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J Barton

Publications and source records attributed to J Barton.

At least 19 recordsLinked to original sources
PubMed1995

Cigarette smoking, tar yields, and non-fatal myocardial infarction: 14,000 cases and 32,000 controls in the United Kingdom. The International Studies of Infarct Survival (ISIS) Collaborators.

OBJECTIVES: To assess the effects of cigarette smoking on the incidence of non-fatal myocardial infarction, and to compare tar in different types of manufactured cigarettes. METHODS: In the early 1990s responses to a postal questionnaire were obtained from 13,926 survivors of myocardial infarction (cases) recently discharged from hospitals in the United Kingdom and 32,389 of their relatives (controls). Blood had been obtained from cases soon after admission for the index myocardial infarction and was also sought from the controls. 4923 cases and 6880 controls were current smokers of manufactured cigarettes with known tar yields. Almost all tar yields were 7-9 or 12-15 mg/cigarette (mean 7.5 mg for low tar (< 10 mg) and 13.3 for medium tar (> or = 10 mg). The cited risk ratios were standardised for age and sex and compared myocardial infarction rates in current cigarette smokers with those in non-smokers who had not smoked cigarettes regularly in the past 10 years. RESULTS: At ages 30-49 the rates of myocardial infarction in smokers were about five times those in non-smokers (as defined); at ages 50-59 they were three times those in non-smokers, and even at ages 60-79 they were twice as great as in non-smokers (risk ratio 6.3, 4.7, 3.1, 2.5, and 1.9 at 30-39, 40-49, 50-59, 60-69, 70-79 respectively; each 2P < 0.00001). After standardisation for age, sex, and amount smoked, the rate of non-fatal myocardial infarction was 10.4% (SD 5.4) higher in medium tar than in low tar cigarette smokers (2P = 0.06). This percentage was not significantly greater at ages 30-59 (16.6% (7.1)) than at 60-79 (1.0% (8.5)). In both age ranges the difference in risk between cigarette smokers and non-smokers was much larger than the difference between one type of cigarette and another (risk ratio 3.39 and 3.95 at ages 30-59 for smokers of similar numbers of low and of medium tar cigarettes, and risk ratio 2.35 and 2.37 at ages 60-79). Most possible confounding factors that could be tested for were similar in low and medium tar users, with no significant differences in blood lipid or albumin concentrations. CONCLUSION: The present study indicates that the imminent change of tar yields in the European Union to comply with an upper limit of 12 mg/cigarette will not increase (and may somewhat decrease) the incidence of myocardial infarction, unless they indirectly help perpetuate tobacco use. Even low tar cigarettes still greatly increase rates of myocardial infarction, however, especially among people in their 30s, 40s, and 50s, and far more risk is avoided by not smoking than by changing from one type of cigarette to another.

Adult↗
PubMed1995

Recovery from work shifts: how long does it take?

Although regulations on work hours usually include a minimum weekly rest period, there is little empirical evidence concerning recovery from work. Shift-working nurses (N = 61) used a handheld computer for 28 days to complete self-ratings, cognitive-performance tasks, and a sleep diary. Many measures were worse on rest days that followed a night shift rather than a day shift and tended to be worse on first rest days compared with subsequent rest days. Alertness was lowest on the 1st rest day following a night shift. Social satisfaction was better on workdays that were preceded by 2 rather than 1 rest day. Reaction time decreased over consecutive night shifts and tended to increase over rest days following night shifts. The results are interpreted as being consistent with the combined adaptive costs of fatigue and adjustment to and from a nocturnal routine. The practical implications for scheduling rest days are considered.

Adult↗
PubMed1995

The use of survey measures to assess circadian variations in alertness.

Current models of sleep regulation postulate both a homeostatic and circadian component and promise an understanding of disturbed and displaced sleep. Estimates of these components have traditionally required relatively cumbersome and costly measures, including sleep electroencephalograms and continuously recorded rectal temperature, but it has recently been demonstrated that they may successfully be based on frequent (e.g. 2-hourly) concurrent ratings of alertness. This paper examines whether similar results might be obtained using retrospective survey measures of alertness obtained from shiftworking nurses at a single sitting. These retrospective measures are shown to be sensitive to both time of day and shift, to have a high level of reliability even for relatively small sample sizes (e.g. 10) and to be valid predictors of more traditional concurrent measures of alertness. It is concluded that retrospective alertness ratings may prove to be an extremely cost-effective method for examining the trends in alertness in various groups, including those suffering from specific types of sleep disorder.

Adult↗
PubMed1995

Complications of fat grafting to the penis.

Fat grafting to the penis has recently become popular in some parts of the country. Surgery is commonly performed in the office, where peer review is lacking or nonexistent. A single case is reported documenting a poor cosmetic and functional result after irregular resorption of grafted fat. The external appearance of the penis remained stable for months, even though later biopsy revealed all the grafted fat to be dead. Analogy with pseudolipoma of Glisson's capsule is provided, showing that dead fat cells can survive for years or even a lifetime without absorption by the body. Several complications are examined in this article, and other potential risks are also discussed. The operation, although technically easy to perform, has many serious potential side effects that should be understood.

Adipose Tissue↗
PubMed1995

Improved prediction of bone mineral content and density.

To establish improved predictive values for normal bone mineral content (BMC) and density (BMD) in adolescent girls a community based study of schoolgirl volunteers was carried out by dual energy x ray absorptimetry. Measurements were performed on 216 subjects aged 11.0 to 17.9 years; measurements were repeated one year later on 84 of the girls, providing a total of 300 studies. For total body BMC the standard error of the prediction was improved from 290.9 g to 134.1 g when weight, height, and shoulder width were added to the normal variable of age. For spine BMD the standard error of the prediction was improved from 0.105 g/cm2 to 0.066 g/cm2 when height, weight, and shoulder width were added to the normal variable of age. Significant improvements were also obtained for total BMD and spine BMC. Despite the normal practice of predicting bone density from age alone this was not selected as the first variable in a multiple stepwise regression for either total body or spine. The prediction of BMC and BMD can be significantly improved by the inclusion of simple body habitus parameters in the prediction equations. As the mean (SE) z score derived from the manufacturer's normal data was - 0.36 (0.02) these American data are probably not appropriate for use in adolescents in the UK.

Absorptiometry, Photon↗
PubMed1994

A population study of food intolerance.

We did a population study to identify the prevalence of reactions to eight foods commonly perceived to cause sensitivity in the UK. A cross-sectional survey of 7500 households in the Wycombe Health Authority area and the same number of randomly-selected households nationwide was followed up by interviews of positive respondents from the Wycombe Health Authority area. Those who agreed entered a double-blind, placebo-controlled food challenge study to confirm food intolerance. 20.4% of the nationwide sample and 19.9% of the High Wycombe sample complained of food intolerance. Of the 93 subjects who entered the double-blind, placebo-controlled food challenge, 19.4% (95% confidence interval 11.4%-27.4%) had a positive reaction. The estimated prevalence of reactions to the eight foods tested in the population varied from 1.4% to 1.8% according to the definition used. Women perceived food intolerance more frequently and showed a higher rate of positive results to food challenge. There is a discrepancy between perception of food intolerance and the results of the double-blind placebo-controlled food challenges. The consequences of mistaken perception of food intolerance may be considerable in financial, nutritional, and health terms.

Adolescent↗
PubMed1994

Choosing to work at night: a moderating influence on individual tolerance to shift work.

The author looked at the impact of choosing to work at night on individual tolerance to shift work. The relative importance of individual circumstances and personality type in influencing this decision was examined. Five hundred eighty-seven nurses and midwives completed measures of physical and psychological health, difficulties with sleep, social and domestic disruption, flexibility of sleeping habits, morning versus evening preferences, and reasons for engaging in shift work. Results high-lighted the advantages of choosing to work at night, rather than engaging in night work as part of a rotating-shift schedule, on tolerance to shift work. The individual circumstances of the shift workers were particularly important in influencing whether they chose to work at night. These results offer some support for the maintenance of permanent night-shift schedules and have implications for the future design of shift systems.

Adult↗
PubMed1994

Biochemical markers of bone turnover in girls during puberty.

OBJECTIVE: Bone turnover and the rate of bone growth increase dramatically during puberty. A number of new assays for the estimation of bone resorption and formation rates have been developed over recent years, and puberty acts as a convenient model for evaluation of these measurements. The aim of this study was to explore the interrelationships between pubertal development, biochemical markers of bone turnover, insulin-like growth factor I and oestradiol in healthy pubertal girls. SUBJECTS: Ninety-one healthy girls (ages 11.6-15.5 years) were studied. All subjects were apparently healthy, and were not taking medications known to influence calcium homeostasis. Breast examination was performed to assess pubertal stage according to Tanner. The adult reference range for biochemical markers of bone turnover was obtained from concurrent studies on 42 healthy premenopausal women ranging in age between 20 and 45 years. DESIGN AND MEASUREMENTS: Blood samples were obtained from subjects between 0800 and 1000 h. Urine samples were collected between 1330 and 1600 h. We measured total and bone specific alkaline phosphatase, osteocalcin, and type I procollagen carboxyterminal propeptide as markers of bone formation. Tartrate resistant acid phosphatase, carboxyterminal pyridinoline cross-linked telopeptide, creatinine corrected urinary deoxypyridinoline, immunoreactive urinary pyridinolines, and urinary galactosyl hydroxylysine were measured as markers of bone resorption. RESULTS: Bone turnover as reflected by each of the markers was maximal in mid puberty (breast Tanner stages II and III) and decreased towards adult levels in late puberty (P < 0.001). However, the magnitude of the mid-pubertal increase differed between markers. In particular, the pubertal increase in levels of bone specific alkaline phosphatase, osteocalcin and urinary deoxypyridinoline were higher than the increase shown by the other markers. All markers were significantly lower after the menarche. Circulating insulin-like growth factor I and insulin like growth factor binding protein-3 were not important determinants of pubertal changes in bone turnover. In contrast, there was a significant negative correlation between oestradiol and all markers of bone formation and resorption during puberty. CONCLUSIONS: The greater pubertal increase in levels of bone specific alkaline phosphatase, osteocalcin and urinary deoxypyridinoline suggests that these markers may be relatively more sensitive as indicators of skeletal health during puberty. The differences between markers may reflect differences in the bone specificity of the analytes, or differing mechanisms of production and clearance. The negative correlation between oestradiol and markers of bone resorption and formation suggests that this hormone may be responsible for the reduction in bone turnover in late puberty.

Acid Phosphatase↗
PubMed1994

Effects on health of a change from a delaying to an advancing shift system.

OBJECTIVES: Shift work can lead to a range of problems for some people that seem to result from the disturbance of the circadian system, and can broadly be classified as: disturbances of sleep, impaired physical and psychological health, and disturbed social and domestic life. The main attempt to try to reduce these problems has focused on the design of the shift system, and the identification of the most problematic features of the shift system. One such feature is believed to be the direction of shift rotation. Systems that advance are thought to be more problematic than those that delay. The present study examines the change in the direction of shift rotation from a delaying to an advancing system on health and wellbeing. METHODS: Self reported measures of tolerance to shift work were taken two months before and six months after the change. These included sleep difficulties, gastrointestinal problems, psychological ill health, chronic fatigue, social and domestic disruption, job satisfaction, and satisfaction with the shift system. RESULTS: The change from a delaying to an advancing system resulted in an increase in sleep difficulties between successive afternoon shifts, but a decrease in social disruption. There was little evidence of impaired health on the advancing compared with the delaying system. CONCLUSIONS: The increase in sleep difficulties was thought to result from the undesired adaptation of the circadian system to night work, as a result of the afternoon shifts now following a series of night shifts, whereas previously they followed a series of morning shifts. The decrease in social disruption was thought to result from the specific sequence of the shifts and the discontinuous nature of the shift system, in particular, the long week-end off every third week. Lack of reported health related differences are explained in terms of the relatively unharmful nature of the shift system in question, and the relatively short time span over which the study was conducted.

Adult↗
PubMed1993

A classification of nursing and midwifery shift systems.

A classification of 122 shift systems worked by nurses and midwives in the larger general hospitals (400+ beds) in England and Wales was made. The systems were classified along two main dimensions: the degree of flexibility for shift rostering (either regular, irregular or flexible); and the speed of rotation between night and day work (either a permanent night shift or systems of fast or slow internal rotation). This resulted in nine possible categories of shift systems. The most common shift system was a flexible day shift with a permanent night shift. Other features of the systems are discussed, e.g. the start times and durations of shifts, and the relative influence of flexible rostering on these features. This classification is a prerequisite for a further research project aimed at identifying those features of shift systems which are likely to cause the least detrimental effects for the individual nurses concerned.

Adaptation, Psychological↗
PubMed1992

Radiotherapy for pleomorphic adenoma of the parotid gland.

A study was made of 187 patients with parotid pleomorphic adenoma treated by radiotherapy. This followed surgery but with incomplete removal or tumor spillage. In the early years of the study radiotherapy was given by radium needle implant done usually at the time of surgery, but from the late 1960s beam-directed external radiotherapy with a head shell was used most commonly. A 3-field technique or wedge pair was the standard technique. The median age was 46 with nearly half the patients (87/187) aged between 40 and 60, and the ratio of women to men was 1.4:1 (110:77). Median follow-up for all patients was 14 years. One hundred fifteen patients had radiotherapy immediately after their first operation with a recurrence rate of 0.9% (1/115). Of the 115 there were 2 cases of radionecrosis (1 major, 1 minor), 1 case of permanent facial nerve palsy, 1 Frey Syndrome (post-gustatory sweating), and 1 salivary fistula. Seventy-two patients had radiotherapy delayed until one or more recurrences had been surgically treated. Nine (12.5%) of these developed yet further recurrence after radiotherapy. There were 2 cases of radionecrosis (1 major), 4 cases of facial nerve palsy (3 of which were complete), 16 cases (22.2%) of Frey Syndrome, and 1 case of malignant change in a parotid tumor. In addition one squamous cell carcinoma developed at the site of a needle implant 25 years later. Recurrences after radiotherapy continued beyond 20 years of follow-up. Patients having unsatisfactory surgery due to spill at operation or residual tumor left behind should have radiotherapy immediately and not delayed until local recurrence occurs because of the increased morbidity and the higher incidence of yet further recurrence.

Adenoma, Pleomorphic↗
PubMed1992

Gene-dosage mapping of 30 DNA markers on chromosome 21.

Using a slot-blot method for the dosage of single-copy sequences, the copy numbers of 30 chromosome 21 markers were assessed in the blood DNA of 11 patients with partial trisomy or monosomy 21 and in the DNA of a patient-derived human-hamster hybrid cell line carrying a microduplication of chromosome 21. The physical order of these markers on chromosome 21 was thereby determined.

Aneuploidy↗
PubMed1991

Biliary obstruction secondary to shrapnel.

Foreign bodies of the biliary tree represent infrequent causes of obstructive jaundice. We report a patient who developed biliary obstruction from metal shrapnel, 44 yr after a war injury. From our review of the literature, the syndrome of shrapnel-induced obstructive jaundice may occur many years after the initial injury. In the majority of patients, the missile lodges in the liver parenchyma, and migrates to the common bile duct. Complications from this injury include cholangitis, pancreatitis, and liver abscesses. As demonstrated by this case, computed tomography scan and endoscopic retrograde cholangio-pancreatogram may reliably detect this infrequent occurrence. With the development of therapeutic biliary procedures, many foreign bodies can be removed endoscopically. Thus, one should consider shrapnel-induced biliary obstruction in those patients with obstructive jaundice and prior combat injury.

Cholangiopancreatography, Endoscopic Retrograde↗
PubMed1990

Angiotensin converting enzyme inhibitors. 10. Aryl sulfonamide substituted N-[1-carboxy-3-phenylpropyl]-L-alanyl-L-proline derivatives as novel antihypertensives.

Compounds 1a-g consisting of enalaprilat covalently bonded to aryl sulfonamides, including several known thiazide diuretics, were synthesized and tested for ACE inhibitory and diuretic and overall antihypertensive effects. All compounds were potent ACE inhibitors in vitro, with IC50 = 6.5-85 nM. At 10 mg/kg iv or ip in the rat, 1a-g inhibited the AI pressor response by 76-100%; inhibition declined significantly upon oral dosing. Compounds 1a and 1f at 100 mg/kg ip in the sodium-depleted, spontaneously hypertensive rats reduced blood pressure 28-35% and 41-42%, respectively. Compounds 1a and 1f elicited natriuresis and kaliuresis without accompanying volume increases in the rat; 1c at 25 mg/kg iv induced delayed diuresis. Compound 1f has been chosen for further development.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1990

The effect of chewing sorbitol-sweetened gum on salivary flow and cemental plaque pH in subjects with low salivary flow.

The purpose of this work was to study the effect of chewing a sorbitol-sweetened gum on whole and parotid salivary flow rates, and on the cemental plaque pH response to a sucrose rinse challenge, in subjects with low salivary flow. The results show that chewing a flavored sugarless gum significantly increases salivary flow rates in individuals with dry mouth. Additionally, chewing the sorbitol-sweetened gum effectively prevents the fall in cemental plaque pH generally seen in response to a sucrose challenge. This indicates that chewing a sorbitol-sweetened gum provides a palliative and possibly a protective benefit for people who suffer from dry mouth.

Chewing Gum↗