Longitudinal analysis of respiratory symptoms in population studies with a focus on dyspnea in marine transportation workers

Purpose

Longitudinal respiratory symptoms are rarely studied in occupational epidemiology. We investigated dyspnea change over time and predictors of change over time using two longitudinal modeling techniques, a semi-parametric group-based approach (SAS^® Proc Traj) and a generalized linear mixed model (SAS^® Proc Glimmix), and compared the two techniques for use in longitudinal studies of respiratory symptoms.

Methods

Data were previously collected from a lung health surveillance study of marine transportation workers. Subjects were seen two to four times over 12 years (1987–1999). At each visit the American Thoracic Society questionnaire was administered and lung function was tested. The semi-parametric group-based model and the generalized linear mixed model were applied to the data.

Results

The group-based trajectory model supported two groups of dyspnea change over time. Group 1 (73%) had a steady low-level probability of reporting dyspnea over follow-up, while Group 2 (27%) had an increasing probability of reporting dyspnea over follow-up. The generalized linear mixed model (random intercept) estimated that the probability of reporting dyspnea was increasing over time in the population. Current smoking, female sex, lower lung function and older age were associated with increased probability of reporting dyspnea in both models.

Conclusions

Results from both models indicate that the probability of reporting dyspnea was increasing over time in this occupational cohort. The group-based model is capable of identifying multiple patterns of linear and non-linear change while the generalized linear mixed model is preferable when the population mean change (linear) is of interest. Both approaches were able to identify similar characteristics associated with longitudinal dyspnea symptoms.

     

Involvement of dopamine D<Subscript>1</Subscript> and D<Subscript>2</Subscript> receptors in the nucleus accumbens core and shell in inhibitory response control

Rationale Impaired inhibitory control over behavior is a key feature in various psychiatric disorders, and recent studies indicated an important role for dopamine D₁ and D₂ receptors and the nucleus accumbens (Acb) in this respect. Objective The present experiments were designed to study the role of dopamine D₁ and D₂ receptors in the Acb in inhibitory response control. Methods Rats were trained in a five-choice serial reaction time task and received bilateral infusions into the Acb core or shell of either SCH 23390 or eticlopride (representing selective dopamine D₁ and D₂ receptor antagonists, respectively). Subsequently, the effects of systemic amphetamine on inhibitory response control were examined. Results Eticlopride into either the Acb core or shell did not affect premature responding, a measure for inhibitory response control, but increased reaction time and errors of omission. In contrast, SCH 23390 into both regions reduced premature responding, slightly improved attentional performance in the core and increased errors of omission in the shell. Amphetamine robustly increased premature responding which was dose-dependently blocked by eticlopride in the Acb core and attenuated by eticlopride in the shell. In addition, amphetamine slightly decreased accuracy and reaction time, and these effects were inhibited by eticlopride in both regions. SCH 23390 infusion into the Acb core or shell did not alter amphetamine’s effects. Conclusion Our data provide evidence for the involvement of dopamine D₁ and D₂ receptors in the Acb core and shell in inhibitory response control and attentional performance.     

Interactions of human Myosin Va isoforms,endogenously expressed in human melanocytes,are tightly regulated by the tail domain

Primary human epidermal melanocytes express six endogenous isoforms of the human actin-associated myosin Va motor protein, involved in organelle transport. As isoforms containing exon F are most abundant in melanocytes, we hypothesized that these isoforms probably have a melanocyte-specific function. To uncover the biologic role of the six isoforms we introduced enhanced green fluorescent protein (eGFP)-myosin Va tail constructs in human melanocytes. We found that the medial tail, undergoing alternative splicing, has to be expressed in combination with the globular tail in order to obtain clear colocalization with organelles. Our data show that isoforms lacking exon F but containing exon D are associated with vesicles near the Golgi area. Myosin Va isoforms containing exon F are able to colocalize with and influence melanosome distribution by indirect interaction with rab27a and direct interaction with melanophilin. These results indicate that the myosin Va medial tail domain provides the globular tail domain with organelle-interacting specificity.     

Being there: parenting the child with acute lymphoblastic leukaemia

Aims and objectives. To gain insight into the lived experience of parenting a child with leukaemia during treatment. Background. Diagnosis of leukaemia in children leads to an existential shock for parents and a reversal of normal family life. Today, in the Netherlands, after diagnosis, children stay at home most of the time. Therefore, their parents face considerable responsibilities for administering home‐based treatment and for the support of their child during illness and treatment. Methods. A grounded theory study was undertaken at a Dutch University Hospital and involved one‐time individual in‐depth interviews with 12 mothers and 11 fathers (n = 23) of 12 children. Findings. ‘Being there’, was identified as the core concept. It means: ‘I’ll be there for you; I will never let you down’. ‘Being there’ is described as a parental response to the perceived vulnerability of the child and the parental need to give meaning to parenthood. It serves two purposes: protection and preservation. Protection means guarding the child against the negative aspects of illness and treatment. Preservation refers to the way parents influence the child’s perception of his/her life, thus contributing to his/her coping and willingness to undergo treatment, to maximise the chances for survival. Six aspects were identified: a trusting relationship, presence, emotional support, advocacy, routines and rituals and effacing oneself. Conclusions. The concept provides a theoretical frame for parenting the child with cancer. It clarifies the actions and reactions of parents and increases insight into the underlying force that enables parents to provide continuing care despite their personal burden. Relevance to clinical practice. The concept offers an essential insight into parenting the child with acute lymphoblastic leukaemia and has relevance for nursing practice and education. Understanding of the concept would improve the ability to understand, communicate and work pro‐actively in partnership with parents.     

The tailored implementation of the nursing programme 'Coping with Itch'

Aim. The aim of the study was to implement the nursing programme ‘Coping with itch’. Background. The nursing programme ‘Coping with itch’ is intended to reduce itch and to help patients to cope with itch. The programme is carried out at a nurse clinic at the dermatology outpatient department. Implementation of this programme was undertaken in five hospitals in the Netherlands using the tailored implementation approach based on the contingency model of van Linge. Method. The implementation procedure started with a diagnostic interview to gather data on the characteristics of the dermatology outpatient departments subsumed in four dimensions: structure, human resource practices, culture and politics. These characteristics were then compared with the demands of the programme. Discrepancies between the demands of the new programme and the characteristics of each organization guided the choice of the implementation strategies. Implementation strategies were mostly directed at the structure or human resource dimensions. Then, the results of the implementation were examined according to three criteria: professional adherence, continuation and barriers, using nurses’ self‐report forms on the consultations and the Barriers and Facilitators questionnaire. Results. Seventy‐seven self‐report forms were completed by the nurses for first consultations at the itch clinic and 81 for follow‐up consultations. Results concerning professional adherence show that nurses are able to carry out the programme ‘Coping with itch’. All five hospitals continued the itch clinic after completion of the implementation study. Two barriers to the implementation were frequently mentioned by the nurses: the necessary time investment and the lack of extra financial compensation. Conclusion. The use of a tailored implementation approach has led to the reasonably successful implementation of the nursing programme ‘Coping with itch’. Relevance to clinical practice. The contingency model is a useful model for the tailored implementation of a nursing programme in daily practice.     

Gene therapy used for tissue engineering applications

This review highlights the advances at the interface between tissue engineering and gene therapy. There are a large number of reports on gene therapy in tissue engineering, and these cover a huge range of different engineered tissues, different vectors, scaffolds and methodology. The review considers separately in-vitro and in-vivo gene transfer methods. The in-vivo gene transfer method is described first, using either viral or non-viral vectors to repair various tissues with and without the use of scaffolds. The use of a scaffold can overcome some of the challenges associated with delivery by direct injection. The ex-vivo method is described in the second half of the review. Attempts have been made to use this therapy for bone, cartilage, wound, urothelial, nerve tissue regeneration and for treating diabetes using viral or non-viral vectors. Again porous polymers can be used as scaffolds for cell transplantation. There are as yet few comparisons between these many different variables to show which is the best for any particular application. With few exceptions, all of the results were positive in showing some gene expression and some consequent effect on tissue growth and remodelling. Some of the principal advantages and disadvantages of various methods are discussed.     

One bird with two stones: Abnormal word length effects in pure alexia and semantic dementia

In pure alexia (PA)—an acquired reading disorder consequent on posterior left-hemisphere stroke—the hallmark is a pronounced and abnormal impact of word length on reading speed. Some patients with semantic dementia (SD)—a neurodegenerative condition affecting semantic memory—have also been reported to show an abnormal word length effect (AWLE) in reading, even though they are not thought to have the basic visual-processing deficits hypothesized to underlie this phenomenon in PA. In the current study, an AWLE in reading was consistently observed in both PA and SD patients, but further manipulations demonstrated marked differences between the groups in the conditions that produce the length effect, its specific manifestation, and the pattern of other deficits accompanying it. All of the results are compatible with the twin hypotheses that the AWLE in reading arises from a visual-processing deficit in PA but from reduced top-down lexical/semantic support for word identification in SD. In other words, the AWLE in the two patient groups appears to be a common symptom arising from different underlying deficits: one bird with two stones.