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Biomedical subjects

M X FitzGerald

Publications and source records attributed to M X FitzGerald.

At least 37 records · Page 2Linked to original sources
PubMed1996

Elastin and collagen remodeling in emphysema. A scanning electron microscopy study.

The relationship between elastin degradation and emphysema is well known. Recent evidence suggests that a complex process of pulmonary remodeling occurs within the emphysematous lung. The aim of this study was to assess the extent of extracellular matrix remodeling in emphysema by ultrastructural examination of elastin and collagen templates in an animal model of emphysema and in human emphysematous lungs. Emphysema was induced in rats by the intratracheal administration of porcine pancreatic elastase. Human lung samples were obtained at surgical resection for lung carcinoma. Emphysema was confirmed morphometrically and quantitated using the mean linear intercept. Matching sections were treated with sodium hydroxide and formic acid to expose collagen and elastin templates, respectively. Scanning electron microscopy with stereo-pair imaging allowed three-dimensional visualization of the exposed templates. In emphysematous lungs from both sources, sheets of elastin were disrupted and perforated with multiple fenestrations. In elastase-induced emphysema, this disintegration was accompanied by a marked increase in thickness of collagen fibrils, which contrasted with the fine fibrillar network of control lungs. Similarly, a pattern of thickened fibrils and disorganized deposition of collagen was observed in human lungs. In conclusion, these findings support the novel concept of increased collagen deposition and aberrant collagen remodeling in the pathogenesis of emphysema.

Animals↗
PubMed1995

Paradoxical vocal cord adduction in an adolescent with cystic fibrosis.

Many patients with cystic fibrosis have symptoms of dyspnoea and wheeze which are responsive to treatment with bronchodilators. An adolescent woman with cystic fibrosis is described who presented with inspiratory stridor and in whom the classical features of paradoxical vocal cord adduction were found.

Adolescent↗
PubMed1995

Three cases of pulmonary aspergilloma in adult patients with cystic fibrosis.

Pulmonary aspergillomas usually occur when Aspergillus fungi colonise lung tissue previously damaged by disease. Pulmonary aspergillomas in three adult patients with cystic fibrosis are reported--an association not previously described. At the time of diagnosis all three patients had previous long term colonisation with Aspergillus fumigatus and severe advanced destructive lung disease with lung function less than 25% of the predicted normal values. It is likely that, with increasing survival in cystic fibrosis, more adult patients will develop aspergillomas during the protracted phase of end stage lung disease that characterises the terminal years of this condition.

Adult↗
PubMed1995

Familial cryptogenic fibrosing pleuritis with Fanconi's syndrome (renal tubular acidosis). A new syndrome.

We describe two siblings with a progressive unrelenting and unique syndrome of bilateral fibrosing pleuritis of unknown cause occurring in association with Fanconi's syndrome (renal tubular acidosis). The parents of the siblings were second cousins. Both siblings had identical pleural histologic characteristics and identical urinary metabolic defects. This condition resulted in the development of severe respiratory failure in both patients and ultimately the death of the older sibling at the age of 21 years.

Acidosis, Renal Tubular↗
PubMed1994

Amnesic syndrome after theophylline associated seizures: iatrogenic brain injury.

Two patients developed a disabling amnesic syndrome after seizures associated with oral theophylline treatment. Such seizures are more likely in the elderly, in the presence of pre-existing neurological disease, and when theophylline is given with certain antibiotics and cimetidine. The mechanism of neuronal injury may be by the excessive release of endogenous excitotoxic glutamate.

Adolescent↗
PubMed1994

Neutrophil collagenase in sputum from patients with cystic fibrosis.

The potential role of neutrophil elastase in causing lung damage and exacerbating the inflammatory response in cystic fibrosis (CF) has received considerable attention. Although another potent neutrophil-derived enzyme, collagenase, is implicated in tissue destruction in several interstitial lung disorders, there has been no reference to this enzyme in CF. The objective of this study was to determine whether neutrophil collagenase is present in active form in CF sputum and, if so, whether it is related to disease severity. High levels of active collagenase were detected in sputum from patients with CF, and the majority of the enzyme present was of neutrophil origin. In a group of 16 patients with CF, negative relations between sputum collagenase activity and Shwachman score (r = -0.55, p < 0.05) and FEV1 (r = -0.59, p < 0.02) were noted, indicating an association between high collagenase activity and severity of disease. A positive correlation was observed between sputum collagenase and elastase activity (r = 0.62, p < 0.05). These results suggest that both neutrophil elastase and collagenase may play a significant role in lung destruction in CF.

Adolescent↗
PubMed1994

Pseudomonas aeruginosa exotoxin A induces pulmonary endothelial cytotoxicity: protection by dibutyryl-cAMP.

In pseudomonal septicaemia, serum levels of antibody to exotoxin A have been demonstrated to be an important independent predictor of survival. Previously, we have demonstrated that exotoxin A directly injures pulmonary endothelial cells, and that dibutyryl-cyclic adenosine monophosphate (Db-cAMP) can attenuate this injury. The object of this study was to examine the mechanisms of this pulmonary endothelial cell injury and the mechanism of Db-cAMP protection. The effects of differing duration of exposure to exotoxin A and a reduction in temperature on endothelial cell injury were examined. In addition, the effect of post-treatment with Db-cAMP on exotoxin A-induced endothelial cell injury was studied. A brief, 5 min, exposure to exotoxin resulted in maximum injury comparable to that produced by 18 h exposure. This injury did not occur at low temperatures, which would inhibit receptor-mediated endocytosis. Db-cAMP protected endothelial cells, even when added up to one hour after exotoxin exposure. These results suggest that, in this model, exotoxin A-induced injury of endothelial cells is receptor-mediated. Furthermore, this injury may be attenuated even after exotoxin A internalization has taken place.

ADP Ribose Transferases↗
PubMed1993

Intestinal bile acid malabsorption in cystic fibrosis.

This study aimed at examining the mechanisms participating in excessive faecal bile acid loss in cystic fibrosis. The study was designed to define the relation between faecal fat and faecal bile acid loss in patients with and without cystic fibrosis related liver disease; to assess terminal ileal bile acid absorption by a seven day whole body retention of selenium labelled homotaurocholic acid (SeHCAT); and to determine if small intestinal bacterial overgrowth contributes to faecal bile acid loss. The study population comprised 40 patients (27 men; median age 18 years) with cystic fibrosis (n = 8) and without (n = 32) liver disease and eight control subjects. Faecal bile acid excretion was significantly higher in cystic fibrosis patients without liver disease compared with control subjects (mean (SEM) 21.5 (2.4) and 7.3 (1.2) micromoles/kg/24 hours respectively; p < 0.01) and patients with liver disease (7.9 (1.3) micromoles/kg/24 hours; p < 0.01). No correlation was found between faecal fat (g fat/24 hours) and faecal bile acid (micromoles 24 hours) excretion. Eight (33%) of cystic fibrosis patients had seven day SeHCAT retention < 10% (normal retention > 20%). SeHCAT retention in cystic fibrosis patients with liver disease was comparable with control subjects (30.0 (SEM) 8.3% v 36.8 (5.9)%; p = NS) while SeHCAT retention in cystic fibrosis patients who did not have liver disease was significantly reduced (19.9 (3.8); p < 0.05). Although evidence of small bowel bacterial overgrowth was present in 40% of patients no relation was found between breath hydrogen excretion, faecal fat, and faecal bile acid loss. The results are consistent with the presence of an abnormality in terminal ideal function in patients with cystic fibrosis who do not have liver disease and that a defect in the ileal absorption of bile acids may be a contributory factor to excessive faecal bile acid loss. Faecal bile acid loss in cystic fibrosis is unrelated to the presence of intraluminal fat or intestinal bacterial overgrowth.

Adolescent↗
PubMed1993

Amyloidosis complicating cystic fibrosis.

Two patients with cystic fibrosis developed acute onset nephrotic syndrome and died within three months of presentation. Examination of renal biopsy specimens indicated amyloid. The onset of proteinuria or a fall in baseline renal function should alert the physician to this rare complication.

Adolescent↗
PubMed1993

Chronic eosinophilic pneumonia. A long-term follow-up of 12 patients.

Chronic eosinophilic pneumonia (CEP) is a rare disorder of unknown etiology characterized by striking systemic and pulmonary manifestations such as fever, weight loss, blood eosinophilia, characteristic fluffy peripheral opacities on chest radiograph, and a prompt response to corticosteroid therapy. While the initial phase has been well documented, there is very limited information concerning the long-term natural history and treated course of this condition. We report the clinical and laboratory findings together with the long-term follow-up data on 12 patients with classic CEP who were followed up for a mean of 10.2 years (range, 4 to 13 years). The most striking feature of the long-term follow-up was the occurrence of relapses of CEP (often on multiple occasions) when corticosteroid therapy was discontinued or the dose was tapered. In those nine patients in whom steroid withdrawal was commenced, there was a clinical, hematologic, and radiologic relapse in seven (58 percent). However, prompt reinstitution of therapy led to a rapid resolution of symptoms. By contrast, two patients (17 percent) showed no evidence of relapse when steroid therapy was discontinued. A further three patients (25 percent) are maintained on a regimen of low-dose steroid therapy with no episodes of relapse. Reassuringly, all 12 patients are well at the end of a long period of follow-up. These data suggest that the long-term prognosis for patients with CEP is excellent but the majority will require long-term low-dose oral corticosteroid therapy in order to prevent relapse.

Adolescent↗
PubMed1993

Three cases of paradoxical vocal cord adduction followed up over a 10-year period.

Paradoxical vocal cord adduction (PVCA) is a rare disorder that may present with symptoms similar to asthma. Incorrect diagnosis may result in patients being unwittingly treated with prolonged high doses of antiasthma medication. PVCA probably forms part of a spectrum of uncommon and complex breathing disorders related to laryngeal dysfunction. Herein, we describe three cases of PVCA that illustrate the spectrum of clinical and physiologic presentation and the long-term natural history over a 10-year follow-up period. We conclude that PVCA, contrary to previous reports, is not always a benign condition; it may feature marked hypoxemia, fail to respond to previously advocated therapeutic strategies, and can persist on a long-term basis.

Adult↗
PubMed1992

Deletion delta F508 and clinical expression of cystic fibrosis-related liver disease.

A study of liver function in 108 adult cystic fibrosis patients showed that 20 had established liver disease, and that these had significantly better pulmonary function than the subgroup without liver disease. The relative risk of liver disease for homozygotes vs heterozygotes was 2:1 in our series. Four of the liver patients had a sibling with CF, but three of the sibships were discordant for liver disease. Environmental or genetic factors other than the deletion Delta F508 may influence the development of cystic fibrosis-related liver disease.

Adolescent↗
PubMed1991

Bacteraemia and fungaemia in adults with cystic fibrosis.

The incidence of bacteraemia and fungaemia was determined in 29 adults with cystic fibrosis (CF) during 50 consecutive admissions to hospital for management of infective exacerbations of pulmonary disease. Blood was drawn for aerobic, anaerobic and fungal cultures from all patients who were febrile on admission or who became febrile during treatment. The population included eight patients who had indwelling venous access systems in situ. The overall incidence of positive blood cultures in febrile patients was 3.5% [95% confidence interval (C.I.), 1-6%]. We recorded one case of Pseudomonas aeruginosa bacteraemia and two cases of Candida albicans fungaemia. The patient with P. aeruginosa bacteraemia died 5 days after isolation of the organism from her blood. The two patients with C. albicans bacteraemia had totally implantable venous access systems (TIVAS) in situ and both recovered following appropriate therapy. These observations suggest that bacteraemia is rare in patients with CF but that there is a significant risk of fungaemia in a susceptible minority. The implications of these findings, as they relate to management of infections and care of indwelling catheters in such patients, are discussed.

Adolescent↗