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Biomedical subjects

Richard Thompson

Publications and source records attributed to Richard Thompson.

At least 37 records · Page 2Linked to original sources
PubMed2005

Toward a definition of neglect in young children.

This study examined the relationship between child experiences identified conceptually as "neglectful" prior to age 4 and child outcomes at age 4. This was done using measures from two sites collected as part of LONGSCAN. Child needs were included within categories of physical and psychological safety and security. Problems with residence safety or cleanliness and untreated behavioral problems predicted child impairments in language. CPS reports of failure to provide shelter predicted impairments in several developmental outcomes. A stimulating home environment predicted less impairment in cognitive development. Multiple changes in residence predicted externalizing behavior problems. Exposure to verbally aggressive discipline predicted more behavioral problems overall. Conversely, some indicators (such as caregiver transitions and lack of medical care) predicted less developmental impairment or fewer behavior problems in certain domains. The approach supports a conceptualization of neglect based on child developmental needs. Implications for practice and future research are discussed.

Affect↗
PubMed2005

Randomised-controlled trial of a fibre supplement on the symptoms of irritable bowel syndrome.

The aim of this study was to assess the effect of coarse wheat bran on specific bowel function parameters and symptoms in patients with irritable bowel syndrome (IBS). A longitudinal, prospective, randomised, placebo-controlled trial was undertaken. The duration of treatment was eight to 12 weeks and this consisted of 10-20 g/day of coarse wheat bran or a low fibre placebo taken in addition to the normal diet. Twenty-eight outpatients fulfilling the Rome criteria for constipation-predominant IBS were recruited to the trial (14 in the treatment group; 14 in the placebo group). Twelve people completed the trial in the treatment group and ten in the placebo group. The main outcome measures included changes in symptoms recorded in a diary, changes in objective measurements of bowel function and subjective overall feelings of improvement. The bran group significantly increased their non-starch polysaccharide (NSP) intake over that of the placebo group (p < 0.05). Mean stool wet weight increased significantly more in the bran group than in the placebo group (p < 0.05), but other bowel function measurements and all recorded symptoms were not different. Many patients reported changes in bowel habit that were not reflected in the objective measurements. The addition of coarse wheat bran to the diet increased NSP ingestion and stool wet weight in this group of IBS patients, but no evidence was obtained that such treatment was of benefit to these patients, other than a placebo effect on symptoms.

Abdominal Pain↗
PubMed2005

Dynamic MRI of bladder cancer: evaluation of staging accuracy.

OBJECTIVE: The purpose of this study was to evaluate the accuracy of gadoliniumenhanced MRI in staging bladder cancer in a series of patients with surgically proven bladder cancer. MATERIALS AND METHODS: Seventy-one patients with biopsy-proven bladder cancer underwent MRI on a 1.5-T scanner with a phased-array pelvic coil. Conventional T1-weighted spin-echo, T2-weighted spin-echo, and unenhanced and enhanced (0.1 mmol/kg gadolinium) fast spoiled gradient-echo images with fat suppression were obtained. Two blinded reviewers evaluated the MR images and assigned a stage that was compared with the pathologic stage (n = 67) or with clinical follow-up for at least 2 years after MRI (n = 4). RESULTS: Agreement among the reviewers was good in assigning a radiologic stage for bladder cancer (kappa = 0.80). On a stage-by-stage basis, MRI accuracy was 62%, and overstaging was the most common error (32%). Staging accuracy improved to 85% and 82% in differentiating superficial from invasive tumors and organ-confined from non-organ-confined tumors, respectively. The time interval between MRI and transurethral resection (</= 60 days and >/=61 days) was not a statistically significant factor in differentiating superficial from invasive and organ-confined from non-organ-confined tumors (p > 0.05). MRI accuracy in staging transitional cell carcinoma was not significantly different from that obtained in staging non-transitional cell carcinoma (p > 0.05). CONCLUSION: MRI shows good reproducibility between reviewers for staging bladder cancer. Although overall staging accuracy was only moderate, the accuracy for differentiating superficial versus invasive disease and organ-confined versus non-organ-confined disease was high.

Adult↗
PubMed2004

The role of life events in depression in primary medical care versus psychiatric settings.

BACKGROUND: The relationship between negative life events and depression is inconsistent. The purpose of the current study is to investigate the hypothesis that depression in the community may be related more to major life events than is depression in psychiatric settings. METHODS: This hypothesis was tested using depressed primary medical care (PC; n=70) and psychiatric patients (n=62). Nondistressed (n=109) and distressed/nondepressed PC patients (n=43) served as comparison-control groups. Life events were rated using the contextual method of Brown and Harris (Brown, G.W., Harris, T.O., 1978. Social origins of depression. Tavistock, London). RESULTS: Depressed PC patients, but not depressed psychiatric patients, were significantly more likely to have recent severe events than the comparison-control groups. Self-reported distress in the absence of depression was not associated with severe life events. LIMITATIONS: History of depression was assessed using a simple count of number of previous episodes, and the assessment of depression history may require more sophisticated assessment. The measure of endogenous depression used in this study was created post-hoc and needs replication. CONCLUSIONS: Diathesis-stress models need to accommodate a lack of universality for severe stress prior to the onset of depression. Clinical strategies may need to reflect patient treatment preferences associated with differences across settings with respect to the perceived role of stress in their depression.

Adult↗
PubMed2004

Influence of inorganic mobile phase additives on the retention, efficiency and peak symmetry of protonated basic compounds in reversed-phase liquid chromatography.

Inorganic eluent additives affect the retention of protonated basic analytes in reversed-phase HPLC. This influence is attributed to the disruption of the analyte solvation-desolvation equilibria in the mobile phase, also known as "chaotropic effect". With an increase of counteranion concentration analyte retention increases with concomitant decrease in the tailing factor. Different inorganic counteranions at equimolar concentrations affect protonated basic analyte retention and peak symmetry to varying degrees. The effect of the concentrations of four different inorganic mobile phase additives (KPF6, NaClO4, NaBF4, NaH2PO4) on the analyte retention, peak symmetry, and efficiency on a C8-bonded silica column has been studied. The analytes used in this study included phenols, toluene, benzyl amines, beta-blockers and ophthalmic drugs. The following trend in increase of basic analyte retention factor and decrease of tailing factor was found: PF6- > ClO4- approximately BF4- > H2PO4-. With the increase of the counteranion concentration greater analyte loading could be achieved and consequently an increase in the apparent efficiency was observed until the maximum plate number for the column was achieved. At the highest concentration of counteranions, the peak efficiency for most of the basic compounds studied was similar to that of the neutral markers. In contrast, the neutral markers, such as phenols, showed no significant changes in retention, efficiency or loading capacity as counteranion concentration was increased.

Algorithms↗
PubMed2004

Kinetic study on the epimerization of trityloxymethyl butyrolactol by liquid chromatography.

The epimerization of trityloxymethyl butyrolactol has been investigated using dynamic chromatography and an approximation function introduced by Trapp and Schurig that is based on stochastic and theoretical plate models. The epimerization rate constants and Gibbs activation energies of epimerization are directly calculated from chromatographic peak parameters, i.e. retention times of the interconverting species, peak width at half height and the relative plateau height by using the approximation function. The relationships between peak shape and chromatographic conditions, such as flow-rate, temperature and pH are investigated.

4-Butyrolactone↗
PubMed2004

Evaluation of chiral purity for a substituted imidazole p38 MAP kinase inhibitor and its intermediates using a single chiral capillary electrophoresis method.

The chiral separation of a substituted imidazole p38 MAP kinase inhibitor and its intermediates was investigated using capillary electrophoresis (CE) with various sulfated cyclodextrins. After initial screens, a single CE chiral method with a randomly sulfated beta-CD was selected for the evaluation of chiral purity for all three compounds. Operational parameters, such as the concentration of the chiral selectors, background electrolyte (or mobile phase) pH, organic modifiers, and temperature were varied in order to achieve an optimized method. The optimal method was validated in terms of linearity, sensitivity, precision, ruggedness, and specificity.

Acetonitriles↗
PubMed2004

Randomized placebo-controlled trial of donepezil in cognitive impairment in Parkinson's disease.

OBJECTIVE: To evaluate the efficacy and safety of donepezil, an acetylcholinesterase inhibitor, as a treatment for cognitive impairment and dementia in patients with Parkinson' s disease (PD). METHODS: Using a randomized, double-blind, placebo-controlled design, nine patients received placebo and seven patients received donepezil (2.5-10 mg/day) for a mean (SD) duration of 15.2 (3.4) weeks. The primary efficacy outcomes were derived from a neuropsychological battery that assessed global cognitive status as well as memory, attention, psychomotor speed, and visuospatial and executive functions. Secondary efficacy outcomes were psychiatric symptom and activities of daily living ratings. Primary safety measures were motor signs and assessments of adverse effects. RESULTS: Patients on donepezil showed selective and significant (p<0.05) improvement on the memory subscale of the Dementia Rating Scale. There was also a trend toward improvement on a measure of psychomotor speed and attention. There were no group differences in psychiatric status, motor function, or activities of daily living as measured at baseline or end-point. Adverse effects resulted in premature withdrawal of four patients on donepezil, two for peripheral cholinergic effects and one for increased parkinsonism. Side effects were associated with dosage increases. CONCLUSION: Donepezil has a beneficial effect on memory and may improve other cognitive deficits in patients with PD and cognitive impairment. However, variable tolerability in our sample underscores the need for careful monitoring when prescribing donepezil to patients with PD, especially with dosage increases.

Aged↗
PubMed2004

Enhanced cognitive performance and cheerful mood by standardized extracts of Piper methysticum (Kava-kava).

The acute effects of the herbal anxiolytic Kava-kava (Piper methysticum G. Forster) on emotional reactivity and cognitive performance were investigated in a double-blind randomized placebo-controlled trial involving healthy volunteers. Subjects' reports of mood change were assessed with the state-trait-cheerfulness-inventory, which measures the three concepts of cheerfulness, seriousness and bad mood as both traits and states. Cognitive performance was examined with the Sperling partial report and the Sternberg item recognition task, which were used as an index for visual attention and short-term memory processing. The intake of a single dose of Kava extract (300 mg; p.o.) led to an increase in state cheerfulness, while the phytopharmacon did not influence state seriousness and bad mood. The mood-elevating effects of Kava were most prominent in trait cheerful subjects, indicating that trait cheerfulness moderated the drug-induced increase in cheerful mood. Furthermore, Kava improved the accuracy and the speed of performing the partial report and the item recognition task, indicative of a beneficial effect of the phytopharmacon on visual attention and short-term memory retrieval, respectively. Thus, unlike conventional benzodiazepine-type anxiolytics, which tend to impair cognitive performance and to increase the occurrence of negative affective states, Kava is a potent anxiolytic agent, which, additionally, can facilitate cognitive functioning and can increase positive affectivity related to exhilaration.

Adolescent↗
PubMed2004

Comparative stability determination of oligonucleotide duplexes in gas and solution phase.

The relative stability of RNA duplexes were determined in both solution and gas phase. Solution stability as determined by a spectrophotometric method indicated that the Watson-Crick duplexes were more stable than duplexes containing one GA mismatch or two tandem GA mismatches. Gas phase stability was determined using ESI-MS through variation of the collision energy in an ion trap. Stability curves similar to the melting curves obtained in solution were observed. The relative stability in gas phase differed, however, from that in solution. The duplexes with two tandem GA mismatches were found to be more stable than the Watson-Crick and single GA mismatch duplexes. The different trends observed in solution versus gas phase can be attributed to the primary means of interaction. In solution, stacking is expected to be the dominant interaction mode. In the gas phase, hydrogen bonding is expected to be the dominant interaction mode. Duplexes with tandem GA mismatches have the potential to undergo additional hydrogen bonding relative to the other duplexes which could account for their increased stability in the gas phase.

Base Pairing↗
PubMed2004

Posttraumatic stress disorder and current relationship functioning among World War II ex-prisoners of war.

This study examined the association of posttraumatic stress disorder (PTSD) with the quality of intimate relationships among present-day male World War II ex-prisoners of war (POWs). Ex-POWs had considerable marital stability; those with PTSD were no less likely to be in an intimate relationship. Ex-POWs in an intimate relationship who had PTSD (N=125 ) were compared with ex-POWs in a relationship who did not have PTSD (N=206). Marital functioning was within a range expected for persons without traumatic exposure. Yet, over 30% of those with PTSD reported relationship problems compared with only 11% of those without PTSD. Ex-POWs with PTSD reported poorer adjustment and communication with their partners and more difficulties with intimacy. Emotional numbing was significantly associated with relationship difficulties independent of other symptom complexes and severity of PTSD. Implications for clinical practice are discussed.

Aged↗
PubMed2004

Influence of 10 wk of soy consumption on plasma concentrations and excretion of isoflavonoids and on gut microflora metabolism in healthy adults.

BACKGROUND: Little information is currently available on the role of the gut microflora in modulating isoflavone bioavailability or on sex differences in isoflavone metabolism and bioavailability. OBJECTIVE: We sought to determine whether chronic soy consumption influences isoflavone bioavailability as judged by plasma isoflavone concentrations and modified gut microflora activities [beta-glucoside hydrolysis and equol and O-desmethylangolensin (O-DMA) production]. We also examined whether sex differences in isoflavone metabolism exist. DESIGN: A randomized, parallel, controlled study design was used to compare a high-soy diet (104 +/- 24 mg total isoflavones/d) with a low-soy diet (0.54 +/- 0.58 mg total isoflavones/d) in 76 healthy young adults for 10 wk. RESULTS: Concentrations of isoflavones and their gut microflora metabolites in the plasma, urine, and feces were significantly higher in the subjects who consumed the high-soy diet than in those who consumed the low-soy diet. Concentrations of O-DMA in plasma and urine were higher in the men than in the women. Fecal bacteria from subjects consuming both diets could convert daidzein to equol ex vivo. Fecal beta-glucosidase activity was significantly higher in the subjects who consumed the high-soy diet than in those who consumed the low-soy diet. CONCLUSIONS: Although interindividual variation in isoflavone metabolism was high, intraindividual variation was low. Only concentrations of O-DMA in plasma and urine appeared to be influenced by sex. Chronic soy consumption does not appear to induce many significant changes to the gut metabolism of isoflavones other than higher beta-glucosidase activity.

Adolescent↗
PubMed2004

Gadolinium-enhanced magnetic resonance imaging: a useful radiological tool in diagnosing pediatric IBD.

BACKGROUND: Recent advances in gadolinium-enhanced magnetic resonance imaging (G-MRI) have been developed to enhance the resolution of the intestinal mucosa and facilitate the differentiation of ulcerative colitis (UC) from Crohn's disease (CD). The objective of this study is to apply this technology in Pediatrics. METHODS: A G-MRI was performed on 58 consecutive children with suspected IBD between 1999 and 2002 using intravenous gadolinium, fat suppression, and respiration-suspended sequences to enhance the resolution of the intestinal wall. The sensitivity and specificity in diagnosing either UC or CD was determined by comparing the G-MRI to the established histologic diagnosis. RESULTS: G-MRI confirmed the diagnosis of either CD (21) or UC (7) with a sensitivity and specificity of 96% and 92%, respectively. Among the 21 patients with CD, 14 showed proximal small bowel involvement by G-MRI. In total, 17 patients were diagnosed with indeterminate colitis (IC) based on histologic criteria alone, and among these patients, G-MRI had a significantly lower non-classification rate (P < 0.02). In comparison, endoscopy was less sensitive (57%), but more specific (100%) than either histology or G-MRI in diagnosing IBD. G-MRI also showed a strong concordance with computed tomography in diagnosing CD (P = 0.001). CONCLUSION: G-MRI is a both a sensitive and specific radiologic tool in diagnosing pediatric IBD. In patients with CD, G-MRI may be useful in identifying proximal small bowel involvement. Longitudinal follow-up studies are needed in those patients diagnosed with IC to determine the predictive value of G-MRI testing.

Adolescent↗
PubMed2004

Treatment effects from UPBEAT: a randomized trial of care management for behavioral health problems in hospitalized elderly patients.

The purpose of this study was to examine the impact of the Unified Psychogeriatric Biopsychosocial Evaluation and Treatment (UPBEAT) Program, an interdisciplinary mental health care management program, on the behavioral health symptoms of elderly veterans. Participants, 60 years and older, included 2637 veterans recruited from medical/surgical units who screened positively for significant depressive or anxiety symptoms and/or at-risk alcohol drinking. Participants were randomized to UPBEAT or to usual care. Primary outcomes were measured at baseline and at 6, 12, and 24 months. Participant nonadherence to the protocol was common and is a major limitation. There were no differences between UPBEAT and usual care patients on symptom or functional outcomes at any follow-up point. Exploratory analyses suggested that among participants with more physical health problems, there were greater improvements in depressive symptoms in those assigned to UPBEAT care. Despite a theoretical and practically sound intervention, participation was low and treatment outcomes, while generally good, appeared unaffected by the addition of the program.

Aged↗
PubMed2003

Mechanistic study of enantiomeric recognition with native gamma-cyclodextrin by capillary electrophoresis, reversed-phase liquid chromatography, nuclear magnetic resonance spectroscopy, electrospray mass spectrometry and circular dichroism techniques.

The possible mechanisms for the chiral recognition of 2(S)-(3,5-bis-trifluoromethyl-phenyl)-2-[3(S)-(4-fluorophenyl)-4-(1H-[1,2,4]triazol-3-ylmethyl)-morpholin-2(R)-yloxy]-ethanol (compound A) and its enantiomer with native gamma-cyclodextrin (gamma-CD) were investigated using capillary electrophoresis (CE), reversed-phase liquid chromatography (RPLC), proton (1H), fluorine (19F) and carbon (13C) nuclear magnetic resonance spectroscopy (NMR), electrospray mass spectrometry (ESI-MS) and circular dichroism (CD). All experiments provided clear evidence of the formation of diastereomeric complexes between the enantiomers and gamma-CD. Proton, fluorine and carbon NMR spectra suggested that both aromatic rings, with mono-fluoro and bis-tri-fluoro functional groups, on the guest molecule were partially included into the cavity of the gamma-CD. ESI-MS spectra indicated that the diastereomeric complexes have a 1:1 stoichiometric ratio. The binding constants of the diastereomeric complexes obtained by CE, RPLC and CD were compared. The effects of the gamma-CD concentration, organic modifiers and temperature on the CE-chiral separation were also investigated.

Chromatography, Liquid↗
PubMed2003

Mechanistic study of the enantiomeric recognition of a basic compound with negatively charged single-isomer gamma-cyclodextrin derivatives using capillary electrophoresis, nuclear magnetic resonance spectroscopy, and infrared spectroscopy.

The possible mechanisms for the chiral recognition of 2-(R)-N-[1-(6-aminopyridin-2-ylmethyl)piperidin-4-yl]-2-[(1R)-3,3-difluorocyclopentyl]-2-hydroxy-2-phenylacetamide (RR-M3), and its enantiomer (SS-M3) with octakis(2,3-di-O-acetyl-6-sulfo)-gamma-cyclodextrin (ODAS-gamma-CD) and octakis(6-sulfo)-gamma-cycöpdextrom enantiomer; (OS-gamma-CD), were investigated using capillary electrophoresis (CE), proton ((1)H), fluorine ((19)F) and carbon ((13)C) nuclear magnetic resonance spectroscopy (NMR), and infrared (IR) spectroscopy. Clear evidence for the formation of diastereomeric complexes between the enantiomers and the two CDs was observed. NMR spectra suggest that the phenyl and difluorocyclopentyl rings are involved in the complexation. The phenyl ring on the guest molecule is deeply penetrated into the cavity of OS-gamma-CD, but it is not included into the cavity of ODAS-gamma-CD. The continuous variation plots built based on the (1)H NMR and IR spectra indicate a 1:1 complex stoichiometric ratio of the M3 enantiomers for both CDs. The affinity of the enantiomers for the two CDs is opposite.

Acetamides↗
PubMed2003

Refining diathesis-stress models of depression or introducing ptolemaic epicycles? Commentary on Santor.

Work guided by diathesis-stress models of depression has not been as productive or clinically relevant as hoped. Santor (this issue) suggests some promising refinements of these theories. He proposes more of a contextual focus and addresses temporal instability in presumed diatheses. However, if carelessly applied, the innovations he proposes risk being so accommodating of diverse findings as to be unfalsifiable. Santor also suggests that the selection of coping strategies may be the means by which personality mediates between life events and subsequent depression; though reasonable, this elaboration too can lead to formulations immune to data. Other issues are raised concerning the distinction between fluctuations and disturbances in mood, the role of a history of depression, and operationalization of life events. One immediate solution to some of the problems inherent in this research may be intensive study of more select samples.

Comment↗