PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “CYSTIC FIBROSIS”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,045 records · Page 58Linked to original sources

A 3' splice site consensus sequence mutation in the cystic fibrosis gene.

In the cystic fibrosis (CF) gene, recently cloned, a three base pair deletion (delta F508) has been identified in a majority of CF patients. This deletion has been found in 80% of CF chromosomes in families from north west Brittany. In order to identify new mutations we have selected 43 chromosomes negative for the three base pair deletion from these families and directly sequenced exon 11 after DNA amplification by the polymerase chain reaction. We have detected a base change (G----A) at the 3' end of the consensus sequence of intron ten (namely 1717-1). This mutation destroys a splice site in the cystic fibrosis gene which probably produces a mutant allele. This single nucleotide mutation has been reported on two other CF chromosomes.

Cystic Fibrosis↗

Hepatic complications of cystic fibrosis.

74 patients with cystic fibrosis aged 1-19 years were assessed prospectively for 1-7 years for evidence of liver involvement. 20 of these patients were referred primarily because of hepatic problems. 3 of 4 with neonatal hepatitis recovered. Chronic active hepatitis developed in a further child but resolved spontaneously. 6 patients had abnormal liver-function tests without clinical evidence of liver disease. In 18 cirrhosis was detected at age 4-13 years. Liver disease was stable in these except terminally in 3 with cor pulmonale. The principal hepatic problem was variceal bleeding, which occurred in 6 patients. 50% of bleeds followed aspirin ingestion. This drug therefore should be avoided in such patients. 13 had hypersplenism. 2 had severe splenic pain necessitating splenectomy with lienorenal shunt, which was performed also in 2 patients who had bled. 3 remain well up to 5 years later. In 3 patients seen in the past 3 years injection sclerotherapy has controlled bleeding. This technique was well tolerated without the pain associated with, or intensive physiotherapy necessary after, shunt surgery; and this may be the method of choice for controlling variceal bleeding in cystic fibrosis.

Adolescent↗

DeltaF508 CFTR protein expression in tissues from patients with cystic fibrosis.

Heterologous expression of the cystic fibrosis transmembrane conductance regulator (CFTR) provided evidence that the major cystic fibrosis (CF) mutation DeltaF508 leads to defective protein folding in the endoplasmic reticulum, which prevents its processing and targeting to the cell surface. In this study, we investigated endogenous CFTR expression in skin biopsies and respiratory and intestinal tissue specimens from DeltaF508 homozygous and non-CF patients, using immunohistochemical and immunoblot analyses with a panel of CFTR antibodies. CFTR expression was detected at the luminal surface of reabsorptive sweat ducts and airway submucosal glands, at the apex of ciliated cells in pseudostratified respiratory epithelia and of isolated cells of the villi of duodenum and jejunum, and within intracellular compartments of intestinal goblet cells. In DeltaF508 homozygous patients, expression of the mutant protein proved to be tissue specific. Whereas DeltaF508 CFTR was undetectable in sweat glands, the expression in the respiratory and intestinal tracts could not be distinguished from the wild-type by signal intensity or localization. The tissue-specific variation of DeltaF508 CFTR expression from null to apparently normal amounts indicates that DeltaF508 CFTR maturation can be modulated and suggests that determinants other than CFTR mislocalization should play a role in DeltaF508 CF respiratory and intestinal disease.

Amino Acid Sequence↗

Defective regulation of gap junctional coupling in cystic fibrosis pancreatic duct cells.

The cystic fibrosis (CF) gene encodes a cAMP-gated Cl- channel (cystic fibrosis transmembrane conductance regulator [CFTR]) that mediates fluid transport across the luminal surfaces of a variety of epithelial cells. We have previously shown that gap junctional communication and Cl- secretion were concurrently regulated by cAMP in cells expressing CFTR. To determine whether intercellular communication and CFTR-dependent secretion are related, we have compared gap junctional coupling in a human pancreatic cell line harboring the DeltaF508 mutation in CFTR and in the same cell line in which the defect was corrected by transfection with wild-type CFTR. Both cell lines expressed connexin45 (Cx45), as evidenced by RT-PCR, immunocytochemistry, and dual patch-clamp recording. Exposure to agents that elevate intracellular cAMP or specifically activate protein kinase A evoked Cl- currents and markedly increased junctional conductance of CFTR-expressing pairs, but not in the parental cells. The latter effect, which was caused by an increase in single-channel activity but not in unitary conductance of Cx45 channels, was not prevented by exposing CFTR-expressing cells to a Cl- channel blocker. We conclude that expression of functional CFTR restored the cAMP-dependent regulation of junctional conductance in CF cells. Direct intercellular communication coordinates multicellular activity in tissues that are major targets of CF manifestations. Consequently, defective regulation of gap junction channels may contribute to the altered functions of tissues affected in CF.

Cell Communication↗

Placebo-controlled trial of misoprostol in cystic fibrosis.

Seventeen children with cystic fibrosis were studied in a 6-week double-blind, placebo-controlled, crossover trial to determine the efficacy of misoprostol, 100 micrograms, four times a day, in improving fat absorption in patients already on pancreatic enzyme therapy. In those patients who had greater than 90% absorption on enzyme therapy alone, no further significant increase in absorption was achieved with misoprostol administration. Those patients who had absorption of less than 90% on standard enzyme therapy showed a significant improvement with misoprostol administration (p less than 0.01). One patient had a significant elevation in the eosinophil count during the period of misoprostol administration, but there were no significant changes in any other hematological or biochemical parameter. Misoprostol appears to be of benefit to those children with cystic fibrosis who have residual malabsorption on standard enzyme therapy.

Alprostadil↗

Evaluation of the forced expiration technique as an adjunct to postural drainage in treatment of cystic fibrosis.

Sixteen patients with cystic fibrosis were treated with conventional physiotherapy aided by an assistant. The results were compared with those produced by physiotherapy using the forced expiration technique cleared more sputum in less time than conventional physiotherapy. A sputum in less time than conventional physiotherapy. A second study showed that an assistant did not further improve the results obtained by the patient performing the forced expiration technique himself. These findings mean that patients with cystic fibrosis who have had to rely on the help of others for their home treatment may now perform more effective treatment without help. The forced expiration technique might also be helpful for patients with chronic bronchitis, asthma, or bronchiectasis.

Adolescent↗

Nyctalopia and conjunctival xerosis indicating vitamin A deficiency in cystic fibrosis.

Thirty-one Cystic Fibrosis patients were investigated for clinical and biochemical evidence of Vitamin A deficiency. All had been prescribed oral pancreatic enzyme replacements and twice the recommended daily requirement of Vitamin A (5000IU). None were aware of any ocular symptoms, but 3 out of 31 (10 per cent) were found to have frank conjunctival xerosis and six (19 per cent) to have abnormal dark adaptation. There was no correlation between the above findings and abnormal liver function or clinical disease severity. All patients with cystic fibrosis should have regular Vitamin A estimations with ophthalmological assessment if serum levels fall below 30 microgram/dl.

Adolescent↗

Cl(-)-dependent HCO3- transport by cystic fibrosis transmembrane conductance regulator.

Cystic fibrosis (CF) affects the function of multiple organs. The inability to maintain luminal hydration of ducts leads to their plugging and destruction of the affected organs. An exacerbating problem is the acidic pH of the fluid produced by CF patients' secretory glands. This is best documented for pancreatic secretion. Alkaline fluid secretion requires vectorial transport of electrolytes and of HCO(3)(-). The mechanism of HCO(3)(-) secretion by cystic fibrosis transmembrane conductance regulator (CFTR) expressing cells is not well understood. In the present communication we discuss results suggesting that CFTR itself can transport large amounts of HCO(3)(-) and that HCO(3)(-) transport by CFTR is mediated by a coupled, Cl(-)-dependent process that is different from a simple HCO(3)(-) conductance.

Chloride-Bicarbonate Antiporters↗

Aerosol scintigraphy in the assessment of therapy for cystic fibrosis.

Thirteen patients with cystic fibrosis (aged 11 to 32 years) who were hospitalized for exacerbation and who had sputum cultures positive for Pseudomonas organisms were treated initially for 4 days with bronchodilators and physiotherapy followed by the addition of antibiotic (14 days, n = 8) or placebo (14 days, n = 4; 7 days, n = 1). Tc-99m DTPA aerosol scintigraphy was performed on the day before bronchodilators and physiotherapy, on the day before antibiotic or placebo, and on the day after completion of antibiotic or placebo therapy. Scintigrams were evaluated for change in the number of nonventilated segments and change in the number of bronchial deposits of aerosol. Sixty-nine percent of patients showed improvement after bronchodilators and physiotherapy alone. Sixty-two percent showed further improvement after antibiotic or placebo was added; this improvement was independent of whether antibiotic or placebo was administered (P greater than 0.1). These aerosol scintigraphy results failed to demonstrate that the effectiveness of bronchodilators and physiotherapy is enhanced by antibiotics in the treatment of cystic fibrosis exacerbations.

Adult↗

Screening for cystic fibrosis and its evaluation.

Cystic fibrosis (CF) is a recessively inherited disorder for which screening has been proposed. A number of different screening strategies have been suggested, including prenatal, preconceptional, school and neonatal carrier screening, as well as screening of newborns to identify affected infants. We discuss the advantages and disadvantages of these strategies, and identify gaps in knowledge relevant to decisions to introduce a screening programme for cystic fibrosis. Screening to identify carriers during the newborn period or among school age children is inadvisable, mainly on psychosocial and cost-effectiveness grounds. Although early diagnosis of CF may improve prognosis, current scientific evidence is not sufficient to support screening newborns to identify affected infants. of the remaining two options, prenatal screening has a practical advantage because of existing facilities, while with screening before conception all reproductive options are, in principle, open to detected carrier couples. If adequate pre- and post-test counselling can be provided, both two types of screening could be introduced.

Cystic Fibrosis↗

Does that child really have cystic fibrosis?

A diagnosis of cystic fibrosis was incorrectly made after false-positive sweat tests in 14 children. 13 of these children had been tested at hospitals where it seems likely that sweat tests were not done very often. All the children had normal sweat-electrolyte values when the test was repeated at a regional paediatric centre where approximately 250 sweat tests are done each year. In 5 cases, detailed testing of pancreatic function was normal. None of the children had typical chest disease and only 2 had gastrointestinal symptoms. In the absence of the typical clinical features of the disease a diagnosis of cystic fibrosis should be made with extreme caution and only after meticulous testing of both sweat electrolytes and pancreatic function.

Amylases↗

Improved activity of an actin-resistant DNase I variant on the cystic fibrosis airway secretions.

In cystic fibrosis (CF), actin and DNA originating from inflammatory cells contribute to the thickness of airway secretions. Actin can bind to DNA-rich fibers and potently inhibit the enzymatic activity of rhDNase. The in vitro effects of the actin-resistant rhDNase variant (A114R) were analyzed and compared with those of the wild-type rhDNase. Frozen and thawed CF airway secretions were incubated for 30 min with different concentrations (0.1, 0.5, 1, 5, or 10 microg/ml) of either actin-resistant rhDNase or wild-type rhDNase. We observed that both the wild-type and the actin-resistant rhDNase significantly decreased (p < 0.05 and p < 0.001, respectively) the airway secretion viscosity. The decrease in airway secretion viscosity was significant even at low concentrations (0.1 microg/ml) of the actin-resistant variant. Incubation with the actin-resistant variant resulted in a significant decrease (p < 0.02) of the airway secretion contact angle and cough transport. A significantly higher (p < 0.01) increase in contact angle and cough transport of airway secretions was observed at 10 microg/ml with the actin-resistant variant as compared with the wild-type rhDNase. The present study had demonstrated that the actin-resistant rhDNase variant (A114R) has an enhanced capacity to improve the physical properties and cough transport of airway secretions from patients with cystic fibrosis.

Actins↗

Cystic fibrosis in South India.

Cystic fibrosis has been diagnosed during life in three South Indian infants on the basis of characteristic clinical features and a positive sweat test. The patients were respectively 81 days, 23 days and 6 months old. All three presented with the rare characteristic triad of gross oedema, hypoproteinaemia and moderate to severe anaemia; it is described for the first time from South India. Three patients were exclusively breast-fed; the third received complements of diluted cow's milk. Sweat sodium and chloride were elevated in the first two cases and was normal in the third. All three died with progressive deterioration 10, 31 and 7 days respectively after admission in the hospital. At autopsy, changes typical of cystic fibrosis were present in pancreas, lung, liver and the small intestine of one, in the lungs of the second and in pancreas and liver of the third case.

Cystic Fibrosis↗

Therapeutic drug monitoring in patients with cystic fibrosis and mycobacterial disease.

Cystic fibrosis (CF) patients require higher dosages of many antibiotics. The relapse of tuberculosis in one CF patient, and the repeated growth of Mycobacterium avium-intracellulare in another, despite conventional therapy, raised the question of whether the serum levels of the antimycobacterial drugs were adequate. Antimycobacterial drug serum concentrations were assayed in 10 CF patients with pulmonary mycobacterial disease. Serum levels below the proposed target range were seen 2 h after drug intake in the initial four patients treated: for rifampicin in 2/3, ethambutol in 3/4 and for clarithromycin in 2/3 patients, despite standard dosages. Reassays after dose adjustment and assays in six other patients showed that adequate levels were not achieved 4 h after clarithromycin in 3/5, ethambutol in 1/5, ciproflaxacin in 1/2 and ofloxacin in 2/2 patients. The patient with relapse of tuberculosis and the patient with continuous growth of M. avium-intracellulare improved and became culture negative after dose adjustment. Low drug serum levels is one reason for therapy failure in cystic fibrosis patients with mycobacterial disease. Therapeutic drug monitoring is recommended.

Adolescent↗

A Japanese adult case of cystic fibrosis causing bone demineralization.

Cystic fibrosis is an inherited, multisystem disorder characterized by an abnormality in exocrine gland function. It leads to chronic pulmonary disease in most cases and pancreatic insufficiency in 85 percent of patients. Although this disease is not uncommon in Caucasians, it has been considered very rare among Japanese. The majority of patients are diagnosed in infancy or childhood. The patient in this case report was a 45-year-old Japanese man who had not been diagnosed as having cystic fibrosis. This patient had recurrent episodes of pulmonary infection that started in childhood, and plain films of the chest showed increased interstitial markings, hyperaeration, and bronchiectasis. CT of the upper abdomen showed a generally enlarged pancreas with complete fatty replacement. Serum and urine pancreatic enzyme levels were low, suggesting pancreatic insufficiency. Repeated sweat tests were positive. A roentgenologic skeletal survey showed general demineralization, which may be multifactorial. In this case, it was concluded that vitamin D deficiency caused by vitamin D malabsorption and/or insufficient sunlight exposure was mainly responsible for the demineralization and that chronic respiratory acidosis might also be partially responsible.

Bone and Bones↗

Short-term clinical, nutritional, and functional effects of continuous elemental enteral alimentation in children with cystic fibrosis.

Ten children with cystic fibrosis, aged 3.5 to 12 years, whose weights were lower than 90% of the expected weight for height, received high-calorie elemental enteral alimentation for four weeks. Clinical, anthropometric, and biochemical evaluations as well as blood gas analyses and chest radiograph scoring were performed in all. Pulmonary function tests were performed in the five older children, and progressive exercise tests in three. These evaluations were done before, immediately after, and two months after termination of therapy. Nutritional therapy resulted in an increase of caloric intake and in dramatic weight gain, which persisted only for a short time and was mainly related to adipose tissue accretion. No functional improvement accompanied the amelioration in nutritional status. This short-term nutritional therapy in malnourished children with cystic fibrosis was effective in increasing relative weight and energy stores, but there was no evidence of any long-term functional benefit.

Blood Chemical Analysis↗

Effect of hypertonic saline, amiloride, and cough on mucociliary clearance in patients with cystic fibrosis.

In patients with cystic fibrosis (CF), dehydration of airway secretions leads to a decrease in mucociliary clearance (MCC). We examined the acute effect of MCC of a single administration by aerosolization of hypertonic saline (7%) (HS), amiloride (0.3% in 0.12% NaCl) (AML) and a combination of AML and HS (AML + HS) in 12 patients with CF using a radioaerosol technique. Isotonic saline [0.9%] (IS) was used as a control solution. As both the AML and HS solutions induced cough in some patients, the last nine patients studied also underwent a cough clearance day. This was to eliminate the possible confounding effect of cough on MCC measurement. Patients ranged from 18 to 28 yr (mean +/- SD, 22 +/- 3) with an FEV1 of 27 to 112% predicted (61 +/- 30%). Following deposition of the radioaerosol, baseline clearance was assessed for 30 min. This was followed by a 30-min intervention period. Assessment of post-intervention clearance for a further 30 min was then performed. Comparison of the amount of radioaerosol cleared from the right lung was made at 60 min (%C60) and 90 min (%C90) using repeated measures ANOVA. The percent cleared at 60 and 90 min was significantly increased with HS (%C60 = 26.5%, %C90 = 29.4%) and the combination of AML + HS (%C60 = 23.1%, %C90 = 27.4%) compared with both IS (%C60 = 14.7%, %C90 = 17.5%) and COUGH (%C60 = 18.0%, %C90 = 19.5%), p < 0.01. Inhalation of hypertonic saline is a potentially useful treatment in patients with cystic fibrosis.

Adolescent↗

Early diagnosis of cystic fibrosis in Jordanian children.

Cystic fibrosis (CF) is the most common fatal genetic disease in childhood. The high infant mortality rate in Jordan and many other developing countries is mostly due to an increased prevalence of malnutrition, diarrhoeal diseases, and chest infections, which are also recognized clinical features of CF. Reports of CF among Arabs in neighbouring countries have stimulated clinical studies to evaluate the prevalence and incidence of this disease among Jordanian children. In a prospective study, 7682 neonates from 10 different hospitals in Jordan were screened for CF using the BM test for meconium albumin. Four cases gave a positive reaction to BM test strips. Cystic fibrosis was confirmed in three by sweat chloride test using pilocarpine iontophoresis. This represents an incidence of 1:2560 live births. In spite of the recognized limitations for the use of the BM test on meconium for mass screening of CF, this study has contributed to the increased awareness of the occurrence of CF among Jordanian children.

Albumins↗