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Biomedical subjects

N W Read

Publications and source records attributed to N W Read.

At least 37 records · Page 2Linked to original sources
PubMed1999

Harnessing the patient's powers of recovery: the role of the psychotherapies in the irritable bowel syndrome.

The aim of this chapter is to provide a clear and balanced account of the role of the various forms of psychotherapy in the irritable bowel syndrome (IBS). It commences with an account of the philosophical basis for psychotherapy, attempting to integrate the concepts of autonomic arousal, repression, conversion and a developmental disorder of thinking and emotional expression. These concepts are used to explain why separation and loss can lead to the development of IBS and how the gut is such an important vehicle for emotional expression. Against this background the role and philosophy of relaxation therapy, hypnotherapy, biofeedback, cognitive behavioural therapy and analytical psychotherapy are discussed. These therapies describe a philosophical approach that is quite different from biomedical treatments in that it attempts to harness the patient's own powers for recovery. For that reason the efficacy of psychotherapies cannot be evaluated by randomized controlled trials. Psychotherapies rely on the relationship between therapist and patient and vary according to whether the locus of responsibility lies mainly with the therapist or mainly with the patient. Different patients may well require different therapies.

Biofeedback, Psychology↗
PubMed1999

The role of psychological and biological factors in postinfective gut dysfunction.

BACKGROUND: Both psychological and physiological disturbances have been implicated in the aetiopathogenesis of irritable bowel syndrome (IBS). AIMS: To investigate how the psychological factors act, and the involvement of infective and physiological factors. METHODS: Consecutive patients hospitalised for gastroenteritis reported life events for the previous 12 months, and past illness experiences on standardised questionnaires. They also completed psychometric questionnaires for anxiety, neuroticism, somatisation, and hypochondriasis. In some patients, rectal biopsy specimens were obtained during the acute illness and at three months postinfection. RESULTS: Ninety four patients completed all questionnaires: 22 patients were diagnosed with IBS after their gastroenteritis (IBS+), and 72 patients returned to normal bowel habits (IBS-). IBS+ patients reported more life events and had higher hypochondriasis scores than IBS- patients. The predictive value of the life event and hypochondriasis measures was highly significant and independent of anxiety, neuroticism, and somatisation scores, which were also elevated in IBS+ patients. Rectal biopsy specimens from 29 patients showed a chronic inflammatory response in both IBS+ and IBS- patients. Three months later, specimens from IBS+ patients continued to show increased chronic inflammatory cell counts but those from IBS- patients had returned to normal levels. IBS+ and IBS- patients exhibited rectal hypersensitivity and hyper-reactivity and rapid colonic transit compared with normal controls, but there were no significant differences between IBS+ and IBS- patients for these physiological measurements. CONCLUSION: Psychological factors most clearly predict the development of IBS symptoms after gastroenteritis but biological mechanisms also contribute towards the expression of symptoms.

Adolescent↗
PubMed1999

Validation of a specific quality of life questionnaire for functional digestive disorders.

BACKGROUND: Dyspepsia and irritable bowel syndrome are suitable conditions for assessment of quality of life. Their similarities justify the elaboration of a single specific questionnaire for the two conditions. AIMS: To examine the process leading to the validation of the psychometric properties of the functional digestive disorders quality of life questionnaire (FDDQL). METHODS: Initially, the questionnaire was given to 154 patients, to assess its acceptability and reproducibility, analyse its content, and reduce the number of items. Its responsiveness was tested during two therapeutic trials which included 428 patients. The questionnaire has been translated into French, English, and German. The psychometric validation study was conducted in France, United Kingdom, and Germany by 187 practitioners. A total of 401 patients with dyspepsia or irritable bowel syndrome, defined by the Rome criteria, filled in the FDDQL and generic SF-36 questionnaires. RESULTS: The structure of the FDDQL scales was checked by factorial analysis. Its reliability was expressed by a Cronbach's alpha coefficient of 0.94. Assessment of its discriminant validity showed that the more severe the functional digestive disorders, the more impaired the quality of life (p<0.05). Concurrent validity was supported by the correlation found between the FDDQL and SF-36 questionnaire scales. The final version of the questionnaire contains 43 items belonging to eight domains. CONCLUSIONS: The properties of the FDDQL questionnaire, available in French, English, and German, make it appropriate for use in clinical trials designed to evaluate its responsiveness to treatment among patients with dyspepsia and irritable bowel syndrome.

Adult↗
PubMed1998

Effects of carbohydrate and lipid on resting energy expenditure, heart rate, sleepiness, and mood.

The effects of gastric infusions of fat and carbohydrate on physiological and psychological measures were compared using a within subject design in 9 healthy subjects (6 males). Each subject received isovolaemic rapid gastric infusions of sucrose solution (100% energy carbohydrate), lipid emulsion (100% energy fat, 20% Intralipid), and a non-nutrient control (0.9% saline) in a randomised order. Nutrient infusions were isoenergetic, containing one-third of an individual subject's estimated daily energy requirements (mean, 3227 kJ; range, 2479-3971 kJ). Measures of heart rate (HR), energy expenditure (EE), mood, and sleepiness were collected before the infusions and every 0.5 h for 3.5 h. Mean postingestive HR, EE, and satiation were significantly greater after the nutrient infusions than after the control. Sucrose induced a rapid increase in HR and EE, whereas lipid had a lesser and more delayed effect. Thirty minutes after the gastric infusions, HR and EE were significantly higher after the sucrose than after the lipid and saline. Hedonic tone was greater and tension lower after the saline and sucrose infusions than after the lipid infusion. From 3 to 3.5 h after ingestion, subjects felt significantly more sleepy after the lipid infusion than they did at these times after the saline infusion, and significantly more dreamy after the lipid infusion than they did after the sucrose infusion. In conclusion, the presence of lipid and sucrose in the intestine induces significant and differing physiological and psychological effects, which are independent of cognitive and orosensory influences.

Adult↗
PubMed1998

Effects of intragastric infusions of fat and carbohydrate on appetite ratings and food intake from a test meal.

Previous studies using meal preloads have indicated that carbohydrate has a greater satiating power than fat. To investigate the effects of macronutrients on ingestion and satiety, without the influence of meal design and orosensory factors, two groups of ten healthy, fasted male volunteers took part in two separate experiments involving rapid direct intragastric infusions of macronutrients. In the first experiment volunteers received isocaloric infusions of either Intralipid, or 1:1 Intralipid and glucose mixture or saline over 15 min on three separate occasions. In a second experiment volunteers received isocaloric infusions of either Intralipid or glucose. For both studies, appetite ratings were recorded for the first two hours of the study and energy and macronutrient intakes were evaluated from a test meal given 1.5 h after the infusion. Food diaries were used to monitor food intake for the remainder of the study day. In the first experiment, both Intralipid and the Intralipid/glucose mixture suppressed appetite ratings and reduced energy intake at lunch compared with saline but had no effect on energy intake during the remainder of the study day. No differences were found between nutrient conditions in suppressing appetite ratings or energy intake. In the second experiment there were no differences between the effects of Intralipid and glucose on hunger, fullness or on energy intake from the test meal or intake over the remainder of the day. Taken together, these results suggest that intragastric infusions of either Intralipid, glucose or a mixture of the two, reduced hunger and increased fullness, but they failed to confirm the hypothesis that different macronutrients have different satiating capacities.

Adolescent↗
PubMed1998

Relative contributions of intestinal, gastric, oro-sensory influences and information to changes in appetite induced by the same liquid meal.

To investigate the contribution of oral, gastric and intestinal factors in the control of appetitc, 425 ml (400 kcal) tomato soup was administered either orally, intragastrically (covertly and overtly) or intraduodenally (overtly) to nine healthy, fasted, male volunteers. Ratings of fullness, hunger and desire to eat were recorded over a period of 2 h and gastric emptying was measured after soup fed orally and intragastrically. Infusion of the soup into the small intestine at a rate commensurate with normal gastric emptying exerted no significant suppression of ratings of hunger and desire to eat and no significant production of fullness. Covert, intragastric infusion of the same soup suppressed appetite and this suppression was increased when the subjects were informed of the nature of the infusion, but there were no differences in gastric emptying profiles between covert and overt intragastric infusions of soup. Oral administration of the soup produced the greatest suppression of appetite compared with other conditions and also generated a slower rate of gastric emptying compared with both intragastric soup infusions. Strong correlations were observed between appetite ratings and both gastric and intestinal contents following intragastric infusions of the soup meal and these were enhanced following oral administration of soup. These results indicate how information, orosensory, gastric and intestinal factors can interact to elicit optimal expression of fullness and suppression of hunger. Specifically, the data not only demonstrate how the influence of gastric distension appears to overwhelm any direct influence of intestinal chemostimulation on appetite and how information modulates this effect, but the data also support an important role in appetite suppression for psychophysiological mechanisms stimulated by orosensory mechanisms.

Adolescent↗
PubMed1998

Food intake responses to upper gastrointestinal lipid infusions in humans.

Previous studies in humans and animals have shown that the presence of lipid in the small intestine can reduce food intake. Studies that have combined intraduodenal lipid infusions with gastric distension produced a greater reduction in food intake than when these two stimuli were separated. In this study, subjects received duodenal lipid (Intralipid 20%) infusions for varying periods before and during the consumption of a liquid test meal. The aim of this procedure was to maximise the interaction between intestinal nutrient stimulation and gastric distension. A dose-dependent decrease in food intake was observed that corresponded to the duration of infusion; 90- (180 kcal) and 45-min (90 kcal) infusions but not 15-min (30 kcal) infusions significantly reduced intake compared to saline. These results show that concomitant intestinal nutrient stimulation and gastric distension is an effective test for the measurement of suppression of food intake by intestinal nutrients.

Adult↗
PubMed1998

Alterations in mood after changing to a low-fat diet.

The effects on mood of reducing dietary fat while keeping the energy constant were examined in ten male and ten female healthy volunteers aged between 20 and 37 years. Each volunteer consumed a diet containing 41% energy as fat for 1 month. For the second month half of the subjects changed to a low-fat diet (25% energy from fat) and the remainder continued to eat the diet containing 41% energy from fat. Changes in mood and blood lipid concentrations were assessed before, during and at the end of the study. Profile of mood states (POMS) ratings of anger-hostility significantly increased in the intervention group after 1 month on the low-fat diet, while during the same period there was a slight decline in anger-hostility in the control subjects (group F 6.72; df 1.14; P = 0.021). Tension-anxiety ratings declined in the control group consuming the higher fat diet but did not change in the group consuming the low-fat diet (group F 6.34; df 1.14; P = 0.025). There was a decline in fasting concentrations of HDL-cholesterol after the low-fat diet and a small increase in subjects consuming the medium-fat diet (group F 4.96; df 1.12; P = 0.046), but no significant changes in concentrations of total serum cholesterol, LDL-cholesterol or triacylglycerol were observed. The results suggest that a change in dietary fat content from 41 to 25% energy may have adverse effects on mood. The alterations in mood appear to be unrelated to changes in fasting plasma cholesterol concentrations.

Adult↗
PubMed1998

Interaction of insulin, glucagon-like peptide 1, gastric inhibitory polypeptide, and appetite in response to intraduodenal carbohydrate.

The relation between gastrointestinal incretin hormones in the control of insulin release and short-term satiety by intestinal carbohydrate was investigated in 8 fasted, healthy male volunteers. Insulin, gastric inhibitory polypeptide (GIP), glucagon-like peptide 1 (GLP-1), and appetite ratings were measured during, and food intake was measured after, intraduodenal infusions of glucose or saline. Studies were conducted under hyperinsulinemic and euglycemic conditions. Raising plasma insulin with intravenous insulin infusion to concentrations slightly above usual postprandial concentrations (356.4 +/- 4.8 pmol/L) had no effect on GIP, GLP-1, or appetite ratings before the intraduodenal infusions began. Intraduodenal glucose infusion resulted in a further increase in plasma insulin to a peak of 779.4 +/- 114.0 pmol/L, caused an early increase in plasma GIP and a later increase in GLP-1 concentrations (P < 0.01), suppressed appetite (P < 0.05), and reduced energy intake (P < 0.01) compared with intraduodenal infusion of saline. There was a close association between the increase in GLP-1 and decrease in appetite. Infusion of octreotide to suppress the release of gastrointestinal hormones prevented the rise in insulin, GIP, and GLP-1 induced by intraduodenal glucose infusion and reversed the suppression of appetite and reduction in energy intake. These results suggest that 1) when infused to result in plasma concentrations slightly above usual postprandial concentrations, insulin does not inhibit its own release and 2) the effects of intraduodenal glucose on appetite may be mediated through the release of GLP-1 and not insulin.

Adult↗
PubMed1998

Effects of meals on objective and subjective measures of daytime sleepiness.

Effects of recent food ingestion on daytime sleepiness were assessed in 16 subjects (8 men and 8 women) who were each studied on two occasions, 28 days apart. On each occasion, subjects ate a high-fat low-carbohydrate (CHO) (fat/CHO energy ratio 54:41) meal and an isoenergetic low-fat high-CHO meal (fat/CHO energy ratio 7:88) 4 h apart in a counterbalanced order. Sleepiness was measured at 2-hr intervals by using the Multiple Sleep Latency Test and the Akerstedt electroencephalograph sleepiness test. To control for circadian factors, one group (4 men, 4 women) ate the meals 2 h later than did the other group of subjects. There were no differences in sleepiness according to the composition of the meal. Sleepiness in the Multiple Sleep Latency Test was significantly greater 1.5 h after the meals were eaten than before (F 11.37; df 1,15; P = 0.004). Sleepiness was also enhanced in the Akerstedt sleepiness test 3 h 20 min after the meals. The results suggest that the meals induced an enhancement in sleepiness that was not solely due to circadian rhythms.

Adult↗
PubMed1997

Influences of fat and carbohydrate on postprandial sleepiness, mood, and hormones.

Paired studies were conducted in 18 healthy volunteers (9 men, 9 women) to investigate whether differences in mood and daytime sleepiness induced by high-fat-low-carbohydrate (CHO) and low-fat-high-CHO morning meals were associated with specific hormonal responses. Plasma insulin concentrations were significantly higher after low-fat-high-CHO meals, and cholecystokinin (CCK) concentrations were significantly higher after high-fat-low-CHO meals. Subjects tended to feel more sleepy and less awake 2-3 h after the high-fat-low-CHO meal, and ratings of fatigue were significantly greater 3 h after the high-fat-low-CHO meal than after the low-fat-high-CHO meal. The results of the present study are consistent with the hypothesis that there is an association between the lassitude experienced after a meal and the release of CCK.

Adult↗
PubMed1997

The influence of food on pain perception in healthy human volunteers.

The aim of this study was to investigate if food could reduce pain perception in a group of 16 healthy human volunteers (8 male and 8 female), and to explore the differential effects of macronutrient composition on the response to cold-induced pain. All subjects underwent the cold pressor test (CPT) on 3 occasions in a counterbalanced order, before and after administration of isoenergetic high-fat low-carbohydrate (CHO) and high-CHO low-fat meals, and when no meal was given. The CPT was carried out 4 times on each test day, once before the meal, and 0.5, 1.5, and 2.5 h after the meal, and at the equivalent times on the day when no food was given. Radial pulse and blood pressure measurements and visual analogue scales of mood/emotional state were carried out before and after each CPT. Mean pain scores were significantly reduced following both meals compared with the no-food condition. The maximum reduction in pain occurred 1.5 h after ingestion, and a significantly greater effect was exerted by the high-fat low-CHO meal compared with the high-CHO low-fat meal. These results demonstrate that food, particularly when rich in fat, significantly reduces the pain induced by the cold pressor stimulus in healthy human subjects.

Adult↗
PubMed1997

Adolescent sexual strategies.

PURPOSE: The aim of this study has been to survey adolescents' strategies to promote sexual encounters and to compare those used by males and females. We examined the predictions that sexual strategies of young adolescents are fewer and less adult-like and that those of male adolescents are more coercive. We also examined the predictions from evolutionary psychology that suggest in sexual strategies, males communicate emotional involvement, long-term interest, and resource investment, whereas females communicate sexual availability and fertility. METHODS: The sample consisted of 153 African-American, white, Chinese-American, and Mexican-American adolescents. A strategy inventory was developed and mention of strategies by males and females were compared. RESULTS: Significant gender differences in mention of strategies were found. Males mentioned a higher percentage of coercive strategies such as pressuring and raping as well as a higher percentage of strategies such as lying and getting a partner drunk or high. Males and females both mentioned a higher percentage of strategies communicating commitment and investment. Females mentioned more strategies which signaled sexual availability. Adolescent strategies were fewer than those reported by adults and less focused on appearance enhancement and the intricacies of dating. CONCLUSIONS: Findings suggest the need for special targeting of coercive situations, use of sexual strategies as a prompt for counterstrategies aimed at abstinence, use of sexual strategies as a context for condom use promotion, and reinforcement of female preparatory strategies.

Adolescent↗
PubMed1997

The effect of sucrose- and aspartame-sweetened drinks on energy intake, hunger and food choice of female, moderately restrained eaters.

OBJECTIVE: To compare the effects of aspartame-sweetened and sucrose-sweetened soft drinks on food intake and appetite ratings of female restrained eaters. SUBJECTS: Fourteen female students, shown to have eating restraint. METHODS: Subjects were given four drinks (330 ml) of aspartame-sweetened lemonade, sucrose-sweetened lemonade and carbonated mineral water on three separate days. Seven of the subjects were informed of the drink type they were consuming on each occasion. MEASUREMENTS: Appetite ratings were recorded and energy and macronutrient intakes were measured during the study day and day after leaving the department. RESULTS: During the first study day energy intake was lower whilst drinking the sucrose-sweetened lemonade compared with the aspartame-sweetened lemonade, although neither differed significantly from energy intakes during the day the drank water. When the calories from the sucrose-sweetened lemonade were included (1381 kJ, 330 Kcal) energy intake did not differ between treatments. The following day energy intake was significantly higher after the aspartame-sweetened lemonade compared with both sucrose-sweetened lemonade and the water due to an increase in the amount of carbohydrate consumed and resulted in a higher total energy intake over the two days studied. Knowledge of the drink types had no effect on energy intake or macronutrient intake. Appetite ratings did not differ between drinks and were not affected by knowledge of the drink types. CONCLUSION: These results suggest that in females with eating restraint, substituting sucrose-sweetened drinks for diet drinks does not reduce total energy intake and may even result in a higher intake during the subsequent day.

Analysis of Variance↗
PubMed1997

The life voyage of a solo circumnavigator: integrating theoretical and methodological perspectives.

In this article, we introduce the case study of Dodge Morgan, who, at the age of 54, completed a nonstop, solo circumnavigation of the earth in his boat American Promise. Our investigation builds upon a unique foundation of qualitative and quantitative data, which includes extensive formal assessments, content analysis of Morgan's voyage log, additional autobiographical material, and diverse collateral biographical sources. We describe our intent of applying two theoretical models of personality, the five-factor model and the life-story model, to the data, and present an overview of their differing perspectives and predictions. We discuss technical challenges of methodology and integration, and introduce the subsequent chapters comprising the full case study.

Cognition↗
PubMed1997

Acute hyperglycaemia affects anorectal motor and sensory function in normal subjects.

BACKGROUND: The pathogenesis of anorectal dysfunction, which occurs frequently in patients with diabetes mellitus, is poorly defined. Recent studies indicate that changes in the blood glucose concentration have a major reversible effect on gastrointestinal motor function. AIMS: To determine the effects of physiological changes in blood glucose and hyperglycaemia on anorectal motor and sensory function in normal subjects. SUBJECTS: In eight normal subjects measurements of anorectal motility and sensation were performed on separate days while blood glucose concentrations were stabilised at 4, 8, and 12 mmol/l. METHODS: Anorectal motor and sensory function was measured using a sleeve/sidehole catheter incorporating a balloon, and electromyography. RESULTS: The number of spontaneous anal relaxations was greater at 12 mmol/l than at 8 and 4 mmol/l glucose (p < 0.05 for both). Anal squeeze pressures were less at a blood glucose of 12 mmol/l when compared with 8 and 4 mmol/l (p < 0.05 for both). During rectal distension, residual anal pressures were not significantly different between the three blood glucose concentrations. Rectal compliance was greater (p < 0.05) at a blood glucose of 12 mmol/l when compared with 4 mmol/l. The threshold volume for initial perception of rectal distension was less at 12 mmol/l when compared with 4 mmol/l (40 (20-100) ml versus 10 (10-150) ml, p < 0.05). CONCLUSIONS: An acute elevation of blood glucose to 12 mmol/l inhibits internal and external anal sphincter function and increases rectal sensitivity in normal subjects. In contrast, physiological changes in blood glucose do not have a significant effect on anorectal motor and sensory function.

Acute Disease↗
PubMed1997

Efficacy and safety of the peripheral kappa agonist fedotozine versus placebo in the treatment of functional dyspepsia.

BACKGROUND: Peripheral kappa receptor agonists may provide a new therapeutic approach for the treatment of functional dyspepsia. AIMS: To evaluate, in a large multicentre trial, the use of the kappa receptor agonist fedotozine to improve symptoms associated with functional dyspepsia. METHODS: Two or more of the following persistent symptoms were required for inclusion: epigastric pain, early satiety, epigastric fullness or distension, nausea, vomiting, and a feeling of slow digestion. On completing a two week placebo washout, 271 patients were randomised into two groups to receive 30 mg fedotozine three times daily or placebo for six weeks under double blind conditions. RESULTS: The improvement in the overall intensity of dyspeptic symptoms (main efficacy criterion) was significantly more pronounced in the fedotozine group (p = 0.002) compared with placebo, as was epigastric pain (p = 0.004) and nausea (p = 0.01); the improvement in postprandial fullness was nearly significant (p = 0.052). Inability to finish a meal and slow digestion were unaffected. The patient global score, the average of the five individual symptoms, was notably ameliorated with fedotozine (p = 0.021). The safety of fedotozine was excellent. CONCLUSIONS: Fedotozine at 30 mg three times daily is safe and more effective than placebo for the relief of key symptoms associated with functional dyspepsia.

Adolescent↗