Regulation of xanthine dehydrogenase and xanthine oxidase activity and gene expression in cultured rat pulmonary endothelial cells.

The central importance of xanthine dehydrogenase (XDH) and xanthine oxidase (XO) in the pathobiochemistry of a number of clinical disorders underscores the need for a comprehensive understanding of the regulation of their expression. This study was undertaken to examine the effects of cytokines on XDH/XO activity and gene expression in pulmonary endothelial cells. The results indicate that IFN-gamma is a potent inducer of XDH/XO activity in rat lung endothelial cells derived from both the microvasculature (LMVC) and the pulmonary artery. In contrast, interferon-alpha/beta, tumor necrosis factor-alpha, interleukin-1 or -6, lipopolysaccharide and phorbol myristate acetate have no demonstrable effect. The increase in XDH/XO activity requires new protein synthesis. By Northern analysis, IFN-gamma markedly increases the level of the 5.0-kb XDH/XO mRNA in LMVC. The increase is due, in part, to increased transcription rate of the XDH/XO gene. Transcriptional activation does not require new protein synthesis. The physiologic relevance of these observations was evaluated by administering IFN-gamma to rats. Intraperitoneal administration leads to an increased XDH/XO activity and XDH/XO mRNA level in rat lungs. In sum, IFN-gamma is a potent and biologically relevant inducer of XDH/XO expression; the major site of upregulation occurs at the transcriptional level.

Metalloproteinases and tissue inhibitor of metalloproteinases in mesothelial cells. Cellular differentiation influences expression.

Mesothelial cells play a critical role in the remodeling process that follows serosal injury. Although mesothelial cells are known to synthesize a variety of extracellular matrix components including types I, III, and IV collagens, their potential to participate in matrix degradation has not been explored. We now report that human pleural and peritoneal mesothelial cells express interstitial collagenase, 72- and 92-kD gelatinases (type IV collagenases), and the counterregulatory tissue inhibitor of metalloproteinases (TIMP). Our initial characterization of the mesothelial cell metalloenzymes and TIMP has revealed: (a) they are likely identical to corresponding molecules secreted by other human cells; (b) they are secreted rather than stored in an intracellular pool; (c) a primary site of regulation occurs at a pretranslational level; (d) phorbol myristate acetate, via activation of protein kinase C, upregulates expression of collagenase, 92-kD gelatinase, and TIMP, but has no effect on expression of 72-kD gelatinase; and (e) lipopolysaccharide fails to upregulate the biosynthesis of either metalloproteinases or TIMP. Of particular interest is the observation that the state of cellular differentiation has a striking influence on the expression of metalloenzymes and TIMP, such that epitheloid cells display a more matrix-degradative phenotype (increased 92-kD gelatinase and decreased TIMP) than their fibroblastoid counterparts. We speculate that mesothelial cells directly participate in the extracellular matrix turnover that follows serosal injury via elaboration of metalloproteinases and TIMP. Additionally, the reactive cuboidal mesothelium which is characteristic of the early response to serosal injury may manifest a matrix-degenerative phenotype favoring normal repair rather than fibrosis.

Identification and characterization of the pulmonary alveolar type II cell Maclura pomifera agglutinin-binding membrane glycoprotein.

The lectin Maclura pomifera agglutinin (MPA) binds to the apical surface of pulmonary alveolar type II but not type I cells. We show that MPA binds to a single membrane glycoprotein in type II cells with a molecular mass of 230 kDa in the rabbit and 200 kDa in the rat. The glycoprotein has an abundance of terminal N-acetylgalactosamine residues. It is a hydrophilic integral membrane protein suggesting that it has an extensive extramembrane domain or is an ion channel. The glycoprotein is similar in rat and rabbit, with the exception that the rat glycoprotein is partially sialylated and is trypsin sensitive. The MPA-binding glycoprotein represents a new integral membrane marker of the apical domain of the pulmonary alveolar type II cell.

Cystic Fibrosis Foundation and European Cystic Fibrosis Society Survey of cystic fibrosis mental health care delivery.

BACKGROUND: Psychological morbidity in individuals with cystic fibrosis (CF) and their caregivers is common. The Cystic Fibrosis Foundation (CFF) and European Cystic Fibrosis Society (ECFS) Guidelines Committee on Mental Health sought the views of CF health care professionals concerning mental health care delivery. METHODS: An online survey which focused on the current provision and barriers to mental health care was distributed to CF health care professionals. RESULTS: Of the 1454 respondents, many did not have a colleague trained in mental health issues and 20% had no one on their team whose primary role was focused on assessing or treating these issues. Insufficient resources and a lack of competency were reported in relation to mental health referrals. Seventy-three percent of respondents had no experience with mental health screening. Of those who did, they utilized 48 different, validated scales. CONCLUSIONS: These data have informed the decision-making, dissemination and implementation strategies of the Mental Health Guidelines Committee sponsored by the CFF and ECFS.

Basic therapies in cystic fibrosis. Does standard therapy work?

Epidemiologic data demonstrate a dramatic improvement in survival for cystic fibrosis (CF) over the last few decades and projections suggest that trend will continue. Standard therapy works and should be aggressively applied to this patient population. Although the specific therapies have evolved over the years, the basic tenets of CF care remain unchanged and include antibiotics to control infection, airway clearance, and adequate nutrition. This article focuses on treatment of the pulmonary disease and includes a discussion of the following specific components of a standard therapeutic approach to CF: (1) antibiotics, (2) airway clearance and exercise, (3) mucolytics, (4) bronchodilators, (5) oxygen, (6) anti-inflammatory therapies, and (7) nutritional support. Judicious application of these therapies coupled with careful monitoring of pulmonary, nutritional, and metabolic parameters results in most CF patients surviving into adulthood with an acceptable quality of life.

Oxygen saturation in adult cystic fibrosis patients during exercise at high altitude.

The objective of this study was to determine the frequency and severity of decreased arterial oxy-hemoglobin saturation during exercise in adults with cystic fibrosis at 1,500 m above sea level. A convenience sample of 50 adults with cystic fibrosis who did not have hypoxemia (oxygen saturation, < 90%) at rest were evaluated. Spirometry was performed according to American Thoracic Society standards, and maximal exercise tests were performed on an electronically braked cycle ergometer using a ramp protocol individualized for each patient. Pulse oximetry was measured every 2 min. When exercising at high altitude, 45 of 50 patients had a decrease in arterial oxy-hemoglobin saturation from baseline to some degree. In 29 patients, oxy-hemoglobin saturation fell below 90%; in 14 patients, it fell below 85%; and in 4 patients, it fell below 80%. Oxy-hemoglobin saturation decreased to < 90% in 12 of 14 patients with severe pulmonary disease (FEV(1) < 40% predicted), in 15 of 26 patients with moderate disease (40% less than or equal to FEV(1) < 70% predicted), in 2 of 6 patients with mild disease (70% less than or equal to FEV(1) < 90% predicted), and in 0 of 4 with normal pulmonary function (FEV(1) greater than or equal to 90%). Percent predicted FEV(1) (r = 0.57; P < 0.0001) and FEV(1)/FVC ratio (r = 0.52; P < 0.0001) most highly correlated with arterial oxy-hemoglobin saturation at peak exercise. We conclude that at 1,500 m above sea level, adult CF patients with obstructive airways disease are at significant risk for decreased arterial oxy-hemoglobin saturation during exercise. A supervised exercise test should be considered prior to recommending an exercise program for such patients.

Histoplasmosis as a cause of pleural effusion in the acquired immunodeficiency syndrome.

Disseminated histoplasmosis is an increasingly important opportunistic infection in patients with the acquired immunodeficiency syndrome (AIDS). We report the first case of histoplasmosis as a cause of pleural effusion in a patient with AIDS. Recognition of the typical intracellular yeast on a Wright-Giemsa stained smear of the pleural fluid cells allowed prompt initiation of amphotericin B.

A cluster of transfusion-associated babesiosis in extremely low birthweight premature infants.

Babesiosis is a parasitic infection of the red blood cells most often acquired by a tick bite. As it has also been known to be transmitted vertically and via transfusion, neonates have occasionally been reported with the infection. Here, we report a series of three premature neonates who acquired babesiosis via blood transfusion from a single donor, one of whom had difficulty clearing the infection and required multiple antimicrobials.

An update on the screening, diagnosis, management, and treatment of vitamin D deficiency in individuals with cystic fibrosis: evidence-based recommendations from the Cystic Fibrosis Foundation.

OBJECTIVE: The objective was to develop evidence-based clinical care guidelines for the screening, diagnosis, management, and treatment of vitamin D deficiency in individuals with cystic fibrosis (CF). PARTICIPANTS: The guidelines committee was comprised of physicians, registered dietitians, a pharmacist, a nurse, a parent of an individual with CF, and a health scientist, all with experience in CF. PROCESS: Committee members developed questions specific to vitamin D health in individuals with CF. Systematic reviews were completed for each question. The committee reviewed and graded the available evidence and developed evidence-based recommendations and consensus recommendations when insufficient evidence was available. Each consensus recommendation was voted upon by an anonymous process. CONCLUSIONS: Vitamin D deficiency is common in CF. Given the limited evidence specific to CF, the committee provided consensus recommendations for most of the recommendations. The committee recommends yearly screening for vitamin D status, preferably at the end of winter, using the serum 25-hydroxyvitamin D measurement, with a minimal 25-hydroxyvitamin D concentration of 30 ng/ml (75 nmol/liter) considered vitamin D sufficient in individuals with CF. Recommendations for age-specific vitamin D intake for all individuals with CF, form of vitamin D, and a stepwise approach to increase vitamin D intake when optimal vitamin D status is not achieved are delineated.

Epidemiology of cystic fibrosis-related diabetes.

OBJECTIVES: Cystic fibrosis-related diabetes (CFRD) has emerged as an important complication of CF. To better understand who is at risk of developing CFRD, to gain insight into the impact of CFRD on pulmonary and nutritional status, and to assess the association of CFRD with various practice patterns and comorbid conditions, we characterized the Epidemiologic Study of Cystic Fibrosis (ESCF) patient population. STUDY DESIGN: Analyses were performed on the 8247 adolescents and adults who were evaluated at one of 204 participating sites during 1998. CFRD was defined as the use of insulin or an oral hypoglycemic agent at any time during the year. RESULTS: Previously reported risk factors for CFRD including age, gender (female), and pancreatic insufficiency were confirmed in this study. Patients with CFRD had more severe pulmonary disease, more frequent pulmonary exacerbations, and poorer nutritional status as compared with those without diabetes. CFRD also was associated with liver disease. CONCLUSIONS: CFRD is a common complication in adolescents and adults that is associated with more severe disease.

Interaction between Pseudomonas aeruginosa and host defenses in cystic fibrosis.

The major causes of morbidity and mortality in cystic fibrosis are chronic pulmonary obstruction and infection. Mucoid Pseudomonas aeruginosa is the primary pathogen in up to 90% of these patients. Once Pseudomonas organisms colonize the airways, they are virtually never eradicated. No defect in systemic host defense has been elucidated, however, several mechanisms contribute to the breakdown in host defenses that allow persistence of this organism in the endobronchial space. These mechanisms involve both bacterial adaptation to an unfavorable host environment and impaired host response. P aeruginosa adapts to the host by expressing excessive mucoid exopolysaccharide and a less virulent form of lipopolysaccharide. These features make it less likely to cause systemic infection, yet still enable it to resist local host defenses. Mucociliary clearance becomes impaired due to abnormal viscoelastic properties of sputum, squamous metaplasia of the respiratory epithelium, and bronchiectasis. Despite a brisk antibody response to a variety of Pseudomonas antigens, several defects in antibody-mediated opsonophagocytosis have been identified. These include (1) development of antibody isotypes that are suboptimal at promoting phagocytosis, (2) formation of immune complexes that inhibit phagocytosis, and (3) proteolytic fragmentation of immunoglobulins in the endobronchial space. Complement-mediated opsonophagocytosis is also compromised by proteolytic cleavage of complement receptors from the cell surface of neutrophils and complement opsonins from the surface of Pseudomonas. The resultant chronic inflammation and infection lead to eventual obliteration of the airways.

HIV-positive males' satisfaction with pharmacy services.

The objective of this study was to describe the pharmacy needs of a group of males infected with human immunodeficiency virus (HIV) and to determine whether those needs were being met. An anonymous survey was used to determine the perceptions of a group of HIV-positive males. Of 62 usable responses, 53.2% of respondents tested positive for HIV more than five years ago and 58.1% reported a CD4 count below 200/mm3, the mean age was 41 years (SD = 8.6). Respondents indicated a need for a pharmacist knowledgeable in HIV disease/treatment (74.5%), a pharmacy that accepts all insurance (66.6%), and information on alternative therapies (29.4%). Most (72.6%) wanted both written and oral information, and more than half expected the pharmacist to provide information on side effects, how medications interact with other medications and with food and how to take the medication. More than 85% indicated satisfaction with pharmacy services. The study concluded that HIV-positive males have certain expectations for pharmacy services, such as the provision of written and oral information, specific medication information, and personal interaction with the pharmacist. These patients are satisfied to varying degrees with different aspects of pharmaceutical care Pharmacists should provide these expected services to increase satisfaction for all patients, especially those who are HIV positive.

Decreased intracellular iron availability suppresses epithelial cell surface plasmin generation. Transcriptional and post-transcriptional effects on u-PA and PAI-1 expression.

Iron and iron metabolism are critical in a variety of physiologic and pathophysiologic processes, including lung injury and repair. The plasmin/plasminogen activator (PA) system is involved in the extensive remodeling process that follows acute lung injury, and alveolar epithelial cells play a key role in this repair process. Herein we report that decreased intracellular iron availability markedly suppresses cell-surface plasmin generation by A549 human carcinoma-derived pulmonary epithelial cells. This effect is mediated by concomitant downregulation of urokinase-type PA and upregulation of PA inhibitor-type 1 expression. Northern analyses, runoff transcription assays, and messenger RNA half-life experiments using actinomycin demonstrate that transcriptional and post-transcriptional mechanisms are operative. Given these potent in vitro effects on the plasmin/PA system, we speculate that adequate intracellular iron stores are important for successful repair of acute lung injury.

Hepatocyte growth factor attenuates collagen accumulation in a murine model of pulmonary fibrosis.

We investigated the in vivo effects of recombinant human hepatocyte growth factor (HGF) on epithelial cell proliferation in normal mouse lung and on the repair process that follows bleomycin-induced lung injury. Intratracheal administration of 100 micrograms of rhHGF to C57BL/6 mice led to proliferation of bronchial and alveolar epithelial cells as indicated by an increased number of cells staining for proliferating cell nuclear antigen (PCNA). The effect of HGF on the lung repair process was examined by administration of 100 micrograms of rhHGF on Day 3 and Day 6 after intratracheal injection of bleomycin to mice. We found that HGF significantly attenuated collagen accumulation induced by bleomycin as determined by quantitation of hydroxyproline content and by scoring of the extent of fibrosis. To explore the potential mechanisms involved in the beneficial effects of HGF, we performed in vitro studies with A549 pulmonary epithelial cells and found that HGF enhanced cell surface plasmin generation, expression of u-PA activity, and cell migration. In summary, HGF has potent in vivo and in vitro effects on epithelial cells, which suggests it may have a role in the therapy of pulmonary fibrosis.

Interaction of secretory leukocyte protease inhibitor with proteinase-3.

Secretory leukocyte protease inhibitor (SLPI) is a 12 kD nonglycosylated serine antiproteinase secreted by cells of mucosal surfaces. In human lung, SLPI is present in the respiratory epithelium. It is the major barrier to tissue destruction mediated by the polymorphonuclear leukocyte (PMN) serine proteinases, elastase and cathepsin G, within the upper respiratory tract. We have recently described a third PMN serine proteinase, proteinase-3, that like elastase causes lung matrix destruction and experimental emphysema. The current studies examine interactions between SLPI and proteinase-3. The results show that: (1) SLPI and its reactive-site variants have no or minimal inhibitory activity against proteinase-3; (2) native SLPI does not complex with proteinase-3; (3) proteinase-3 selectively degrades both native and oxidized SLPI; (4) the cleavage of SLPI by proteinase-3 occurs at the peptide bond COOH-terminal to Ala-16 in the NH2-terminal domain of SLPI.