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Biomedical subjects

M P Jones

Publications and source records attributed to M P Jones.

At least 19 recordsLinked to original sources
PubMed1995

Randomised trial of an asthma self-management programme for adults.

BACKGROUND: A hospital based, community service asthma education programme for adults to improve asthma knowledge, promote compliance with medication, and reduce morbidity was evaluated. METHODS: The programme was evaluated using a randomised experimental and control group design with repeated measurements over 12 months. A volunteer community sample of 192 respondents was recruited of whom 116 satisfied the inclusion criteria. At the 12 month follow up some data were obtained for all subjects. Intervention subjects attended four 2.5 hour education sessions at weekly intervals. An asthma knowledge questionnaire was administered and compliance was assessed from diary records. Morbidity was assessed retrospectively by questionnaire, prospectively by diary, and objectively by spirometry and serial peak expiratory flow rate monitoring. The adequacy of medical treatment was also assessed. Data were collected at baseline, immediately after the intervention, and at three, six, nine, and 12 months after intervention. RESULTS: Improvements occurred in knowledge and compliance in the intervention group but the impact on morbidity was modest; this was due, at least in part, to the inadequacy of medical treatment. CONCLUSIONS: Treatment of asthma should be reviewed and optimised in conjunction with self-management programmes in order to improve health outcomes.

Adolescent↗
PubMed1994

Predictive value of symptom profiles in patients with suspected oesophageal dysmotility.

The main aim of the study was to determine prospectively, in patients referred for oesophageal manometry, whether certain combinations of oesophageal symptoms are more likely than others to predict the presence of oesophageal dysmotility or a positive response to acid perfusion testing. In 524 consecutive patients, presenting predominantly with (non-cardiac) chest pain (n = 277), dysphagia (n = 186), or heartburn (n = 61), a standardized symptom assessment was completed before oesophageal manometry and acid perfusion testing. Half the patients in each group reported additional ('secondary') oesophageal symptoms as well as the predominant symptom. Oesophageal dysmotility was categorized in accordance with standard manometric criteria for achalasia, diffuse oesophageal spasm, nutcracker oesophagus, hypertensive lower oesophageal sphincter, or non-specific oesophageal motility disorder. In the predominant chest pain group, the prevalence of abnormal manometry was 33%; in the presence of secondary symptoms, especially dysphagia rather than heartburn, however, the prevalence was significantly (p < 0.01) increased. Also in the predominant chest pain group the prevalence of positive acid perfusion testing (44%) was significantly greater (p < 0.05) in those with than in those without secondary symptoms. In the predominant dysphagia group, the prevalence of abnormal manometry was higher than in the other two groups (56%; p < 0.001) but was not affected by the presence or absence of secondary symptoms; this latter finding was also true for the predominant heartburn group. The distribution of specific manometric disorders in any group was not related to the presence or type of secondary symptoms, although a combination of dysphagia and chest pain discriminated achalasia from other manometric disorders.(ABSTRACT TRUNCATED AT 250 WORDS)

Aphasia↗
PubMed1994

A biomechanical comparison evaluating the use of intermediate screws and cross-linkage in lumbar pedicle fixation.

In lumbar fusion, controversy remains regarding the effectiveness of cross-linking and the necessity of placing pedicle screws at the intermediate levels of the segment to be fused. The purpose of this study is to evaluate the stiffness of various rod/screw constructs used to instrument a three-level fusion with specific emphasis on the effect of cross-linking and the intermediate pedicle screws. Nine lumbar calf spines were mounted at L1 and L5. Pedicle screws (TSRH, Danek, Memphis, TN) were then placed bilaterally in the L2, L3, and L4 pedicles. Random sequence testing of the following constructs was then conducted: TSRH rods connected bilaterally to the L2 and L4 pedicles with and without a cross-link, and rods connected bilaterally at the L2, L3, and L4 levels with and without a cross-link. The tests were conducted on a modified MTS testing machine (MTS, Minneapolis, MN) and consisted of cyclic application of axial load, torsion, and flexion and extension. The tests yielded axial, sagittal, and torsional stiffness values. Statistical analysis was performed using log transformation and Fischer's test of least significant difference. In axial testing the use of additional screws in the intermediate pedicles increased stiffness an average of 160% (p = .007). The addition of a cross-link did not increase stiffness with axial loading. In flexion testing the six-screw construct was 84% stiffer when compared with the four-screw construct (p = 0.0001). There was no significant change in flexion stiffness with addition of cross-links. In torsional testing the six-screw construct was 38% stiffer than the four-screw construct (p = 0.042).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Cigarette smoking and nicotine delay postprandial mouth-cecum transit time.

The acute effects of both cigarette smoking and nicotine on postprandial mouth-cecum transit were studied in 20 habitual smokers, 10 males and 10 females. Mouth-cecum transit time was measured by the breath hydrogen technique, following ingestion of a standard mixed liquid meal. Each subject was studied on four separate occasions, either (1) sham or actively smoking two standard cigarettes, commencing 20 min after the meal, or (2) chewing two placebo or nicotine tablets over a 60-min period, commencing immediately after the meal. The time of administration of these stimuli was designed to minimize the effects on mouth-cecum transit time of alterations in gastric emptying. Mouth-cecum transit time was prolonged in response to both smoking [median and interquartile range: 120 (95, 150) min vs 100 (75, 140) min, P = 0.01] and nicotine [120 (80, 170) min vs 100 (70, 140) min, P = 0.002]. No difference was observed between sexes with respect to nicotine; the effect of smoking on mouth-cecum transit time, however, was less pronounced in females compared to males [difference active-placebo: 10 (10, 20) min vs 35 (20, 60) min, P = 0.01]. We conclude that acute cigarette smoking delays mouth-cecum transit time, an effect most likely due to nicotine.

Adult↗
PubMed1992

Suppression of anger and gastric emptying in patients with functional dyspepsia.

Psychologic distress and gastric motor dysfunction have both been implicated in the pathogenesis of functional (non-ulcer) dyspepsia (FD). This study assesses the association between psychologic factors and gastric emptying in 28 FD patients. Subjects completed an extensive range of psychologic questionnaires and underwent dual-isotope scintigraphic assessment of solid and liquid gastric emptying. Attempts to resist, control, suppress, and hold in anger, to adopt a fighting spirit whilst dealing with chronic stressors, and manifest unhappiness were predictors of prolonged gastric emptying. These findings suggest that psychologic factors may be important in the aetiology of gastric stasis and subsequent upper gastrointestinal symptoms in patients with functional dyspepsia.

Adaptation, Psychological↗
PubMed1992

Symptom provocation in irritable bowel syndrome. Effects of differing doses of fructose-sorbitol.

The role of fructose and sorbitol, when ingested together, in the aetiology of irritable bowel syndrome (IBS) is controversial. The aims of this study in IBS patients, therefore, were to compare differences in symptom provocation with various doses of fructose-sorbitol and to relate differences in the extent of colonic hydrogen production after each dose to such symptom provocation. Two different mixtures of fructose and sorbitol--20 g fructose plus 3.5 g sorbitol ('lower' dose) and 25 g fructose plus 5 g sorbitol ('higher' dose)--were administered to 15 patients with IBS and to 24 healthy controls. Breath hydrogen concentrations were determined at 10-min intervals for 3 h after ingestion of each mixture, and the presence and severity of a range of gastrointestinal symptoms were recorded on a standard form before, during, and after the study. Total symptom score in IBS patients, but not controls, was greater (p < 0.05) after the higher than after the lower dose of fructose-sorbitol mixture, and, for the higher dose, symptoms were significantly greater in IBS patients than in controls (p < 0.05). Moreover, the increase in total symptom score between the higher and lower dose mixtures was of a greater magnitude (p = 0.01) in IBS patients than in controls. No significant correlation was observed between the increase in symptom score and the increase in peak hydrogen concentration or the increase in integrated hydrogen response between lower and higher dose mixtures, although these latter increases were at times substantial.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗
PubMed1992

Effects of acute psychologic stress on small-intestinal motility in health and the irritable bowel syndrome.

Psychologic stress may be a provoking factor in the alterations in phase-2 motor activity of the migrating motor complex (MMC) which have been recorded in patients with the irritable bowel syndrome (IBS). To test this, changes in phase-2 duodenojejunal motor activity during 20 min of psychologic stress in 10 patients with IBS were compared with those shown by 10 healthy subjects. Autonomic arousal in response to the stressor was assessed by cardiovascular responses and self-reported levels of anxiety and tension. IBS and controls showed a significant cardiovascular and subjective response to stress which was comparable in the two groups. In general, duodenal phase-2 motor activity was suppressed during stress in both IBS and controls. Jejunal motor activity showed a similar inhibitory response in both groups, but the change in motility index was significant for controls only. Qualitatively, stress did not cause clustered contractions in either the IBS or the control group. However, in IBS patients with clustered contractions in the basal period there was inhibition of this pattern during stress. These findings suggest that acute psychologic stress profoundly suppresses, rather than enhances, duodenojejunal MMC phase-2 motility in healthy subjects. IBS patients, irrespective of their underlying phase-2 motor pattern show similar, although less marked, changes in motility.

Adult↗
PubMed1991

Prolonged QT interval and risk of sudden death in South-East Asian men.

Sudden death in sleep occurs in substantial numbers among young men in South-East Asia. The frequencies of electrocardiographic abnormalities were measured in groups with varying risks of such sudden death. The mean heart-rate-corrected QT interval (QTc) was significantly (p less than 0.05) greater among 123 Laotian refugees in Thailand at high risk (405 [95% confidence interval 397-413] ms) than in 77 Laotian refugees in the United States at lower risk (364 [359-369] ms) and 199 non-Asian US residents at negligible risk (358 [354-362] ms). Among refugees in Thailand, prolonged QTc interval was associated with poor thiamine status and a history of seizure-like episodes in sleep. Thiamine deficiency may be a cause of prolonged QT interval and sudden death in this region.

Adolescent↗
PubMed1991

Cancer registry problems in classifying invasive bladder cancer.

A slide review of diagnostic pathologic tissue obtained from 364 bladder cancer cases, identified through the Iowa Surveillance, Epidemiology, and End Results (SEER) Program in 1983, classified 97 (26.6%) of these cases as invasive bladder cancers. These findings contrasted sharply with the Iowa SEER Program classification that coded 289 (79.4%) of these cases as invasive bladder cancers. These results were validated further by the hazard ratio of 4.54 (95% confidence interval, 2.57 to 8.03) among invasive relative to noninvasive bladder cancer cases when the slide review findings were used. In contrast, the hazard ratio was only 1.70 (95% confidence interval, 0.76 to 3.79) when the Iowa SEER Program findings were used. The traditional method used by the National Cancer Institute's SEER Program to deal with this problem is described and its implications are discussed.

Humans↗
PubMed1991

Enhanced perception of physiological intestinal motility in the irritable bowel syndrome.

An increased awareness of intestinal distention or contraction is implicated in the pathogenesis of the irritable bowel syndrome. This study aimed to test this hypothesis in 20 patients with the irritable bowel syndrome and 10 controls by relating the reporting of abdominal sensations to the occurrence of the duodenal phase 3 activity front of the migrating motor complex. During prolonged recordings of interdigestive small bowel motility, subjects were asked to report any episodes of abdominal sensation they experienced. Diurnally, the rate of occurrence of abdominal sensation was significantly greater in patients with the irritable bowel syndrome than in controls (P less than 0.001); such episodes were coincident with a duodenal activity front in 9 patients with the irritable bowel syndrome and in 1 control (P less than .05). Moreover, the rate of occurrence of episodes of sensation was greater (P less than 0.01) during diurnal phase 3 activity than during diurnal phase 2 activity. When episodes were coincident with duodenal phase 3 activity, these activity fronts were of significantly greater amplitude (irritable bowel syndrome: median, 23 mm Hg) than "noncoincident" activity fronts (median, 17 mm Hg; P less than 0.05) in both patients and controls. These data strongly suggest that certain physiological small bowel motor events, if of sufficient contraction amplitude, are able to be perceived by a greater proportion of irritable bowel syndrome patients and with greater frequency than by healthy subjects. The authors conclude that the threshold for perception of intestinal contraction is lower than normal in at least some patients with the irritable bowel syndrome.

Abdomen↗
PubMed1991

Response of pre-adult and adult stages of Trichuris muris to common anthelmintics in mice.

The common anthelmintics, oxantel, mebendazole, albendazole and pyrantel were assessed for their comparative activity against Trichuris muris in mice. Mice were infected with T. muris and the infection was maintained by a brief cortisone administration during the second week of infection. Mice carrying the infection with different life cycle stages, viz. fourth stage larvae (L4), pre-adult and adult stages were dosed with anthelminitics. The worm burdens in control infection groups varied although infection dose and other conditions were uniformly followed. With various dose regimens tested, oxantel was highly potent; it eliminated completely pre-adult and adult stages, respectively at 25 and 12.5 mg kg-1 dose levels with significant activity also against adult worms at a 1.56 mg kg-1 dose level and against pre-adults at a 6.25 mg kg-1 level. Pre-adults required twice the dose given to that of adults for complete (100%) activity. Mebendazole was the next most active; a dosage of 37.5 mg kg-1 was completely active against pre-adults whereas a dosage of 2 x 50 mg kg-1 was required for complete elimination of adult worms. In addition, about 90% of the worms were eliminated with a single dose of 150 mg kg-1. However, a significant activity was seen against adults at a 25 mg kg-1 level and pre-adults at 37.5 mg kg-1, the lowest level tested. In comparison, albendazole did not induce complete clearance of pre-adult and adult stages even when tested at dose levels as high as 150 and 2 x 75 mg kg-1, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Albendazole↗
PubMed1991

Determinants of recurrent ischaemia and revascularisation procedures after thrombolysis with recombinant tissue plasminogen activator in primary coronary occlusion.

This paper reports the immediate effects of thrombolysis and their subsequent influence on revascularisation procedures and clinical outcome over the subsequent twelve months. Coronary arteriography was performed at 21 days on 131 of 145 patients who received recombinant tissue plasminogen activator (n = 68) or placebo (n = 63) within 2.5 hours of symptom onset after primary coronary occlusion. Patency rates (TIMI grades 2 and 3) of the infarct-related artery were 81% with plasminogen activator and 63% with placebo (P = 0.02). Early (within 21 days) angiography for recurrent ischaemia was necessary in 31 (21%) patients (20 plasminogen activator, 11 placebo NS) and definite reinfarction occurred in 8 (5%) patients (4 plasminogen activator, 4 placebo). During one year follow-up without planned secondary intervention, coronary artery bypass grafting was more frequent in patients who had received thrombolytic therapy (23% plasminogen activator, 4% placebo P = 0.001); coronary angioplasty procedures were similar in both groups (12% plasminogen activator, 11% placebo NS). Mortality at 21 days was 5% (4 plasminogen activator, 4 placebo) and at one year was 7% (5 plasminogen activator, 5 placebo). Logistic regression analysis identified models comprising characteristics predictive of subsequent bypass grafting (plasminogen activator, multivessel disease, occluded infarct-related artery) and coronary angioplasty (non-q wave infarction, severe (91-99%) residual stenosis, left anterior descending infarct-related artery). Initial non-q wave infarction was the only predictor of early recurrent ischemia (odds ratio 4, P = 0.02) irrespective of residual stenosis severity.

Angioplasty, Balloon, Coronary↗
PubMed1991

Medulloblastoma: a population-based study of 532 cases.

Five hundred thirty-two cases of medulloblastoma (males n = 327 and females n = 205), aged 0 to 86 years diagnosed between 1973 and 1986 were studied to determine the incidence in different geographic regions of the United States and to evaluate the effect of various factors on survival. The median age was 9 years and average follow-up time was 45 months. The overall incidence rate was 1.8 per one million person-years. Variables that were statistically significant (p less than 0.05) in a multivariate model determining survival in rank order were treatment group, sex, geographic region, year group and age. This observational study found that 1) age and sex were statistically significant factors in describing the incidence rates, whereas year group and geographic region were not; 2) no incidence peak in the third decade of life was observed; 3) a significant improvement in survival was observed in the combined 1978 to 1986 year groups relative to the 1973 to 1977 year group; 4) the overall 5-year survival probability was 45%; and 5) there has been an increase over time in the use of more than two modalities of treatment.

Adolescent↗
PubMed1991

Ischemic cerebrovascular complications and risk factors in idiopathic hypertrophic subaortic stenosis.

To determine the risk and time to cerebrovascular complications with idiopathic hypertrophic subaortic stenosis, we studied 119 patients (66 men and 53 women) with evidence of this disease based on strict echocardiographic criteria and followed them up for a mean +/- SEM of 6.5 +/- 0.6 years. Cerebral ischemic events occurred in 26 patients (22%), and in five patients stroke was the initial presenting event. Men had cardiac symptoms at a younger age than women, but there was no significant difference in age at the time of stroke. Cardioembolic cerebrovascular events were associated with atrial fibrillation and left atrial enlargement, whereas atheroembolic events were associated with hypertension. An increased risk of stroke was associated with female sex, mitral anulus calcification, hypertension, and atrioventricular conduction delay. Unlike most previous series, this study shows that patients with idiopathic hypertrophic subaortic stenosis may present with stroke.

Adult↗