High-resolution MR imaging using loop-gap resonators. Work in progress

Representative results using loop-gap resonator (LGR) configurations for local high-resolution MR imaging (0.6 mm X 0.6 mm pixel size with 3-mm section thickness) are presented. Four geometries were employed: flat single loops, coplanar (planar pair) loops, coaxial (axial pair) loops, and symmetrically angled (butterfly pair) loops. The LGRs were used as receiver coils with the body coil as transmitter. Butterfly pairs and planar pairs are intrinsically decoupled from a transmitted field of arbitrary orientation, whereas the single loops and axial pairs are decoupled from a field that is linearly polarized and orthogonal to its axis. The coils were evaluated using computer-generated and experimentally determined field distributions and by the imaging of human subjects on a 1.5-T MR system. Matching the region of sensitivity of the coil to the region of anatomic interest is emphasized.     

Interferon treatment for hepatitis C virus infection in patients on haemodialysis

BACKGROUND: This study examined the efficacy and tolerability of interferon alpha-2b (IFN) in the treatment of chronic hepatitis C virus (HCV) infection in patients on maintenance haemodialysis. METHODS: A 24- month prospective cohort study was performed in 11 HCV RNA-positive haemodialysis patients, who were treated with IFN at 3 MU thrice weekly for 6 months. Serial biochemical and virological monitors included serum alanine aminotransferase levels, and HCV RNA by both qualitative PCR assay and quantitative bDNA assay. HCV genotypes were determined by PCR and nucleotide sequencing. Ten patients had baseline liver biopsy. RESULTS: HCV genotypes 1b and 2b were identified in 10 and one patients respectively. Six (55%) patients had biochemical and/or histological features of chronic active hepatitis before treatment. All 11 patients became HCV RNA-negative by PCR, with normalization of deranged aminotransferase levels, within 2-8 weeks of IFN therapy. HCV RNA reappeared in eight (73%) patients 2-8 weeks after the cessation of IFN, while biochemical relapse occurred in six (55%) patients. Sustained eradication of HCV was achieved in three (27%) patients. Sustained responders were characterized by pretreatment HCV RNA level < 3.5 x 10(5) Eq/ml as determined by the bDNA assay, and less severe histological abnormalities ('Total score' 1.7 +/- 1.2 compared to 5.4 +/- 2.2 in relapsers, P < 0.05). HCV RNA levels were similar before and after IFN treatment in non-responders and relapsers. Persistent malaise and poor appetite were noted in eight (73%) patients during IFN therapy. Other side-effects of IFN included the exacerbation of anaemia, induction of resistance to erythropoietin, weight loss, and reduced serum albumin level. CONCLUSIONS: Eradication of chronic HCV infection with IFN can be achieved in 27% of haemodialysis patients. Predictors of sustained response include low baseline HCV RNA level and mild liver pathology. Virological relapse can occur despite normal liver biochemistry. Exacerbation of anaemia, erythropoietin resistance, and malnutrition constitute the side-effects of IFN that deserve special attention in uraemic subjects.      

A novel missense mutation in exon 4 of the factor VIII:C gene resulting in moderately severe hemophilia A

A new point mutation due to C----T transition at codon 189 (TCA) of the factor VIII:C gene was found in a Chinese patient with moderately severe hemophilia A. This mutation abolishes the EcoRI site (GAATTC) in exon 4 and can be directly detected by polyacrylamide gel electrophoresis of amplified genomic DNA.     

Acanthamoeba keratitis: a sobering case and a promising new treatment

This case report describing Acanthamoeba keratitis in a 41-year-old male disposable contact lens wearer, adds some sobering and some encouraging information for the future management of this infection. Initial treatment with topical propamidine isethionate (Brolene) and polymyxin B/neomycin/ gramicidin (Neosporin) led to an unsatisfactory clinical response. Topical miconazole 1%, prednisolone acetate 0.12% and oral itraconazole were then added to his treatment. This was later discontinued on noticing ipsilateral toxic cataract formation and an unresponsive pupil. The above medications were replaced with topical polyhexamethylene biguanide (PHMB) 0.02%, which we had shown to have superior in-vitro amoebicidal activity when compared to the other antiamoebic agents used in this case. Withdrawal of the multitreatment schedule and commencement of PHMB was associated with resolution of his keratitis, healing of a large epithelial defect and settling of severe conjunctivitis. The identical Acanthamoeba strain was isolated from the patient's contact lens storage case and cornea, possibly implicating the contaminated contact lens case in the aetiology of his keratitis. This is the first Australasian experience using PHMB to treat Acanthamoeba keratitis. It appears to be a promising new treatment for this infection.