Intra-Arterial Chemotherapy for Retinoblastoma in Infants ≤10 kg: 74 Treated Eyes with 222 IAC Sessions.

BACKGROUND AND PURPOSE: Intra-arterial chemotherapy for retinoblastoma has dramatically altered the natural history of the disease. The remarkable outcomes associated with a high safety profile have pushed the envelope to offer treatment for patients weighing ≤10 kg. The purpose was to determine the efficacy and safety of IAC infusions performed in infants weighing ≤10 kg with intraocular retinoblastoma. MATERIALS AND METHODS: A retrospective chart review was performed for patients diagnosed with retinoblastoma and managed with intra-arterial chemotherapy. RESULTS: The total study cohort included 207 retinoblastoma tumors of 207 eyes in 196 consecutive patients who underwent 658 intra-arterial chemotherapy infusions overall. Of these, patient weights were ≤10 kg in 69 (35.2%) and >10 kg in 127 (64.8%) patients. Comparison (≤10 kg versus >10 kg) revealed that the total number of intra-arterial chemotherapy infusions was 222 versus 436. Periprocedural complications were not significantly different (2 [0.9%] versus 2 [0.5%]; P = .49). Cumulative radiation exposure per eye was significantly lower in infants weighing ≤10 kg (5.0 Gym2 versus 7.7 Gym2; P = .01). Patients weighing ≤10 kg had a greater frequency of complete tumor regression (82.6% versus 60.9%; P = .02). Mean fluoroscopy time was not significantly different (7.5 versus 7.2; P = .71). There was a significant difference in the frequency of enucleation (16 [21.6%] versus 52 [39.1%]; P = .01). Patients weighing ≤10 kg had greater number of aborted procedures (12 [5.4%] versus 7 [1.6%]; P = .01). On multivariate analysis, weight ≤10 kg was not an independent predictor of complications or procedure failure. CONCLUSIONS: Intra-arterial chemotherapy in patients weighing ≤10 kg is a safe and effective treatment.

Rifampin enhances the glucose-lowering effect of metformin and increases OCT1 mRNA levels in healthy participants.

We evaluated the effect of the pregnane X receptor (PXR) agonist rifampin on metformin pharmacokinetics, organic cation transporter 1 (OCT1) and OCT2 mRNA levels, and glucose levels, using the oral glucose tolerance test (OGTT) in 16 healthy subjects. The glucose-lowering effects of metformin were evaluated by OGTT before and after metformin treatment on days 1 and 2 and again on days 13 and 14 after a 10-day course of rifampin. Rifampin increased the difference in maximum glucose levels (ΔG(max)) by 41.9% (P = 0.024) and the area under the concentration-time curve (AUC) during the first 60 min after glucose ingestion (ΔAUC(gluc60)) by 54.5% (P = 0.020). Renal clearance (CL(R)) of metformin was increased by 16% (P = 0.008), but the systemic exposure was only slightly increased (13%, P = 0.049), possibly because of increased absorption. Rifampin increased OCT1 mRNA levels 4.1-fold in peripheral blood cells (P = 0.001); however, OCT2 mRNA was not detected. Our results suggest that rifampin increases OCT1 expression and hepatic uptake of metformin, leading to enhanced glucose-lowering action.

Comparison of the ETDRS logMAR, 'compact reduced logMar' and Snellen charts in routine clinical practice.

AIM: To compare the performance of the ETDRS logMAR, compact reduced logMAR and Snellen charts in an ophthalmic outpatient setting. METHODS: The reliability and reading times of the charts were compared in a stratified sample of 40 eyes of 40 ophthalmic patients with a variety of stable eye diseases. In order to simulate a clinical setting, forced-choice testing was not used. RESULTS: Similar acuity results were recorded from all three charts, suggesting a lack of a systematic bias as regards chart design. A small practice effect was observed for all charts but was greatest for Snellen and least for ETDRS. The test-retest variability of the charts was similar, with the 95% tolerance limit for change being +/-0.14 logMAR for ETDRS, +/-0.16 for reduced logMAR and +/-0.18 for Snellen. The mean reading times for the subjects were 34.65 s for ETDRS, 21.17 s for reduced logMAR and 18.67 s for Snellen. CONCLUSION: The performance of the compact reduced logMAR chart was intermediate between Snellen and ETDRS. The theoretical advantages of the ETDRS design were still measurable in a clinical setting but the magnitude of the advantage in terms of test-retest reliability was fairly small and the time taken to complete the EDTRS was 1.86 times that of the Snellen chart.

Effects of SLCO1B1 and ABCB1 genotypes on the pharmacokinetics of atorvastatin and 2-hydroxyatorvastatin in healthy Korean subjects.

OBJECTIVE: This study aimed to evaluate the effect of genetic polymorphisms of SLCO1B1 and ABCB1 on the pharmacokinetics of atorvastatin and its metabolites. METHODS: 290 Koreans were genotyped for SLCO1B1, ABCB1 and CYP3A5, and 28 subjects were selected for the pharmacokinetic study. Each subject received a single oral dose of 20 mg atorvastatin and blood samples were collected up to 48 hr after dosing. The relationship between the genotypes and atorvastatin pharmacokinetics was examined. RESULTS: For SLCO1B1 genotypes, the mean area under the concentration-time curve from time 0 to infinity (AUC0-infinity) of atorvastatin was 148.2 ng x hr/ml for *15/*15 subjects (n = 3), which was significantly larger than for 1a/*15 and *1b/*15 (n = 8) (80.7 ng x hr/ml, p = 0.0121) and also larger than for *1a/*1a, *1a/*1b and *1b/*1b (n = 17) (66.3 ng x hr/ml, p = 0.0018). The mean AUC0-infinity of 2-hydroxyatorvastatin for *15/*15 was also larger than in *1a/*1a, *1a/*1b and *1b/*1b (p = 0.012). In lactone forms, no significant pharmacokinetic difference was found among the genotypes. For ABCB1 genotypes, the half-lives of atorvastatin, atorvastatin lactone, 2-hydroxyatorvastatin and 2-hydroxyatorvastatin lactone were significantly longer in c.2677TT-c.3435TT (n = 3) vs. c.2677GG-c.3435CC and c.2677GT-c.3435CT (n = 10), yielding p = 0.049, 0.007, 0.007 and 0.007, respectively. CONCLUSION: This study shows that the SLCO1B1*15 allele may be associated with the individual difference in the AUC0-infinity of atorvastatin whereas the ABCB1 TT-TT diplotype may affect the elimination half-life of the drug in the Korean population.

Failure of the stem-condyle junction of a modular femoral stem in revision total knee arthroplasty: a report of five cases.

We report 5 cases of failure of the stem condyle junction of a modular femoral stem in revision total knee arthroplasy.

Cyclic pamidronate infusion improves bone mineralisation and reduces fracture incidence in osteogenesis imperfecta.

UNLABELLED: A prospective open study was performed to determine the efficacy and safety of pamidronate in improving bone mineralisation and reducing fracture incidence in osteogenesis imperfecta (OI). Intravenous pamidronate was administered at 1.5 mg/kg bi-monthly to six children with OI, over 12-23 months. The number of fractures decreased from median of 3 (range 1-12) to 0 fractures/year (range 0-4) (P<0.05). After 12 months of treatment, there was significant improvement in areal bone mineral density (BMD) z-scores of the lumbar spine from median of -2.40 (range -3.20 to -1.67) to -1.90 (range -2.38 to -0.91) (P<0.05) and in the volumetric BMD which increased from median of 0.095 to 0.146 g/cm3 (P<0.05). Urine N-telopeptide levels (bone resorption marker) decreased from a median of 461.5 bone collagen equivalent/creatinine (BCE/Cr) (range 129-721 BCE/Cr) to 223.5 BCE/Cr (range 107-312 BCE/Cr) (P<0.05) and serum alkaline phosphatase (ALP) (bone formation marker) from a median of 230.0 U/l (range 148-305 U/l) to 133.5 U/l (range 79-233 U/l) (P<0.05), reflecting reduced bone turnover. This may represent a net reduction in bone resorption and provides a biochemical explanation for the increase in bone mineralisation. Height standard deviation scores were not affected and there were no significant adverse effects. CONCLUSION: 1 year cyclical pamidronate is effective and safe in improving bone mineralisation and reducing fracture incidence in osteogenesis imperfecta.

Biomechanics of total hip arthroplasty.

The biomechanics of the hip joint provide an understanding of the development, evolution, and treatment of many disabling conditions of this joint. The available methods of biomechanical analysis include in vitro studies, in vivo studies, and theoretical mathematic analyses. The information obtained from these analyses have enabled the design of therapeutic programs to alleviate the symptoms of, and possibly delay the progression of, hip disease. The design of surgical procedures has been based on alterations of the biomechanics of the hip. These procedures have proven useful for treating pathologies such as osteoarthritis, hip dysplasia, and hip fractures. The study of biomechanics and biomaterials are integral to the current success of total hip arthroplasty in achieving pain relief and functional restoration.