Biomedical subjects

Michael Lewis

Publications and source records attributed to Michael Lewis.

At least 19 recordsLinked to original sources

PubMed2007

Brief report: brain activation to social words in a sedated child with autism.

A functional magnetic resonance imaging (fMRI) study was performed on a 4-year-old girl with autism. While sedated, she listened to three utterances (numbers, hello, her own first name) played through headphones. Based on analyses of the fMRI data, the amount of total brain activation varied with the content of the utterance. The greatest volume of overall activation was in response to numbers, followed by the word 'hello', with the least activation to her name. Frontal cortex activation was greatest in response to her name, with less activation for numbers, and the least for the word 'hello.' These findings indicate that fMRI can identify and quantify the brain regions that are activated in response to words in children with autism under sedation.

Autistic Disorder↗

PubMed2006

Traveler's diarrhea in Thailand: randomized, double-blind trial comparing single-dose and 3-day azithromycin-based regimens with a 3-day levofloxacin regimen.

BACKGROUND: Traveler's diarrhea in Thailand is frequently caused by Campylobacter jejuni. Rates of fluoroquinolone (FQ) resistance in Campylobacter organisms have exceeded 85% in recent years, and reduced fluoroquinolone efficacy has been observed. METHODS: Azithromycin regimens were evaluated in a randomized, double-blind trial of azithromycin, given as a single 1-g dose or a 3-day regimen (500 mg daily), versus a 3-day regimen of levofloxacin (500 mg daily) in military field clinics in Thailand. Outcomes included clinical end points (time to the last unformed stool [TLUS] and cure rates) and microbiological end points (pathogen eradication). RESULTS: A total of 156 patients with acute diarrhea were enrolled in the trial. Campylobacter organisms predominated (in 64% of patients), with levofloxacin resistance noted in 50% of Campylobacter organisms and with no azithromycin resistance noted. The cure rate at 72 h after treatment initiation was highest (96%) with single-dose azithromycin, compared with the cure rates of 85% noted with 3-day azithromycin and 71% noted with levofloxacin (P=.002). Single-dose azithromycin was also associated with the shortest median TLUS (35 h; P=.03, by log-rank test). Levofloxacin's efficacy was inferior to azithromycin's efficacy, except in patients with no pathogen identified during the first 24 h of treatment or in patients with levofloxacin-susceptible Campylobacter isolates, in whom it appeared to be equal to azithromycin. The rate of microbiological eradication was significantly better with azithromycin-based regimens (96%-100%), compared with levofloxacin (38%) (P=.001); however, this finding was poorly correlated with clinical outcome. A higher rate of posttreatment nausea in the 30 min after receipt of the first dose (14% vs. <6%; P=.06) was observed as a mild, self-limited complaint associated with single-dose azithromycin. CONCLUSIONS: Single-dose azithromycin is recommended for empirical therapy of traveler's diarrhea acquired in Thailand and is a reasonable first-line option for empirical management in general.

Adult↗

PubMed2006

Arene-cation interactions of positive quadrupole moment aromatics and arene-anion interactions of negative quadrupole moment aromatics.

Intermolecular interactions involving aromatic pi-electron density are widely believed to be governed by the aromatic molecular quadrupole moment, Theta(zz). Arene-cation binding is believed to occur primarily with negative Theta(zz) aromatics, and arene-anion binding is believed to occur largely with positive Theta(zz) aromatics. We have performed quantum mechanical computations that show the cation binding of positive Theta(zz) aromatics and the anion binding of negative Theta(zz) aromatics is quite common in the gas phase. The pi-electron density of hexafluorobenzene, the prototypical positive Theta(zz ) aromatic (experimental Theta(zz) = 9.5 +/- 0.5 DA), has a Li+ binding enthalpy of -4.37 kcal/mol at the MP2(full)/6-311G**level of theory. The RHF/6-311G** calculated Theta(zz) value of 1,4-dicyanobenzene is +11.81 DA, yet it has an MP2(full)/6-311G** Li+ binding enthalpy of -12.65 kcal/mol and a Na+ binding enthalpy of -3.72 kcal/mol. The pi-electron density of benzene, the prototypical negative Theta(zz) aromatic (experimental Theta(zz) = -8.7 +/- 0.5 DA), has a F- binding enthalpy of -5.51 kcal/mol. The RHF/6-311G** calculated Theta(zz) of C6H2I4 is -10.45 DA, yet it has an MP2(full)/6-311++G** calculated F- binding enthalpy of -20.13 kcal/mol. Our results show that as the aromatic Theta(zz) value increases the cation binding enthalpy decreases; a plot of cation binding enthalpies versus aromatic Theta(zz) gives a line of best of fit with R2 = 0.778. No such correlation exists between the aromatic Theta(zz) value and the anion binding enthalpy; the line of best fit has R2 = 0.297. These results are discussed in terms of electrostatic and polarizability contributions to the overall binding enthalpies.

Benzene↗

PubMed2006

Brain activation when hearing one's own and others' names.

Using functional magnetic resonance imaging, brain activation patterns were examined in response to hearing one's own first name in contrast to hearing the names of others. There are several regions in the left hemisphere that show greater activation to one's own name, including middle frontal cortex, middle and superior temporal cortex, and cuneus. These findings provide evidence that hearing one's own name has unique brain functioning activation specific to one's own name in relation to the names of others.

Adult↗

PubMed2006

Preliminary in vivo evidence of increased N-acetyl-aspartate following eicosapentanoic acid treatment in patients with bipolar disorder.

Ethyl-eicosapentanoic acid (ethyl-EPA) may be beneficial in the treatment of bipolar disorder (BD) and may have a neurotrophic/neuroprotective role in patients with neuropsychiatric disorders. To investigate this we examined whether ethyl-EPA treatment of BD patients is associated with increased brain levels of N-acetylaspartate (NAA), a putative marker of neuronal integrity. Fourteen female BD outpatients with moderate depressive symptoms were administered 2 g of ethyl-EPA per day or placebo for 12 weeks in a randomized, double-blind fashion. Quantitative, proton magnetic resonance spectroscopy imaging data were obtained prior to randomization and after 12 weeks of treatment from a single 12 ml volume of interest centred above the body of the corpus callosum. A significant rise in NAA levels was observed in the ethyl-EPA treatment group compared with the placebo group (p = 0.027). These results provide the first evidence for a probable neurotrophic role of ethyl-EPA treatment in BD underlining the need for more detailed investigation of its mechanism of action and therapeutic potential.

Adult↗

PubMed2006

Adults' ability to detect children's lying.

Adults are poor deception detectors when examining lies told by adults, on average. However, there are some adults who are better at detecting lies than others. Children learn to lie at a very young age, a behavior that is socialized by parents. Yet, less is known about the ability to detect children's lies, particularly with regard to individual differences in the ability to detect this deception. The current study explored adult raters' ability to discern honesty in children who lied or told the truth about committing a misdeed. Results showed that adults are no better at detecting children's lies than they are with adult lies. In particular, adults were very poor at identifying children's honest statements. However, individual differences did emerge, suggesting that the ability to detect lying in children might be facilitated by relevant experience working with children. Implications for legal and mental health contexts are discussed.

Adult↗

PubMed2006

The relation of ANS and HPA activation to infant anger and sadness response to goal blockage.

This study examined the relation of anger and sadness to heart rate and cortisol in 4-month-old infants' (n = 56) response to a goal blockage. The blockage occurred during a contingency learning procedure where infants' response no longer produced a learned interesting event. Anger and sadness were the major emotional expressions to the blockage. The two emotional expressions were differentially related to heart rate and cortisol. Anger was related to increased heart rate, but not cortisol, whereas sadness was related to increased cortisol, but not heart rate. Along with other work, the present results support the view that infant anger in response to goal blockage involves autonomic as opposed to adrenocortical activation as a consequence of an expectation of control over the event. In contrast, sadness in response to goal blockage involves adrenocortical as opposed to autonomic activation stemming from the absence of an expectation of control.

Affect↗

PubMed2006

Reactivity and regulation in children prenatally exposed to cocaine.

Children prenatally exposed to cocaine may be at elevated risk for adjustment problems in early development because of greater reactivity and reduced regulation during challenging tasks. Few studies have examined whether cocaine-exposed children show such difficulties during the preschool years, a period marked by increased social and cognitive demands and by rapid changes in reactivity and regulation. The authors addressed this question by examining frustration reactivity and regulation of behavior during a problem-solving task in cocaine-exposed and -unexposed preschoolers. Participants were 174 4.5-year-olds (M age = 4.55 years, SD = 0.09). Frustration reactivity was measured as latency to show frustration and number of disruptive behaviors, whereas regulation was measured as latency to approach and attempt the problem-solving task and number of problem-solving behaviors. Results indicated that cocaine-exposed children took longer to attempt the problem-solving task but that cocaine-exposed boys showed the most difficulties: They were quicker to express frustration and were more disruptive. Effect sizes were relatively small, suggesting both resilience and vulnerabilities.

Adaptation, Psychological↗

PubMed2006

Transcriptional levels of growth factors in skeletal muscle of maintenance hemodialysis patients.

This study was performed to assess the mRNA levels in skeletal muscle of maintenance hemodialysis (MHD) patients. Fifty-one sedentary MHD patients and 21 sedentary normal adults of similar age, gender distribution, and racial/ethnic mix as the patients were examined. The subjects had needle muscle biopsy to measure mRNA levels. They were assessed in right vastus lateralis muscle for insulinlike growth factor I (IGF-IEa and IGF-IEc), IGF-II, the IGF-I receptor, the IGF-II receptor, and myostatin. mRNA was measured by real-time polymerase chain reaction amplification of reverse transcribed cDNA. The results showed that in the MHD patients, as compared with the normal control patients, skeletal muscle mRNA levels for IGF-IEa, IGF-II, and the IGF-I receptor were significantly reduced, whereas mRNA for IGF-IEc, IGF-II receptor, and myostatin were not different than normal. We conclude that sedentary MHD patients show reductions in mRNA levels in the right vastus lateralis muscle for certain growth factor proteins, notably IGF-IEa, IGF-II, and the IGF-I receptor. These abnormalities may contribute to the sarcopenia and impaired endurance capacity, strength, and physical performance that occur in MHD patients.

Adult↗

PubMed2006

Effect of exercise on mRNA levels for growth factors in skeletal muscle of hemodialysis patients.

OBJECTIVES: Muscle mass and muscle mRNA levels for certain growth factors are reduced in maintenance hemodialysis (MHD) patients. This study tested the hypothesis that in MHD patients endurance exercise training (EET) increases mRNA levels for insulin-like growth factors and reduces myostatin mRNA. DESIGN: Biopsies of the right vastus lateralis muscle were performed before and at the end of 8.9 +/- 0.9 (SEM) weeks of EET in MHD patients. Muscle tissue was analyzed histologically by electron microscopy and for fiber cross-sectional area, and, in 8 pairs of biopsies, muscle was examined for mRNA levels for the following proteins: myostatin, insulin-like growth factor-I (IGF-I), IGF-I receptor (IGF-IR), IGF binding proteins (IGFBPs)-1, -2, -3, -4, and -5, and IGF-binding protein-related protein-1 (IGFBP-rP1). SETTING: Outpatient MHD centers. PATIENTS: This was a pilot study conducted in sedentary clinically stable MHD patients undergoing EET with no control group. INTERVENTION: EET that was carefully supervised by exercise trainers. MAIN OUTCOME MEASURE: Skeletal muscle mRNA levels, especially myostatin mRNA. RESULTS: With EET, skeletal muscle myostatin mRNA decreased by 51%, mRNA levels increased significantly for IGF-IR (by 41%), IGFBP-2, -4, and -5, and IGFBP-rP1. IGF-I mRNA increased by 35%; this change was not significant. IGFBP-3 mRNA did not change, and IGFBP-1 mRNA was undetectable. There were mild to moderate alterations in skeletal muscle ultrastructure that did not change significantly with EET. Muscle fiber size, measured in 5 patients, did not change. CONCLUSION: In MHD patients who undergo approximately 9 weeks of EET, skeletal muscle mRNA for myostatin decreases and mRNA for IGF-IR, IGFBPs -2, -4, and -5 and IGFBP-rP1 increases. These changes may indicate mechanisms by which EET improves muscle exercise capacity in MHD patients.

Adult↗

PubMed2006

The development of an innovative education curriculum for 11-16 yr old children with type 1 diabetes mellitus (T1DM).

BACKGROUND: Evidence-based, structured education is recommended for all people with diabetes; tailored to meet their personal needs and learning styles. Adult courses exist in the UK but are of limited value for children. The aim of this study was to adapt the adult Dose Adjustment For Normal Eating (DAFNE) course to design a skills training course, for children aged 11-16 yr, focusing on self-management skills within an intensive insulin regime. To ensure that the course format meets the developmental, intellectual and social needs of children and adolescents and is delivered using educationally sound techniques. METHODS: Relevant professionals and potential users of the course were involved in curriculum design and content in the following ways: (i) The views of 95 pediatric diabetes specialist nurses were sought through a postal survey; (ii) Focus group discussions were conducted with children with type 1 diabetes mellitus (T1DM) and their families to contribute to content and design; and (iii) Secondary school teachers worked with experienced pediatric diabetes staff advising on educational content and teaching format. RESULTS: The developed curriculum uses a progressive modular-based structure to improve self-management in a variety of medical and social situations. It has clear learning objectives and is based on the format of UK schools curricula. Additional support is provided through dedicated parent sessions, involvement of friends and the provision of a school resource pack. CONCLUSION: Collaborative working between health professionals, school teachers and families has resulted in an age-appropriate curriculum, which employs validated educational techniques. This will be refined following pilot courses before formal evaluation in a multicentre randomized controlled trial.

Adolescent↗

PubMed2006

Relations of parental report and observation of parenting to maltreatment history.

Parenting assessments (the Parent-Child Conflict Tactics Scale, CTSPC; and a mother-child observation) were examined for their ability to identify mothers with a history of physically abusing or neglecting their child. Participants were mothers of 139 children (age 3 to 6 years; 58 with a history of maltreatment). Mothers with a history of maltreatment reported higher scores on the Neglect, Nonviolent Discipline, and Psychological Aggression subscales of the CTSPC. These group differences, however, were limited to mothers who acknowledged a history of maltreatment, as mothers who concealed their maltreatment history rated themselves similar to controls. Observation of parental behaviors during a brief, nonstressful task did not discriminate mothers who maltreated from mothers who did not maltreat. The findings suggest that parental report using the CTSPC may be useful in assessing parenting behaviors among mothers with a history of maltreatment, although socially desirable responding is a significant problem.

Adult↗

PubMed2006

Efficacy of ethyl-eicosapentaenoic acid in bipolar depression: randomised double-blind placebo-controlled study.

BACKGROUND: Epidemiological and clinical studies suggest that increased intake of eicosapentaenoic acid (EPA) alleviates unipolar depression. AIMS: To examine the efficacy of EPA in treating depression in bipolar disorder. METHOD: In a12-week, double-blind study individuals with bipolar depression were randomly assigned to adjunctive treatment with placebo (n=26) or with 1 g/day (n=24) or 2 g/day (n=25) of ethyl-EPA. Primary efficacy was assessed by the Hamilton Rating Scale for Depression (HRSD), with changes in the Young Mania Rating Scale and Clinical Global Impression Scale (CGI) as secondary outcome measures. RESULTS: There was no apparent benefit of 2 g over 1 g ethyl-EPA daily. Significant improvement was noted with ethyl-EPA treatment compared with placebo in the HRSD (P=0.04) and the CGI (P=0.004) scores. Both doses were well tolerated. CONCLUSIONS: Adjunctive ethyl-EPA is an effective and well-tolerated intervention in bipolar depression.

Adult↗

PubMed2006

Associative priming in faces: semantic relatedness or simple co-occurrence?

In two experiments, we explored the effects of co-occurrence and semantic relationships in the associative priming of faces. In Experiment 1, pairs of computer-generated human faces were presented simultaneously (i.e., they co-occurred) with no associated semantic information attached to them. A significant facilitation effect in the subsequent recognition of these paired faces (priming) was observed. Thus, repeatedly presenting faces together while keeping semantic information to a minimum appears to be enough to produce associative priming. In Experiment 2, the computer-generated faces were associated with semantic information and again presented ipairs. Priming effects arising from co-occurrence and semantic relatedness were observed. The results from these experiments show that semantic relatedness is not the sole cause of the association between faces; co-occurrence plays a crucial role too. This conclusion has significant implications for the current computational models of face processing.

Adult↗

PubMed2006

Surveillance for febrile respiratory infections during Cobra Gold 2003.

The Naval Health Research Center conducted laboratory-based surveillance for febrile respiratory infections at the 2003 Cobra Gold Exercise in Thailand. Seventeen individuals met the case definition for febrile respiratory illness, and diagnostic specimens were obtained from 16. Laboratory testing identified influenza A for 44%; sequence analysis demonstrated that these were Fujian-like influenza strains, which represented the predominant strain found globally in 2003/2004. Other pathogens identified included coronavirus OC43, respiratory syncytial virus, and rhinovirus. Logistical challenges were overcome as laboratory-supported febrile respiratory illness surveillance was conducted during a military training exercise. With heightened concern over the potential for another global influenza pandemic, such surveillance could prove critical for the detection of emerging influenza and respiratory pathogen strains with potential for importation to the United States.

Adult↗

PubMed2006

Is there a role for serum endothelin in predicting the severity of acute pancreatitis?

BACKGROUND: Acute pancreatitis remains a common presentation to acute surgical units and carries significant morbidity and mortality. The progression of the disease to necrotizing pancreatitis and multi-organ dysfunction syndrome (MODS) is associated with a very poor clinical outcome, and persistently high mortality. Increases in serum endothelin (ET) have been seen in animal models of acute pancreatitis and this study aims to investigate whether there is a change in serum ET-1 in patients with acute pancreatitis and whether any such change is linked to disease severity. METHODS: All patients admitted with acute pancreatitis were prospectively recruited from the emergency admissions at the Norfolk and Norwich University Hospital. Serum ET levels were determined on admission, at 24 hours and 5 days post admission. Healthy adult controls were recruited from dermatology outpatients. RESULTS: A total of 21 patients joined the trial after giving informed consent. There were 3 men and 18 women with a median age of 65 years (range 26-87 years). Serum ET levels were significantly higher in acute pancreatitis patients than in normal controls (P<0.05). An association was seen between persistently raised serum ET levels and progression to MODS. CONCLUSIONS: The study does demonstrate a correlation between the circulating levels of ET and acute pancreatitis in humans, although it does not elicit its involvement in the pathogenesis of the disease. The observation that a persistently high level of circulating ET-1 is associated with progression to MODS may indicate a role for ET in the monitoring of acute pancreatitis patients for recovery or progression to MODS.

Acute Disease↗

PubMed2005

Steroid-induced alterations of mood and behavior in children during treatment for acute lymphoblastic leukemia.

Despite their therapeutic utility, children may experience emotional and behavioral side effects from steroids during treatment for leukemia. However, clinical manifestations and treatment options have rarely been described in the pediatric literature. The aim of this current paper is to address this knowledge gap via four brief case examples and a review of the literature. In addition, we review recent data to indicate how concurrent use of antifolates may place these children at particular risk for adverse psychological reactions.

Affect↗

PubMed2005

Case-control study on analgesics and nephropathy (SAN): protocol.

BACKGROUND: The association between intake of non-phenacetin-containing analgesics and the occurrence of chronic renal failure is still controversially discussed. A new epidemiologic study was planned and conducted in Germany and Austria. METHODS/DESIGN: The objective of the international, multicenter case-control study was to evaluate the association between end-stage renal disease (ESRD) and use of non-phenacetin-containing analgesics with particular emphasis on combined formulations. A targeted sample of 1000 new (incident) dialysis patients, aged less than 50 years, was planned to recruit between January 1, 2001 and December 31, 2004. The age limit was chosen to avoid contamination of the study population with phenacetin-containing analgesics to the extent possible. Four control subjects per ESRD case, matched by age, sex, and region were selected from the population living in the region the case came from. Lifetime exposure to analgesics and potential renal risk factors were recorded in a single face-to-face interview. A set of aids was introduced to reinforce the memory of study participants. A standardized, pre-tested interview questionnaire (participants), a medical documentation sheet (physicians in dialysis centres), a logbook for all activities (dialysis centres) were used to collect the necessary data. Quality management consisted of the standardized procedures, (re-) training and supervision of interviewers, regular checks of all incoming data for completeness and plausibility. The study is scientifically independent and governed by a international Scientific Advisory Committee that bridged the gap between the sponsoring companies and the investigators. Also other advisory groups assisted the managing committee of the study. All relevant German and Austrian nephrological associations supported the study, and the study design was carefully reviewed and approved by the Kidney Foundation of Germany. DISCUSSION: The study is expected to answer the main research question by end 2005. There is however a high potential for various biases that we tried to address with adequate measure. One limitation however cannot be overcome: The methodologically needed age-limitation of the study will make it not easy to generalize the results to age groups over 50 years. It might be suggested to repeat the study for persons over 50 years in 10 years when contamination with phenacetin use early in life is likely to be outgrown.

Analgesics↗