John Rhodes
University of Hertfordshire, Clinical Psychology, Department Member
... Richard GT Gipps Richard Gipps gained his PhD on the philosophical understanding of schizophrenia from Warwick University in 2002, and his doctorate in Clinical Psychology from Christ Church University, Canterbury in 2009. ...
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Page 1. Page 2. © 2009 by The Johns Hopkins University Press Delusions, Certainty, and the Background John Rhodes and Richard GT Gipps Abstract: Cognitive psychologists have recently identified alterations in perception ...
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Research Interests: Meteorites, Data, XRF, Trace Elements, Procedure, and 3 moreFractionation, Trace element, and Meteorite
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Right ventricular outflow tract (RVOT) conduit dysfunction is a limitation of the Ross procedure. Transcatheter pulmonary valve replacement (TPVR) could alter the impact of conduit dysfunction and the risk-benefit balance for the Ross... more
Right ventricular outflow tract (RVOT) conduit dysfunction is a limitation of the Ross procedure. Transcatheter pulmonary valve replacement (TPVR) could alter the impact of conduit dysfunction and the risk-benefit balance for the Ross procedure. Retrospective review of databases from 3 prospective Melody TPV (Medtronic Inc, Minneapolis, MN) trials. Among 358 patients who were catheterized with the intent to implant a Melody TPV for RVOT conduit stenosis or regurgitation (PR) as part of 3 prospective multicenter studies, 67 (19%) had a prior Ross procedure. Of these, 56 (84%) received a Melody valve; in 5 of the 11 patients who did not, the implant was aborted due to concern for coronary artery compression, and 1 implanted patient required emergent surgery for left coronary compression. The RVOT gradient decreased from a median 38 mm Hg to 13.5 mm Hg (p < 0.001). There was no or trivial PR in all but 4 patients, in whom it was mild. At a median follow-up of 4.0 years, 1 patient died from sepsis. Twelve patients underwent 14 transcatheter (n = 8) or surgical (n = 6) TPV reinterventions for obstruction with stent fracture (n = 9), endocarditis with conduit obstruction (n = 3), or reoperation (n = 2). Freedom from TPV explant was 89% ± 5% at 4 years. Among patients who did not undergo reintervention for obstruction, there was no change in RVOT gradient over time, and all but 1 patient had mild or less PR at last follow-up. The TPVR with the Melody valve provides acceptable early outcomes and durable valve function in the majority of Ross patients. Recurrent RVOT obstruction associated with stent fracture was the main reason for reintervention. Coronary compression is not uncommon in Ross patients and should be assessed prior to TPVR.
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Speckle-tracking echocardiographic (STE) measures of right ventricular (RV) function appear to improve after transcatheter pulmonary valve implantation (TPVI). Measures of exercise function, such as ventilatory efficiency (the minute... more
Speckle-tracking echocardiographic (STE) measures of right ventricular (RV) function appear to improve after transcatheter pulmonary valve implantation (TPVI). Measures of exercise function, such as ventilatory efficiency (the minute ventilation [VE]/carbon dioxide production [Vco2] slope), have been shown to be prognostic of mortality in patients who may require TPVI. The aim of this study was to evaluate the correlation between STE measures of RV function and changes in VE/Vco2 after TPVI. Speckle-tracking echocardiography and cardiopulmonary exercise testing were performed at baseline and 6 months after TPVI in 24 patients from four centers. Conventional echocardiographic measures of RV function were also assessed. Echocardiographic and exercise stress test results were interpreted by single blinded observers at separate core laboratories. All patients demonstrated relief of pulmonary regurgitation and stenosis after TPVI. Improvements in RV longitudinal strain (-16.9 ± 3.5% vs -...
The relationship between smoking and inflammatory bowel disease is a curious but well-established one. It is negatively associated with ulcerative colitis but positively associated with Crohn's disease. It also has opposite influences... more
The relationship between smoking and inflammatory bowel disease is a curious but well-established one. It is negatively associated with ulcerative colitis but positively associated with Crohn's disease. It also has opposite influences on the clinical course of the two conditions with possible beneficial effect in ulcerative colitis and detrimental effect in Crohn's disease. The diametrically "opposite" relationship of smoking status with the two conditions has been the subject of much interest in the hope that it may reveal pathogenic mechanisms responsible for the two conditions and possibly offer the key to alternative therapeutic options. Nicotine may be the principal agent in smoking responsible for the association; trials have shown it to be of some benefit in ulcerative colitis, but further research is required to establish its therapeutic role and possible mechanisms of action. In this article, we review the historical, clinical, and therapeutic aspects of t...
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The state of activation of human peripheral blood monocytes was examined by using a rosette assay that detects changes in Fc receptor expression. Monocytes from patients with uncomplicated Plasmodium falciparum malaria showed a... more
The state of activation of human peripheral blood monocytes was examined by using a rosette assay that detects changes in Fc receptor expression. Monocytes from patients with uncomplicated Plasmodium falciparum malaria showed a significant increase in the number of rosettes relative to healthy controls. In addition, the monocytes from these patients were tested for their ability to phagocytose Candida albicans, but this ability did not differ from that of normal individuals. Finally, the monocytes from patients with cerebral malaria were also tested for Fc receptor expression. In contrast to the results from uncomplicated cases, the activity of the monocytes from these patients was no different from that of controls. We concluded that uncomplicated P. falciparum malaria caused an increase in monocyte Fc receptor expression which did not occur in cerebral malaria and that this difference in activation may be important in the pathogenesis of cerebral malaria.
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Ulcerative colitis is largely a disease of nonsmokers, and transdermal nicotine is of therapeutic value in the active disease. Because side effects are common, we developed a topical enema formulation of nicotine. To study the... more
Ulcerative colitis is largely a disease of nonsmokers, and transdermal nicotine is of therapeutic value in the active disease. Because side effects are common, we developed a topical enema formulation of nicotine. To study the pharmacokinetics of nicotine complexed with a polyacrylic carbomer and administered by enema to eight healthy volunteers and to eight patients with active ulcerative colitis, verified sigmoidoscopically. All 16 subjects were nonsmokers. The mean age for normal subjects was 33 years; the mean for patients with ulcerative colitis was 60 years. Median stool frequency for patients with ulcerative colitis was four daily. Patients were taking 5-amino salicylic acid compounds and five were taking oral prednisolone (median dose, 12 mg daily). Nicotine, 6 mg, complexed with carbomer 974P, 400 mg, was administered in a 100 ml enema after an overnight fast, with serial blood measurements taken over 8 hours. Serum nicotine and cotinine were measured by gas liquid chromatography. Area under the concentration-time curves were calculated by the trapezoidal method, and the terminal elimination half-life was derived by extrapolation of the log-linear terminal phase. With the exception of nicotine time to reach peak concentration, which was longer in patients (median of 60 minutes compared with 45 minutes; p < 0.005), other comparisons between normal subjects and patients showed no statistically significant difference, although there was considerable inter-subject variation. Maximum concentration of nicotine, 8.1 +/- 3.5 ng/ml, in the 16 subjects occurred after a median of 60 minutes (range, 30 to 180 minutes); maximum cotinine concentrations of 60.4 +/- 11.5 ng/ml occurred after 4 hours. Side effects in five subjects were mild (four subjects) or moderate (one subject) and included lightheadedness, nausea, and headache; these five subjects were female lifelong nonsmokers of low body weight. Because most of the active ingredient of nicotine is converted to continine on the first pass through the liver, substantial concentrations can be achieved at the site of disease with only modest rises in serum nicotine, which are responsible for side effects; cotinine has low pharmacologic activity. Topical administration of nicotine may be useful treatment for distal ulcerative colitis.
Research Interests: Treatment, Pharmacokinetics, Clinical Pharmacology, Dosage Form, Humans, and 19 moreUlcerative colitis, Nicotine, Female, Male, Statistical Significance, Aged, Middle Aged, GAS LIQUID CHROMATOGRAPHY, Adult, Time Factors, Body Weight, Acrylic Resins, Side Effect, Active Ingredient, Drug Carriers, Area Under Curve, Cotinine, Case Control Studies, and ENEMA
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Adult drone honey bees from 4 Australian breeding lines were reared under similar conditions and examined for semen and sperm production when 14, 21 and 35 days old, during spring, summer and autumn. Almost half (40.5%) of all drones... more
Adult drone honey bees from 4 Australian breeding lines were reared under similar conditions and examined for semen and sperm production when 14, 21 and 35 days old, during spring, summer and autumn. Almost half (40.5%) of all drones examined did not release any semen when manually everted. For those that released semen, the average volume released per drone was
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Research Interests: Mathematical Biology, Molecular Evolution, Symbiosis, Construction, Mitochondria, and 23 moreAlgorithm, Bootstrapping, Model, Distance, ROOT, Molecular clock, Method, Parallel Evolution, Interior, Phylogenetic, Edge, Tree, UPGMA, Vertex, Pattern, GenBank, Outgroup, AN INTRODUCTION, Leaf, Metric, Gene Transfer, Likelihood, and Maximum Likelihood Method
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Research Interests: Surgery, Fracture, Biology, Treatment, Treatment Outcome, and 18 moreAdolescent, Medicine, Humans, Child, Age, United States, Female, Male, Young Adult, Cardiac Catheterization, Middle Aged, Adult, Time Factors, Retrospective Studies, eNDOCARDITIS, prosthesis Design, Short Term, and Pulmonary Artery
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Thin-Walled Structures 16 (1993) 11 !-i43 Tests on Intermediately Stiffened Plate Elements and Beam Compression Elements KH Hoon,~ J. Rhodesb & LK Seah" School of Mechanical & Production Engineering, Nanyang Technological... more
Thin-Walled Structures 16 (1993) 11 !-i43 Tests on Intermediately Stiffened Plate Elements and Beam Compression Elements KH Hoon,~ J. Rhodesb & LK Seah" School of Mechanical & Production Engineering, Nanyang Technological University, Nanyang Avenue, Singapore 2263 b ...
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THIS paper presents some interim results 1 of research being undertaken into the effects of regional policy with particular orientation towards an evaluation of the effects of the Regional Employment Premium (REP). The results presented... more
THIS paper presents some interim results 1 of research being undertaken into the effects of regional policy with particular orientation towards an evaluation of the effects of the Regional Employment Premium (REP). The results presented here are derived from an analysis of largely ...
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Research Interests: China, Adolescent, Hong Kong, Medical Students, Humans, and 8 moreChild, Postgraduate medical education, Wales, Female, Male, Aged, Middle Aged, and Adult
Research Interests: Multidisciplinary, Humans, Mice, Female, Ovulation Induction, and 14 moreAnimals, Regression Analysis, Temperature, Blastocyst, Embryo Transfer, PLoS one, Laboratories, Observer Variation, Fertilization in Vitro, Somatic Cell Count, Oocytes, Hydrogen-Ion Concentration, Equipment Design, and Fetal Viability
Critically ill children with cardiac disease often require prolonged central venous access. Thrombosis of systemic veins or the need to preserve vessels for future cardiac procedures limits sites for placement of central venous catheters... more
Critically ill children with cardiac disease often require prolonged central venous access. Thrombosis of systemic veins or the need to preserve vessels for future cardiac procedures limits sites for placement of central venous catheters in these patients. This study evaluates the use of Broviac placement via the transhepatic approach for this patient population. A retrospective review. A tertiary care center. All children with complex congenital heart disease who underwent transhepatic Broviac placement between May 2000 and April 2004. Transhepatic Broviac placement. Thirty-two children with a median age of 5 months (20 days-5.3 yrs) and a median weight of 4.2 kg (2.2-24.9 kg) underwent 40 transhepatic Broviac placements. There were three (8.8%) procedural-related complications. One patient suffered an intra-abdominal bleed requiring an urgent laparotomy and removal of the Broviac, one patient required transfusion because of a mild self-contained intra-abdominal bleed, and one patient developed temporary complete heart block. There was one catheter infection. Thrombus was noted by echocardiography on the tip of two Broviacs; however, no intracardiac vegetations or embolic events occurred. There was no mortality related to the procedure. Broviacs remained in place for a median of 36 days (1 day-6 months). Five Broviacs were dislodged inadvertently (two during cardiac massage and three resulting from patient manipulation). The remaining Broviacs were electively removed safely without coil embolization. At a median follow-up of 3.5 months (10 days-3 yrs), there have been no long-term complications related to the Broviacs. Transhepatic Broviac catheters can be used safely in critically ill children with cardiac disease and remain indwelling for adequate periods of time. This modality of prolonged vascular access should be considered for children whose veins are occluded or need to be preserved for future procedures.
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Ulcerative colitis is largely a disease of nonsmokers. Having found previously that treatment with transdermal nicotine patches and mesalamine (5-aminosalicylic acid) has a beneficial effect on active colitis, we examined the value of... more
Ulcerative colitis is largely a disease of nonsmokers. Having found previously that treatment with transdermal nicotine patches and mesalamine (5-aminosalicylic acid) has a beneficial effect on active colitis, we examined the value of transdermal nicotine for the maintenance of remission. We treated 80 patients with ulcerative colitis in remission with either transdermal nicotine or placebo patches for six months in a randomized, double-blind study. Incremental doses of nicotine were given for the first three weeks to achieve a maintenance dose; most patients tolerated 15 mg for 16 hours daily. All patients were taking mesalamine preparations as maintenance treatment at entry into the study; this treatment was stopped once the maintenance dose of nicotine was achieved. Clinical, sigmoidoscopic, and histologic assessments were made at the beginning and the end of the study, or at relapse. Side effects and serum nicotine and cotinine concentrations were monitored throughout the study. There was no significant difference in the number of relapses between the groups. Twenty-two patients in the nicotine group were prematurely withdrawn from the study, 14 because of relapse and 8 for other reasons, including side effects and protocol violations. In the placebo group, 20 patients were withdrawn prematurely, 17 because of relapse and 3 for other reasons. Among patients using 15-mg nicotine patches, serum nicotine and cotinine concentrations were lower than expected and may reflect poor compliance. Side effects were reported by 35 patients--21 in the nicotine group and 14 in the placebo group--the most common of which were nausea, lightheadedness, and itching. Transdermal nicotine alone was no better than placebo in the maintenance of remission of ulcerative colitis, and premature withdrawal due to side effects was more common in the nicotine group.