, practice arrangements, patient volume, and reimbursement. The 22-question survey instrument was developed by the authors. The response rate for the survey was 86% (42 of 49 surveys were returned).

RESULTS

The results identified that most of the hospitals surveyed reported less than 50,000 clinic visits per year, NPs were used most often in the specialties of neonatology, hematology/oncology, and primary care, more than one half of the surveyed hospitals required a masters degree for NPs, only 22% of NPs had prescriptive authority, and NPs practiced in 88% of surveyed pediatric hospitals.

DISCUSSION

Institutional and statutory boundaries continued to limit the practice of the NP. Inconsistent education and practice standards and a lack of understanding and acceptance of the role also inhibit NPs from being used to the fullest potential in pediatric hospitals.

Solution structure of a mini IGF-1

Mini insulin-like growth factor 1, an inactive insulin-like growth factor 1 mutant lacking the C region, was studied by 2D NMR spectroscopy. Resonances were assigned for almost all protons of the 57 amino acid residues. The 3D structure of the protein was determined by distance geometry methods. Three helical segments; Ala 8-Cys 18, Gly 42-Phe 49, and Leu 54-Cys 61, were identified, corresponding to those present in wild-type insulin-like growth factor 1 and in single-chain insulin. Their relative orientation, however, was found to be changed. This change is connected with a displacement of the Phe 23-Tyr 24-Phe 25-Asn 26 beta-strand-like segment, i.e., of aromatic side chains known to be important for receptor binding. Thus, deletion of the C region of IGF-1 results in a substantial tertiary structural rearrangement that accounts for the loss of receptor affinity.

Engineering the C-region of human insulin-like growth factor-1: implications for receptor binding

Recombinant wild-type human IGF-1 and a C-region mutant in which residues 28-37 have been replaced by a 4-glycine bridge (4-Gly IGF-1) were secreted and purified from yeast. An IGF-1 analogue in which residues 29-41 of the C-region have been deleted (mini IGF-1) was created by site-directed mutagenesis and also expressed. All three proteins adopted the insulin-fold as determined by circular dichroism. The significantly raised expression levels of mini IGF-1 allowed the recording of two-dimensional NMR spectra. The affinity of 4-Gly IGF-1 for the IGF-1 receptor was approximately 100-fold lower than that of wild-type IGF-1 and the affinity for the insulin receptor was approximately 10-fold lower. Mini IGF-1 showed no affinity for either receptor. Not only does the C-region of IGF-1 contribute directly to the free energy of binding to the IGF-1 receptor, but also the absence of flexibility in this region eliminates binding altogether. As postulated for the binding of insulin to its own receptor, it is proposed that binding of IGF-1 to the IGF-1 receptor also involves a conformational change in which the C-terminal B-region residues detach from the body of the molecule to expose the underlying A-region residues.

The development of a 'Standardised Learner' in researching teaching behaviours

Standardised patients are increasingly used in medical education and the reliability and validity of their use as an assessment method are supported by published research. This paper details the application of this methodology to the educational interaction between a teacher and a learner using a standardised learner.In contrast with standardised patients, a standardised learner must use a level of medical knowledge and experience appropriate for the role assumed. Some aspects of reliability and validity have been considered and appear supportive of this methodology.The feasibility and value of this method for researching actual teacher behaviour are discussed.

The use of genetic marking to assess the interaction of sensitive and multidrug-resistant cells in mixed culture

The interaction of normal (CHO-K1) and multidrug-resistant (Adrr) Chinese hamster ovary cells was examined in mixed monolayer and spheroid culture. In order to assess the individual response of the two cell types in mixed culture, CHO-K1 was genetically marked by transfection with a bacterial beta-galactosidase gene. The enzyme product can be detected histochemically and allows identification of the marked cell line, designated CHO-K1-BG. Following administration of doxorubicin or mitozantrone, there was a large difference in the clonogenic survival of CHO-K1-BG and Adrr, whereas the overall survival of a 50:50 mixture of the two cell lines had intermediate values. When the survival of marked and unmarked colonies from mixed culture was assessed separately, there was no detectable alteration in chemosensitivity. We have found no evidence for interaction of sensitive and multidrug-resistant cells in this system.

Lacrimal surgery in patients with congenital cranial or facial anomalies

A series of 26 patients with lacrimal dysfunction due to congenital cranial or facial anomalies are reviewed. The underlying anatomical abnormalities responsible for symptoms and their influence on surgical management and outcome are discussed and illustrated with representative cases. It is shown that by adaptation of standard surgical techniques a high success rate can be achieved.

General practitioners' reasons for not attending a higher professional education course

BACKGROUND

A proposal to run a higher professional education course attracted strong initial interest. However, only 12% of those 74 general practitioners expressing an interest subsequently enrolled on the course.

AIM

A study was undertaken to examine the factors that demotivated the remaining 88% from attending.

METHOD

A questionnaire was sent to the non-attenders, asking them to rank the impact of each of six factors on their decision not to attend.

RESULTS

Major factors included time commitment, general practice workload and family pressures. Cost, attitudes of practice partners and structure of the course were much less important.

CONCLUSION

It seems that the conditions imposed by the current demands of working as a general practitioner, rather than the attitudes of the general practitioners themselves, inhibit this form of continuing professional development.

Relationship between intercellular communication and adriamycin resistance in non-small cell lung cancer

The adriamycin chemosensitivity and extent of gap junctional intercellular communication were assessed in a panel of seven human non-small cell lung cancer (NSCLC) cell lines. Communication was assessed by autoradiographic detection of transfer of 3H uridine nucleotides between coupled cells. The strength of coupling varied widely between the cell lines and they could be separated into 3 groups: those which exhibited strong coupling, L-DAN and A549; those which exhibited weak coupling, SK-MES-1, Calu-3 and NCI-H125; and an intermediate group, WIL and NCI-H23. Adriamycin chemosensitivity was assessed by both clonogenic and MTT assays. The range of IC50 values as measured by either assay was extremely narrow, with no important differences between the lines. Thus, despite the wide spectrum of intercellular communication observed in these lines, this did not correlate with their adriamycin resistance.