Safety and adequacy of percutaneous biopsies in pediatric orthotopic kidney transplantation.

BACKGROUND: The gold standard for investigating the cause of renal graft dysfunction is renal biopsy. However, as this procedure is invasive and has inherent risks, its safety must be established. OBJECTIVE: To determine the safety of percutaneous renal biopsy in pediatric orthotopic renal transplantation. METHODS: Percutaneous renal biopsies performed on pediatric orthotopic renal transplants in a single center between 1987 and 2010 were studied. Biopsy specimen adequacy and post-procedure complications were reviewed by prospectively collected data. RESULTS: A total of 54 ultrasound "real-time" guided biopsies in 25 patients were performed. Minimum specimen adequacy was achieved in 98% of biopsy specimens. No major complications were identified; 6% of patients developed minor complications-e.g., grade 3 macroscopic hematuria that did not require intervention. CONCLUSION: Percutaneous renal biopsies using "real-time" ultrasound guidance on pediatric orthotopic kidney transplants is safe.

The training environment of junior anaesthetic registrars learning epidural labour analgesia in Australian teaching hospitals.

Junior anaesthetic registrars perform epidural labour analgesia in many Australian hospitals, however data evaluating training and outcomes are scarce. We aimed to describe and evaluate training practices and environments provided for registrars who learn epidural labour analgesia in their first year of training. Twenty-nine registrars audited their epidurals, participated in semi-structured interviews and completed surveys for six months. The median (inter-quartile range) number of epidurals performed by each registrar was 17 (15-25). Fifty percent performed less than 20. Among 216 audited cases, complications were reported in 19% (dural puncture in 1.4%) and technical difficulties in 16%. Direct supervision was provided for a median (range) of 2.5 (6) epidurals per registrar and for a significantly higher proportion of epidurals performed in tertiary hospitals compared with district metropolitan and rural hospitals (35%, 6% and 22% respectively; P = 0.001). Registrars felt senior staff had supportive attitudes, however the onus for initiating supervision appeared to be with the registrars and responses to survey items addressing role clarity and access to supervision showed wide variation. Only 33% of registrars agreed that they received adequate training before their first epidural and 67% reported workplace stress. None received formal assessments designed to ensure adequate supervision and competency. These results suggest that current training practices for these trainees are inadequate and could be improved by audit and structured workplace learning and assessment activities. We have demonstrated the potential value of measuring a range of training outcomes and environmental factors and have provided baseline data for future research.

HBV associated nephrotic syndrome: resolution with oral lamivudine.

A 6 year old boy presenting with a five month history of fever, lethargy, and anorexia, was found to have hepatitis B associated membranous glomerulonephropathy and nephrotic syndrome. After two months treatment with oral lamivudine, his proteinuria cleared and serum albumin and aminotransferases normalised, associated with disappearance of hepatitis B e antigen (HBeAg) and appearance of anti-HBeAg antibodies. After 12 months, without side effects, lamivudine was discontinued. He remains well 11 months off treatment.

Calcineurin-mediated BAD dephosphorylation activates the caspase-3 apoptotic cascade in traumatic spinal cord injury.

We report here that activation of the caspase-3 apoptotic cascade in spinal cord injury is regulated, in part, by calcineurin-mediated BAD dephosphorylation. BAD, a proapoptotic member of the bcl-2 gene family, is rapidly dephosphorylated after injury, dissociates from 14-3-3 in the cytosol, and translocates to the mitochondria of neurons where it binds to Bcl-x(L). Pretreatment of animals with FK506, a potent inhibitor of calcineurin activity, or MK801, an NMDA glutamate receptor antagonist, blocked BAD dephosphorylation and abolished activation of the caspase-3 apoptotic cascade. These findings extend previous in vitro observations and are the first to implicate the involvement of glutamate-mediated calcineurin activation and BAD dephosphorylation as upstream, premitochondrial signaling events leading to caspase-3 activation in traumatic spinal cord injury.

Rapid calpain I activation and cytoskeletal protein degradation following traumatic spinal cord injury: attenuation with riluzole pretreatment.

Immunocytochemical and immunoblotting techniques were used to investigate calpain I activation and the stability of the calpain-sensitive cytoskeletal proteins microtubule-associated protein 2 (MAP2) and spectrin at 1, 4, and 24 h after contusion injury to the spinal cord. Spinal cord injury resulted in the activation of calpain I at all time points examined, with the highest level of activation occurring at 1 h. At the same early time point, there was a loss of dendritic MAP2 staining in spinal cord sections, accompanied by pronounced perikaryal accumulation. The loss in MAP2 staining in the injured spinal cord progressed over the 24-h survival period to affect regions 3 mm distant to the site of injury. The presence of calpain I-specific spectrin degradation was apparent in neuronal cell bodies and fibers as early as 1 h after injury, with the most intense staining occurring within and juxtaposed to the injury site. Spectrin breakdown products in neuronal cell bodies declined rapidly at 4 h and were nearly undetectable at 24 h after injury. Immunoblot studies confirmed the immunocytochemical results by demonstrating a significant increase in calpain I activation, a significant decrease in MAP2 levels, and a significant increase in spectrin breakdown. Finally, treatment of animals with riluzole, an inhibitor of glutamate release, before surgery reduced significantly the loss of MAP2 levels observed at 24 h after injury. These results demonstrate that Ca2+-dependent protease activation and degradation of critical cytoskeletal proteins are early events after spinal cord injury and that treatments that minimize the actions of glutamate may limit their breakdown.

Characterization of long-range electron transfer in mixed-metal [zinc,iron] hybrid hemoglobins.

Measurements characterizing electron transfer from a photoexcited zinc protoporphyrin triplet (3ZnP) to a ferriheme electron acceptor within the [alpha 1,beta 2] electron-transfer complex of [FeIII,Zn] hybrid hemoglobins are reported. Analytical results demonstrate that the hybrids studied are pure, homogeneous proteins with 1:1 ZnP:FeP content. Within the T quaternary structure adopted by these hybrids, the optical spectrum of a FeIIIP is perturbed by the protein environment. Room temperature kinetic studies of the rate of 3ZnP decay as a function of the heme oxidation and ligation state demonstrate that quenching of 3ZnP by FeIII(H2O)P occurs by long-range intramolecular electron transfer with rate constant kt = 100 (+/- 10) s-1 and is not complicated by spin-quenching or energy-transfer processes; results are the same for alpha(Zn) and beta(Zn) hybrids. Replacement of H2O as a ligand to the ferriheme changes the 3ZnP----FeIIIP electron-transfer rate constant, kt, which demonstrates that electron transfer, not conformational conversion, is rate limiting. However, the trend is not readily explained by simple considerations of spin-state and bonding geometry: kt decreases in the order imidazole greater than H2O greater than F- approximately CN- approximately N3-. The reverse electron-transfer process FeIIP----ZnP+ has not been observed directly but has been shown to be much more rapid, with rate constant kb greater than 10(3) s-1, consistent with the possible importance of "hole" superexchange in electron tunneling within protein complexes.