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Biomedical subjects

C I Jack

Publications and source records attributed to C I Jack.

At least 19 recordsLinked to original sources

Effect of antioxidant supplementation on the adaptive response of human skin fibroblasts to UV-induced oxidative stress.

The effect of supplementation with substances having antioxidant properties on the adaptive responses of human skin fibroblasts to UV-induced oxidative stress was studied in vitro. UVR was found to induce a substantial oxidative stress in fibroblasts, resulting in an increased release of superoxide anions and an increase in lipid peroxidation (shown by an elevated malonaldehyde content). Sub-lethal doses of UVR were also found to induce adaptive responses in the fibroblast antioxidant defences, with a transient rise in catalase and superoxide dismutase activities followed by a slower, large increase in cellular glutathione content. Supplementation of the fibroblasts with the antioxidants, Trolox (a water soluble analogue of alpha-tocopherol), ascorbic acid or beta-carotene, had differential effects on these responses. Trolox supplementation reduced the UVR-induced cellular oxidative stress and adaptive response in a predictable concentration-dependent manner. This was in contrast to ascorbic acid which increased superoxide release from fibroblasts. At low doses, ascorbate supplements also reduced the magnitude of the adaptive increases in catalase and superoxide dismutase activities and increase in glutathione content. Beta-carotene had a similar effect to ascorbic acid, reducing the extent of the adaptations to UVR at lower doses while simultaneously increasing superoxide release and malonaldehyde content. These in vitro data indicate that only the vitamin E analogue suppressed UVR-induced oxidative stress in a predictable manner and suggest that common dietary antioxidants may not be equally effective in reducing the potential deleterious effects of UVR-induced oxidative stress in skin.

Adaptation, Physiological↗

Surgery for lung cancer: age alone is not a contraindication.

A retrospective analysis of the clinical features, operative procedures, postoperative complications and subsequent survival of 70 (50 male) elderly patients undergoing surgery for lung cancer compared with 74 (53 male) younger patients treated at the same hospital during the same period was performed, to determine if elderly people with lung cancer are less likely to benefit from and/or tolerate surgery. The elderly group had to wait longer for operation (p = 0.001) and were more likely to have pre-existing disease (p = 0.019). In contrast, they had fewer recognised postoperative complications (p = 0.032) and there was no difference between the two groups in perioperative mortality and subsequent survival. Surgical treatment of localised lung cancer represents the best chance for cure and this study suggests that age should not be a consideration in the decision to operate or not. The patient's general state of health should be assessed and management decisions based on individual status rather than on age.

Adult↗

Indicators of free radical activity in patients developing radiation pneumonitis.

PURPOSE: Radiation pneumonitis is thought to occur as the result of excess free radical generation following radiotherapy. Various in vitro studies have shown that large doses of irradiation can cause membrane lipid peroxidation and the oxidation of protein sulphuryl groups. We, therefore, studied two circulating markers of lipid peroxidation and an indicator of "catalytic iron" (potentially available iron to catalyze the generation of free radicals) in patients undergoing radiotherapy. METHODS AND MATERIALS: The 9,11 diene conjugate of 9,12 linoleic acid, expressed as their molar ratio (percentage molar ratio (MR)) and thiobarbituric acid reactive acid-substances (TBARS), as well as levels of circulating desferrioxamine-chelatable iron assay, were assayed. Serial blood samples were taken over a 3-month period in 25 patients with inoperable nonsmall cell lung cancer. RESULTS: Ten patients developed radiation pneumonitis. The patients who developed pneumonitis showed a tendency for the serum percentage molar ratio to increase after a week. The change in the percentage molar ratio between Time 0 and 1 week of radiotherapy was significantly higher in the group that subsequently developed pneumonitis compared to the group that did not (p = 0.002). The initial serum TBARS levels in patients were not significantly elevated compared to controls and there was no difference in the serum TBARS levels in the pneumonitis and nonpneumonitis groups throughout the study period. After 1 week of radiotherapy the group that subsequently developed pneumonitis had a significantly higher level of desferrioxamine-chelatable iron (DFx-iron) compared with the nonpneumonitis group (p = 0.05). CONCLUSION: These data suggest that both the percentage MR and DFx-iron appear to reflect an increased susceptibility to develop radiation pneumonitis and after 1 week of radiotherapy they indicate patients who are likely to subsequently develop pneumonitis. Hence, these indicators could indicate the group of patients that could benefit from intervention therapies with antioxidants.

Adult↗

Use of restraints and bedrails in a British hospital.

OBJECTIVE: To determine the prevalence of restraint and bedrail use in a British hospital. DESIGN: Cross-sectional observational study. SUBJECTS: Six hundred sixty-eight patients in the acute medical, surgical, and geriatric beds of a large British teaching hospital on a single night. MEASUREMENTS: Observed use of restraints and bedrails. Reasons for restraint use were determined by interviews with nursing staff and examination of the case notes. RESULTS: Fifty-six (8.4%) patients had bedrails raised. No other restraints were in use. Reported indications for bedrail use were: prevention of falls (52 patients), prevention of wandering (1), and patient request (3). In stepwise logistic regression analysis, bedrail use was associated significantly with agitated confusion, age 70 years or more, and stroke, while patients on the acute geriatric wards were significantly less likely to have bedrails raised. CONCLUSIONS: Restraint use is relatively uncommon in Britain. Nevertheless, inappropriate use of bedrails is a reason for concern.

Accidental Falls↗

Asthma in the elderly patient.

Asthma is common in old age and carries significant morbidity and mortality. Most deaths due to asthma occur in old people. Often the diagnosis of asthma is overshadowed by other medical problems such as heart failure and emphysema, and thus elderly people may not receive optimal treatment. The treatment of an elderly patient with asthma is further complicated by concomitant disease and pharmacological interactions.

Aged↗

Serum indicators of free radical activity in idiopathic pulmonary fibrosis.

Serum levels of free radical activity were measured in 37 patients with idiopathic pulmonary fibrosis (IPF) and 16 control subjects. Three assays used were (1) simultaneously measured levels of the 9,11-diene conjugate of linoleic acid and 9,12-linoleic acid expressed as a percent molar ratio (%MR), a measure of free-radical-mediated lipid peroxidation; (2) thiobarbituric acid reactive substances (TBARS), one of which is malondialdehyde; (3) desferrioxamine-chelatable iron assay, a measure of the potential iron available to catalyze free radical generation. Mean %MR, TBARS and desferrioxamine-chelatable iron were all elevated initially in patients with IPF compared with control subjects (%MR, p < 0.0001; TBARS, p = 0.0013; desferrioxamine-chelatable iron, p = 0.0029). Furthermore, the serum %MR was higher in a subset of patients with clinically worsening IPF than in those patients with clinically stable disease (p = 0.002). Treatment did not appear to affect the three different serum indicators of free radical activity. Thus, lipid peroxidation appears to be increased in patients with IPF and is associated with an increase in desferrioxamine-chelatable iron levels. Serum % MR levels appeared to correlate with clinical disease activity, and they may have a role in monitoring disease activity.

Aged↗

Legionnaires' disease--a potential hazard of rationalisation.

The cases of two elderly patients who complained of general malaise after they had undergone ward transfer (due to rationalisation of the rehabilitation service) are discussed. Both were pyrexial and had signs of pneumonic consolidation. Subsequent investigation revealed that their symptoms were due to infection with Legionella pneumophila. Their cases highlight the problems associated with ward closures and the hazards of stagnant water.

Aged↗

The use of expandable metal stents for large airway obstruction in older patients.

OBJECTIVE: To review the indications, management, and outcome of 30 older patients who had expandable metal stents inserted for large airway obstruction. DESIGN: Information was collected retrospectively from case notes about presentation, radiographic appearances, pulmonary function, including arterial oxygen tension, and histology. Survival data were collected by reviewing hospital or General Practice records. MEASUREMENTS: Spirometry, peak expiratory flow rate, and blood gases were recorded before and after stent insertion. MAIN RESULTS: There was a significant improvement in the patient's mean forced expiratory volume in 1-second (FEV1) and mean peak expiratory flow rate (PEFR). The arterial oxygen tension (pO2) increased from 8.6 Kpa to 10.6 Kpa. The mean length of survival for the whole group was just under 5 months. CONCLUSIONS: Airway stenting for obstruction provides palliative and functional benefits in these severely disabled patients and a consequent improvement in quality of remaining life.

Aged↗

Simultaneous tracheal and oesophageal pH measurements in asthmatic patients with gastro-oesophageal reflux.

BACKGROUND: An association between asthma and gastro-oesophageal reflux is well recognised but the underlying mechanism is unclear. One suggestion is that gastric juice is aspirated into the tracheal and upper airways but detection of these events is difficult and involves radioisotopic studies. A new method of making direct measurements of tracheal and oesophageal pH over a 24 hour period is described, together with its application to patients with asthma. METHODS: The technique involves insertion of simultaneous tracheal and oesophageal pH probes under general anaesthesia. Continuous monitoring of pH over a 24 hour period is possible, permitting comparison with peak flow readings during wakefulness and at night should the patient be disturbed. Representative data from four patients with asthma (mean FEV1 62% predicted) and symptomatic gastro-oesophageal reflux, together with data from three non-asthmatics, is presented. RESULTS: Thirty seven episodes of gastro-oesophageal reflux lasting more than five minutes were recorded. Of these, five were closely followed by a fall in tracheal pH from a mean (SE) of 7.1 (0.2) to 4.1 (0.4) and a fall in peak expiratory flow (PEFR) of 84 (16) l/min. When gastro-oesophageal reflux occurred without tracheal aspiration the fall in PEFR was 8 (4) l/min. CONCLUSIONS: This new technique was well tolerated and allowed quantitation of the number, duration, and timing of episodes of tracheal micro-aspiration. Unlike acid reflux without aspiration, these events appear to be related to significant acute changes in lung function in asthmatic patients. Further studies with this new method may elucidate the role of gastro-oesophageal reflux in asthma.

Asthma↗

Prevalence of low vision in elderly patients admitted to an acute geriatric unit in Liverpool: elderly people who fall are more likely to have low vision.

The prevalence of visual impairment among elderly patients admitted to hospital is unknown. This group of patients may be particularly at risk from poor vision which could jeopardise their independence. A prospective study of visual imapairment and its aetiology in acute geriatric admissions assessed after the acute illness had settled was performed. Subjects were all patients aged 65 years or over, excluding those chronically confused, admitted to the Department of Geriatric Medicine at the Royal Liverpool University Hospital with an acute medical illness. After the acute illness had settled visual impairment, as defined by the American criteria (best acuity 6/18), was assessed on the ward with a Snellen chart read at 6 m using binocular vision and current glasses. Those patients identified with impaired vision on initial screening were formally assessed in the ophthalmology department to identify the cause. 200 patients were examined. 101 patients (50.5%) had impaired vision. In these patients, correctable refractive errors were present in 40%, cataract in 37% and senile macular degeneration in 14%. Of the 101 patients with impaired vision 79% had a reversible cause. Comparing these results with a recent study in the community showed a much higher incidence for patients admitted to hospital. There was a particularly high prevalence in those elderly patients who were admitted with falls (76%, p = 0.0003). In conclusion, elderly patients, especially those presenting with falls, admitted to hospital have a high prevalence of visual impairment. Visual impairment may be compounding or causing falls.(ABSTRACT TRUNCATED AT 250 WORDS)

Accidental Falls↗

A comparison of two techniques for ankle jerk assessment in elderly subjects.

The reported prevalence of absent ankle jerks in elderly people varies greatly. This variation may be due to differences in the method of testing. Eight physicians examined 12 patients for the presence of ankle jerks using two techniques: plantar strike and tendon strike. Both intra-observer agreement (kappa 0.47 vs 0.20; p = 0.01) and inter-observer agreement (0.57 vs 0.21; p < 0.001) were greater with plantar strike. Reliability of ankle jerk assessment was greater for more experienced examiners. Differences in technique may explain some of the discrepancy between studies examining the prevalence of absent ankle jerks in elderly people.

Aged↗

Serum octadeca-9,11 dienoic acid--an assay of free radical activity or a result of bacterial production?

The diene conjugated linoleic acid isomer is currently used as an assay of free radical activity, but recent studies have cast doubt on the specificity of the assay. Therefore, 180 strains of common bacterial lung pathogens were studied to determine whether they could produce the diene conjugated isomer of linoleic acid in vitro. The various strains were grown in tissue culture fluid spiked with linoleic acid. Concentrations of the diene conjugated 18:2 [9,11] linoleic acid isomer and the parent compound, 18:2 [9,12] linoleic acid were then determined using a high performance liquid chromatography method. The percentage molar ratio of these two isomers was found to be significantly elevated in 12.8% of all bacterial strains examined. In contrast the thiobarbituric acid reactivity, a non-specific measure of lipid peroxidation, was not elevated in any of the strains incubated in an identical fashion. These results suggest that the diene conjugated linoleic assay may not be a reliable marker of the free radical processes in the lung in the presence of certain bacterial infections.

Bacteria↗

Circulating markers of free radical activity in patients with pulmonary tuberculosis.

SETTING: Toxic free radicals have been implicated in the development of lung fibrosis which may be a long-term sequela of pulmonary tuberculosis. OBJECTIVE: To measure circulating indicators of free radical activity in patients with pulmonary tuberculosis in order to determine whether patients with active pulmonary TB have elevated levels of circulating free radical activity, and whether these levels correlated with disease activity as determined by other blood markers of inflammation. DESIGN: 17 patients with active pulmonary tuberculosis were studied. Serial serum levels of 3 assays of free radical activity were measured at diagnosis (17 patients), and over a 2-7 month period on chemotherapy (8 patients). 3 patients with active lymph node tuberculosis were also studied and 4 patients with old lung scarring from previously treated tuberculosis had their serum markers analysed. RESULTS: All 3 serum markers of free radical activity were elevated in patients with active pulmonary tuberculosis. During serial measurement in 8 patients the % molar ratio of 9,11 linoleic acid/9,12 linoleic acid fell progressively with treatment. Thiobarbituric acid reactive substances (TBARS) were initially elevated in 6/8 patients and remained elevated despite treatment. In 2 patients TBARS were in the normal range at presentation but subsequently rose with treatment. Desferrioxamine-chelatable iron was initially normal in all but 1 patient, remained normal in 2 patients, rose in 4 patients and fell in 1 patient. CONCLUSIONS: These results suggest that increased circulating levels of free radical activity are found in active pulmonary tuberculosis and hence may play a role in the resultant fibrosis. It also reinforces the belief that a range of free radical activity (FRA) indicators are produced in any inflammatory process with fibrogenic potential and that these indicators may be measuring different stages of the disease process.

Adolescent↗

Twenty-four-hour tracheal pH monitoring--a simple and non-hazardous investigation.

Prolonged oesophageal pH monitoring is commonly used in the investigation of gastro-oesophageal reflux. In contrast, tracheal pH monitoring is virtually unknown. We report a simple technique of measuring tracheal pH where the pH probe is inserted under local anaesthetic and can be left in position for 24 h to allow prolonged monitoring. Ten control individuals were studied. All completed the study without complication. One patient with mixed connective tissue disease, failed hiatal hernia repair and subsequent recurrent aspiration pneumonia was studied, on and off ranitidine, using simultaneous tracheal and oesophageal pH monitoring. This method showed evidence of gastro-oesophageal reflux and tracheal aspiration off treatment. When repeated with the patient taking ranitidine, the frequency of significant gastro-oesophageal reflux was reduced and no episodes of tracheal acid aspiration were recorded. Prolonged tracheal pH monitoring is a simple and non-hazardous technique. It is sensitive in detecting tracheal aspiration and may be more sensitive than pre-existing radiolabelled isotope techniques.

Esophagus↗

Simple cytokeratins in the serum of patients with lung cancer: relationship to cell death.

An important role in differentiation and proliferation has been demonstrated for the 20 cytokeratin (CK) polypeptides. The serum of 24 patients with biopsy-proven non-small cell lung cancer (NSCLC) and a similar number of controls was examined for evidence of CK8 and CK18. Using enzyme-linked immunosorbent assay (ELISA), all the control sera were negative, but 9 of the 24 patients were positive (mean 2.62 ng/ml; range 1.4-5.8; P = 0.0036). Western blotting confirmed the results of the ELISA in all cases, and indicated full size CK polypeptides. Advanced stage disease patients were more likely to be seropositive (P = 0.00024). Biopsy specimens showed CK8 expression in all 24 cases by immunochemistry and CK18 in 22 cases. This is the first study to demonstrate that a subgroup of NSCLC patients have intact CK8 and CK18 peptides in their serum, and their detection may correlate with advanced disease.

Adenocarcinoma↗