Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 63
Filter
1.
Xenotransplantation ; 31(2): e12858, 2024.
Article in English | MEDLINE | ID: mdl-38646921

ABSTRACT

One of the prerequisites for successful organ xenotransplantation is a reasonable size match between the porcine organ and the recipient's organ to be replaced. Therefore, the selection of a suitable genetic background of source pigs is important. In this study, we investigated body and organ growth, cardiac function, and genetic diversity of a colony of Auckland Island pigs established at the Center for Innovative Medical Models (CiMM), LMU Munich. Male and female Auckland Island pig kidney cells (selected to be free of porcine endogenous retrovirus C) were imported from New Zealand, and founder animals were established by somatic cell nuclear transfer (SCNT). Morphologically, Auckland Island pigs have smaller body stature compared to many domestic pig breeds, rendering their organ dimensions well-suited for human transplantation. Furthermore, echocardiography assessments of Auckland Island pig hearts indicated normal structure and functioning across various age groups throughout the study. Single nucleotide polymorphism (SNP) analysis revealed higher runs of homozygosity (ROH) in Auckland Island pigs compared to other domestic pig breeds and demonstrated that the entire locus coding the swine leukocyte antigens (SLAs) was homozygous. Based on these findings, Auckland Island pigs represent a promising genetic background for organ xenotransplantation.


Subject(s)
Genetic Variation , Swine , Transplantation, Heterologous , New Zealand , Swine/genetics , Animals , Male , Female , Humans , Heart/anatomy & histology , Heart/diagnostic imaging , Echocardiography , Genotype , Homozygote
2.
Access Microbiol ; 5(6): acmi000432, 2023.
Article in English | MEDLINE | ID: mdl-37424570

ABSTRACT

Objective. The present study was carried out to establish the chemical profile of the methanolic extract of Polyalthia longifolia stem bark and investigate its antibacterial property against some human pathogenic bacteria. Methods. The extract was analysed using liquid and gas chromatography coupled to mass spectrometry. Antibacterial activity of P. longifolia extract against some human pathogenic bacteria was screened using the AlamarBlue method, and MIC and MBC were determined. Results and Conclusion. Liquid chromatography-mass spectrometry (LC-MS) revealed the presence of 21 compounds among which 12 were identified. Gas chromatography-mass spectrometry (GC-MS) allowed identification of 26 compounds, the three major ones being the following: cis vaccenic acid (17.79 %), 3-ethyl-3-hydroxyandrostan-17-one (13.80 %) and copaiferic acid B (12.82 %). P. longifolia extract was active against Gram-positive bacteria with MIC ranging from 1 to 2 mg ml-1 and MBC from 2 to 6 mg ml-1. This study demonstrated the bactericidal effect of the methanolic extract of Polyalthia longifolia stem bark against some human pathogenic bacteria, including methicillin-resistant S. aureus . This effect could be related to the presence in the extract of a broad diversity of well-known compounds with established pharmacological properties. These results support the ethnomedicinal use of P. longifolia stem bark in Cameroon for the management of methicillin-resistant S. aureus (MRSA)-related infections.

3.
Biomed Res Int ; 2023: 2657278, 2023.
Article in English | MEDLINE | ID: mdl-36654868

ABSTRACT

Aim: This study is aimed at establishing phenolic compound profile and assessing the possible antiulcer activities of aqueous extracts of some staple plant foods from the West and North-West regions of Cameroon against chronic gastric ulcer models in rats. Materials and Methods: Phenolic constituents of extracts were evaluated using HPLC-DAD. Aqueous extracts of Corchorus olitorius, Solanum nigrum, Vigna unguiculata, Triumfetta pentandra, "nkui" spices, and "yellow soup" spices were tested at two doses (200 and 400 mg/kg). After treatments, animals were sacrificed, healing percentage and antioxidant status (catalase, superoxide dismutase, and glutathione peroxidase) were evaluated, and histological examination of gastric mucosa was realized. Results: HPLC-DAD revealed that p-hydroxybenzoic and protocatechuic acids were the phenolic compound present in all extracts. Oral administration of extracts (200 and 400 mg/kg) significantly reduced ulcer surface value and significantly increased mucus production compared to the control groups (p < 0.05). Histological study supported the observed healing activity of different extracts characterized by a reduced inflammatory response. Moreover, administration of aqueous extracts increased the activity of antioxidant enzymes. Conclusion: This study revealed that aqueous extracts of Solanum nigrum, Corchorus olitorius, Vigna unguiculata, Triumfetta pentandra, "yellow soup" spices, and "nkui" spices possess healing antiulcer effects against models of gastric ulcers. The antiulcer mechanisms involved may include increase of gastric mucus production and improvement of the antioxidant activity of gastric tissue. These activities may be due to the phenolic compounds identified in the extracts, especially p-hydroxybenzoic and protocatechuic acids present in all extracts and with known antioxidant, cytoprotective, and healing properties. However, all the diets may promote the healing process of chronic ulcers caused by excessive alcohol consumption/stress.


Subject(s)
Anti-Ulcer Agents , Stomach Ulcer , Rats , Animals , Stomach Ulcer/drug therapy , Stomach Ulcer/pathology , Plant Extracts/pharmacology , Plant Extracts/therapeutic use , Phytotherapy , Antioxidants/pharmacology , Antioxidants/therapeutic use , Cameroon , Anti-Ulcer Agents/pharmacology , Rats, Wistar , Phenols/pharmacology , Gastric Mucosa/pathology
4.
Article in English | MEDLINE | ID: mdl-35140799

ABSTRACT

OBJECTIVE: The objective of this study was to elucidate the antisecretory mechanism of the root bark aqueous extract of Diospyros mespiliformis (RBAEDM) in Wistar rats. Materials and methods. RBAEDM was tested on three experimental animal models of gastric acid hypersecretion including pyloric ligation (PL), PL with histamine, and carbachol pretreatments. The ulcerated surface, mucus mass, pH, gastric acidity, and pepsin activity were determined. Some bioactive compounds revealed by qualitative phytochemistry were quantified. Some markers of oxidative stress in vivo such as malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), reduced glutathione (GSH), and in vitro antioxidant tests (ABTS: 2,2'-azinobis-3-ethylbenzothiazoline-6-sulfonic acid, DPPH: 2,2-diphenyl-2-picrylhydrazyl, and FRAP: ferric reducing antioxidant power) were determined. RESULTS: In the three models studied, RBAEDM resulted in increases in the percentages of inhibition ranging from 9.50 to 59.52% of gastric ulcer and mucus mass. This increase was accompanied by the reduction in acidity and pepsin activity. The administration of RBAEDM resulted in a significant decrease (p < 0.05, p < 0.01) in MDA levels correlated with a significant increase (p < 0.05, p < 0.01) in CAT and nitrite levels compared with the negative control. RBAEDM has the ability to scavenge ABTS and DPPH radicals and to reduce FRAP, and the inhibitory concentration of 50% (IC50) of the ABTS radical was 220 µg/mL compared with the butylhydroxytoluene (BHT) control (175 µg/mL). Quantitative phytochemistry revealed abundant polyphenols, flavonoids, tannins, saponins, and anthocyanin. CONCLUSION: RBAEDM protected gastric mucous membrane for gastric acid by mechanisms that would involve both anticholinergic and antihistaminergic pathways.

5.
Arthritis Rheumatol ; 74(6): 1059-1069, 2022 06.
Article in English | MEDLINE | ID: mdl-34927391

ABSTRACT

OBJECTIVE: To determine whether a therapeutic approach of intensive serum urate lowering results in improved bone erosion scores in patients with erosive gout. METHODS: We undertook a 2-year, double-blind randomized controlled trial of 104 participants with erosive gout who were receiving serum urate-lowering therapy orally and who had serum urate levels of ≥0.30 mmoles/liter at baseline. Participants were randomly assigned to either an intensive serum urate target of <0.20 mmoles/liter or a standard target of <0.30 mmoles/liter (considered the standard according to rheumatology guidelines). Oral serum urate-lowering therapy was titrated to target using a standardized protocol (with the maximum approved doses of allopurinol, probenecid, febuxostat, and benzbromarone). The primary end point was the total computed tomography (CT) bone erosion score. Outcome Measures in Rheumatology (OMERACT) gout core outcome domains were secondary end points. RESULTS: Although the serum urate levels were significantly lower in the intensive target group compared to the standard target group over the study period (P = 0.002), fewer participants in the intensive target group achieved the randomized serum urate target level by year 2 (62% versus 83% of patients in the standard target group; P < 0.05). The intensive target group required higher doses of allopurinol (mean ± SD 746 ± 210 mg/day versus 497 ± 186 mg/day; P < 0.001) and received more combination therapy (P = 0.0004) compared to the standard target group. We observed small increases in CT bone erosion scores in both serum urate target groups over 2 years, with no between-group difference (P = 0.20). OMERACT core outcome domains (gout flares, tophi, pain, patient's global assessment of disease activity, health-related quality of life, and activity limitation) improved in both groups over 2 years, with no between-group differences. Adverse event and serious adverse event rates were similar between the groups. CONCLUSION: Compared to a serum urate target of <0.30 mmoles/liter, more intensive serum urate lowering is difficult to achieve with an oral urate-lowering therapy. Intensive serum urate lowering leads to a high medication burden and does not improve bone erosion scores in patients with erosive gout.


Subject(s)
Allopurinol , Gout , Allopurinol/therapeutic use , Febuxostat/therapeutic use , Gout/diagnostic imaging , Gout/drug therapy , Gout Suppressants , Humans , Quality of Life , Treatment Outcome , Uric Acid
6.
J Ethnopharmacol ; 279: 114374, 2021 Oct 28.
Article in English | MEDLINE | ID: mdl-34181961

ABSTRACT

ETHNOPHARMACOLOGICAL RELEVANCE: Information collected from local traditional healers reported that Eremomastax speciosa (Hochst.) Cufod. has for a long time been used to manage gastric ulcers in many regions of Cameroon and beyond. This traditional use is supported by numerous studies. However, efficacy of this plant has never been tested in case of chronic gastric ulcers associating Helicobacter pylori infection. AIM OF THE STUDY: This study was designed to investigate curative effects of the aqueous extract of E. speciosa leaves (AEESL) against chronic gastric ulcers associated to Helicobacter pylori infection. MATERIALS AND METHODS: Two experimental methods of chronic gastric ulcers, involving H. pylori infection, were performed using Wistar rats, namely: acetic acid-induced ulcers and "unhealed ulcers". E. speciosa extract was tested at three doses (100; 200; 400 mg/kg) and at the end of experiments, some in vivo antioxidant parameters were measured, bacterial load in stomach tissue calculated and histopathological examinations performed. RESULTS: E. speciosa reduced ulcer index at all the doses and significantly increased mucus production as well as antioxidant (mainly SOD and GSH) level. Bacterial load in stomach significantly decreased (p < 0.05) in extract-treated groups (200 and 400 mg/kg) as confirmed by histopathological observations. The extract was found to be non toxic to healthy and cancerous cells (IC50 > 1000 µg/mL). CONCLUSIONS: E. speciosa accelerated healing of gastric ulcers even in presence of indomethacin, while decreasing bacterial loads in rats' stomachs. These results provide supplementary support to the use of E. speciosa in ethnomedicine and open new perspectives regarding development of a herbal-based monotherapy able to efficiently replace/supplement standard antiulcer tri/quadritherapy.


Subject(s)
Acanthaceae/chemistry , Helicobacter Infections/complications , Plant Extracts/pharmacology , Stomach Ulcer/prevention & control , Acetic Acid , Animals , Anti-Ulcer Agents/isolation & purification , Anti-Ulcer Agents/pharmacology , Antioxidants/metabolism , Disease Models, Animal , Dose-Response Relationship, Drug , Helicobacter Infections/drug therapy , Helicobacter pylori/isolation & purification , Indomethacin/toxicity , Inhibitory Concentration 50 , Male , Plant Extracts/administration & dosage , Plant Leaves , Rats , Rats, Wistar , Wound Healing/drug effects
7.
J Rheumatol ; 48(2): 293-298, 2021 02.
Article in English | MEDLINE | ID: mdl-32358154

ABSTRACT

OBJECTIVE: To determine the relationship between gout flare rate and self-categorization into remission, low disease activity (LDA), and patient acceptable symptom state (PASS). METHODS: Patients with gout self-categorized as remission, LDA, and PASS, and reported number of flares over the preceding 6 and 12 months. Multinomial logistic regression was used to determine the association between being in each disease state (LDA and PASS were combined) and flare count, and self-reported current flare. A distribution-based approach and extended Youden index identified possible flare count thresholds for each state. RESULTS: Investigators from 17 countries recruited 512 participants. Remission was associated with a median recalled flare count of zero over both 6 and 12 months. Each recalled flare reduced the likelihood of self-perceived remission compared with being in higher disease activity than LDA/PASS, by 52% for 6 months and 23% for 12 months, and the likelihood of self-perceived LDA/PASS by 15% and 5% for 6 and 12 months, respectively. A threshold of 0 flares in preceding 6 and 12 months was associated with correct classification of self-perceived remission in 58% and 56% of cases, respectively. CONCLUSION: Flares are significantly associated with perceptions of disease activity in gout, and no flares over the prior 6 or 12 months is necessary for most people to self-categorize as being in remission. However, recalled flare counts alone do not correctly classify all patients into self-categorized disease activity states, suggesting that other factors may also contribute to self-perceived gout disease activity.


Subject(s)
Gout , Gout/drug therapy , Humans , Needs Assessment , Self Report , Symptom Flare Up
9.
Arthritis Rheumatol ; 71(10): 1739-1746, 2019 10.
Article in English | MEDLINE | ID: mdl-31081595

ABSTRACT

OBJECTIVE: To examine whether allopurinol dose escalation to achieve serum urate (SU) target can influence bone erosion or monosodium urate (MSU) crystal deposition, as measured by dual-energy computed tomography (DECT) in patients with gout. METHODS: We conducted an imaging study of a 2-year randomized clinical trial that compared immediate allopurinol dose escalation to SU target with conventional dosing for 1 year followed by dose escalation to target, in gout patients who were receiving allopurinol and who had an SU level of ≥0.36 mmoles/liter. DECT scans of feet and radiographs of hands and feet were obtained at baseline, year 1, and year 2 visits. DECT scans were scored for bone erosion and urate volume. RESULTS: Paired imaging data were available for 87 patients (42 in the dose-escalation group and 45 in the control group). At year 2, the progression in the CT erosion score was higher in the control group than in the dose-escalation group (+7.8% versus +1.4%; P = 0.015). Changes in plain radiography erosion or narrowing scores did not differ between groups. Reductions in DECT urate volume were observed in both groups. At year 2, patients in the control group who had an SU level of <0.36 mmoles/liter and patients in the dose-escalation group had reduced DECT urate volume (-27.6 to -28.3%), whereas reduction in DECT urate volume was not observed in control group patients with an SU level of ≥0.36 mmoles/liter (+1.5%) (P = 0.023). CONCLUSION: These findings provide evidence that long-term urate-lowering therapy using a treat-to-SU-target strategy can influence structural damage and reduce urate crystal deposition in gout.


Subject(s)
Allopurinol/administration & dosage , Bone Resorption/diagnostic imaging , Foot Joints/diagnostic imaging , Gout Suppressants/administration & dosage , Gout/drug therapy , Hand Joints/diagnostic imaging , Uric Acid/metabolism , Aged , Dose-Response Relationship, Drug , Female , Foot Bones/diagnostic imaging , Gout/diagnostic imaging , Gout/metabolism , Hand Bones/diagnostic imaging , Humans , Male , Middle Aged , Tomography, X-Ray Computed , Treatment Outcome
10.
Arthritis Res Ther ; 20(1): 255, 2018 Nov 16.
Article in English | MEDLINE | ID: mdl-30446002

ABSTRACT

OBJECTIVE: Allopurinol dosing has frequently been limited based on creatinine clearance (CrCL), resulting in failure to achieve target serum urate (SU). The aim of this analysis was to determine how many milligrams of allopurinol above the recommended CrCL-based dose (R+) are required to achieve target SU and to investigate the factors that influence R+. METHODS: We analysed data from participants in a 24-month open, randomized, controlled, parallel-group, comparative clinical trial. Data obtained during the 12-month dose escalation (DE) phase of the study (year 1 for DE/DE and year 2 for control/DE) were combined. R+ dose was defined as the number of milligrams of allopurinol above the CrCL-based dose at the final visit. RESULTS: Of the 132 participants, R+ allopurinol dose at the final visit was ≤ 100 mg/day in 38 (28.8%), 101-200 mg/day in 46 (34.8%) and > 200 mg/day in 48 participants (37.1%). There was no significant difference between the R+ groups in the number of participants achieving target SU. There was an increase in plasma oxypurinol and a larger percentage and absolute change in SU as R+ increased. Multivariate analysis revealed CrCL, weight, baseline SU and allopurinol dose, were significantly positively associated with allopurinol dose at 12 months. There were no significant differences across R+ groups in renal or liver function adverse events, although there were numerically more serious adverse events in the higher R+ groups. CONCLUSION: A wide range of R+ doses are required to achieve target SU. Four easily obtained clinical variables (baseline SU, CrCL, weight, and allopurinol dose) may be helpful to predict allopurinol dose. TRIAL REGISTRATION: ANZCTR, ACTRN12611000845932 . Registered on 10 August 2011.


Subject(s)
Allopurinol/administration & dosage , Creatinine/blood , Gout Suppressants/administration & dosage , Gout/blood , Metabolic Clearance Rate/drug effects , Uric Acid/blood , Adult , Aged , Dose-Response Relationship, Drug , Drug Delivery Systems/methods , Female , Gout/drug therapy , Humans , Male , Metabolic Clearance Rate/physiology , Middle Aged , Uric Acid/antagonists & inhibitors
11.
Rheumatology (Oxford) ; 57(12): 2183-2189, 2018 12 01.
Article in English | MEDLINE | ID: mdl-30107437

ABSTRACT

Objectives: To determine factors that predict inadequate serum urate (SU) lowering response in a randomized controlled trial of allopurinol dose escalation (DE) in gout. Methods: Participants undergoing allopurinol DE were classified as: complete response (CR)-reached target SU at month 9 and 12 of the DE phase or if still dose escalating at month 9 reached target SU by month 12; partial response (PR)-reached target at some stage but not fulfilling criteria for CR; or inadequate response (IR)-did not reach target SU at any time. Results: IR was uncommon, occurring in 13/150 (8.7%), compared with 82 (54.7%) CR, and 55 (36.6%) PR. Mean (s.e.m.) SU was higher at the end of the 12-month DE in IR compared with both CR and PR groups; 7.6 (0.31) vs 5.01 (0.06) and 5.97 (0.17) mg/dl respectively (P < 0.001). In univariate analysis, compete responders tended to be older, be receiving less allopurinol, have longer gout duration and were more likely to be New Zealand (NZ) European ethnicity, compared with IR+PR. Using multi-variate logistic regression analysis, only longer duration of gout and NZ European ethnicity remained significant independent predictors of CR. Baseline SU ⩾ 8 mg/dl had a sensitivity of 69.2% and specificity of 85.1% in predicting IR. The odds ratio for an IR if baseline SU was ⩾8 mg/dl was 11.7 (95% CI 3.3, 41.2). Conclusion: A minority of people with gout never reach target SU when allopurinol dose is increased in a treat-to-target manner. Approximately one-third of those with SU ⩾ 8mg/dl despite allopurinol ⩾300mg/d have an IR to DE. Trial registration: Australian New Zealand Clinical Trails Registry, https://www.anzctr.org.au, ACTRN12611000845932.


Subject(s)
Allopurinol/administration & dosage , Gout Suppressants/administration & dosage , Gout/blood , Gout/drug therapy , Uric Acid/blood , Dose-Response Relationship, Drug , Female , Humans , Male , Middle Aged , Treatment Outcome
12.
J Vis Exp ; (131)2018 01 31.
Article in English | MEDLINE | ID: mdl-29443083

ABSTRACT

Compared to other tissues, white adipose tissue has a considerably less RNA and protein content for downstream applications such as real-time PCR and Western Blot, since it mostly contains lipids. RNA isolation from adipose tissue samples is also challenging as extra steps are required to avoid these lipids. Here, we present a procedure to collect three anatomically different white adipose tissues from mice, to process these samples and perform RNA isolation. We further describe the synthesis of cDNA and gene expression experiments using real-time PCR. The hereby described protocol allows the reduction of contamination from the animal's hair and blood on fat pads as well as cross-contamination between different fat pads during tissue collection. It has also been optimized to ensure adequate quantity and quality of the RNA extracted. This protocol can be widely applied to any mouse model where adipose tissue samples are required for routine experiments such as real-time PCR but is not intended for isolation from primary adipocytes cell culture.


Subject(s)
Adipose Tissue/pathology , Gene Expression/genetics , Proteins/metabolism , RNA/metabolism , Animals , Mice
13.
Br J Clin Pharmacol ; 84(5): 937-943, 2018 05.
Article in English | MEDLINE | ID: mdl-29341237

ABSTRACT

AIM: This research aims to evaluate the predictive performance of a published allopurinol dosing tool. METHODS: Allopurinol dose predictions were compared to the actual dose required to achieve serum urate (SU) <0.36 mmol l-1 using mean prediction error. The influence of patient factors on dose predictions was explored using multilinear regression. RESULTS: Allopurinol doses were overpredicted by the dosing tool; however, this was minimal in patients without diuretic therapy (MPE 63 mg day-1 , 95% CI 40-87) compared to those receiving diuretics (MPE 295 mg day-1 , 95% CI 260-330, P < 0.0001). ABCG2 genotype (rs2231142, G>T) had an important impact on the dose predictions (MPE 201, 107, 15 mg day-1 for GG, GT and TT, respectively, P < 0.0001). Diuretic use and ABCG2 genotype explained 53% of the variability in prediction error (R2  = 0.53, P = 0.0004). CONCLUSIONS: The dosing tool produced acceptable maintenance dose predictions for patients not taking diuretics. Inclusion of ABCG2 genotype and a revised adjustment for diuretics would further improve the performance of the dosing tool.


Subject(s)
ATP Binding Cassette Transporter, Subfamily G, Member 2/genetics , Allopurinol/therapeutic use , Decision Support Techniques , Diuretics/adverse effects , Neoplasm Proteins/genetics , Adult , Aged , Aged, 80 and over , Drug Interactions , Female , Genotype , Gout Suppressants/therapeutic use , Humans , Male , Middle Aged , Polymorphism, Single Nucleotide/genetics , Randomized Controlled Trials as Topic , Uric Acid/blood , Young Adult
14.
Calcif Tissue Int ; 102(1): 73-84, 2018 01.
Article in English | MEDLINE | ID: mdl-29018897

ABSTRACT

INTRODUCTION: Numerous observational studies have reported that serum urate concentration positively correlates with bone density and reduced risk of fractures. The aim of this study was to examine whether soluble urate directly influences bone remodelling. METHODS: In laboratory studies, the in vitro effects of soluble urate were examined in osteoclast, osteoblast and osteocyte assays at a range of urate concentrations consistent with those typically observed in humans (up to 0.70 mmol/L). The clinical relevance of the in vitro assay findings was assessed using serial procollagen-1 N-terminal propeptide (P1NP) and Month 12 bone density data from a randomised controlled trial of allopurinol dose escalation in people with gout. RESULTS: Addition of urate in the RAW264.7 cell osteoclastogenesis assay led to small increases in osteoclast formation (ANOVA p = 0.018), but no significant difference in bone resorption. No significant effects on osteoclast number or activity were observed in primary cell osteoclastogenesis or resorption assays. Addition of urate did not alter viability or function in MC3T3-E1 pre-osteoblast, primary human osteoblast, or MLO-Y4 osteocyte assays. In the clinical trial analysis, reducing serum urate over a 12 month period by allopurinol dose escalation did not lead to significant changes in P1NP or differences in bone mineral density. CONCLUSION: Addition of soluble urate at physiological concentrations does not influence bone remodelling in vitro. These data, together with clinical trial data showing no effect of urate-lowering on P1NP or bone density, do not support a direct role for urate in influencing bone remodelling.


Subject(s)
Bone Remodeling/drug effects , Osteoclasts/drug effects , Osteocytes/drug effects , Uric Acid/pharmacology , Bone Remodeling/physiology , Bone Resorption/metabolism , Bone and Bones/drug effects , Bone and Bones/metabolism , Cell Differentiation/drug effects , Humans , Osteoclasts/metabolism , Osteocytes/metabolism , Osteogenesis/drug effects
15.
Arthritis Res Ther ; 19(1): 283, 2017 12 21.
Article in English | MEDLINE | ID: mdl-29268756

ABSTRACT

BACKGROUND: The use of allopurinol in people with chronic kidney disease (CKD) remains one of the most controversial areas in gout management. The aim of this study was to determine the effect of baseline kidney function on safety and efficacy of allopurinol dose escalation to achieve serum urate (SU) <6 mg/dl. METHODS: We undertook a post hoc analysis of a 24-month allopurinol dose escalation treat-to-target SU randomized controlled trial, in which 183 people with gout were randomized to continue current dose allopurinol for 12 months and then enter the dose escalation phase or to begin allopurinol dose escalation immediately. Allopurinol was increased monthly until SU was <6 mg/dl. The effect of baseline kidney function on urate lowering and adverse effects was investigated. RESULTS: Irrespective of randomization, there was no difference in the percentage of those with creatinine clearance (CrCL) <30 ml/min who achieved SU <6 mg/dl at the final visit compared to those with CrCL ≥30 to <60 ml/min and those with CrCL ≥60 ml/min, with percentages of 64.3% vs. 76.4% vs. 75.0%, respectively (p = 0.65). The mean allopurinol dose at month 24 was significantly lower in those with CrCL <30 ml/min as compared to those with CrCL ≥30 to <60 ml/min or CrCL ≥60 ml/min (mean (SD) 250 (43), 365 (22), and 460 (19) mg/day, respectively (p < 0.001)). Adverse events were similar among groups. CONCLUSIONS: Allopurinol is effective at lowering urate even though and accepting that there were small numbers of participants with CrCL <30 ml/min, these data indicate that allopurinol dose escalation to target SU is safe in people with severe CKD. The dose required to achieve target urate is higher in those with better kidney function. TRIAL REGISTRATION: Australian and New Zealand Clinical trials Registry, ACTRN12611000845932 . Registered on 10 August 2011.


Subject(s)
Allopurinol/administration & dosage , Gout Suppressants/administration & dosage , Gout/complications , Gout/drug therapy , Renal Insufficiency, Chronic/complications , Adult , Aged , Allopurinol/adverse effects , Creatinine/blood , Dose-Response Relationship, Drug , Female , Gout Suppressants/adverse effects , Humans , Male , Middle Aged , Uric Acid/blood
16.
Ann Rheum Dis ; 76(12): 2065-2070, 2017 Dec.
Article in English | MEDLINE | ID: mdl-28830881

ABSTRACT

OBJECTIVES: To determine the long-term safety and efficacy of allopurinol dose escalation (DE) to achieve target serum urate (SU) in gout. METHODS: People, including those with chronic kidney disease, who completed the first 12 months of a randomised controlled trial continued into a 12-month extension study. Participants randomised to continue current dose for the first 12 months began allopurinol DE at month 12 if SU was ≥6 mg/dL (control/DE). Immediate DE participants who achieved target SU maintained allopurinol dose (DE/DE). The primary endpoints were reduction in SU and adverse events (AEs) at month 24. RESULTS: The mean (SE) change in SU from month 12 to 24 was -1.1 (0.2) mg/dL in control/DE and 0.1 (0.2) mg/dL in DE/DE group (p<0.001). There was a significant reduction in the percentage of individuals having a gout flare in the month prior to months 12 and 24 compared with baseline in both groups and in mean tophus size over 24 months, but no difference between randomised groups. There were similar numbers of AEs and serious adverse events between groups. CONCLUSIONS: The majority of people with gout tolerate higher than creatinine clearance-based allopurinol dose and achieve and maintain target SU. Slow allopurinol DE may be appropriate in clinical practice even in those with kidney impairment. TRIAL REGISTRATION NUMBER: ACTRN12611000845932.


Subject(s)
Allopurinol/administration & dosage , Gout Suppressants/administration & dosage , Gout/blood , Gout/drug therapy , Uric Acid/blood , Aged , Dose-Response Relationship, Drug , Female , Humans , Male , Middle Aged , Time Factors , Treatment Outcome
17.
Ann Rheum Dis ; 76(9): 1522-1528, 2017 Sep.
Article in English | MEDLINE | ID: mdl-28314755

ABSTRACT

OBJECTIVES: To determine the efficacy and safety of allopurinol dose escalation using a treat-to-target serum urate (SU) approach. METHODS: A randomised, controlled, parallel-group, comparative clinical trial was undertaken. People with gout receiving at least creatinine clearance (CrCL)-based allopurinol dose for ≥1 month and SU ≥6 mg/dL were recruited. Participants were randomised to continue current dose (control) or allopurinol dose escalation for 12 months. In the dose escalation group, allopurinol was increased monthly until SU was <6 mg/dL. The primary endpoints were reduction in SU and adverse events (AEs). RESULTS: 183 participants (93 control, 90 dose escalation) were recruited. At baseline, mean (SD) urate was 7.15 (1.6) mg/dL and allopurinol dose 269 mg/day. 52% had CrCL<60 mL/min. Mean changes in SU at the final visit were -0.34 mg/dL in the control group and -1.5 mg/dL in the dose escalation group (p<0.001) with a mean difference of 1.2 mg/dL (95% CI 0.67 to 1.5, p<0.001). At month 12, 32% of controls and 69% in the dose escalation had SU <6 mg/dL. There were 43 serious AEs in 25 controls and 35 events in 22 dose escalation participants. Only one was considered probably related to allopurinol. Five control and five dose escalation participants died; none was considered allopurinol related. Mild elevations in LFTs were common in both groups, a few moderate increases in gamma glutamyl transferase (GGT) were noted. There was no difference in renal function changes between randomised groups. CONCLUSIONS: Higher than CrCL-based doses of allopurinol can effectively lower SU to treatment target in most people with gout. Allopurinol dose escalation is well tolerated. TRIAL REGISTRATION NUMBER: ANZCTR12611000845932; Results.


Subject(s)
Allopurinol/administration & dosage , Gout Suppressants/administration & dosage , Gout/drug therapy , Patient Care Planning , Uric Acid/blood , Aged , Alanine Transaminase/blood , Alkaline Phosphatase/blood , Aspartate Aminotransferases/blood , Chemical and Drug Induced Liver Injury/blood , Chemical and Drug Induced Liver Injury/etiology , Dose-Response Relationship, Drug , Female , Gout/blood , Humans , Male , Middle Aged , Treatment Outcome , gamma-Glutamyltransferase/blood
18.
Mol Metab ; 5(10): 959-969, 2016 Oct.
Article in English | MEDLINE | ID: mdl-27689008

ABSTRACT

OBJECTIVE: We previously demonstrated that the handle-region peptide, a prorenin/renin receptor [(P)RR] blocker, reduces body weight and fat mass and may improve insulin sensitivity in high-fat fed mice. We hypothesized that knocking out the adipose tissue (P)RR gene would prevent weight gain and insulin resistance. METHODS: An adipose tissue-specific (P)RR knockout (KO) mouse was created by Cre-loxP technology using AP2-Cre recombinase mice. Because the (P)RR gene is located on the X chromosome, hemizygous males were complete KO and had a more pronounced phenotype on a normal diet (ND) diet compared to heterozygous KO females. Therefore, we challenged the female mice with a high-fat diet (HFD) to uncover certain phenotypes. Mice were maintained on either diet for 9 weeks. RESULTS: KO mice had lower body weights compared to wild-types (WT). Only hemizygous male KO mice presented with lower total fat mass, higher total lean mass as well as smaller adipocytes compared to WT mice. Although food intake was similar between genotypes, locomotor activity during the active period was increased in both male and female KO mice. Interestingly, only male KO mice had increased O2 consumption and CO2 production during the entire 24-hour period, suggesting an increased basal metabolic rate. Although glycemia during a glucose tolerance test was similar, KO males as well as HFD-fed females had lower plasma insulin and C-peptide levels compared to WT mice, suggesting improved insulin sensitivity. Remarkably, all KO animals exhibited higher circulating adiponectin levels, suggesting that this phenotype can occur even in the absence of a significant reduction in adipose tissue weight, as observed in females and, thus, may be a specific effect related to the (P)RR. CONCLUSIONS: (P)RR may be an important therapeutic target for the treatment of obesity and its associated complications such as type 2 diabetes.

19.
Arthritis Res Ther ; 18(1): 208, 2016 09 15.
Article in English | MEDLINE | ID: mdl-27629724

ABSTRACT

BACKGROUND: It is currently unknown whether bone erosion in gout occurs through an 'inside-out' mechanism due to direct intra-osseous crystal deposition or through an 'outside-in' mechanism from the surface of bone. The aim of this study was to examine the mechanism ('outside-in' vs. 'inside-out') of monosodium urate (MSU) crystal deposition in bone erosion in gout. Specifically, we used three-dimensional dual-energy computed tomography (DECT) to analyse the positional relationship between bone and MSU crystal deposition in tophaceous gout, and to determine whether intra-osseous crystal deposition occurs in the absence of erosion. METHODS: One hundred forty-four participants with gout and at least one palpable tophus had a DECT scan of both feet. Two readers independently scored all metatarsal heads (1433 bones available for scoring). For bones in contact with urate, the bone was scored for whether urate was present within an erosion, on the surface of bone or within bone only (true intra-osseous deposit). Data were analysed using generalised estimating equations. RESULTS: Urate in contact with bone was present in 370 (54.3 %) of 681 joints with urate deposition. For those bones in contact with urate, deposition was present on the surface of bone in 143 (38.6 %) of 370 joints and within erosion in 227 (61.4 %) of 370. True intra-osseous urate deposition was not observed at any site (p < 0.0001). For all bones with apparent intra-osseous deposition in one plane, examination in other planes revealed urate deposition within an en face erosion. CONCLUSIONS: In tophaceous gout, MSU crystal deposition is present within the joint, on the bone surface and within bone erosion, but it is not observed within bone in the absence of a cortical break. These data support the concept that MSU crystals deposit outside bone and contribute to bone erosion through an 'outside-in' mechanism.


Subject(s)
Bone and Bones/diagnostic imaging , Bone and Bones/pathology , Gout/diagnostic imaging , Gout/pathology , Adult , Aged , Female , Humans , Male , Middle Aged , Tomography, X-Ray Computed , Uric Acid
20.
Obesity (Silver Spring) ; 24(9): 1946-54, 2016 09.
Article in English | MEDLINE | ID: mdl-27458124

ABSTRACT

OBJECTIVE: Administration of the handle region peptide (HRP), a (pro)renin receptor blocker, decreases body weight gain and visceral adipose tissue (VAT) in high-fat/high-carbohydrate (HF/HC) diet-fed mice. The objective of this study was to elucidate potential mechanisms implicated in these observations. METHODS: Mice were given a normal or a HF/HC diet along with saline or HRP for 10 weeks. RESULTS: In HF/HC-fed mice, HRP increased the expression of several enzymes implicated in lipogenesis and lipolysis in subcutaneous fat (SCF) while the expression of the enzyme implicated in the last step of lipogenesis decreased in VAT. A reduction was also observed in circulating free fatty acids in these animals which was accompanied by normalized adipocyte size in VAT and increased adipocyte size in SCF. ''Beiging'' is the evolution of a white adipose tissue toward a brown-like phenotype characterized by an increased mitochondrial density and small lipid droplets. HRP increased the expression of' "beiging" markers in SCF of HF/HC diet-fed mice. CONCLUSIONS: HRP treatment may favor healthy fat storage in SCF by activating a triglyceride/free fatty acid cycling and "beiging," which could explain the body weight and fat mass reduction.


Subject(s)
Receptors, Cell Surface/physiology , Renin-Angiotensin System/physiology , Renin/metabolism , Adipocytes/metabolism , Adipose Tissue/metabolism , Adipose Tissue, White/metabolism , Animals , Diet, High-Fat , Fatty Acids, Nonesterified/metabolism , Lipogenesis/genetics , Male , Mice , Mice, Inbred C57BL , Mice, Obese , Obesity/metabolism , Receptors, Cell Surface/metabolism , Triglycerides/metabolism , Prorenin Receptor
SELECTION OF CITATIONS
SEARCH DETAIL
...