Search PubMed⌕ Search

Biomedical subjects

David Thompson

Publications and source records attributed to David Thompson.

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

Does participation in a nurse visitation programme reduce the frequency of adverse perinatal outcomes in first-time mothers?

Children First (C1), a nurse home visitation programme for first-time mothers, was implemented statewide in Oklahoma in mid-1997. The objective of this study was to compare the risks of low (< 2500 g) and very low birthweight (< 1500 g), preterm (< 37 weeks) and very preterm (< 30 weeks) deliveries and infant mortality between mothers participating and not participating in C1. All 239,466 Oklahoma birth certificates were reviewed. The C1 and birth certificate databases were matched to identify C1 participants. Mother's age at delivery, education level, race, marital status, prior pregnancy loss or pregnancy risk factors, birthweight and gestational age at delivery were measured from the birth certificates. Death certificates were matched to the birth certificates to identify infant deaths. A Bayesian multivariable logistic regression was used to analyse the data. Among single mothers without pregnancy risk factors, the risks of all study outcomes were lower for participants in C1: adjusted odds ratio (aOR) 0.89, [95% Bayesian Credible Interval (BCI) 0.79, 1.00] for preterm delivery; aOR 0.71, [95% BCI 0.50, 0.98] for very preterm delivery; aOR 0.86, [95% BCI 0.75, 0.98] for low birthweight; aOR 0.77, [95% BCI 0.56, 1.02] for very low birthweight and aOR 0.36, [95% BCI 0.17, 0.63] for infant mortality. These risk reductions were not observed among married mothers. In both single and married mothers, the presence of pregnancy risk factors reduced the impact of C1 on lowering the risk of low birthweight and preterm deliveries. The C1 programme targets young, pregnant women of low socio-economic level. We found that among single mothers, the risks of perinatal adverse outcomes are reduced or similar to those found in non-participating mothers. A reduced effect of C1 in the presence of pregnancy risk factors may be because mothers with pregnancy risk factors who did not participate in C1 received better prenatal care, or that C1 interventions do not impact these particular factors. C1 shows promise in reducing infant mortality in single mothers. Lower incidence of preterm and very preterm deliveries is especially interesting and future analyses should focus on isolating programme components specifically associated with influencing these outcomes.

Adult↗
PubMed2005

Developmentally restricted genetic determinants of human arsenic metabolism: association between urinary methylated arsenic and CYT19 polymorphisms in children.

We report the results of a screen for genetic association with urinary arsenic metabolite levels in three arsenic metabolism candidate genes, PNP, GSTO, and CYT19, in 135 arsenic-exposed subjects from the Yaqui Valley in Sonora, Mexico, who were exposed to drinking water concentrations ranging from 5.5 to 43.3 ppb. We chose 23 polymorphic sites to test in the arsenic-exposed population. Initial phenotypes evaluated included the ratio of urinary inorganic arsenic(III) to inorganic arsenic(V) and the ratio of urinary dimethylarsenic(V) to monomethylarsenic(V) (D:M). In the initial association screening, three polymorphic sites in the CYT19 gene were significantly associated with D:M ratios in the total population. Subsequent analysis of this association revealed that the association signal for the entire population was actually caused by an extremely strong association in only the children (7-11 years of age) between CYT19 genotype and D:M levels. With children removed from the analysis, no significant genetic association was observed in adults (18-79 years). The existence of a strong, developmentally regulated genetic association between CYT19 and arsenic metabolism carries import for both arsenic pharmacogenetics and arsenic toxicology, as well as for public health and governmental regulatory officials.

Adolescent↗
PubMed2005

Stark II and physician compensation models: integrating business and legal issues.

In March of 2004, the Centers for Medicare & Medicaid Services released new regulations that interpreted the Federal Physician Self Referral Act, otherwise known as Stark II. The new regulations, commonly referred to as the Phase II regulations, must be carefully considered when structuring physician compensation models. Stark II generally holds that physicians may not make a referral for designated health services to an entity with which they have a direct or indirect financial relationship. This Article outlines the provisions of Stark II that are applicable to physician compensation methodologies. In addition, the authors evaluate hypothetical transactions involving physician groups seeking viable compensation schemes and explore the validity and risks of each.

Group Practice↗
PubMed2004

Cost analysis of "bridging therapy" with low-molecular-weight heparin versus unfractionated heparin during temporary interruption of chronic anticoagulation.

Patients on long-term anticoagulation who require interruption of therapy for surgery may receive "bridging therapy" with continuous-infusion unfractionated heparin or low-molecular-weight heparin (LMWH). We estimated the costs of bridging therapy with: (1) LMWH self-administered at home, (2) LMWH administered by a nurse to patients at home, and (3) continuous-infusion unfractionated heparin in the hospital. For surgeries requiring an overnight stay, bridging costs are estimated to be 672, 933, and 3,816 US dollars, respectively, for each of these strategies.

Ambulatory Care↗
PubMed2004

Simulating the allocation of organs for transplantation.

The demand for donated organs greatly exceeds supply and many candidates die awaiting transplantation. Policies for allocating deceased donor organs may address equity of access and medical efficacy, but typically must be implemented with incomplete information. Simulation-based analysis can inform the policy process by predicting the likely effects of alternative policies on a wide variety of outcomes of interest. This paper describes a family of simulations developed by the US Scientific Registry of Transplant Recipients and initial experience in the application of one member of this family, the Liver Simulated Allocation Model (LSAM).

Humans↗
PubMed2004

Induction of long-term plasticity in human swallowing motor cortex following repetitive cortical stimulation.

OBJECTIVE: The excitability of corticobulbar projections to swallowing musculature undergoes remarkable long-term increases after short periods of pharyngeal stimulation. The aim of this study was to investigate the excitability of swallowing motor cortex following repetitive transcranial magnetic stimulation (rTMS). METHODS: Twelve healthy subjects were given 100 rTMS pulses over motor cortex at frequencies of 1, 5 and 10 Hz at an intensity of 80% threshold for corticobulbar activation. The excitability of the corticobulbar projection was assessed before and after rTMS and compared both to sham stimulation and to the corticospinal projection. RESULTS: Stimulation at 5 Hz, but not 1 Hz, 10 Hz or sham stimulation increased the excitability of the corticobulbar projection to the pharynx, reaching a peak 60 min after rTMS (Delta increase: 65%, P=0.016). Excitability in the projection from the opposite hemisphere also increased, suggesting the presence of inter-hemispheric interactions, whereas excitability in the projection to thenar muscles was unchanged. CONCLUSIONS: Corticobulbar and corticospinal projections may differ in response to rTMS, implying differences in relative thresholds of inhibitory and excitatory elements in hand versus swallowing cortex. SIGNIFICANCE: This might be a useful approach in the motor rehabilitation of dysphagic stroke patients who have damage to sensory projections to the swallowing cortex.

Adult↗
PubMed2004

Evaluation of patients' preferences for triamcinolone acetonide aqueous, fluticasone propionate, and mometasone furoate nasal sprays in patients with allergic rhinitis.

OBJECTIVE: To compare product attributes, preferences, and expected compliance associated with triamcinolone acetonide aqueous (TAA-AQ), fluticasone propionate (FP), and mometasone furoate (MF) nasal sprays in patients with allergic rhinitis. STUDY DESIGN AND SETTING: Data from 2 randomized, double-blind crossover studies with identical design were pooled (N = 215). Patients completed a 14-item sensory attributes questionnaire immediately after each product, and stated their preference and expected compliance with a prescription after receiving all products. RESULTS: Compared with FP and MF, TAA-AQ was associated with significantly less odor and greater liking of odor ( P < 0.001); and less taste, less dryness of nose/throat, less aftertaste, and greater overall liking ( P < 0.05). Significantly more patients preferred most a prescription of TAA-AQ (50.0%) versus FP (25.0%; P < 0.001) and MF (25.0%; P < 0.001), and would "definitely comply" with TAA-AQ (62.5%) versus FP (49.0%; P < 0.01) and MF (51.0%; P < 0.01). CONCLUSION: TAA-AQ was associated with significantly more positive sensory attributes, higher preference, and better expected compliance than FP and MF. SIGNIFICANCE: Patients' preferences for the sensory attributes of an intranasal corticosteroid may affect adherence to treatment.

Administration, Intranasal↗
PubMed2004

Prostaglandin E2 receptor subtype EP-2 is not involved in the induction of non-pregnant guinea pig uterine contractions associated with terminal pregnancy.

Prostaglandin E2 (PGE2) exerts its biological effects through 4 different receptor subtypes, EP-1, EP-2, EP-3, and EP-4. Recently we have demonstrated the importance of the prostaglandin E2 receptor subtype EP-2 in the healing of bone defects and fractures. This discovery led to the identification of CP-533,536, an EP-2 selective agonist, a promising therapeutic alternative for the enhancement of bone healing and the treatment of fractures (J Bone Miner Res 18 (2003) 2033). PGE2 has a myriad of effects throughout the body including the induction of uterine contractions, which results in termination of pregnancies. Our objective in this study was to determine the role of the EP-2 receptor and specifically that of CP-533,536, an EP-2 specific agonist, to induce uterine contractions and terminate pregnancy in guinea pigs, an animal model of human pregnancy. Preliminary experiments confirmed earlier reports that the guinea pig uterus was more sensitive than that of the rat. The guinea pig uterus contains the four PGE2 receptor subtypes, and ex vivo treatment of the uterus with PGE2 as expected causes profound uterine contractions. However, using receptor selective prostaglandin agonists including CP-533,536 we showed that the EP-1 and 3 receptors not the EP-2 receptor is responsible for the induction of uterine contractions of PGE2. Further, CP-533,536 did not antagonize the ability of PGE2 to induce uterine contractions in this model.

Animals↗
PubMed2004

Retrospective database analysis of the prevention of venous thromboembolism with low-molecular-weight heparin in acutely III medical inpatients in community practice.

BACKGROUND: Clinical trials have demonstrated that prophylaxis with low-molecular-weight heparin reduces the occurrence of venous thromboembolism (VTE) among acutely ill medical inpatients in the experimental setting. OBJECTIVE: The goal of this retrospective database analysis was to examine the outcomes of low-molecular-weight heparin thromboprophylaxis among acutely ill medical inpatients in community practice. METHODS: Using a large, geographically diverse, multihospital US database, we identified persons aged > or =40 years who had a hospital stay > or =6 days for an acute medical condition (including selected circulatory disorders, respiratory disorders, infectious diseases, or neoplasms) during calendar-year 2000. From these patients, those who received either enoxaparin thromboprophylaxis or no thromboprophylaxis were identified. Surgical patients, patients with nonthrombotic conditions requiring anticoagulant therapy, those transferred from or discharged to another acute care facility, and those medically ineligible for anticoagulation therapy were excluded. We compared the incidence of deep-vein thrombosis (DVT), pulmonary embolism (PE), all VTE (ie, DVT and/or PE), and death during the hospital stay in the 2 cohorts. RESULTS: A total of 162 patients receiving enoxaparin thromboprophylaxis and 3557 receiving no thromboprophylaxis were identified. The risk of VTE over the course of hospitalization was 1.9% with enoxaparin thromboprophylaxis versus 6.2% with no thromboprophylaxis (relative risk = 0.30; P=0.023 ); mortality was similar in the 2 groups (8.0% vs 7.3; P=NS ). CONCLUSIONS: Using hospital administrative data, we observed a 70% lower risk of VTE for hospitalized acutely ill medical patients receiving low-molecular-weight heparin thromboprophylaxis verus those receiving no thromboprophylaxis; these results are consistent with findings from clinical trials of low-molecular-weight heparin versus placebo. We conclude that the low-molecular-weight heparin enoxaparin is effective in reducing the risk of VTE in acutely ill medical inpatients in community practice.

Acute Disease↗
PubMed2004

Cost effectiveness of thromboprophylaxis with a low-molecular-weight heparin versus unfractionated heparin in acutely ill medical inpatients.

OBJECTIVE: To compare the cost effectiveness of prophylaxis with a low-molecular-weight heparin with that of prophylaxis with unfractionated heparin for the prevention of venous thromboembolism in acutely ill medical inpatients. STUDY DESIGN: Cost-effectiveness analysis based on decision-tree model. PARTICIPANTS AND METHODS: A hypothetical cohort of 10 000 patients was assumed to receive either (1) prophylaxis with enoxaparin, a low-molecular-weight heparin, 40 mg daily; (2) prophylaxis with unfractionated heparin, 5000 IU twice daily; or (3) no prophylaxis. We developed a decision-analytic model with parameter estimates derived from published clinical trials and other secondary sources. Then, for each strategy, we estimated the risks of venous thromboembolism, complications of prophylaxis and treatment (heparin-induced thrombocytopenia and bleeding), mortality, and costs of prophylaxis and treatment within a 30-day period. RESULTS: In a hypothetical cohort of 10 000 inpatients, expected numbers of deaths attributable to venous thromboembolism or drug complications related to both prophylaxis for and treatment of VTE over a 30-day period were 37 with enoxaparin prophylaxis, 53 with unfractionated heparin prophylaxis, and 81 with no prophylaxis. In 2001, corresponding expected costs of prevention, diagnosis, and management of VTE were $3 502 000 for enoxaparin, $3 772 000 for unfractionated heparin, and $3 105 000 for no prophylaxis. The incremental cost per death averted with enoxaparin prophylaxis versus no prophylaxis was $9100. Enoxaparin dominated unfractionated heparin by being both more effective and less costly in the base-case analysis, as well as in sensitivity analyses in which equal efficacy and equal risks of bleeding were assumed. CONCLUSIONS: Thromboprophylaxis with this low-molecular-weight heparin represents a cost-effective use of healthcare resources in acutely ill medical inpatients and dominates thromboprophylaxis with unfractionated heparin.

Acute Disease↗
PubMed2004

[Lasofoxifene, a next generation estrogen receptor modulator: preclinical studies].

Estrogen replacement therapy, in spite of efficacy in the prevention of osteoporotic fractures, has significant side effects and risks that limit its widespread usage in postmenopausal women. Thus significant medical need exists to find modalities that prevent osteoporosis, but without the side effects of estrogen. Selective estrogen receptor modulators (SERMs) have the potential to provide the skeletal benefits of estrogen without the increased risk of uterine and breast cancer. Tamoxifen, a first generation SERM is approved for the prevention and treatment of breast cancer, and raloxifene, a second generation SERM has been approved for the prevention and treatment of osteoporosis. Lasofoxifene, a new potent, nonsteroidal SERM, binds with high affinity to human estrogen receptors and acts as a tissue selective estrogen antagonist or agonist. In preclinical models of postmenopausal osteoporosis, lasofoxifene inhibited bone turnover and prevented bone loss throughout the skeleton. In studies designed to investigate the combination of lasofoxifene with estrogen, lasofoxifene blocked the hypertrophic effects of estrogen in the uterus, but did not block the bone protective effects. In immature and aged female rats, lasofoxifene did not affect the uterine weight and uterine histology. In preclinical studies designed to evaluate the effects of lasofoxifene on the uterus, a slight increase in wet uterine weight was observed in immature and aged female rats, but this difference was not observed in dry uterine weight suggesting that the increased uterine weight was due to increased water content in the tissue. In preclinical studies designed to evaluate the effects of lasofoxifene in breast cancer, lasofoxifene inhibited breast tumor formation in mice injected with human MCF-7 breast cancer cells and in rats bearing mammary carcinomas. Thus, in preclinical models, lasofoxifene, a next generation SERM, prevents estrogen deficiency-induced bone loss, inhibits breast tumor formation, and reduces serum cholesterol, without causing uterine hypertrophy. These data suggest that lasofoxifene is a new potential therapy for the prevention of osteoporosis in postmenopausal women.

Animals↗
PubMed2003

Differential changes in human pharyngoesophageal motor excitability induced by swallowing, pharyngeal stimulation, and anesthesia.

We investigated the effects of water swallowing, pharyngeal stimulation, and oropharyngeal anesthesia on corticobulbar and craniobulbar projections to human swallowing musculature. Changes in pathway excitability were measured via electromyography from swallowed intraluminal pharyngeal and esophageal electrodes to motor cerebral and trigeminal nerve magnetic stimulation. After both water swallowing and pharyngeal stimulation, pharyngoesophageal corticobulbar excitability increased (swallowing: pharynx = 59 +/- 12%, P < 0.001; esophagus = 45 +/- 20%, P < 0.05; pharyngeal stimulation: pharynx = 76 +/- 19%, P < 0.001; esophagus = 45 +/- 23%, P = 0.05), being early with swallowing but late with stimulation. By comparison, craniobulbar excitability increased early after swallowing but remained unaffected by pharyngeal stimulation. After anesthesia, both corticobulbar (pharynx =-24 +/- 10%, P < 0.05; esophagus = -28 +/- 7%, P < 0.01) and craniobulbar excitability showed a late decrease. Thus swallowing induces transient early facilitation of corticobulbar and craniobulbar projections, whereas electrical stimulation promotes delayed facilitation mainly in cortex. With removal of input, both corticobulbar and craniobulbar projections show delayed inhibition, implying a reduction in motoneuron and/or cortical activity.

Adult↗
PubMed2003

Advances in neuropathic pain: diagnosis, mechanisms, and treatment recommendations.

Chronic neuropathic pain, caused by lesions in the peripheral or central nervous system, comes in many forms. We describe current approaches to the diagnosis and assessment of neuropathic pain and discuss the results of recent research on its pathophysiologic mechanisms. Randomized controlled clinical trials of gabapentin, the 5% lidocaine patch, opioid analgesics, tramadol hydrochloride, and tricyclic antidepressants provide an evidence-based approach to the treatment of neuropathic pain, and specific recommendations are presented for use of these medications. Continued progress in basic and clinical research on the pathophysiologic mechanisms of neuropathic pain may make it possible to predict effective treatments for individual patients by application of a pain mechanism-based approach.

Analgesics↗
PubMed2003

Psychological responses to episodic chest pain.

Patients with chronic musculo-skeletal pain have been profiled as "dysfunctional", "interpersonally distressed" or "adaptive copers". The relevance of these for episodic visceral pain is unknown. Our aim was to replicate conceptually the taxonomy in patients with episodic visceral pain. Patients with chest pain and gastro-esophageal reflux disease (GERD; n=25), coronary artery (CAD; n=20), or with chest pain but without either reflux or coronary artery disease (non-cardiac chest pain--NCCP; n=23) were assessed using several standard affective and cognitive measures relevant to pain. Differences between the diagnostic groups were explored. K-means cluster analysis broadly replicated the three groups found in previous research but the "interpersonally distressed" group had few members. An additional cluster analysis suggested a more parsimonious solution for the sample was a two-cluster one, which approximated to the "adaptive coper" and "dysfunctional" profiles. Membership of both the three- and two-cluster profiles was not associated with membership of specific diagnostic category.

Adaptation, Psychological↗
PubMed2003

A cluster-randomised controlled trial of a patient-centred guidebook for patients with ulcerative colitis: effect on knowledge, anxiety and quality of life.

A randomised controlled trial was undertaken to evaluate the impact of a patient-centred, evidence-based guidebook on knowledge, anxiety and quality of life (QoL) in patients with ulcerative colitis. The information in the book was developed closely with patients and focused on their identified needs. All 240 subjects in the study were on long-term follow-up for ulcerative colitis and were effectively responsible for the day-to-day management of their condition in the community. Outcomes were measured at 1 month and 9 months. Patients attended outpatient clinics at six hospitals: three hospitals were randomised to be control sites; and three were intervention sites where patients were given a copy of the guidebook. The results showed that patients receiving the guidebook demonstrated significantly better knowledge of their ulcerative colitis at 1 month, which persisted at 9 months, than patients in the control group. Anxiety and QoL scores were unchanged throughout. The present authors conclude that appropriate information is an essential prerequisite to greater patient involvement in chronic disease management. Patient-centred information increases knowledge without increasing anxiety and should be made available to patients through an appropriate health provider.

Adolescent↗
PubMed2003

Localization of orexin-1 receptors to vagal afferent neurons in the rat and humans.

BACKGROUND & AIMS: Orexin-A and -B are brain-gut peptides that stimulate food intake via orexin-R1 and -R2 receptors. Cholecystokinin (CCK) inhibits food intake via CCK(A) receptors expressed on vagal afferent neurons. The purpose of the study was to determine whether vagal afferent neurons express OX-R1 and OX-R2 and whether orexin-A inhibits responses to CCK. METHODS: OX-R1 and -R2 expression by rat and human nodose ganglia was examined by reverse-transcriptase polymerase chain reaction (RT-PCR). Receptor localization was determined by immunohistochemistry. Responses of rat jejunal afferent fibers were examined by electrophysiology. RESULTS: Both rat and human nodose ganglia expressed OX-R1 as detected by RT-PCR, and humans also expressed OX-R2. The identity of the products was confirmed by sequencing. Immunohistochemistry indicated expression of OX-R1 in both species in neurons that also expressed CCK(A) and leptin receptors. In human ganglia there was also expression in glial cells that was absent in rats. Orexin-A had no effect on the resting discharge of afferent nerve fibers but inhibited responses to CCK. CONCLUSIONS: OX-R1 and CCK(A) receptors are expressed by human and rat vagal afferent neurons. Orexin inhibits responses to CCK suggesting a role in modulation of gut to brain signaling.

Animals↗
PubMed2003

The cost-effectiveness of psychotherapy and paroxetine for severe irritable bowel syndrome.

BACKGROUND & AIMS: Psychotherapy and antidepressants are effective in patients with severe irritable bowel syndrome (IBS), but the cost-effectiveness of either treatment in routine practice has not been established. METHODS: Patients with severe IBS were randomly allocated to receive 8 sessions of individual psychotherapy, 20 mg daily of the specific serotonin reuptake inhibitor (SSRI) antidepressant, paroxetine, or routine care by a gastroenterologist and general practitioner. Primary outcome measures of abdominal pain, health-related quality of life, and health care costs were determined after 3 months of treatment and 1 year later. RESULTS: A total of 257 subjects (81% response rate) from 7 hospitals were recruited; 59 of 85 patients (69%) randomized to psychotherapy and 43 of 86 (50%) of the paroxetine group completed the full course of treatment. Both psychotherapy and paroxetine were superior to treatment as usual in improving the physical aspects of health-related quality of life (SF-36 physical component score improvement, 5.2 [SEM, 1.26], 5.8 [SEM, 1.0], and -0.3 [SEM, 1.17]; P < 0.001), but there was no difference in the psychological component. During the follow-up year, psychotherapy but not paroxetine was associated with a significant reduction in health care costs compared with treatment as usual (psychotherapy, $976 [SD, $984]; paroxetine, $1252 [SD, $1616]; and treatment as usual, $1663 [SD, $3177]). CONCLUSIONS: For patients with severe IBS, both psychotherapy and paroxetine improve health-related quality of life at no additional cost.

Absenteeism↗