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Biomedical subjects

M Lewis

Publications and source records attributed to M Lewis.

At least 55 records · Page 3Linked to original sources
PubMed2001

A comparative study of the effects of carbamazepine and the NMDA receptor antagonist remacemide on road tracking and car-following performance in actual traffic.

RATIONALE: Antiepileptic drugs are known to produce side effects which may impair driving performance. Performance effects, however, may differ substantially between individual antiepileptic drugs. OBJECTIVE: To compare the effects of carbamazepine, remacemide, and placebo on actual driving performance during a 12-day incremental dosing regimen. METHODS: Twenty-two healthy volunteers participated in a three-way, double-blind, cross-over driving study. Treatment effects were assessed in two actual driving tests carried out on days 8, 10, and 12 of each treatment period. The Road Tracking Test involved driving an instrumented vehicle at a constant speed and steady lateral position between the delineated lane boundaries. Standard deviation of lateral position (SDLP) was measured to indicate precision of road tracking control. The Car-Following Test involved driving the same vehicle behind a leading car and maintaining that distance while the latter executed a series of deceleration/acceleration maneuvers. Time to speed adaptation (TSA) and brake reaction time were the primary measures. RESULTS: Remacemide did not affect the subjects' driving performance. Carbamazepine increased SDLP throughout treatment and lengthened TSA on day 8. Changes in SDLP relative to placebo were comparable to those previously seen in drivers conducting the same test with blood alcohol concentrations of 0.05 g/dl. CONCLUSION: Remacemide, at the given dose regimen, does not affect driving performance. Carbamazepine, at the given dose regimen, can produce mild but sufficient impairment to put epileptic patients at risk when driving, at least during initiation therapy.

Acetamides↗
PubMed2001

Crystal structure of human type III 3alpha-hydroxysteroid dehydrogenase/bile acid binding protein complexed with NADP(+) and ursodeoxycholate.

The crystal structure of human type III 3alpha-hydroxysteroid dehydrogenase (HSD)/bile acid binding protein (AKR1C2) complexed with NADP(+) and 3alpha,7beta-dihydroxy-5beta-cholanic acid (ursodeoxycholate) at 3.0 A resolution is presented. Thus, the three-dimensional structure has now been solved for a human HSD member of the aldo-keto reductase superfamily. AKR1C2 is implicated in the prostatic production of the potent androgen 5alpha-dihydrotestosterone and the hepatic transport of bile acids. It also catalyzes the formation of the neurosteroid 3alpha-hydroxy-5alpha-pregnan-20-one in the central nervous system, and its allosteric modulation by fluoxetine has been linked to the use of this drug for premenstrual dsyphoria. Like other members of the superfamily, AKR1C2 folds into an alpha/beta-barrel and binds NADP(+) in an extended conformation. The carboxylate of ursodeoxycholate binds to AKR1C2 in the oxyanion hole at the active site. More interestingly, the orientation of ursodeoxycholate is essentially "backwards" and "upside-down" from that observed for testosterone in the related rat 3alpha-HSD.NADP(+).testosterone ternary complex, where testosterone assumes the position of a 3-ketosteroid substrate. The orientation of ursodeoxycholate is thus similar to that expected of a 17beta-HSD substrate. The ternary structure explains the ability of AKR1C2 to catalyze 3alpha-, 17beta-, and 20alpha-HSD reactions. Comparison of the steroid binding pocket of AKR1C2 with that of rat 3alpha-HSD reveals significant differences in the positions of conserved and nonconserved loop residues, providing insights into the structural basis for the functional flexibility that is observed in all the human 3alpha-HSD isoforms but not in the rat isoform.

Allosteric Regulation↗
PubMed2001

Psychological interventions for non-ulcer dyspepsia.

BACKGROUND: Studies have also shown that NUD patients have higher scores of anxiety, depression, neurotism, chronic tension, hostility, hypochondriasis, and tendency to be more pessimistic when compared with the community controls. OBJECTIVES: This review aims to determine the effectiveness of psychological interventions including psychotherapy, psychodrama, cognitive behavioral therapy, relaxation therapy, guided imagery or hypnosis in the improvement of either individual or global dyspepsia symptom scores and also quality of life scores patients with non-ulcer dyspepsia (NUD). SEARCH STRATEGY: Trials were located through electronic searches of the Cochrane Controlled Trials Register (CCTR), MEDLINE, EMBASE, CINAHL and PsycLIT, using appropriate subject headings and text words and searching bibliographies of retrieved articles. SELECTION CRITERIA: All randomised controlled trials (RCTs) or quasi-randomised studies assessing the effectiveness of psychological interventions (including psychotherapy, psychodrama, cognitive behavioural therapy, relaxation therapy, guided imagery or hypnosis) for non-ulcer dyspepsia (NUD). DATA COLLECTION AND ANALYSIS: Data were collected on individual, global dyspepsia symptom scores, as well as measures of quality of life (QoL) scores and adverse effects. MAIN RESULTS: The three trials identified showed that there was improvement in the dyspepsia symptom scores at the end of treatment and one trial showed improvement in the psychological parameters. However, meta-analysis was not possible as these trials used different psychological interventions and two of the trials only reported mean change in symptoms and did not give standard deviations of this change. REVIEWER'S CONCLUSIONS: Psychological intervention in the form of psychodynamic psychotherapy and cognitive behavioral therapy may be useful in the treatment of NUD. However, we need more trials to assess dyspepsia symptom scores and also psychological intervention in order to give us a clearer picture of the role of psychological intervention in NUD.

Cognitive Behavioral Therapy↗
PubMed2001

Prediction of readmission to acute psychiatric units.

BACKGROUND: Many factors are known to influence readmission to psychiatric wards, and readmission rates have been suggested as proxy outcome indicators of quality. METHOD: Korner returns were used to ascertain readmission rates for all psychiatric admissions to acute wards in North Staffordshire, 1987-1993. Predictor variables were derived from Korner returns or obtained from the 1991 Census data. Survival analysis techniques were used to examine which variables predicted readmission. RESULTS: A predictive model was derived using Cox regression, which followed the observed data at greater than chance probability (chi2=48.5, df=4, P < 0.001). A psychotic diagnosis was the most influential predictor of readmission. CONCLUSION: Length of stay is not predictive in the Cox regression model, which suggests patients are not being prematurely discharged. The derived models may have value in service planning, audit and resource allocation.

Adolescent↗
PubMed2001

Alopecia in three women of Southeast Asian descent with chronic renal failure: possible association with erythropoietin use.

Recombinant human erythropoietin (Epo) has been used successfully to correct the anemia caused by chronic renal failure in patients undergoing dialysis, as well as the anemia associated with other conditions, including cancer therapy. Despite its benefits, it can be associated with adverse side effects. These include hypertension, headaches, increased seizure activity, clotted vascular access, and occasional thromboembolic events, such as myocardial infarction or stroke. We report a potentially new side effect associated with Epo of a cosmetic nature. Three Southeast Asian women with chronic renal failure developed diffuse, nearly total, hair loss during erythropoietin use. Two cases were strongly associated with Epo use, and a third had other intercurrent illnesses as well. Alopecia may be associated with Epo use in certain ethnic populations.

Adult↗
PubMed2001

Use of a cross-sectional survey to estimate outcome of health care: the example of anxiety and depression.

Our study proposes that a population-based cross-sectional survey can be used to estimate the outcome of health care by linking general practice morbidity records to the survey. Using the example of anxiety and depression to test this idea, we conducted a survey of an adult population registered with one general practice in the UK. The Hospital Anxiety and Depression (HAD) questionnaire was used to identify cases and controls. After mailing to a randomly selected adult population of 4002, there was an adjusted response rate of 66% (n = 2,606), with 416 (16%) high-score cases, 506 (19%) medium-score cases, and 1684 (65%) low-score controls. All cases were compared with a sample of controls (n = 450). In the 12 months before the survey, the high-score case group had experienced significantly higher GP contacts (n = 377 [91%] versus 354 [79%]), diagnoses for anxiety or depression (119 [29%] versus 21 [5%]), and related drug treatments (111 [27%] versus 22 [5%]) compared with the control sample. Most of the diagnoses and drug treatments had been initiated at least 9 months before the survey. The linkage between the survey and the clinical records suggested that the health outcome of previously identified anxious and depressed patients was poor, with an estimated two-thirds who will not have fully recovered within an average of 9 months. This study demonstrates the potential for using cross-sectional population surveys to estimate not only the need for health care but also the outcome of health care.

Adolescent↗
PubMed2001

The Lac repressor: a second generation of structural and functional studies.

In the past year, the crystal structure of a dimeric version of the Escherichia coli Lac repressor bound to operator DNA was determined at 2.6A resolution, providing a closer view of the operator-bound conformation of the repressor. Refined NMR studies of the DNA-binding portion of the repressor complexed to operator DNA have revealed further details of the unique DNA-binding interactions of the repressor. The structural studies have been complemented by continued biochemical studies, with the overall goal of understanding the mechanism of allosteric regulation.

Bacterial Proteins↗
PubMed2001

Volatile compounds from Salix spp. varieties differing in susceptibility to three willow beetle species.

The volatile compounds emitted by leaves of 10 willow varieties that differ in their susceptibility to damage by blue (Phratora vulgatissima), brassy (P. vitellinae), and brown (Galerucella lineola) willow beetles were examined both before and after mechanical damage and correlated with feeding preferences of these beetles determined under laboratory conditions. Three compounds were identified from intact undamaged leaves of six willow varieties, namely cis-3-hexenyl acetate, cis-3-hexenol, and benzaldehyde. After mechanical damage, the yield and number of volatile compounds increased for all varieties. There were significant differences among willow varieties for both the concentration of cis-3-hexenyl acetate and the relative proportion of this compound to cis-3-hexenol (green leaf volatile ratio). The 10 varieties collectively showed a significant negative correlation between the relative resistance of each variety to blue and brown willow beetles and the yield of cis-3-hexenyl-acetate from damaged plants. The green leaf volatile ratio of damaged plants was also negatively correlated with the relative resistance of willow variety to these two beetle species.

Animals↗
PubMed2001

Prevalence and morbidity associated with non-malignant, life-threatening conditions in childhood.

OBJECTIVE: To determine the prevalence of non-malignant life-threatening illness in childhood and associated morbidity in the affected child and their family members. DESIGN: Cross-sectional survey. SETTING: Bath Clinical Area (total population 411,800). SUBJECTS: Children aged 0-19 years. RESULTS: One hundred and twenty-three children were identified, giving a prevalence of 1.2/1000 children. Morbidity assessed in 93 children showed 60% in pain or discomfort, 35% unable to walk and 25% with severe cognitive impairment. Mental health problems were found in 54% of mothers and 30% of fathers, and significant emotional and behavioural problems in 24% of healthy siblings. CONCLUSIONS: Non-malignant life-threatening illness is more prevalent than reported in previous studies. Considerable morbidity is experienced by the child and their family. An individual and family approach is required. Key messages (1) The prevalence of non-malignant life-threatening illness is four times greater than previous estimates. (2) This group of conditions have significant implications for all family members. (3) Early comprehensive assessment and access to effective interventions may pre-empt later problems.

Adolescent↗
PubMed2001

Five cases of severe cardiac disease in pregnancy: outcomes and costs.

The obstetric, medical and anaesthetic management of five pregnant patients with a variety of significant cardiac problems is briefly reviewed. The duration of hospitalisation, and the use of high dependency and intensive care are documented. Financial costs are estimated and their implications for the care of such patients during and following pregnancy are discussed.

Journal Article↗
PubMed2001

The management of eclampsia by obstetric anaesthetists in UK: a postal survey.

Eclampsia and pre-eclampsia are major causes of morbidity and mortality in the obstetric population. The latest triennial report on Confidential Enquiries into Maternal Deaths found hypertensive disorders of pregnancy to be the second most common cause of maternal deaths directly attributable to pregnancy. The management of eclampsia includes the control and prevention of further convulsions by pharmacological methods but the choice of drugs may vary. Current evidence supports the use of magnesium sulphate as the drug of first choice for treating eclampsia. Until recently, UK clinicians used other anticonvulsants for this purpose. Questionnaire studies conducted amongst UK obstetricians published in 1991 and 1998 showed that magnesium sulphate was used in the management of severe pre-eclampsia by 2% and 40% of clinicians respectively. We conducted a survey among lead obstetric anaesthetists in 264 obstetric units in the UK to examine their current practice. We also asked how magnesium was used and included a question on the use of nimodipine. The response rate was 86%. Our results show that magnesium sulphate is used for the treatment of eclampsia in 90% of units and for severe pre-eclampsia in 68%. Most administered magnesium for 24-48 h while nimodipine was used by very few units.

Journal Article↗
PubMed2001

Long-term morbidity following dural puncture in an obstetric population.

Immediate and long-term symptoms, particularly headache, are recognised complications of dural puncture. To investigate long-term symptoms, a case-controlled retrospective questionnaire study was performed. The questionnaire was sent to 194 mothers who had suffered either accidental dural puncture during the placement of an epidural catheter or had developed a significant headache following spinal anaesthesia. The mothers were questioned about the nature and severity of symptoms and the impact upon their normal daily lives. They were also asked about the type and efficacy of any treatment they had received for these symptoms. An equal number of controls matched for ethnicity, age, modes of delivery and needle type were also questioned. There was increased reporting of new long-term headache and neckache in the spinal study group and an increased reporting of new long-term backache in the accidental dural puncture group compared to the epidural controls. These symptoms had a significant impact upon the mother's daily life and in some instances lasted for years. Disappointingly, although epidural blood patching was beneficial in the short term, it failed to produce any reduction in the incidence of long-term symptoms.

Journal Article↗
PubMed2001

Mother-infant interaction at 12 months in prenatally cocaine-exposed children.

This study examined mother-infant interactions of 12-month-old African-American prenatally cocaine-exposed infants and their mothers. Videotaped observations were made during a free-play dyadic interaction, a brief separation, and a reunion period. Videotapes were coded for maternal and child behaviors during each phase of the procedure. Although there were few differences in interactive behaviors between prenatally cocaine-exposed and nonexposed children and their mothers, children who were prenatally exposed to cocaine ignored their mother's departure (odds ratio [OR] = 3.0, p < .05) during separation significantly more often than nonexposed subjects. In addition, mothers who abused cocaine engaged in significantly more verbal behavior (F(2,104) = 7.00, p < .001) with their children than mothers of nonexposed children. These findings indicate that women who used cocaine during pregnancy may not differ from nonusers in their interactions with their 12-month-old infants.

Adult↗
PubMed2001

A brief screening tool for knee pain in primary care. 1. Validity and reliability.

OBJECTIVES: To design and test the performance of a new knee pain screening tool (KNEST), both separately and together with a combination of existing questionnaires, which will be used to assess the general health status of knee pain sufferers in primary care. METHODS: A postal survey of knee pain and disability was sent to a random sample of 240 individuals aged over 55 yr registered with two general practices in North STAFFORDSHIRE: The survey questionnaire consisted of the KNEST; a pain manikin; the Short Form 36 (SF-36); the Hospital Anxiety and Depression Scale (HADS); demographic questions; and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) for those who reported knee pain. A second, identical questionnaire was sent 2 weeks later to a random subsample of responders (n=80) to test repeatability. RESULTS: An 85% baseline response rate was achieved for the first questionnaire. The 12-month prevalence of knee pain identified from baseline responders to the survey was 45%. A response rate of 74% was achieved for the repeatability questionnaire. Each section of the questionnaire was well completed and repeatability was good for nearly all measures (most reliability scores exceeded 0.6). A new core question about knee pain showed good internal reliability, with an agreement score of 91% between baseline and retest assessment, and good construct validity in relation to knee pain identified on the pain manikin (agreement 95%). Good agreement was found between recalled consultation for knee pain in the questionnaire and evidence of consultation for knee pain in general practice records. CONCLUSIONS: The KNEST appears to be a reliable and valid composite tool for the study of population needs and outcomes of care for people aged over 55 yr with knee pain.

Disability Evaluation↗
PubMed2001

Lessons to be learned: a case study approach insulinoma presenting as a change in personality.

A 43-year-old man presented with attacks of altered behaviour over a short period of time; they were associated with episodes of hypoglycaemia. The clinical suspicion of insulinoma prompted investigations that quickly established serum insulin and C-peptide levels to be elevated at the times when blood glucose values were low. A physical lesion was found in the head of the pancreas by means of computerised tomography and endo-duodenal ultrasound scan; an octreotide scan was negative. The patient underwent laparotomy and enucleation of a benign tumour, measuring 2.6 cm in diameter, lying within the head of the pancreas; histological examination confirmed it to be an insulinoma. Postoperatively, the patient's personality gradually became more normal and his fasting blood glucose concentrations returned to within normal limits. The diagnosis and management of insulinoma are discussed in the context of this clinical case; there is also reference to the protean clinical manifestations that may occur in this condition- and its differential diagnosis.

Adult↗
PubMed2001

A case-control study of differences between regular and causal adult attenders in general dental practice.

OBJECTIVES: To assess whether adults attending a dental practice for regular dental care have better oral health than adults attending casually in response to a dental problem, and to explore the barriers to asymptomatic attendance. METHODS: An observational case-control study comparing the characteristics of 100 regular attenders with 100 causal attenders in one general dental practice in North Staffordshire. All study subjects were aged 18 years or over. Sociodemographic characteristics of the two groups were collated, including age, gender, social class, marital status, employment status and smoking status. The primary outcome measure was the observed number of teeth with dentinal caries diagnosed using bitewing radiographs. RESULTS: Regular attenders were observed to have better oral health with respect to dental caries and tooth mobility (p < 0.05). This was not explained by the observation that causal attenders were more likely than regular attenders to be male, aged 18-44 years, in social class III or IV. Secondary outcomes, including number of subjects with mobile teeth and teeth with > 30% bone-loss, were also significantly worse in the casual attenders. However, the median number of teeth present in both groups was 27. In regular attenders, the most common reason for attending was to 'keep the teeth' (96%). In casual attenders, 'fear/dislike of dental treatment' was the most frequent indicator of non-attendance (56%). CONCLUSIONS: In our study, adults who regularly attended general dental practice were shown to have better oral health, including less overall tooth decay, mobility and bone-loss, compared with adults who did not attend on a regular basis. Assuming this result to be externally valid, a challenge for the dental profession in the future will be to develop effective oral health promotion initiatives.

Adolescent↗
PubMed2001

Maximal replacement of forage and concentrate with a new wet corn milling product for lactating dairy cows.

Three experiments were conducted to determine the maximal amount of concentrate and forage that could be replaced with a new wet corn milling product. The corn milling product contained 23.1% crude protein, 9.9% ruminally undegradable protein, 13.7% acid detergent fiber, 40.3% neutral detergent fiber, and 2.6% ether extract (% of dry matter; DM). In experiment 1, 16 Holstein cows were assigned to one of four diets in a replicated 4 x 4 Latin square design with 28-d periods. The four diets contained 54.3% forage (alfalfa:corn silages, 1:1 DM basis) with the wet corn milling product replacing 0, 50, 75, or 100% of the concentrate portion (corn and soybean meal) of the diet (DM basis). The diets containing wet corn milling product resulted in 7.8% lower DM intake, equivalent milk production (28.5 kg/d), and 13.6% greater efficiency of 4% fat-corrected milk (FCM) production than the control diet. There was no effect of diet on ruminal pH. In experiment 2, 16 Holstein cows were assigned to one of four diets in a replicated 4 x 4 Latin square design with 28-d periods. The 100% concentrate replacement diet from experiment 1 was used as control diet. For the test diets, forage was replaced with 15, 30, or 45% of the corn milling product (DM basis). Efficiency of FCM production (1.16) was not affected by diet. Rumination time was reduced for the 30 and 45% forage replacement diets, but ruminal pH was unaffected. In experiment 3, 30 Holstein cows were assigned at parturition to either a control diet (no corn milling product) or a diet containing 40% corn milling feed in place of both forage and concentrate (optimal levels from experiments 1 and 2) for 9 wk. The diet containing corn milling feed resulted in 21% greater efficiency of FCM production than the control diet. These results indicate that a new feed product based on wet corn milling ingredients has the potential to effectively replace all of the concentrate and up to 45% of the forage in the diet for lactating dairy cows.

Animal Feed↗