Research in cystic fibrosis (first of three parts)

Nonmucoid gram-negative Pseudomonas rods can readily be observed in cystic fibrosis patients' smears stained by the PATS reaction

Cystic fibrosis(CF) is responsible for much of the chronic pulmonary disease seen in children. Progressive pulmonary insufficiency accompanied by respiratory tract infection is the cause of death in 90% of CF patients. Although gram-positive staphylococci were responsible for most of these pulmonary infections prior to 1960, gram-negative Pseudomonas aeruginosa(PA) colonization is now the major cause of the progressive pulmonary disease responsible for the morbidity and mortality in CF patients. Sputum has long been used for cultural purposes for CF patient evaluation. It has not been a good source for Gram stain specimens inasmuch as large numbers of deep blue gram-positive bacteria (Fig. 1) can overlie and mask the smaller numbers of pink or red rods such as PA which are being sought in the stained smear.

Expression of cystic fibrosis transmembrane conductance regulator in paracervical ganglia

The cystic fibrosis transmembrane conductance regulator (CFTR) is an important protein that acts as a chloride channel and regulates many physiological functions, including salt transport and fluid flow. Mutations in the gene encoding the CFTR protein cause cystic fibrosis. CFTR is expressed in the epithelial cells of the lungs, pancreas, intestines, and other organs. In the peripheral and central nervous system, CFTR expression has been detected in the neurons of rat brains, ganglion cells of rat hearts, human hypothalamus, human spinal cord, and human spinal and sympathetic ganglia. However, CFTR has not been identified in other parts of the nervous system. In this study, we used immunohistochemistry, in situ hybridization, and laser-assisted microdissection (LMD) followed by reverse transcriptase (RT) PCR to identify CFTR proteins and messenger RNA in human and rat paracervical ganglion cells. CFTR and its gene expression were both detected in paracervical ganglion cells, a finding that might link this important protein to the neuronal regulation of female urogenital function. These findings could provide new insights into the symptoms related to the reproductive system frequently observed in female cystic fibrosis patients.

Cystic fibrosis transmembrane conductance regulator expression in human spinal and sympathetic ganglia

Cystic fibrosis transmembrane conductance regulator (CFTR) is a chloride channel protein, and mutations of its gene cause cystic fibrosis. CFTR is known to be expressed in epithelial cells of the respiratory, digestive and reproductive tracts. It is also present in rat neurons and heart ganglion cells. In humans, it is expressed in the hypothalamus, but has not been identified in other parts of the human nervous system. In this study, immunohistochemistry, double-staining immunofluorescence, in situ hybridization, nested reverse transcription-PCR and relative quantification of real-time PCR analysis were performed on spinal and sympathetic ganglia from seven human autopsies with no known nervous system disease. CFTR protein was expressed in most ganglion cells with no obvious difference in the amounts of mRNA transcript in ganglia of different sites. We conclude that CFTR protein and its mRNA were extensively expressed at relatively constant levels in human spinal and sympathetic ganglion cells, and may be important in physiological and pathological conditions. Moreover, CFTR in ganglia may be associated with pathophysiological changes seen in cystic fibrosis.

Antibiotic use in Cystic Fibrosis

Chronic pulmonary infections contribute significantly to the morbidity and mortality of patients with CF. The primary pathogens are Pseudomonas aeruginosa (PA) and Staphylococcus aureus. Hemophilus influenzae has been isolated from a significant number of patients also. A number of the β-lactam and aminoglycoside antibiotics reportedly have altered pharmacokinetic variables in CF. Therapy of acute pulmonary deterioration consists of intravenous antibiotics for two weeks. Antibiotic selection is based on culture and sensitivity results. Currently, the combination of a broad-spectrum penicillin and an aminoglycoside seems to provide the best results. Prophylactic antibiotics are effective if the primary isolates are sensitive to the agents used. Chronic PA infections are problematic because effective oral agents are not available. Aerosolized antibiotics do not improve results over adequate systemic therapy for acute exacerbations. Questions regarding optimal dosages, frequency, and duration of therapy remain.

Three autopsied cases of cystic fibrosis in Japan

The incidence of cystic fibrosis (CF) is very rare in Japanese, while it is frequent in Caucasians. Here we report on three Japanese cases of CF. One of the patients had consanguineous parents. All three patients initially developed meconium ileus, and hepatobiliary and pancreatic changes became more severe as age increased. The DeltaF508 mutation, the most frequent mutation associated with CF in Caucasians, was not found in these patients. To evaluate the relationship between the severity of hepatic lesions and a history of meconium ileus, we examined hepatic lesions in the present three cases, and we reviewed 22 Japanese autopsied cases of CF in the literature. No correlation was found between the incidence of biliary cirrhosis and a history of meconium ileus, because the cases with meconium ileus showed a high mortality during the neonatal period, before biliary cirrhosis developed. The high incidence of meconium ileus in Japanese CF patients may relate to a clinically severe phenotype and reflect a different genetic background between Caucasians and Japanese.

Sweat testing following newborn screening for cystic fibrosis

Sweat testing remains the "gold standard" for the diagnosis of cystic fibrosis (CF) and is a critical component of newborn screening programs. We retrospectively reviewed sweat test results reported to a neonatal screening program for CF with respect to completeness of reported results and the values recorded for sweat chloride (Cl(-)) and sodium (Na(+)) concentrations and the Cl(-):Na(+) ratio in screened infants. Thirty-nine of 85 DeltaF508 homozygous (DeltaF508/DeltaF508) and 270 of 274 DeltaF508 heterozygous (DeltaF508/-) infants had sweat tests reported to the screening program. Of those, 30 and 213 sweat test reports, respectively, were complete, i.e., sweat weight, sweat chloride, and sodium were reported. Three centers accounted for 37 of 68 (54%) incomplete results, and 4 centers performed 4 or less post-screening sweat tests in the study period. There were 6 DeltaF508 heterozygous infants with sweat Cl(-) concentrations of 40-60 mmol/L and 4 had CF confirmed by additional genotyping (n = 2) or clinical and repeat sweat Cl results (n = 2). Forty-one percent of DeltaF508/-infants with sweat Cl(-) <40 mmol/L had Cl:Na >1. We conclude that the reporting of incomplete sweat tests is common following newborn screening for CF. Infants with sweat Cl(-) levels of 40-60 mmol/L require further investigation and review, but they almost certainly have CF. The Cl(-):Na(+) ratio does not appear useful in establishing a diagnosis of CF in infants.

Comprehensive analysis of risk factors for acquisition of Pseudomonas aeruginosa in young children with cystic fibrosis

The objective of this study was to identify risk factors of significance for acquisition of Pseudomonas aeruginosa by children with cystic fibrosis (CF). Our working hypothesis is that exposure of infants and young children with CF to older, infected patients increases their risk for acquiring this organism. A special opportunity arose to study this question in detail, as we have been performing a randomized clinical trial of neonatal screening for CF throughout the state of Wisconsin during the period of 1985-1994. Patients were selected for this study based on either early identification through screening or diagnosis by standard methods. A longitudinal protocol employed at Wisconsin's two CF Centers includes routine cultures of respiratory secretions and collection of clinical, demographic, and activity information on patients and their families. Previous observations in our trial revealed that one center at an old hospital in an urban location showed a significantly shorter time to acquisition of P. aeruginosa for CF patients followed there. To study the center effect further, we performed statistical analyses using survival curves and stepwise regression analysis of all life history covariates available. The results of these analyses showed that the statistically significant correlations involve the following risk factors: 1) center and old hospital (r=0.42); 2) center and original physician (r=0.61); 3) center and exposure to pseudomonas-positive patients (r=0.29); and 4) population density and urban location (r=0.49). The final statistical model demonstrated that increased risk due to aerosol use (odds ratio=3.45, P=0.014) and a protective effect associated with education of the mother (odds ratio=0.81, P=0.024) were the most significant factors for acquisition of P. aeruginosa. The previously observed center effect was confined to the 1985-1990 interval at the old hospital (odds ratio=4.43, P < 0.001). We conclude that multiple factors are involved in increasing the risk of young children with CF to acquire P. aeruginosa, and that the observed center effect can best be explained by a combination of factors. These results suggest that facilities and methods used to care for young children with CF can significantly influence their likelihood of acquiring pseudomonas in the respiratory tract.

Nonneoplastic disorders of the eccrine glands

Eccrine glands are uniquely susceptible to a variety of pathologic processes. Alteration in the rate of sweat secretion manifests as hypohidrosis and hyperhidrosis. Obstruction of the eccrine duct leads to miliaria. The excretion of drugs into eccrine sweat may be a contributory factor in neutrophilic eccrine hidradenitis (NEH), syringosquamous metaplasia (SSM), coma bulla, and erythema multiforme (EM). Alterations in the electrolyte composition of eccrine sweat can be observed in several systemic diseases, most notably cystic fibrosis. This article summarizes current knowledge of eccrine gland pathophysiology.

Eradication of methicillin-resistant Staphylococcus aureus from the lower respiratory tract of patients with cystic fibrosis

Two of 95 patients followed in an adult cystic fibrosis clinic consistently grew methicillin-resistant Staphylococcus aureus (mrsa) on sputum culture. Sputum Gram stain consistently showed +4 polymorphonuclear leukocytes and +4 Gram-positive cocci in clusters. Both patients were co-infected with Pseudomonas aeruginosa and required multiple hospitalizations for treatment of pulmonary exacerbation, resulting in significant infection control concerns. Multiple courses of antibiotics, including ciprofloxacin and clindamycin regimens, failed to eliminate the mrsa. A combination of oral rifampin and clindamycin was successful in eradicating the organism from both patients. Over a 12-month period following therapy, in both patients none of 13 sputums showed Gram-positive cocci in clusters on Gram stain and none of 13 sputum cultures grew mrsa. Successful eradication of mrsa has greatly simplified infection control measures on subsequent hospitalizations, reducing costs and enhancing patient comfort.

Cystic fibrosis and phosphatidylcholine biosynthesis

The cystic fibrosis (CF) gene defect may be associated with a defect in membrane recycling. We have investigated the metabolism of the main constituent of plasma membrane, phosphatidylcholine (PC). In this study of platelets and fibroblasts, we show an increased uptake of choline into PC of CF cells as compared with normal cells. No accumulation of PC was seen. Other patients with respiratory disease (not CF) showed normal rates of incorporation of choline into platelet PC. Platelets from heterozygote individuals showed intermediate turnover rates of choline incorporation into PC. The increase in choline incorporation into PC in CF platelets was not due to modified or increased sensitivity to either cAMP or prostaglandin E2. The total amount and the proportions of the major phospholipids in platelets of control and CF individuals were identical. These findings indicate an increased turnover rate of this phospholipid in CF cells rather than an increased net synthesis.

Meconium ileus

Meconium ileus is a manifestation of intestinal and pancreatic dysfunction that results in the accumulation of a sticky and inspissated intraluminal meconium, which in most cases results from the autosomal recessive disease cystic fibrosis. Both nonoperative and operative therapies are effective in relieving this small-bowel obstruction; in the past, although less so today, a successful nonoperative treatment was associated with a more favorable outcome. Once the meconium ileus is relieved successfully, and the diagnosis of cystic fibrosis is established, the treatment for the intestinal manifestations of the disease focuses on enzyme replacement to augment patient nutritional status. Simultaneously, the treatment of the life-threatening pulmonary disease focuses on mucous retention and chronic infection in the lungs. Future therapies for patients with cystic fibrosis include lung transplantation, pharmacologic manipulation of the epithelial cell abnormality, and gene transfer therapy into the respiratory epithelium.

Mucociliary function, ciliary ultrastructure, and ciliary orientation in Young's syndrome

BACKGROUND

Mucociliary clearance is impaired in patients with Young's syndrome (obstructive azoospermia with recurrent sinobronchial disease), cystic fibrosis, and primary ciliary dyskinesia. No defect of cilia or mucus has been detected in Young's syndrome.

METHODS

Ciliary function and ultrastructure, including ciliary orientation, were studied quantitatively in 20 patients with Young's syndrome and 20 normal subjects to determine the incidences of ciliary defects. Nasal ciliated epithelium was obtained from each subject and used for measurement of ciliary beat frequency and ultrastructural analyses. Ciliary orientation was determined by measuring ciliary deviation in electron micrographs; ciliary deviation is a measure of the relative orientation of cilia in relation to each other in which high values indicate ciliary disorientation.

RESULTS

Ciliary beat frequency and the incidence of microtubular defects and numbers of dynein arms did not differ between patients with Young's syndrome and control subjects. In patients with Young's syndrome basal ciliary deviation (16.0 degrees) was similar to that in control subjects (14.1 degrees), but at the ciliary tip ciliary deviation (21.9 degrees) was greater than in healthy subjects (14.5 degrees).

CONCLUSION

The relative disorientation of the distal ciliary axoneme in patients with Young's syndrome compared with normal subjects may be due to a structural defect but is more likely to be a consequence of abnormal mucus.

Abnormal fucosylation of ileal mucus in cystic fibrosis: I. A histochemical study using peroxidase labelled lectins

Peroxidase conjugated lectins were used to analyse the glycoproteins of small intestinal mucins in normal infants and those with cystic fibrosis to ascertain whether there are any detectable histochemical differences in saccharide composition. A significant decrease in Lotus tetragonolobus (LTG) binding fucose was shown in normal small intestinal mucin starting around 36 weeks' gestation with total absence of staining at term and beyond. In contrast, the age matched patients with cystic fibrosis showed persistent and intense LTG binding of fucose. These results provide the first clear histochemical evidence that cystic fibrosis mucin is abnormal and confirm the findings of previous biochemical studies.

The role of mucous glycoproteins in the rheologic properties of cystic fibrosis sputum

Cystic fibrosis (CF) is characterized by excessive amounts of thick and tenacious mucous secretions that obstruct organ ducts and passages. In the respiratory tract this is associated with chronic infection resulting in the hypersecretion of purulent sputum, which the patient finds difficult to clear. We have studied the rheologic properties of purulent sputum from six patients with CF and five patients with chronic bronchitis to assess whether CF is associated with increased sputum viscoelasticity. In addition, we have isolated the major rheologic determinants, mucous glycoproteins, from CF and chronic bronchitis sputa and, using a magnetic microrheometer, investigated the possibility that the altered properties of mucus in CF are associated with abnormalities in these glycoproteins. Creep compliance analysis indicated that the CF sputa possessed raised levels of both elasticity (p less than 0.01) and viscosity (p less than 0.01). These increases in both rheologic parameters were found to be associated with increases in the DNA content (p less than 0.01) and dry weight (p less than 0.05). Mucous glycoproteins were isolated from CF and chronic bronchitis sputum samples by gel filtration on Sepharose CL4B, followed by concentration to form 8% wt/wt gels. In the absence of other sputum components, no abnormality in the rheologic properties of CF mucin gels could be detected. However, when DNA was added, the CF gels responded with increases in both elasticity and viscosity of as much as 30% (p less than 0.05), an effect not observed in the chronic bronchitis gels. These results suggest that a subtle abnormality may exist in CF mucous glycoproteins and that this could have a role in the altered physical properties of mucous secretions in CF.

T- and B-cell dysregulation of IgE synthesis in cystic fibrosis patients with allergic bronchopulmonary aspergillosis

Since Aspergillus fumigatus (Af)-specific and polyclonal serum IgE levels are characteristically elevated in patients with allergic bronchopulmonary aspergillosis (ABPA), we evaluated in vitro regulation of IgE synthesis in cystic fibrosis (CF) patients with ABPA. We studied 11 CF patients with ABPA, 37 patients with positive Af prick skin tests and/or IgG precipitating antibodies (ST/PPT+), and 35 patients with no humoral or skin responses to Aspergillus (ST/PPT-). Mean serum IgE concentration was significantly elevated in CF subjects with ABPA compared to ST/PPT+ and ST/PPT- patients, 2866 vs 303 and 61 IU/ml, respectively (P less than 0.01). In vitro studies demonstrated that ABPA patients' B cells spontaneously synthesized significantly increased amounts of IgE compared to ST/PPT positive and negative subjects, 1980 vs 220 and 13 pg/ml, respectively (P less than 0.01). In addition, preformed B-cell-associated IgE was also significantly elevated in ABPA subjects (P less than 0.01), indicating prior in vivo activation. Supernatant cultures of Af-stimulated T cells from ABPA subjects significantly induced allogeneic B-cell IgE synthesis compared to ST/PPT positive and negative CF subjects, 206 vs 13 and 4 pg/ml, respectively (P less than 0.01). Thus T cells stimulated with Aspergillus antigens secrete cytokines that induce B-cell IgE synthesis in ABPA subjects. B-cell IgE hyperactivity is manifested by in vivo and in vitro increased IgE concentrations. Analyses of T-cell regulation and B-cell IgE synthesis distinguish CF subjects with ABPA from Aspergillus sensitive non-ABPA subjects.

MR imaging of pancreas in cystic fibrosis

The pancreatic regions of 18 patients with cystic fibrosis were analyzed with a 1.5 Tesla MR unit. Signal intensity of the pancreas was correlated with clinical data and ultrasound. A hyperintense pancreas on T1-weighted image was consistent with fatty replacement of pancreatic insufficiency. A pancreas of normal soft tissue intensity was found in two asymptomatic and one symptomatic patient. A very hypointense pancreas on any pulse sequence was considered to be an intermediate stage of pancreatic degeneration.

Renal handling of beta 2-microglobulin in patients with cystic fibrosis

We evaluated the renal handling of beta 2-microglobulin (beta 2-M) and creatinine in healthy outpatients (n = 6), normal children hospitalized for infections treated with antibiotics (not including an aminoglycoside) (n = 4); outpatients with cystic fibrosis (CF; n = 12), and hospitalized patients with CF (n = 6) who received a 10- to 14-day course of antibiotic treatment that included an aminoglycoside. The serum beta 2-M concentrations in the normal outpatients (2020.1 +/- 276.6 micrograms/L) were significantly lower (p less than 0.05) than those observed for outpatients (2833.3 +/- 202.6 micrograms/L) or patients with CF (2861.8 +/- 340.5 micrograms/L. There were no significant differences found for creatinine clearance or fractional excretion of beta 2-M when subjects without CF were compared with those with the disease. Furthermore, no significant differences were observed in hospitalized patients with CF when creatinine clearance and fractional excretion of beta 2-M were compared between the initiation and conclusion of aminoglycoside treatment. Glomerular filtration and proximal tubular reabsorption of beta 2-M were not altered in patients with CF. These findings do not support a global defect in proximal renal tubular reabsorption as the underlying cause for altered aminoglycoside clearance in patients with CF.

The ocular surface in cystic fibrosis

Seventeen patients with cystic fibrosis and 17 age-, race-, and sex-matched controls were examined under standardized conditions. Testing included slit-lamp biomicroscopy, fluorescein staining, rose bengal staining, Schirmer's basic tear test, tear film break-up time, tear pH, tear lysozyme, tear protein, lid and conjunctival cultures, and conjunctival impression cytology. Cystic fibrosis patients showed a statistically significant increase in the incidence of fluorescein staining and clinical blepharitis, as well as significantly decreased Schirmer testing and tear lysozyme. Ocular surface abnormalities in these patients may be attributable to aqueous and lipid tear film deficiencies. Cystic fibrosis patients showed normal conjunctival epithelial cell morphology, grew no pathogenic organisms, and had a decreased incidence of conjunctival bacterial colonization.

Aberrant free radical activity in cystic fibrosis

It has been suggested that the molar ratio of octadeca 9,11 dienoic acid to linoleic acid in biological material provides an index of activity along the non-peroxide pathway of a free radical attack on polyunsaturated fatty acids. In 17 adults with cystic fibrosis the 'molar ratio' in nasal epithelial cells--a recognised target of the disease--exceeded that in 20 controls (median 2.09%, range 1.70-3.01% versus 1.56, 0.92-2.23%, p = 0.0002). The difference was also apparent, although less stark, upon analysis of serum in a further 22 CF patients (2.48%, 1.60-5.24%) and 25 controls (1.96%, 0.81-3.90%, p = 0.0348). There was no correlation between the 'molar ratio' and blood white cell count or erythrocyte sedimentation rate, severity of lung or liver disease, indicating that the raised values are a primary feature, rather than reflecting disease severity. Aberrant free radical activity may underlie cellular dysfunction in cystic fibrosis.

Biology of sweat glands and their disorders. I. Normal sweat gland function

The basic mechanisms of sweat gland function and an updated review of some relatively common disorders of sweat secretion, are presented. Although sweat secretion and ductal absorption are basically biophysical and biologic cellular processes, a detailed description of the basic biophysical principles of membrane transport has been avoided to make the discussion more readable. The cited references will, however, help those readers primarily interested in the basic details of sweat gland function. Part I of this article includes a discussion of morphologic characteristics, central and peripheral nervous control of sweat secretion, neurotransmitters, intracellular mediators and stimulus secretion coupling, Na-K-Cl cotransport model for the ionic mechanism of sweat secretion, ingredients of sweat, ductal function, the pathogenesis of abnormal sweat gland function in cystic fibrosis, and the discovery of the apoeccrine sweat gland. Part II, to be published in the May issue of the Journal, reviews reports of all those major disorders of hyperhidrosis and hypohidrosis that have appeared in the literature during the past 10 years. It is hoped that this review will serve as a resource for clinicians who encounter puzzling disorders of sweating in their patients, as well as for investigators who wish to obtain a quick update on sweat gland function.

The effect of some preservatives used in nasal preparations on mucociliary clearance

The effect of methyl-p-hydroxybenzoate, propyl-p-hydroxybenzoate, chlorbutol, chlorocresol, EDTA, benzalkonium chloride, chlorhexidine, phenylmercuric nitrate and phenylmercuric borate on mucociliary transport rate of the frog palate has been examined. Following a variable number of applications all these preservatives halted transport, the first three reversibly. However, applications of thiomersal (0.01%) were well tolerated. The frog palate possesses a ciliated epithelium protected by mucus, since some of our findings are at variance with those previously reported results where the protective effect of mucus was negligible in the in-vitro model (usually trachea) employed, it would appear that the contribution of mucus to effective mucociliary clearance should not be underestimated.

The hypervitaminosis-A rat: a model for mucin hypersecretion in cystic fibrosis?

Cystic fibrosis is a devastating disease with pathognomonic features typically displayed in the exocrine system. An obvious drawback with human clinical studies of the disease is the relative inaccessibility of its "target-tissues," i.e., the salivary glands, intestine, pancreas, and tracheobronchial tree. Thus, little is known about its underlying cellular mechanisms. For this reason, physiologically relevant animal models for the disease are vitally needed. At present, there are animal models available for certain salivary gland biochemical aspects of the disease and for bicarbonate ion secretory alterations. However, no adequate model exists for excessive mucus production, an aspect of the disease which sets the stage for life-threatening infections and digestive disorders. This manuscript examines morphological and biochemical changes occurring in various biological systems exposed to high levels of vitamin A and correlates such changes with abnormalities commonly seen in cystic fibrosis.

Alterations in specific activity of lysosomal alpha-glucosidase in cystic fibrosis

Cultured skin fibroblasts derived from patients with cystic fibrosis contain 2.1-fold more acid alpha-glucosidase (EC 3.2.1.3) than normal fibroblasts. This difference is amplified to 2.3-fold when the cells are extracted in Triton X-100. In a study of 14 fibroblast cell lines derived from CF homozygotes and heterozygotes, normal individuals and patients with other recessively inherited disorders, normal individuals could be distinguished from either CF homozygotes or heterozygotes based on the ratio of acid alpha-glucosidase to beta-hexosaminidase when fibroblasts were extracted in either water or Triton X-100. However, the best distinction could be made with water extracts as there was no overlap among individual data points in the three categories. The acid to neural alpha-glucosidase ratio only distinguished CF homozygotes from normal individuals when cells were extracted in Triton X-100. The use of a ratio relationship of acid alpha-glucosidase with beta-hexosaminidase allows the comparison of data from multiple experiments on different days of assay and on cells at different passage numbers. These results suggest that alpha glucosidase may have a role in the primary defect in cystic fibrosis.

Resistance of mucoid Pseudomonas aeruginosa to nonopsonic phagocytosis by alveolar macrophages in vitro

A unique, recently described rat alveolar macrophage cell line (NR8383) was used to study the interaction of the pulmonary immune system with a mucoid cystic fibrosis isolate of Pseudomonas aeruginosa (SRM-3), its nonmucoid revertant (SRM-3R), and a non-cystic fibrosis isolate (PAO-1). Strain SRM-3 was cultivated in a chemostat system to allow maintenance of an entirely mucoid population. The alveolar macrophage response to the mucoid and nonmucoid strains of P. aeruginosa was determined by visually quantitating phagocytosis in acridine orange-stained monolayers and measuring the induction of an oxidative burst as indicated by chemiluminescence and H2O2 production. In all experiments, fewer than 2% of the NR8383 cells engulfed the mucoid SRM-3 isolate, while SRM-3R and PAO-1 were phagocytized by 15 and 41%, respectively. Opsonization by normal serum (complement) provided minimal phagocytic enhancement of these strains, whereas specific anti-P. aeruginosa antibody slightly elevated phagocytic responses to strains with nonmucoid phenotypes while providing a sevenfold increase in uptake of SRM-3. Chemiluminescent and H2O2 responses were comparable with the levels of phagocytosis observed, with very little or no response to the mucoid strain SRM-3. The data indicate that the strains with mucoid phenotypes are refractile to ingestion and that studies which describe ingestion of mucoid strains were likely measuring ingestion of revertants. Alginic acid (2 mg/ml) was found to inhibit stimulation of macrophage response to the opsonized and unopsonized nonmucoid strain PAO-1.

Calmodulin in normal and cystic fibrosis human intestine at different developmental stages

Calmodulin concentrations and localisation have been analysed as a function of development in human intestinal epithelial cells from normal and cystic fibrosis individuals. In normal fetuses up to eight weeks of gestation intestinal epithelial cells which were still undifferentiated were not immunoreactive and their calmodulin content was low. From eight weeks onwards there was a significant overall increase in calmodulin content concomitant with its segregation to the apical side of epithelial cells. At 14 weeks of gestation calmodulin concentrations and localisation closely resembled those of adults. The developmental pattern of calmodulin appeared to parallel the morphological and functional maturation of brush borders which occurs during the first trimester of pregnancy. In the intestinal epithelial cells from a 19 weeks cystic fibrosis fetus and a cystic fibrosis newborn infant neither calmodulin concentration, nor its localisation were affected. Similarly, brush border calmodulin binding proteins and enzymatic activities were similar in normal subjects and the cystic fibrosis intestine.

Pseudomonas aeruginosa and Pseudomonas cepacia isolated from cystic fibrosis patients bind specifically to gangliotetraosylceramide (asialo GM1) and gangliotriaosylceramide (asialo GM2)

Pseudomonas aeruginosa infection in the lungs is a leading cause of death of patients with cystic fibrosis, yet a specific receptor that mediates adhesion of the bacteria to host tissue has not been identified. To examine the possible role of carbohydrates for bacterial adhesion, two species of Pseudomonas isolated from patients with cystic fibrosis were studied for binding to glycolipids. P. aeruginosa and P. cepacia labeled with 125I were layered on thin-layer chromatograms of separated glycolipids and bound bacteria were detected by autoradiography. Both isolates bound specifically to asialo GM1 (Gal beta 1-3GalNAc beta 1-4Gal beta 1-4Glc beta 1-1Cer) and asialo GM2 (GalNAc beta 1-4Gal beta 1-4Glc beta 1-1Cer) but not to lactosylceramide (Gal beta 1-4Glc beta 1-1Cer), globoside (GalNAc beta 1-3Gal alpha 1-4Gal beta 1-4Glc beta 1-1Cer), paragloboside (Gal beta 1-4GlcNAc beta 1-3Gal beta 1-4Glc beta 1-1Cer), or several other glycolipids that were tested. Asialo GM1 and asialo GM2 bound the bacteria equally well, exhibiting similar binding curves in solid-phase binding assays with a detection limit of 200 ng of either glycolipid. Both isolates also did not bind to GM1, GM2, or GDla suggesting that substitution of the glycolipids with sialosyl residues prevents binding. As the Pseudomonas do not bind to lactosylceramide, the beta-N-acetylgalactosamine residue, positioned internally in asialo GM1 and terminally in asialo GM2, is probably required for binding. beta-N-Acetylgalactosamine itself, however, is not sufficient as the bacteria do not bind to globoside or to the Forssman glycolipid. These data suggest that P. aeruginosa and P. cepacia recognize at least terminal or internal GalNAc beta 1-4Gal sequences in glycolipids which may be receptors for these pathogenic bacteria.

The end organ defect in cystic fibrosis; a hypothesis: disinhibited inositol cycle activation?

Activation of the inositol cycle by a factor capable of by-passing the normal controls on exocrine secretion by an interaction with a coupling protein could produce effects similar to a calcium ionophore or the ciliary dyskinesia factor. The chloride permeability defect may represent a secondary adaptive change, able to limit the consequences of this via an acid shift in intracellular pH. The model predicts that lithium treatment would limit the effects of the disease.

Cystic fibrosis--a single locus disease? Results of a population genetics study

In a population genetics study of cystic fibrosis (CF), we investigated the state of health of 1276 first cousins of CF index patients. Six hundred seventy-five married aunts and uncles (siblings of CF index patients' mothers and fathers) who had at least one child were interviewed. In only 1 of these 675 families, three children of a total of eight had died of CF. If CF occurs more frequently than in 1 in 3000 newborn babies in our population, our investigation supports the hypothesis that CF is caused by mutations at more than one locus. We also determined that the evidence furnished by such a study of other, more uncommon autosomal recessive disorders is limited.

Pathophysiology of Cystic Fibrosis with Emphasis on Salivary Gland Involvement

Cystic fibrosis (CF) is a fatal autosomal recessive disorder which affects all exocrine glands, or perhaps all epithelial surfaces. The three organs most consistently affected are the eccrine sweat gland, which produces excessively salty sweat; the lung, in which chronic obstructive pulmonary disease invariably develops and is usually the cause of mortality; and the pancreas, which fails to produce adequate bicarbonate ion and water in nearly all patients, and produces inadequate digestive enzymes in most, giving rise to pancreatic insufficiency. However, the liver, reproductive tracts, intestine, sinuses, and salivary glands are also regularly affected. In the sweat gland and in the airways, passive chloride permeability is reduced, accounting for the salty sweat and probably contributing to the dehydrated mucus in the airways. In organs apart from the sweat gland, a common feature of the disease is the plugging of glandular acini and ductules by precipitated secretions. Salivary glands have been extensively studied in CF because of both the accessibility of the glands and their products, and the mix of mucous and serous components in the salivary glands. However, there is no unanimity in the results from parotid and submandibular glands. In the labial (mucous) glands, the sodium content of secreted product and in the secretory granules is markedly elevated, and histologically the acini are plugged with eosinophilic material. Functional studies of CF salivary glands have also yielded inconsistent data. Cultured cell systems combined with molecular biologic approaches offer promise in tracing the fundamental CF defect in salivary and other epithelial systems.

Pathophysiology of cystic fibrosis with emphasis on salivary gland involvement

Cystic fibrosis (CF) is a fatal autosomal recessive disorder which affects all exocrine glands, or perhaps all epithelial surfaces. The three organs most consistently affected are the eccrine sweat gland, which produces excessively salty sweat; the lung, in which chronic obstructive pulmonary disease invariably develops and is usually the cause of mortality; and the pancreas, which fails to produce adequate bicarbonate ion and water in nearly all patients, and produces inadequate digestive enzymes in most, giving rise to pancreatic insufficiency. However, the liver, reproductive tracts, intestine, sinuses, and salivary glands are also regularly affected. In the sweat gland and in the airways, passive chloride permeability is reduced, accounting for the salty sweat and probably contributing to the dehydrated mucus in the airways. In organs apart from the sweat gland, a common feature of the disease is the plugging of glandular acini and ductules by precipitated secretions. Salivary glands have been extensively studied in CF because of both the accessibility of the glands and their products, and the mix of mucous and serous components in the salivary glands. However, there is no unanimity in the results from parotid and submandibular glands. In the labial (mucous) glands, the sodium content of secreted product and in the secretory granules is markedly elevated, and histologically the acini are plugged with eosinophilic material. Functional studies of CF salivary glands have also yielded inconsistent data. Cultured cell systems combined with molecular biologic approaches offer promise in tracing the fundamental CF defect in salivary and other epithelial systems.

Salivary gland changes in disease

Ultrastructural alterations occurring in human salivary glands as a result of a variety of diseases are described. Major changes in these organs in cases of cystic fibrosis are probably the result of duct blockage, as indicated by study of chronically inflamed salivary glands. A new disease of salivary glands is reported in which parotid serous granules are distorted by bundles of fine filaments, which may be due to the untoward polymerization of a secretory protein, perhaps proline-rich protein. Finally, a clear-cell adenocarcinoma of palatine gland origin is described in which the nuclei display complex pseudoinclusions and the cytoplasm contains numerous herpes-type viruses.

Combined evaluation of circulating immune complexes and antibodies to Pseudomonas aeruginosa as an immunologic profile in relation to pulmonary function in cystic fibrosis

We developed a solid-phase radioimmunoassay with a reference standard pseudomonas antigen and used this with 125I-labeled anti-human immunoglobulin to evaluate specific antibodies to Pseudomonas aeruginosa, qualitatively and quantitatively, in sera from children with cystic fibrosis (CF) whose lungs were colonized by this bacterium. The results of this IgG assay correlated with the number of precipitin antibodies to the standard reference antigen determined by cross-immunoelectrophoresis in the same sera. Forced expiratory volume (FEV1; percentage predicted), determined as an indicator of lung injury in CF, was evaluated as an immunologic response to pseudomonas, against a profile derived from combined serial data on both the circulating immune complexes (CIC) and the Ps. aeruginosa antibodies (N = 25 CF patients; 108 sera). This revealed that in CF patients who had no specific IgG antibodies to Ps. aeruginosa and no IgG-CIC had the best pulmonary function (FEV1 = 115 +/- 14.52%) and those with high levels of antibodies to this organism and high IgG-CIC levels had the poorest lung function (FEV1 = 69.75 +/- 10.99%) (P less than 0.05). We believe that this indicates an immunologic basis for lung injury in cystic fibrosis.

Supraventricular tachycardia in patients with cystic fibrosis

Reports on arrhythmias in cystic fibrosis (CF) patients are limited. Four CF patients treated at our center had recurrent supraventricular tachycardia (SVT). Three had cor pulmonale, as evidenced by echocardiogram, and all had baseline tachycardia. Twenty-four hour Holter monitoring in three patients showed ectopic atrial pacing and premature atrial and ventricular contractions in one patient, rare PVCs in another, and SVT in all three. All patients had significant bronchospasm requiring the use of theophylline, prednisone, and frequent daily doses of beta-2 adrenergic agonists; two also used nebulized atropine. Average theophylline level for the group was 13.4 micrograms/ml during SVT. There was no correlation between pulmonary obstruction and the frequency of SVT. Factors such as cor pulmonale, ectopy, hypoxia, infection, intensive combination bronchodilator therapy, and corticosteroids probably interacted to precipitate SVT. Altered autonomic responses and a myocardial infiltrative process noted in some patients with CF may also play a role in causing arrhythmias.

The pathogenesis of cystic fibrosis: a proposal for calmodulin as the basic biochemical defect

In cystic fibrosis (CF) there are two major defects which lead to most clinical manifestations of the disease. These are the electrolyte sweat defect and the abnormality of mucous secretions. Both may be satisfactorily explained by increased intracellular Ca++. In Na+ reabsorbing cells, such as exocrine sweat glands, increased Ca++ inhibits transepithelial Na+ transport. In mucus-secreting cells, high Ca++ levels may lead to physiochemical changes in secreted mucus. Increased intracellular Ca++ levels are hypothesized to be caused either by a defective Ca++ efflux cellular mechanism, or by increased intracellular binding of Ca++.

Probe of the (Ca2+ + Mg2+)-ATPase in erythrocyte membranes of cystic fibrosis patients

There are several conflicting reports regarding a defective (Ca2+ + Mg2+)-ATPase in tissues from cystic fibrosis (CF) patients. The work presented in this paper represents an independent assessment of (Ca2+ + Mg2+)-ATPase function in CF and, at the same time, provides a somewhat more detailed analysis of the enzyme from CF patients than has previously existed. We found no significant differences in either the Km value for Ca2+ or the Vm value of the (Ca2+ + Mg2+)-ATPase in membrane preparations from CF patients and control subjects when the red cell membranes were prepared by methods which utilize Tris-glycylglycine-Mg2+ buffers. In contrast, the Vm value of the (Ca2+ + Mg2+)-ATPase in the preparations from CF patients was found to be lower than that from control subjects when the membranes were prepared by a series of washes with EDTA-containing buffers (i.e., 1-10 mmol/1 EDTA). The EDTA treatment, however, did not produce any significant difference in the Km between the two groups. The fluorescent ATP analogue, trinitrocyclohexadienylidine-ATP, appeared to interact with erythrocyte ghosts as evidenced from an enhancement of its fluorescence. This enhancement was greater in control preparations than in samples from CF patients. In addition, the kinetic profiles, with respect to ATP, were quite different between the two enzyme populations. The overall results suggest that the lower rate of ATP hydrolysis observed with membranes from CF patients may reflect an impaired utilization of the substrate by the (Ca2+ + Mg2+)-ATPase from these individuals.

Kinetic alterations of cytochrome-c oxidase in cystic fibrosis

We compared the kinetics of cytochrome-c oxidase (cytochrome-c:oxygen oxidoreductase, EC 1.9.3.1) in fibroblasts derived from normal and cystic fibrosis individuals. The Km of the enzyme for reduced cytochrome c was significantly increased in CF cells; the change, however, was observed only at temperatures above 25 degrees C. The Vmax values were comparable in both types of individuals.

Diagnosis of cystic fibrosis during adolescence

The manifestations of cystic fibrosis (CF) may be minimal, absent, or overlooked during childhood, thus 8-10% of cases are diagnosed during adolescence. Between 1970 and 1982, 14/157 (8.9%) patients were diagnosed as having CF as teenagers, based on clinical findings and elevated sweat electrolyte levels. Of these 14 patients (means = 15 years, range = 12-20 years), 50% had pulmonary and gastrointestinal symptoms dating from childhood; 50% became symptomatic during adolescence (primarily with pulmonary manifestations). None had a family history of CF. Four had false-negative sweat tests resulting in a mean diagnostic delay of 7.3 years. Because of the potential long-term complications of CF on physical maturation, completion of the psychosocial tasks of adolescence, adaptation to a chronic illness, and issues of sexuality and fertility, consideration of this diagnosis is crucial.

The nature of the Ca2+-pump defect in the red blood cells of patients with cystic fibrosis

The reduction in (Ca2+ + Mg2+)-ATPase activity in the cystic fibrosis red blood cells can be attributed to a reduction in the number of active Ca2+ pumps per red blood cell and an altered interaction of calcium ions with the pump. Despite this, the normal free intracellular [Ca2+] is preserved due to a lower rate of passive calcium entry.

Survival of cystic fibrosis patients in South Australia. Evidence that cystic fibrosis centre care leads to better survival

Life tables were calculated for 205 South Australians with cystic fibrosis. An improvement in survival was noted between 1948 and 1982. Ninety-three per cent of patients who were diagnosed as having cystic fibrosis after 1973 were alive at 14 years of age, compared with 40% of those who were diagnosed between 1948 and 1973. A Cystic Fibrosis Clinic was established in 1973 and much of this improvement is attributed to the care provided by this centre. Deaths from meconium ileus fell from 58% of infants with this complication between 1948 and 1973 to only 8% between 1973 and 1983, in spite of the increasing incidence of patients who were chronically colonized with Pseudomonas aeruginosa (currently 68% of patients). These figures are similar to those from Victoria and from other cystic fibrosis centres in North America. The improvement in survival means that adults now comprise a quarter of the patients with cystic fibrosis in South Australia, and that adult institutions need to be aware of these patients and their needs.

Pseudomonas cepacia colonization in patients with cystic fibrosis: risk factors and clinical outcome

During the period of 1979 to 1983, 38 patients with cystic fibrosis (CF) at the CF center of St. Christopher's Hospital for Children in Pennsylvania developed respiratory tract colonization with Pseudomonas cepacia. Seventeen (45%) of the patients with colonization died. Yearly incidence rates of P. cepacia colonization fluctuated between 1.3% and 6.1%, suggesting an endemic phenomenon. Case-control studies showed that severe underlying CF, use of aminoglycosides, and having a sibling with CF and P. cepacia colonization were significant risk factors for P. cepacia colonization. Once colonized with P. cepacia, patients with CF were likely to be hospitalized longer (P = 0.008) and to die sooner (P = 0.0001) than control patients with CF. Environmental and microbiologic studies did not identify a common source or mode of transmission of P. cepacia among patients. The results of this investigation suggest that P. cepacia colonization of patients with CF was endemic in the hospital, occurred more frequently in those with severe disease, and was associated with adverse clinical outcome.