Acute effects of L-tryptophan on brain extracellular 5-HT and 5-HIAA levels in chronic experimental portal-systemic encephalopathy

Portal-systemic encephalopathy (PSE) is associated with increased brain turnover of serotonin (5-hydroxytryptamine; 5-HT). Despite this metabolic increase, neuronal release of 5-HT is unaltered in neocortex of portacaval shunted (PCS) rats. In the present study, frontal neocortical extracellular 5-HT and 5-hydroxyindole-3-acetic acid (5-HIAA) levels were determined in PCS rats and sham-operated controls prior to, as well as, after acute challenge with L-tryptophan (L-TRP; a bolus dose of 280 mg/kg i.p. followed by 5 consecutive hourly doses of 50 mg/kg). Neither basal 5-HT nor 5-HIAA extracellular levels were significantly altered in PCS rats compared to controls. L-TRP administration resulted in unaltered extracellular 5-HT but elevated 5-HIAA levels in PCS and sham rats. These findings do not suggest that changes in brain neuronal 5-HT release play any major functional role in the pathogenesis of chronic PSE. The present data also emphasize the importance of distinguishing between brain 5-HT metabolism and brain 5-HT release.     

The self-reported use of research in clinical practice: A survey of occupational therapists in Sweden

Background: Today, healthcare providers and occupational therapists are increasingly required to rely on evidence-based practices. In both outpatient and inpatient settings, the use of research-based practices can be identified using the Research Utilization Measure questionnaire. Aim: This study explores how occupational therapists in Sweden perceive research utilization. Method: The Research Utilization Measure was sent to 807 randomly selected occupational therapists in Sweden, and the response rate was 59% (n = 472). Results: The majority of respondents (56%, n = 256) reported use of research-based knowledge in their practice “very or rather often”, although 49% (n = 225) of the therapists noted that they “very seldom or never” discussed research findings with their managers. Differences in answers for most items were related to degree of education and length of experience. Occupational therapists with higher education levels more often reported use of research in their clinical practice and therapists with greater experience less often reported use of research in their clinical practice. Conclusion: Education seems to influence the degree to which occupational therapists rely on research to inform their practices. A future challenge for managers and occupational therapists is to create strategic discussions on how to implement treatment that is based on current research.     

Thromboxane Synthesis and the Platelet Release Reaction in Bernard-Soulier Syndrome, Thrombasthenia Glanzmann and Hermansky-Pudlak Syndrome

Thromboxane (TX) synthesis was investigated in some characterized platelet disorders and correlated with release of ADP or [¹⁴C]serotonin and platelet aggregation. In a case with Bernard-Soulier syndrome TX-synthesis as well as ADP-[¹⁴C]serotonin release and platelet aggregation were found to be essentially normal when platelets were incubated with collagen, ADP, arachidonic acid or prostaglandin G₂ (PGG₂). In a case with Hermansky-Pudlak syndrome aggregation was normal with ADP, whereas aggregation with collagen and PGG₂ was markedly decreased. Release of ADP and [₁₄C]serotonin was found to be decreased with all investigated inducers in this platelet disorder, whereas TX-synthesis was normal with arachidonic acid and PGG₂. In three cases with Glanzmann's thrombasthenia almost no aggregation was observed with any of these compounds. However, in this disorder platelet TX-formation from arachidonic acid or PGG₂ was also normal whereas ADP and collagen both induced less TX-formation than in normal platelets.
These results indicate that none of the investigated platelet disorders was associated with abnormal TX-synthesis from arachidonic acid as found in platelet cyclo-oxygenase deficiency. These observations provide further evidence for the hypothesis that the Bernard-Soulier syndrome and Glanzmann's thrombasthenia are primarily associated with glycoprotein abnormalities at receptor level (Nurden & Caen, 1974, 1975, 1976). A hypothetical model for the interrelationship of two specific glycoproteins and thromboxane-synthesis is discussed.     

Type A dissection following endovascular thoracic aortic stent-graft repair.

PURPOSE: To describe our experience with endovascular stent-graft repairs in the thoracic aorta focusing on the secondary complication of type A dissection. METHODS: Between January 1996 and April 2004, 73 patients were treated for traumatic thoracic aortic rupture (n=15), type B dissection (n=22), or atherosclerotic descending thoracic aortic aneurysms (TAA, n=36). A retrospective review of the records found 5 (6.8%) patients (3 men; median age 64 years, range 43-87) who experienced a type A dissection at a median 20 days (range 2-124) after thoracic stent-graft repair for 3 type B dissections, 1 TAA, and a late type I endoleak that appeared 28 months after initial stent-graft repair of a traumatic dissection. RESULTS: In 3 patients (2 dissections, 1 endoleak), a tear in the aortic wall at the proximal stent-graft was responsible for a retrograde type A dissection. Underlying disease was the cause of the type A dissection in the 2 other patients (1 dissection, 1 TAA) and was unrelated to the stent-grafts. Three patients underwent open surgery at 3, 26, and 124 days after stent-graft placement; 2 procedures were successful, but the third patient died 3 months later due to multiorgan failure. Two type A dissections were untreated: one patient died from cardiac tamponade 14 days after successful stent-graft exclusion of the type I endoleak; the other patient refused further treatment and survived. The procedure-related mortality following acute retrograde type A dissection was 40%. CONCLUSIONS: Endovascular stent-graft repair of the thoracic aorta is associated with lower morbidity and mortality rates than surgical repair, although potentially lethal complications, acute or delayed, may occur.     

Amount of systemic steroid medication is a strong predictor for the use of complementary and alternative medicine in patients with inflammatory bowel disease: results from a German national survey

OBJECTIVES: Previous studies have suggested that inflammatory bowel disease (IBD) patients rank high among users of complementary and alternative medicine (CAM). To further elucidate this phenomenon, we sent questionnaires to a large sample of IBD patients in Germany to determine the patterns and predictors of their CAM use. METHODS: Pretested 73-item questionnaires were mailed to a randomly selected representative sample of 1000 IBD patients from the approximately 16,000 members and associates of the German Crohn's and Colitis Association. Predictors of CAM use were evaluated by logistic regression models. RESULTS: Completed questionnaires were returned by 684 patients (female patients, 61.4%; Crohn's disease patients, 58.3%; ulcerative colitis patients, 38.2%). Of the 671 adult respondents, 344 (51.3%) had experience with CAM, and significantly more of the ulcerative colitis patients (59.8%) than the Crohn's disease patients (48.3%) had experience with CAM. There was no difference by gender. Homeopathy (52.9%) and herbal medicine (43.6%) were the most commonly used types of CAM. The most frequent personal reasons for CAM use were the search for an "optimum treatment" (78.9%) and the wish to stop taking steroids (63.8%). Using logistic regression, we found that total cortisone intake (P = 0.0077), but not duration of disease, was a strong predictor of CAM use. Other predictors were experience with psychosomatic and psychotherapeutic support (P = 0.0029), relaxation techniques (P = 0.0284), an academic education (P = 0.0173), a diet utilizing whole grains (P = 0.0123), and a normal body weight (P = 0.0215). Although 80% of patients indicated that they were interested in using CAM in the future, only 24.7% felt sufficiently informed about it. CONCLUSIONS: More than 50% of a large group of German IBD patients had used CAM. Prolonged or intensive steroid treatment, an academic education, active ways of coping, and a health-conscious life-style are associated with CAM use. Given the potential side effects and interactions, the treating physician should focus on thorough information about the benefits and limitations of conventional and complementary treatment options, especially for IBD patients who have received prolonged or intensive steroid treatment.     

Plasma homocysteine in 80-year-olds: relationships to medical, psychological and social variables

Plasma homocysteine concentrations in a group of 80-year-old persons were related to symptoms and signs. Plasma homocysteine concentrations higher than 15 mumol/l were associated with lower total life satisfaction (P<0.01), mood (P<0.05), zest for life (P<0.05), lower scores for reasoning (P<0.05), spatial ability (P<0.05), memory recognition (P<0.05), and subjective health (P<0.01). In an instrument comprising of 30 symptoms, plasma homocysteine concentrations higher than 15 mumol/l were associated with impaired concentration (P<0.05), restlessness (P<0.05), feeling cold (P<0.05), loss of weight (P<0.05), and feeling depressed (P<0.01). The above data indicate that plasma homocysteine values over 15 mumol/l could be relevant markers for clinical intervention.     

Impairment of vascular endothelial function and left ventricular filling : association with the severity of apnea-induced hypoxemia during sleep

STUDY OBJECTIVE: To investigate whether a dose-effect relationship exists between the severity of obstructive sleep apnea (OSA) and subclinical indicators of myocardial or vascular dysfunction. DESIGN: Cross-sectional study using correlation analysis. PARTICIPANTS: Twenty subjects referred to our sleep laboratory for screening or therapy of OSA but without regular medication and without known cardiovascular disease. MEASUREMENTS: Severity of OSA was quantified by polysomnography. Moreover, nocturnal excretion of norepinephrine was determined. Left ventricular (LV) myocardial function was assessed with Doppler echocardiography. Using ultrasonographic measurements, endothelium-dependent and endothelium-independent conduit artery dilation were measured as flow-mediated and glyceryltrinitrate-induced changes in brachial artery diameter. RESULTS: Worsening nocturnal hypoxemia, measured as nocturnal oxygen saturation nadir or percentage of sleep time spent in hypoxemia (< 90% hemoglobin oxygen saturation), predicted increased interventricular septum thickness (corrected for age and body mass index), prolonged isovolumetric relaxation time, decreased ratio between peak early and late mitral flow velocities, as well as reduced endothelium-dependent dilatory capacity of the brachial artery (all relationships corrected for cofactor age and with p < 0.05) were observed. Associations between these cardiovascular function markers and nocturnal excretion of norepinephrine followed the same trend, but relations with interventricular septum thickness and flow-mediated artery dilation missed significance (p = 0.064 and p = 0.061, respectively). LV posterior wall thickness, measures of LV systolic function, early mitral flow deceleration time, and endothelium-independent artery dilation were not significantly related to the degree of nocturnal hypoxemia or norepinephrine excretion. None of the correlations with apnea-hypopnea index were statistically significant. CONCLUSIONS: The severity of apnea-related hypoxemia is associated with a gradual deterioration of LV diastolic function as well as large-artery endothelial function.