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Biomedical subjects

D Tran

Publications and source records attributed to D Tran.

At least 19 recordsLinked to original sources
PubMed2006

Hygiene behaviour of adolescents in the Pacific: associations with socio-demographic, health behaviour and school environment.

This study presents findings on health-related hygiene behaviours of 9,013 adolescents from Vanuatu, Tonga and Pohnpei in the Federal States of Micronesia as part of the Health Behaviour of Pacific Youth Life surveys. We examined the prevalence of and relationship between tooth brushing, hand washing before eating, hand washing after toileting and a range of psychosocial factors such as sociodemographic charac-teristics, health behaviour and school affiliation. The results showed that patterns of prevalence and relationships were consistent for all countries, with weaker associations observed in Pohnpei. In general, adolescents reported moderate levels of optimal hygiene practice. Girls reported significantly more frequent optimal hygiene practice than boys. Logistic regression analysis confirmed that frequent hygiene behaviours were significantly associated with gender, parental occupations and high levels of school affiliation. These findings suggest the need to consider psycho-social and economic factors when examining potential influences on hygiene behaviour to ensure effective interventions.

Adolescent↗
PubMed2005

The effectiveness of treating juvenile dermatomyositis with methotrexate and aggressively tapered corticosteroids.

OBJECTIVE: Childhood dermatomyositis (DM) is often a chronic disease, lasting many years. It has traditionally been treated with long-term corticosteroid therapy; side effects are often seen. For more than a decade, methotrexate (MTX) has been safely used for the treatment of juvenile arthritis. Here, we report use of MTX as first-line therapy for DM, along with aggressively tapered corticosteroids, in an attempt to reduce treatment-related side effects. METHODS: We studied an inception cohort of 31 children with DM who were rigorously followed up in our myositis clinic, and compared them with a control group of 22 patients with incident cases of juvenile DM who received treatment just before we instituted a policy of first-line therapy with MTX. The mean starting dosage of MTX in the study group was 15 mg/m(2)/week. RESULTS: Both groups had similar improvement in strength and physical function; however, the median time during which patients in the study group received corticosteroids was 10 months, compared with 27 months for controls (P < 0.0001). As a result, the cumulative prednisone dose in the study group was approximately half that in the control group (7,574 mg versus 15,152 mg; P = 0.0006). The study group had greater height velocity during the first year of treatment and a smaller increase in the body mass index over the first 2 years. In the control group, the relative risk of cataracts developing was 1.95 (95% confidence interval 1.05-4.17). Side effects of MTX were rarely observed. CONCLUSION: Use of MTX in conjunction with an aggressively tapered course of prednisone may be as effective as traditional long-term corticosteroid therapy for children with DM, while decreasing the cumulative dose of corticosteroids.

Dermatomyositis↗
PubMed2005

Cellular destruction following transmyocardial laser revascularization (TMR).

During transmyocardial revascularization, cellular destruction of cardiomyocytes occurs as a result of the high-energy laser. However, the features of myocardial cellular destruction are unclear. The present study was undertaken to examine the structural characteristics of cell death in the myocardium following transmyocardial revascularization. Myocardial specimens from 3 male patients who had died within 11 days following laser revascularization were collected within 1 h of death and were analyzed by immunohistochemistry and electron microscopy. For immunohistochemistry, antibodies to pro-apoptotic proteins CPP32 and BAX were used. Immunohistochemical examination demonstrated the presence of cells expressing both CPP32 and BAX along the laser channel. Electron microscopic analysis revealed that the lining surface of laser channels consisted of condensed acellular debris and dead cells. No endothelialization of channels was noted. The lumen of laser channels were surrounded by a rim of acellular debris with several outer concentric rims of cardiomyocytes showing features of cellular destruction. The present study identified features of both necrotic and apoptotic cellular death following laser revascularization.

Adult↗
PubMed2005

Effects of cerivastatin on forearm vascular responses, blood pressure responsiveness and ambulatory blood pressure in type 2 diabetic men.

OBJECTIVE: The objective of the study was to investigate the effects of cerivastatin therapy on forearm endothelial dependent acetylcholine (ACH) and independent (nitroprusside) vasodilator responses, blood pressure (BP) responses to intravenous infusions of angiotensin II (AII) and noradrenaline (NA) and on 24-h ambulatory BP recordings in type 2 diabetic men. DESIGN: Eleven type 2 diabetic men aged 59 +/- 9 years with total cholesterol levels of 5.0 +/- 1.26 mmol/l, triglycerides of 2.23 mmol/l and high-density lipoprotein cholesterol levels of 1.24 mmol/l completed a double-blind, randomized, crossover trial comparing 8 weeks of cerivastatin therapy (800 microg of nocte) with placebo. Forearm vascular resistance (FVR) responses to intrabrachial-arterial infusions of ACH (3-24 microg/min), nitroprusside (2-16 microg/min), the nitric oxide(NO) synthase inhibitor l-nitro-mono-methyl arginine (l-nmma) (8 micromol/min), ACH during l-NMMA infusion and BP responses to intravenous infusions of AII (12.5-50 ng/min) and NA (20-400 ng/min) were measured at the end of each treatment period. Twenty-four-hour ambulatory BP recordings were also performed. RESULTS: FVR responses to ACH during l-NMMA infusion were significantly (p = 0.026) greater during cerivastatin than during placebo therapy. In contrast, FVR responses to ACH in the absence of NO synthase inhibition did not differ significantly between cerivastatin and placebo therapies (p = 0.81). FVR increased by 31.4 +/- 57.3% in response to l-NMMA infusion during cerivastatin therapy compared with 6.1 +/- 41.2% during placebo therapy (p = 0.20). FVR responses to nitroprusside did not differ between cerivastatin and placebo therapies (p = 0.28), nor did BP responses to AII (systolic BP, p = 0.99; diastolic BP, p = 0.98) or NA (systolic BP, p = 0.21; diastolic BP, p = 0.48). Mean 24-h BP was similar during cerivastatin (123 +/- 10 or 70 +/- 7 mmHg) and placebo therapies (129 +/- 11 or 74 +/- 7 mmHg) (systolic BP, p = 0.26; diastolic BP, p = 0.41). CONCLUSION: Cerivastatin increases FVR responses to ACH in type 2 diabetic men with mild dyslipidaemia but only following NO synthase inhibition. This may indicate an improvement in endothelium-derived hyperpolarizing factor-mediated responses.

Acetylcholine↗
PubMed2004

[Congenital malformations of the tricuspid valve in domestic carnivores: a retrospective study of 50 cases].

A retrospective study was done on 14 cats and 36 dogs diagnosed with right atrioventricular valve malformations (RAVM), either tricuspid dysplasia (n = 38) or Ebstein's anomaly (n = 12). Comparison with a large reference population including 85 250 animals allowed an epidemiologic analysis of these RAVM, demonstrating that Labrador, Boxer and Chartreux cats had a 35, 7 and 11-fold higher risk respectively to be affected by one of these heart diseases than other breeds, without sexual predisposition. In 93% of cases, cardiac auscultation revealed a heart murmur, whose grade was not significantly correlated with the echographic stages of the valvular disease. The echocardiographic examination confirmed the frequent association between RAVM and other congenital anomalies, particularly mitral dysplasia, in 84% and 20% of tricuspid dysplasia and Ebstein anomaly respectively. Last, the prognosis of RAVM was worsened by atrial fibrillation and right-sided heart failure.

Age Factors↗
PubMed2003

Pharmacokinetic profile of a modified release formulation of trimetazidine (TMZ MR 35 mg) in the elderly and patients with renal failure.

Objectives - To study the effect of age and renal function on the pharmacokinetic profile of a modified release tablet of trimetazidine (TMZ MR 35 mg) administered twice daily.Methods- Study 1: Twelve healthy elderly subjects (CL(creat) 72+/-8 ml/min, 72+/-4 years mean+/-SD) and eight young volunteers (CL(creat) 134+/-18 ml/min, 25+/-8 years) received TMZ MR 35 mg b.i.d. (eight doses). Study 2: eight patients with severe renal failure (CL(creat.) 17+/-5 ml/min, 54+/-10 years), five patients with moderate renal failure (CL(creat.) 39+/-6 ml/min, 54+/-15 years) and eight volunteers (CL(creat.) 104+/-17 ml/min, 53+/-9 years) received TMZ MR 35 mg b.i.d. (patients: ten doses, volunteers: eight doses). Serial blood and urine samples were obtained following administration of the last dose in each study. TMZ plasma and urine concentrations were determined by gas chromatography (NPD-detector). The resulting data were analysed using standard non-compartmental pharmacokinetic methods.Results- Study 1: Elimination half-life of TMZ was significantly longer and renal clearance significantly lower in the elderly subjects. Study 2: In patients with either moderate or severe renal failure, exposure (AUC(0-24)) was significantly increased and renal clearance (CL(R)) was significantly decreased. Significant correlations were observed between CL(creat) and CL(R) (r=0.94) and between CL(creat) and AUC(0-24) (r=-0.94). Conclusion - With repeated administration of TMZ MR 35 mg b.i.d., a decrease in CL(creat) is directly related to a decrease in CL(R) and results in an increase in exposure to TMZ.

Adolescent↗
PubMed2003

[Clopidogrel and thrombopenia. A case report].

We report our experience with a case of isolated profound thrombocytopenia after clopidogrel (thienopyridine) administration. No adverse event such as bleeding or thrombotic event had occurred, although clopidogrel has been discontinued two weeks after the coronary artery stenting. Despite the safety of clopidogrel, this case demonstrates that clopidogrel can be associated not only with thrombotic thrombocytopenic purpura but also with isolated thrombocytopenia.

Angioplasty, Balloon, Coronary↗
PubMed2003

Disposable laryngoscope blades do not interfere with ease of intubation in scheduled general anaesthesia patients.

BACKGROUND AND OBJECTIVE: Intubation of the trachea has been a risky cross-contamination procedure over the past decade because no perfect decontamination procedures exist. Infectious agents found on laryngoscopic devices have the potential for devastating spread of the human immunodeficiency virus, hepatitis viruses B and C and transmissible non-conventional agents. The purpose of this prospective observational study was to assess the quality of endotracheal intubation with disposable laryngoscope blades, under normal intubating conditions. METHODS: Anaesthetists were asked to complete daily questionnaires regarding the difficulty of intubation experienced using the Vital View disposable laryngoscope blade (Vital Signs Inc, Totowa, NC, USA). The choice of the type of blade (conventional or disposable blade) for the first attempt at intubation depended only on the operating room assignment. Glottic visualization during laryngoscopy was assessed by the modified Cormack and Lehane classification. Difficult tracheal intubation was evaluated by the intubation difficulty scale (> 5, procedure involving moderate to major difficulty). RESULTS: The anaesthetic staff recorded 219 intubations. One hundred-and-nineteen of first attempts at laryngoscopy were with disposable blades (DB group) and another 100 with conventional blades (CB group). There were no significant differences between the two groups for Cormack and Lehane score 3, for intubation difficulty scale scores > 5 and for intubation difficulty scale score 0. There were 12 blade changes before successful intubation. CONCLUSIONS: In routine use, the Vital View disposable laryngoscope blade appears to be an efficient device because it does not modify the ease of endotracheal intubation in most cases. Nonetheless, it may be advisable to maintain conventional laryngoscopes in reserve for difficult intubations.

Anesthesia, General↗
PubMed2003

Effects of dietary supplementation with isoflavones from red clover on ambulatory blood pressure and endothelial function in postmenopausal type 2 diabetes.

OBJECTIVE: The aim of this study was to determine whether dietary supplementation with isoflavones from red clover affected ambulatory blood pressure and forearm vascular endothelial function in postmenopausal type 2 diabetic women. DESIGN: Sixteen postmenopausal type 2 diabetics treated with diet or oral hypoglycaemic therapy completed a randomized double-blind crossover trial of dietary supplementation with isoflavones from red clover (approximately 50 mg/day) for 4 weeks compared to placebo. Twenty-four-hour ambulatory blood pressure recordings and forearm vascular responses to acetylcholine, nitroprusside and L-nitromonomethylarginine (L-NMMA) were measured at the end of each treatment period. RESULTS: Mean daytime systolic and diastolic blood pressures were significantly lower during isoflavone therapy compared to placebo (-8.0 +/- 3.4 and -4.3 +/- 1.9 mmHg respectively, p < 0.05). The increase in forearm vascular resistance following L-NMMA was significantly greater during isoflavone supplementation (20.9 +/- 6.5) than placebo (3.7 +/- 2.9 arbitrary units, p < 0.05), suggesting an improvement in basal endothelial function. Plasma lipoproteins, glycated haemoglobin and forearm vascular responses to acetylcholine and nitroprusside did not differ significantly between isoflavone and placebo therapy. CONCLUSION: Isoflavone supplementation from red clover may favourably influence blood pressure and endothelial function in postmenopausal type 2 diabetic women.

Aged↗
PubMed2002

Cutaneous melioidosis.

Melioidosis is a rare tropical disease caused by infection with the bacterium Burkholderia pseudomallei. It occurs predominantly in south-east Asia, northern and central Australia and central and south America. Patients often present to the internal medicine physicians with a severe, potentially fatal sepsis. We report three patients who presented to our dermatology department with cutaneous melioidosis.

Adult↗
PubMed2001

Utility of semiquantitative polymerase chain reaction for Epstein-Barr virus to measure virus load in pediatric organ transplant recipients with and without posttransplant lymphoproliferative disease.

We examined the utility of Epstein-Barr virus (EBV) load as a test for the presence of posttransplant lymphoproliferative disease (PTLD). A semiquantitative (SQ) EBV polymerase chain reaction (PCR) on peripheral blood mononuclear cells (PBMC) was used to determine virus load. We compared the values from pediatric patients, both with and without PTLD, with those from healthy pediatric and adult subjects. The virus loads for asymptomatic healthy subjects had a range of 0-1 log10 cells/10(6) PBMCs. Among transplant recipients (n=135), the mean virus load (+/- standard deviation) at the time of diagnosis of PTLD was 3.1+/-1.2 log(10) cells/10(6) PBMCs versus a baseline value of 1.3+/-1.4 log(10) cells/10(6) PBMCs in children without PTLD (P<.0001). A cutoff of > or =3 log10 cells/10(6) peripheral blood leukocytes resulted in the following values for use of virus load as a test for PTLD: sensitivity, 69%; specificity, 76%; positive predictive value, 28%; and negative predictive value, 95%. We conclude that determination of EBV load by use of SQ PCR is more useful in ruling out than in indicating the presence of PTLD.

Adult↗
PubMed2001

Cerebral cortical blood flow during loss of consciousness induced by gravitational stress in rhesus monkeys.

We investigated the influence of +Gz acceleration (head-to-foot inertial forces) onset on cerebral cortical blood flow (CBF) of rhesus monkeys to study the mechanisms underlying +Gz-induced loss of consciousness (G-LOC). CBF was measured through a chronic cranial window by laser-Doppler flowmetry and electrodes in contact with the dura mater were used to detect G-LOC (suppression of the cortical electrical activity). The animals were centrifuged up to +12 Gz with different G-onset rate until G-LOC occurred. G-LOC was preceded by a 2-5 s decrease in CBF. At G-LOC detection, CBF was not related to G-onset rate (mean CBF change: -76 +/- 9% of control value). We conclude that G-LOC results from cerebral ischemia rather than from mechanical stresses applied to the brain.

Animals↗
PubMed2001

Serotonin transporter promoter polymorphism is associated with attenuated prolactin response to fenfluramine.

Disturbances in central serotonin (5-HT) function may have a role in impulsive aggression in patients with a wide range of psychiatric diagnoses. The underlying mechanism, however, remains unknown. There are several naturally occurring mutations in the 5-HT signaling pathway that may underlie differences in 5-HT function and responsivity to drugs that affect 5-HT functioning. In the present study, we examined the relationship between polymorphisms in the promoter region of the gene coding for the neuronal 5-HT transporter, fenfluramine-induced prolactin release, and aggressive impulsivity (as measured by Barratt Impulsivity Scale, Buss-Durkee Hostility Inventory, and Brown-Goodwin Aggression Scale scores), in a group of abstinent alcoholic patients and healthy volunteers. We report here that possession of the short variant of the 5-HT transporter promoter polymorphism was associated with a blunting of overall central 5-HT function, as measured by fenfluramine-induced prolactin release. We found no relationship between aggressive, hostile, or impulsive traits and fenfluramine-induced prolactin release or between these traits and polymorphisms in the 5-HT transporter promoter. Thus, we have shown that a 5-HT transporter promoter genotype, which has previously been associated with anxiety-based behaviors, alters an in vivo measure of central 5-HT function (fenfluramine-induced prolactin release), providing an important mechanism for linkage between a gene, physiological function, and behavior. Published 2001 Wiley-Liss, Inc.

Adult↗
PubMed2001

Immunohistochemical and ultrastructural evidence that dendritic cells infiltrate stenotic aortocoronary saphenous vein bypass grafts.

We earlier speculated that antigen-presenting dendritic cells may be involved in the immune reactions leading to saphenous vein bypass graft failure. The purpose of this study was to confirm whether dendritic cells are present in stenotic human saphenous vein bypass grafts. Segments of stenotic saphenous vein grafts were explanted from 14 patients at re-do bypass operation and ten normal saphenous veins were harvested during femoro-popliteal grafting. Sections of specimens were analysed using cell type specific antibodies to identify dendritic cells (CD1a, S-100), T-lymphocytes (CD3), macrophages (CD68), smooth muscle cells (alpha-SMA) and endothelial cells (FVIII). Dual immunostaining, confocal immunofluorescent laser scanning microscopy and electron microscopy were used. Stenotic grafts showed structural alterations of intimal hyperplasia and varying degrees of atherosclerotic degeneration. No cells expressing CD1a and S-100 were observed in the intima and media of normal saphenous veins. Cells expressing these antigens were present around areas of medial neovascularization and within intimal atherosclerotic lesions in saphenous vein bypass grafts. Electron microscopy demonstrated the presence of cells containing a well-developed tubulovesicular system which is unique to cells from the dendritic cell family. Double immunohistochemistry and confocal immunofluorescent microscopy revealed the co-localization of T-lymphocytes with dendritic cells. Dendritic cells are present in stenotic saphenous vein bypass grafts. Dendritic cells may be responsible for antigen presentation and modulation of immune reactions in accelerated graft atherosclerosis through their interaction with T-lymphocytes.

Adult↗