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Biomedical subjects

Richard Freeman

Publications and source records attributed to Richard Freeman.

18 recordsLinked to original sources
PubMed2006

Safety, tolerability, and efficacy of everolimus in de novo liver transplant recipients: 12- and 36-month results.

Everolimus is a macrolide immunosuppressive agent with known consistent absorption. In this double-blind study, we examined the safety and tolerability of everolimus vs. placebo in de novo liver transplant recipients. One hundred and nineteen liver allograft recipients were randomized to 1 of 4 groups: everolimus 0.5 mg bid, everolimus 1.0 mg bid, everolimus 2 mg bid, or placebo. Patients received oral cyclosporine to achieve a target trough level of 150-400 ng/mL in combination with prednisone. Primary and secondary endpoints of safety, tolerability, and efficacy were determined at 12 months, and patients were followed through 36 months. There was a trend toward fewer treated acute rejections in the everolimus group than in the placebo group: everolimus 0.5 mg: 39.3%; everolimus 1.0 mg: 30.0%; everolimus 2 mg: 29.0%; placebo: 40.0% (P = not significant). Adverse events were higher in everolimus-treated patients especially at the 4-mg/day dose, but there was no difference in the incidence of thrombocytopenia or leukopenia between all groups and renal function as determined by serum creatinine, and creatinine clearance remained stable to 36 months in everolimus-treated patients. Mean cholesterol and triglycerides increased from baseline in all treatment groups, and maximum levels were seen at 6 months. In conclusion, this study demonstrates that everolimus in combination with oral cyclosporine had an acceptable safety and tolerability profile, paving the way for additional studies in this transplant indication.

Adult↗
PubMed2006

Invited commentary.

Explore the source record for details and available documents.

Academic Medical Centers↗
PubMed2006

A psychometric typology of U.K. domestic violence offenders.

A number of studies have described subtypes of domestically violent men, and the heterogeneity of domestically violent men is well established. The aim of the current study was to investigate the distribution of subtypes using psychometric measures in convicted domestically violent offenders in England. Four subtypes of offenders were identified: low pathology, borderline, narcissistic, and antisocial. These subtypes were broadly comparable with the family-only, dysphoric/borderline, and generally violent/antisocial types proposed by Holtzworth-Munroe and Stuart. The majority of the sample (60%) best fit the generally violent/antisocial profile. However, the reliance on psychometric measurement and lack of corroborative evidence from partners means that further research is necessary to test these findings.

Adult↗
PubMed2006

Incorporation of proteins within alginate fibre-based scaffolds using a post-fabrication entrapment method.

In this study, a physical entrapment process was explored for the incorporation of proteins within preformed fibrous alginates and the release profile was tuned by varying the processing parameters. The entrapment process was carried out in a series of aqueous solutions at room temperature and involved pre-swelling of the fibrous alginate within a Na(+)-rich solution, followed by exposure to the protein of choice and entrapping it by re-establishing cross-links of alginate with BaCl2. Entrapment and release of fluorescein isothiocyanate-labelled bovine serum albumin (FITC-BSA), a model protein, was studied. It was found that a sustained release of the incorporated protein in cell culture medium for about 6 days was achieved. The main factors determining the release profile included the NaCl/CaCl2 ratio in the pre-swelling solution, protein concentration, and the exposure time. To retard protein release, alginate fibres with entrapped FITC-BSA were processed together with poly(D, L-lactide) (PDLLA) into porous alginate fibre/PDLLA composites using supercritical CO2. In this manner, release of the protein for up to 3 months was achieved.

3T3 Cells↗
PubMed2006

The work the document does: research, policy, and equity in health.

At the center of the politics of health equity, in many countries and circumstances, stands a signal report of research. This article is concerned with what might be described as the architecture of such documents, including how they are produced and organized and the relationships they demonstrate with others that parallel, precede, and succeed them. The article examines how scientific and political authority is established and comments on the evidence of cross-national learning that these documents reveal. It discusses differences in how the problem of health equity is constructed in different countries and how research findings are converted into policy recommendations. It begins to trace a process of implementation by noting how these documents are referred to and written about. The argument is that the politics of health equity are expressed or realized in the documents and reports, which are its principal vehicle. This is not to claim that there is no world beyond the text or that the world somehow is a text, but that to fully understand that world we must understand the text and the work it does.

Documentation↗
PubMed2005

Pharmacodynamics of oral ganciclovir and valganciclovir in solid organ transplant recipients.

BACKGROUND: A randomized, double-blind study was conducted to evaluate the pharmacokinetics of ganciclovir following oral administration of ganciclovir or valganciclovir for prophylaxis of cytomegalovirus (CMV) disease in solid organ transplant recipients (n = 240/372). METHODS: The correlations between individual exposure to ganciclovir during prophylaxis, with CMV viremia incidence during and after treatment, CMV disease up to 12 months posttransplant, and hematological toxicity were assessed. RESULTS: Mean daily areas under the curve (AUCs) of ganciclovir from valganciclovir and oral ganciclovir were 46.3 +/- 15.2 and 28.0 +/- 10.9 microg.h/ml (mean +/- SD), respectively. Viremia was suppressed during prophylaxis when exposure to ganciclovir was 40-50 microg.h/ml, AUCs typical of those achieved in valganciclovir-treated patients. The development of viremia 1 month after ending prophylaxis was also reduced with higher ganciclovir AUC (median predicted incidence, 20% and 10% at AUCs of 33 and 50 microg h/ml, respectively). The development of CMV disease within 1 year of transplant was 17.6% and independent of prophylactic exposure to ganciclovir. There was only a weak tendency to increased neutropenia and leukopenia with higher ganciclovir exposure. CONCLUSIONS: The greater systemic exposure to ganciclovir delivered by valganciclovir was associated with delayed development of viremia. There was only a weak association between AUC and hematological toxicity.

Administration, Oral↗
PubMed2005

Impact of cytomegalovirus prophylaxis on rejection following orthotopic liver transplantation.

With improved cytomegalovirus (CMV) prophylaxis, CMV disease after liver transplantation has decreased dramatically, and patient and graft survival have improved. We examined the impact of CMV prophylaxis on biopsy proven rejection after orthotopic liver transplantation by analyzing data on 192 liver recipients over 5 years (1994-1999). Risk factors assessed for biopsy proven rejection including donor and recipient age, CMV serostatus; CMV prophylaxis; immunosuppression; bacteremia and blood product use were examined over a 2-year follow-up. Multivariate analysis of risk factors for rejection showed that bacteremia (HR 3.57, 95% CI 1.39-9.36, P=0.008), donor age (HR 1.20, 95% CI 1.06-1.36, per 10 year increase, P=0.004), and use of cyclosporine as initial immunosuppression compared to tacrolimus (HR 1.98, 95% CI 1.27-3.09, P=0.003) were associated with increased risk; ganciclovir prophylaxis for 3 months (HR 0.51, 95% CI 0.33 to 0.79, P=0.003) and recipient age (HR 0.78; 95% CI 0.63-0.96, for each 10 year increase, P=0.03) were associated with decreased risk. We conclude that, the use of CMV prophylaxis with ganciclovir significantly reduces the incidence of biopsy proven rejection in liver transplant recipients.

Antiviral Agents↗
PubMed2005

Pharmacokinetic profile of ganciclovir after its oral administration and from its prodrug, valganciclovir, in solid organ transplant recipients.

BACKGROUND: Valganciclovir (Valcyte) has recently been approved for the prevention of cytomegalovirus (CMV) disease in high-risk (CMV donor positive [D+]/recipient negative [R-]) solid organ transplant (SOT) recipients. Large-scale studies describing the pharmacokinetics of valganciclovir in SOT recipients are lacking. A recent randomised, double-blind study of valganciclovir in 364 D+/R- (intent-to-treat population) SOT recipients provided valuable data on which a population pharmacokinetic analysis was performed. METHODS: The pharmacokinetics of ganciclovir from oral ganciclovir (Cymevene, 1000 mg three times daily) and from valganciclovir (900 mg once daily) were described with plasma levels from 240 patients (1181 datapoints describing 449 pharmacokinetic profiles) using nonlinear mixed-effects modelling (NONMEM) software. A two-compartment pharmacokinetic model with separate absorption/metabolism and absorption parameters for valganciclovir and ganciclovir, respectively, was developed. RESULTS: Exposure to ganciclovir from valganciclovir averaged 1.65-fold greater than that from oral ganciclovir (95% CI 1.58, 1.81); respective daily area under the plasma concentration-time curve values were 46.3 +/- 15.2 microg . h/mL and 28.0 +/- 10.9 microg . h/mL. The relative systemic exposure of ganciclovir was approximately 8-fold higher from valganciclovir than oral ganciclovir. Exposure to ganciclovir from valganciclovir was similar among liver, heart and kidney transplant recipients (46.0 +/- 16.1, 40.2 +/- 11.8 and 48.2 +/- 14.6 microg . h/ mL, respectively). Adherence to the prescribed dosing regimens, which were reduced for renal impairment, gave consistent exposure to ganciclovir. CONCLUSION: Oral valganciclovir produces exposures of ganciclovir exceeding those attained with oral ganciclovir, but in line with those reported after standard intravenous administration of ganciclovir. This indicates that oral valganciclovir is suitable in circumstances requiring prophylactic use of ganciclovir and allows for more convenient management of patients at risk of CMV disease.

Administration, Oral↗
PubMed2004

The clinical impact of ganciclovir prophylaxis on the occurrence of bacteremia in orthotopic liver transplant recipients.

BACKGROUND: Cytomegalovirus (CMV) infection or receipt of a CMV-seropositive donor liver has been shown to be an independent predictor of bacteremia in orthotopic liver transplant (OLT) recipients. However, prevention of CMV infection through use of intense CMV prophylaxis has not been examined to assess the impact on bacteremia in liver transplant recipients. METHODS: We analyzed the impact of CMV prophylaxis on rates of bacteremia by examining 192 consecutive OLT recipients during a 2-year follow-up period. RESULTS: There were 29 episodes of bacteremia. Univariate analysis of risk factors for bacteremia showed that invasive fungal disease, initial anti-lymphocyte immunosuppression, treatment for rejection, and use of solumedrol were significantly associated with increased risk. Receipt of >or=14 days of ganciclovir prophylaxis (hazard ratio [HR], 0.40; 95% CI [confidence interval], 0.18-0.87; P=.02), end-to-end biliary anastomosis, and receipt of <10 units of red blood cells (RBCs) were significantly associated with a decreased risk. Three-variable analysis controlling for end-to-end anastomosis and use of <10 units of RBCs, showed that use of >or=14 days of ganciclovir was still associated with a reduced risk of bacteremia (HR, 0.44; 95% CI, 0.20-0.98; P=.0437). CONCLUSIONS: Among factors associated with bacteremia, use of prophylactic ganciclovir is independently associated with a significant reduction of bacteremia in OLT recipients.

Adult↗
PubMed2004

Absence of cytomegalovirus-resistance mutations after valganciclovir prophylaxis, in a prospective multicenter study of solid-organ transplant recipients.

We investigated the emergence of cytomegalovirus (CMV) ganciclovir-resistance mutations in 301 high-risk solid-organ transplant (SOT) recipients after oral prophylaxis, for 100 days, with either valganciclovir or ganciclovir. For patients treated with ganciclovir, the incidence of CMV UL97 mutations was 1.9% (2/103) at the end of prophylaxis and 6.1% (2/33) for patients with suspected CMV disease up to 1 year after transplantation. No resistance mutations were detected in samples from valganciclovir-treated patients. Dual polymerase (UL54) and UL97 resistance mutations were not seen. Valganciclovir was associated with negligible risk of resistance and thus constitutes a useful alternative to ganciclovir prophylaxis for CMV in high-risk SOT recipients.

Adolescent↗
PubMed2004

Efficacy and safety of valganciclovir vs. oral ganciclovir for prevention of cytomegalovirus disease in solid organ transplant recipients.

We compared the efficacy and safety of valganciclovir with those of oral ganciclovir in preventing cytomegalovirus (CMV) disease in high-risk seronegative solid organ transplant (SOT) recipients of organs from seropositive donors (D+/R-). In this randomised, prospective, double-blind, double-dummy study, 364 CMV D+/R- patients received valganciclovir 900 mg once daily or oral ganciclovir 1000 mg three times a day (tid) within 10 days of transplant and continued through 100 days. CMV disease, plasma viremia, acute graft rejection, graft loss and safety were analyzed up to 6 and 12 months post-transplant. Endpoint committee-defined CMV disease developed in 12.1% and 15.2% of valganciclovir and ganciclovir patients, respectively, by 6 months, though with a difference in the relative efficacy of valganciclovir and ganciclovir between organs (i.e. an organ type-treatment interaction). By 12 months, respective incidences were 17.2% and 18.4%, and the incidence of investigator-treated CMV disease events was comparable in the valganciclovir (30.5%) and ganciclovir (28.0%) arms. CMV viremia during prophylaxis was significantly lower with valganciclovir (2.9% vs. 10.4%; p=0.001), but was comparable by 12 months (48.5% valganciclovir vs 48.8% ganciclovir). Time-to-onset of CMV disease and to viremia were delayed with valganciclovir; rates of acute allograft rejection were generally lower with valganciclovir. Except for a higher incidence of neutropenia with valganciclovir (8.2%, vs 3.2% ganciclovir) the safety profile was similar for both drugs. Overall, once-daily oral valganciclovir was as clinically effective and well-tolerated as oral ganciclovir tid for CMV prevention in high-risk SOT recipients.

Administration, Oral↗
PubMed2004

Clinical utility of cytomegalovirus viral load testing for predicting CMV disease in D+/R- solid organ transplant recipients.

Despite prophylaxis, cytomegalovirus (CMV) disease is common in donor seropositive (D+)/recipient seronegative (R-) transplant patients after cessation of prophylaxis. Early detection of CMV may allow for pre-emptive therapy to prevent active disease. The clinical utility of quantitative plasma viral load measurements for predicting CMV disease was determined in 364 D+/R- organ transplant patients receiving prophylaxis (100 d of valganciclovir or oral ganciclovir). Measurements were performed every 2 weeks until day 100 and at months 4, 4.5, 5, 6, 8 and 12 post-transplant. CMV disease occurred in 64 (17.6%) patients by 12 months. Using a positive cut-off value of >400 copies/mL, sensitivity was 38%, specificity 60%, positive predictive value 17%, and negative predictive value 82% for prediction of CMV disease. Therefore, routine monitoring would have predicted disease in only 24/64 (38%) patients. The test characteristics were not improved by changing the viral load cut-off point for defining a positive result. Similarly, single time point measures at the end of prophylaxis or month 4 had low sensitivity for disease prediction. Overall, regular CMV plasma viral load measurements were only of modest value in predicting CMV disease.

Administration, Oral↗
PubMed2003

Model for end-stage liver disease (MELD) and allocation of donor livers.

BACKGROUND & AIMS: A consensus has been reached that liver donor allocation should be based primarily on liver disease severity and that waiting time should not be a major determining factor. Our aim was to assess the capability of the Model for End-Stage Liver Disease (MELD) score to correctly rank potential liver recipients according to their severity of liver disease and mortality risk on the OPTN liver waiting list. METHODS: The MELD model predicts liver disease severity based on serum creatinine, serum total bilirubin, and INR and has been shown to be useful in predicting mortality in patients with compensated and decompensated cirrhosis. In this study, we prospectively applied the MELD score to estimate 3-month mortality to 3437 adult liver transplant candidates with chronic liver disease who were added to the OPTN waiting list at 2A or 2B status between November, 1999, and December, 2001. RESULTS: In this study cohort with chronic liver disease, 412 (12%) died during the 3-month follow-up period. Waiting list mortality increased directly in proportion to the listing MELD score. Patients having a MELD score <9 experienced a 1.9% mortality, whereas patients having a MELD score > or =40 had a mortality rate of 71.3%. Using the c-statistic with 3-month mortality as the end point, the area under the receiver operating characteristic (ROC) curve for the MELD score was 0.83 compared with 0.76 for the Child-Turcotte-Pugh (CTP) score (P < 0.001). CONCLUSIONS: These data suggest that the MELD score is able to accurately predict 3-month mortality among patients with chronic liver disease on the liver waiting list and can be applied for allocation of donor livers.

Adult↗
PubMedDate not supplied

Novel surface entrapment process for the incorporation of bioactive molecules within preformed alginate fibers.

A physical entrapment technique has been developed for the surface engineering of preformed alginate fibers. Surface engineering was carried out at room temperature in aqueous solutions without additional solvent, a catalyst/initiator, a chemical cross-linking agent, or a temperature increase. Entrapment of surface-modifying molecules was achieved by exposing the alginate fibers to a Na(+)-rich NaCl/CaCl2 mixture solution, which caused the formation of a moderate dissociation layer into which the modifier could diffuse within a few seconds. The surface dissociation was then reversed by the addition of a large excess of multivalent cations, which resulted in collapse of the interface and immobilization of the modifying species. Rhodamine-tagged poly(ethylene glycol)s of different molecular weights were used as model molecules to investigate the effect of process parameters on the entrapment efficiency. It was found that the entrapment efficiency as well as the distribution of the modifier within the alginate fibers was determined by several factors, including the NaCl/CaCl2 ratio in the preswelling solution, exposure time, and concentration and molecular weight of the modifiers. The morphology of the fibers was not significantly changed in terms of shape and size after the entrapment process. By this technique, poly(L-lysine) (PLL) coupled with cell adhesion peptide sequence GRGDS (PLL-GRGDS) was entrapped within alginate fibers, and it was demonstrated that the modification promoted the attachment of mouse 3T3 fibroblasts.

3T3 Cells↗
PubMedDate not supplied

The impact of health professionals' attitudes about being registered donors on the availability of organs.

The mismatch between supply and demand in organ donation is well documented. Although there are many reasons for this mismatch, failure of health professionals to identify potential donors or to gain consent from bereaved relatives is considered to be significant. Such failures may be due to the attitudes of health professionals themselves towards becoming organ donors. This study focuses on the level of commitment shown by health care professionals and their student equivalents to organ donation, and assesses the ways in which they identify themselves as potential organ donors. These findings are evaluated and suggestions for future practice are offered.

Adolescent↗