Current Concepts of Transition of Care in Cystic Fibrosis

Over the past 6 decades, advances in cystic fibrosis (CF) diagnosis and management have extended the life expectancy of patients far beyond childhood; therefore, all pediatric CF patients must prepare for transition to adult care. Readiness assessment, knowledge and skill education, and support structures are all elements of ideal transition. Transition should begin early in life with teaching skills and knowledge for disease care, and in adolescence the readiness to transition should be addressed. Transition is a gradual process of increasing responsibilities in self-care and disease management, an improvement in the understanding of CF, and an iterative process of self-assessment with knowledge acquisition. Communication and collaboration between pediatric and adult providers is necessary to ensure a smooth and successful transition with minimum effect on outcomes. Although there is increased knowledge of successful transition practices, this area presents many opportunities for advancement of care for the patient with CF. [Pediatr Ann. 2017;46(5):e188-e192.].

High-throughput screening for modulators of cellular contractile force

When cellular contractile forces are central to pathophysiology, these forces comprise a logical target of therapy. Nevertheless, existing high-throughput screens are limited to upstream signalling intermediates with poorly defined relationships to such a physiological endpoint. Using cellular force as the target, here we report a new screening technology and demonstrate its applications using human airway smooth muscle cells in the context of asthma and Schlemm's canal endothelial cells in the context of glaucoma. This approach identified several drug candidates for both asthma and glaucoma. We attained rates of 1000 compounds per screening day, thus establishing a force-based cellular platform for high-throughput drug discovery.

Airway smooth muscle dynamics: a common pathway of airway obstruction in asthma

Excessive airway obstruction is the cause of symptoms and abnormal lung function in asthma. As airway smooth muscle (ASM) is the effecter controlling airway calibre, it is suspected that dysfunction of ASM contributes to the pathophysiology of asthma. However, the precise role of ASM in the series of events leading to asthmatic symptoms is not clear. It is not certain whether, in asthma, there is a change in the intrinsic properties of ASM, a change in the structure and mechanical properties of the noncontractile components of the airway wall, or a change in the interdependence of the airway wall with the surrounding lung parenchyma. All these potential changes could result from acute or chronic airway inflammation and associated tissue repair and remodelling. Anti-inflammatory therapy, however, does not "cure" asthma, and airway hyperresponsiveness can persist in asthmatics, even in the absence of airway inflammation. This is perhaps because the therapy does not directly address a fundamental abnormality of asthma, that of exaggerated airway narrowing due to excessive shortening of ASM. In the present study, a central role for airway smooth muscle in the pathogenesis of airway hyperresponsiveness in asthma is explored.

Tidal breathing pattern differentially antagonizes bronchoconstriction in C57BL/6J vs. A/J mice

There is abundant evidence that tidal breathing, and especially tidal breathing at elevated minute ventilation, antagonizes the development and persistence of airflow obstruction during bronchoconstrictor stimulation in normal animals and people. Here, we studied the antiobstructive effect of different tidal breathing patterns in C57Bl/6J and A/J mice during bronchoconstriction induced by continuous or bolus infusion of methacholine. Anesthetized, paralyzed mice were mechanically ventilated at 1,500 ml.kg(-1).min(-1), using each of three breathing patterns: 5 ml/kg, 300 breath/min; 10 ml/kg, 150 breath/min; or 20 ml/kg, 75 breath/min. Changing from 10 ml/kg, 150 breath/min to 20 ml/kg, 75 breath/min, breathing functionally antagonized bronchoconstriction, reducing the level of airflow obstruction induced by methacholine infusion or boluses equivalently in both strains. In marked contrast, changing from 10 ml/kg, 150 breath/min to 5 ml/kg, 300 breath/min, breathing substantially exacerbated methacholine-induced airflow obstruction in A/J mice, whereas it had no significant effect in C57Bl/6J mice. Our results therefore demonstrate that 1) even at moderate, fixed minute ventilation, the precise breathing pattern can influence the degree of airflow obstruction substantially, and 2) the influence of breathing pattern on bronchoconstriction differs considerably between genetically diverse inbred mouse strains. These findings imply that differences in antiobstructive effects of breathing can contribute to differences in apparent airway constrictor responsiveness. Much attention has been placed on dysregulation of contractile function of airway smooth muscle in human disease. We suggest that important pathophysiology might also be found in impairment of the functional antagonist effect of tidal breathing on airflow obstruction.

On the terminology for describing the length-force relationship and its changes in airway smooth muscle

The observation that the length-force relationship in airway smooth muscle can be shifted along the length axis by accommodating the muscle at different lengths has stimulated great interest. In light of the recent understanding of the dynamic nature of length-force relationship, many of our concepts regarding smooth muscle mechanical properties, including the notion that the muscle possesses a unique optimal length that correlates to maximal force generation, are likely to be incorrect. To facilitate accurate and efficient communication among scientists interested in the function of airway smooth muscle, a revised and collectively accepted nomenclature describing the adaptive and dynamic nature of the length-force relationship will be invaluable. Setting aside the issue of underlying mechanism, the purpose of this article is to define terminology that will aid investigators in describing observed phenomena. In particular, we recommend that the term "optimal length" (or any other term implying a unique length that correlates with maximal force generation) for airway smooth muscle be avoided. Instead, the in situ length or an arbitrary but clearly defined reference length should be used. We propose the usage of "length adaptation" to describe the phenomenon whereby the length-force curve of a muscle shifts along the length axis due to accommodation of the muscle at different lengths. We also discuss frequently used terms that do not have commonly accepted definitions that should be used cautiously.

Methodologic advancements in the study of airway smooth muscle

The study of isolated airway myocytes has provided important information relative to specific processes that regulate contraction, proliferation, and synthetic properties of airway smooth muscle (ASM). To place this information in physiological context, however, improved methods to examine airway biology in vivo are needed. Advances in genetic, biochemical, and optical methods provide unprecedented opportunities to improve our understanding of in vivo physiology and pathophysiology. This article describes 4 important methodologic advances in the study of ASM: (1) the development of transgenic mice that could be used to investigate ASM proliferation and phenotype switching during the development of hypersensitivity, and to investigate excitation-contraction coupling; (2) the use of CD38-deficient mice to confirm the role of CD38-dependent, cyclic adenosine diphosphate-ribose-mediated calcium release in airway responsiveness; (3) investigation of the role of actin filament length and p38 mitogen-activated protein kinase activity in regulating the mechanical plasticity-elasticity balance in contracted ASM; and (d) the use of bronchial biopsies to study ASM structure and phenotype in respiratory science.

Do inflammatory mediators influence the contribution of airway smooth muscle contraction to airway hyperresponsiveness in asthma?

It is now accepted that a host of cytokines, chemokines, growth factors, and other inflammatory mediators contributes to the development of nonspecific airway hyperresponsiveness in asthma. Yet, relatively little is known about how inflammatory mediators might promote airway structural remodeling or about the molecular mechanisms by which they might exaggerate smooth muscle shortening as observed in asthmatic airways. Taking a deep inspiration, which provides relief of bronchodilation in normal subjects, is less effective in asthmatic subjects, and some have speculated that this deficiency stems directly from an abnormality of airway smooth muscle and results in airway hyperresponsiveness to constrictor agonists. Here, we consider some of the mechanisms by which inflammatory mediators might acutely or chronically induce changes in the contractile apparatus that in turn might contribute to hyperresponsive airways in asthma.

The RhoA/Rho kinase pathway regulates nuclear localization of serum response factor

RhoA and its downstream target Rho kinase regulate serum response factor (SRF)-dependent skeletal and smooth muscle gene expression. We previously reported that long-term serum deprivation reduces transcription of smooth muscle contractile apparatus encoding genes, by redistributing SRF out of the nucleus. Because serum components stimulate RhoA activity, these observations suggest the hypothesis that the RhoA/Rho kinase pathway regulates SRF-dependent smooth muscle gene transcription in part by controlling SRF subcellular localization. Our present results support this hypothesis: cotransfection of cultured airway myocytes with a plasmid expressing constitutively active RhoAV14 selectively enhanced transcription from the SM22 and smooth muscle myosin heavy chain promoters and from a purely SRF-dependent promoter, but had no effect on transcription from the MSV-LTR promoter or from an AP2-dependent promoter. Conversely, inhibition of the RhoA/Rho kinase pathway by cotransfection with a plasmid expressing dominant negative RhoAN19, by cotransfection with a plasmid expressing Clostridial C3 toxin, or by incubation with the Rho kinase inhibitor, Y-27632, all selectively reduced SRF-dependent smooth muscle promoter activity. Furthermore, treatment with Y-27632 selectively reduced binding of SRF from nuclear extracts to its consensus DNA target, selectively reduced nuclear SRF protein content, and partially redistributed SRF from nucleus to cytoplasm, as revealed by quantitative immunocytochemistry. Treatment of cultured airway myocytes with latrunculin B, which reduces actin polymerization, also caused partial redistribution of SRF into the cytoplasm. Together, these results demonstrate for the first time that the RhoA/Rho kinase pathway controls smooth muscle gene transcription in differentiated smooth muscle cells, in part by regulating the subcellular localization of SRF. It is conceivable that the RhoA/Rho kinase pathway influences SRF localization through its effect on actin polymerization dynamics.

What evidence implicates airway smooth muscle in the cause of BHR?

Bronchial hyperresponsiveness (BHR), the occurrence of excessive bronchoconstriction in response to relatively small constrictor stimuli, is a cardinal feature of asthma. Here, we consider the role that airway smooth muscle might play in the generation of BHR. The weight of evidence suggests that smooth muscle isolated from asthmatic tissues exhibits normal sensitivity to constrictor agonists when studied during isometric contraction, but the increased muscle mass within asthmatic airways might generate more total force than the lesser amount of muscle found in normal bronchi. Another salient difference between asthmatic and normal individuals lies in the effect of deep inhalation (DI) on bronchoconstriction. DI often substantially reverses induced bronchoconstriction in normals, while it often has much less effect on spontaneous or induced bronchoconstriction in asthmatics. It has been proposed that abnormal dynamic aspects of airway smooth muscle contraction velocity of contraction or plasticity- elasticity balance might underlie the abnormal DI response in asthma. We suggest a speculative model in which abnormally long actin filaments might account for abnormally increased elasticity of contracted airway smooth muscle.

The RhoA/Rho kinase pathway regulates nuclear localization of serum response factor

RhoA and its downstream target Rho kinase regulate serum response factor (SRF)-dependent skeletal and smooth muscle gene expression. We previously reported that long-term serum deprivation reduces transcription of smooth muscle contractile apparatus encoding genes, by redistributing SRF out of the nucleus. Because serum components stimulate RhoA activity, these observations suggest the hypothesis that the RhoA/Rho kinase pathway regulates SRF-dependent smooth muscle gene transcription in part by controlling SRF subcellular localization. Our present results support this hypothesis: cotransfection of cultured airway myocytes with a plasmid expressing constitutively active RhoAV14 selectively enhanced transcription from the SM22 and smooth muscle myosin heavy chain promoters and from a purely SRF-dependent promoter, but had no effect on transcription from the MSV-LTR promoter or from an AP2-dependent promoter. Conversely, inhibition of the RhoA/Rho kinase pathway by cotransfection with a plasmid expressing dominant negative RhoAN19, by cotransfection with a plasmid expressing Clostridial C3 toxin, or by incubation with the Rho kinase inhibitor, Y-27632, all selectively reduced SRF-dependent smooth muscle promoter activity. Furthermore, treatment with Y-27632 selectively reduced binding of SRF from nuclear extracts to its consensus DNA target, selectively reduced nuclear SRF protein content, and partially redistributed SRF from nucleus to cytoplasm, as revealed by quantitative immunocytochemistry. Treatment of cultured airway myocytes with latrunculin B, which reduces actin polymerization, also caused partial redistribution of SRF into the cytoplasm. Together, these results demonstrate for the first time that the RhoA/Rho kinase pathway controls smooth muscle gene transcription in differentiated smooth muscle cells, in part by regulating the subcellular localization of SRF. It is conceivable that the RhoA/Rho kinase pathway influences SRF localization through its effect on actin polymerization dynamics.

Antral washout with nasal polypectomy: should both be combined?

Two hundred and sixteen patients with nasal polyps were studied. All patients had antral washouts performed at the same time as nasal polypectomy. Two hundred and sixty aspirates were sent for culture and microscopy; bacteria were cultured from 58 of these specimens in 38 patients. One hundred and one patients had pre-operative sinus radiographs of which 94 were reported as abnormal with a 52% false-positive result. It is concluded that antral washouts should be routine in all patients having nasal polypectomy. Sinus radiographs are an unnecessary pre-operative investigation in patients with uncomplicated nasal polyps.

Nasal polypectomy: should antral washout be a routine?

Seventy patients with nasal polyps were studied. Forty-seven of these had pre-operative sinus radiographs and all seventy patients had antral washouts at the time of nasal polypectomy. One hundred and seventeen antral aspirates were sent for culture and microscopy. The naked eye appearance of aspirates were turbid in 34 patients. Bacteria were cultured from 15 of the specimens in 10 patients. It was concluded that antral washout should be recommended in all patients who have nasal polypectomy and that there is no need for sinus radiographs in those patients who have uncomplicated nasal polyps.

Postoperative respiratory failure secondary to Pneumocystis carinii pneumonia

Pneumocystis carinii pneumonia (PCP) occurs frequently in individuals infected with the HIV virus. Malignancy, immunosuppressive drugs, and congenital immune deficiency may be associated with PCP. We describe a patient with stage 1 testicular carcinoma who developed hypoxemic respiratory failure two days after retroperitoneal lymph node dissection. Pneumocystis carinii organisms were demonstrated by catheter lavage samples and confirmed on bronchoalveolar lavage. Testing for HIV antibody by ELISA and the Western blot test were negative; HIV viral culture and polymerase chain reaction were also negative. Pneumocystis carinii pneumonia is unusual in localized surgically cured malignancies without obvious immunodeficiency and, to our knowledge, has not been described as a cause of postoperative respiratory failure.

Sexual Harassment in Academia: Legal and Administrative Challenges

Guidelines and institutional policies regarding sexual harassment in academia have a relatively short and controversial background. Deference to Equal Employment Opportunity Commission (EEOC) guidelines in employment sexual harassment incidents guides much of the thinking in contemporary courts. Title IX of the Educational Amendments and the Civil Rights Restoration Act of 1987 are but two of the legal redresses available to students with harassment grievance complaints. Lack of definition of the term as well as research studies in nursing complicate the issue of sexual harassment. The potential impact of harassment on nursing students both in the classroom and in the practice area is significant. Nursing administrators and educators must be proactive in writing and implementing policies regarding sexual harassment.

Unusual manifestations of pneumococcal infection in human immunodeficiency virus-infected individuals: the past revisited

Although AIDS was largely recognized and defined because of the increased presence of diseases that reflect deficiencies in cell-mediated immunity, susceptibility to common extracellular bacterial pathogens has also been shown to be increased. To our knowledge, adults with concurrent infection due to human immunodeficiency virus (HIV) and Streptococcus pneumoniae whose cases have been described to date have all had pneumococcal pneumonia and/or bacteremia. We describe five cases of HIV-infected patients who had unusual manifestations of pneumococcal infection, which include recurrent exudative pleural effusion, pyopneumothorax, purpura fulminans, mediastinitis with chest wall abscess, and multiple brain abscesses. Such complications of pneumococcal infection occurred more or less commonly in the preantibiotic era, but on the basis of our experience and an exhaustive literature search, these complications have been exceedingly rare in the past few decades. In four of our five patients, the unusual, complicated pneumococcal disease preceded and prompted a search for HIV infection. Because concurrent HIV infection increases the susceptibility to pneumococcal disease, other such cases are likely to be seen.