Fundamentals and innovations in regional anaesthesia for infants and children.

Regional anaesthesia in children has evolved rapidly in the last decade. Although it previously consisted of primarily neuraxial techniques, the practice now incorporates advanced peripheral nerve blocks, which were only recently described in adults. These novel blocks provide new avenues for providing opioid-sparing analgesia while minimising invasiveness, and perhaps risk, associated with older techniques. At the same time, established methods, such as infant spinal anaesthesia, under-utilised in the last 20 years, are experiencing a revival. The impetus has been the concern regarding the potential long-term neurocognitive effects of general anaesthesia in the young child. These techniques have expanded from single shot spinal anaesthesia to combined spinal/epidural techniques, which can now effectively provide surgical anaesthesia for procedures below the umbilicus for a prolonged period of time, thereby avoiding the need for general anaesthesia. Continuous 2-chloroprocaine infusions, previously only described for intra-operative regional anaesthesia, have gained popularity as a means of providing prolonged postoperative analgesia in epidural and continuous nerve block techniques. The rapid, liver-independent metabolism of 2-chloroprocaine makes it ideal for prolonged local anaesthetic infusions in neonates and small infants, obviating the increased risk of local anaesthetic systemic toxicity that occurs with amide local anaesthetics. Debate continues over certain practices in paediatric regional anaesthesia. While the rarity of complications makes comparative analyses difficult, data from large prospective registries indicate that providing regional anaesthesia to children while under general anaesthesia appears to be at least as safe as in the sedated or awake patient. In addition, the estimated frequency of serious adverse events demonstrates that regional blocks in children under general anaesthesia are no less safe than in awake adults. In infants, the techniques of direct thoracic epidural placement or caudal placement with cephalad threading each have distinct advantages and disadvantages. As the data cannot support the safety of one technique over the other, the site of epidural insertion remains largely a matter of anaesthetist discretion.

Using an amplitude analysis to measure the photon polarisation in B → K π π γ decays.

A method is proposed to measure the photon polarisation parameter λ γ in b → s γ transitions using an amplitude analysis of B → K π π γ decays. Simplified models of the K π π system are used to simulate B + → K + π - π + γ and B 0 → K + π - π 0 γ decays, validate the amplitude analysis method, and demonstrate the feasibility of a measurement of the λ γ parameter irrespective of the model parameters. Similar sensitivities to λ γ are obtained with both the charged and neutral hadronic systems. In the absence of any background and distortion due to experimental effects, the statistical uncertainty expected from an analysis of B + → K + π - π + γ decays in an LHCb data set corresponding to an integrated luminosity of 9  fb - 1 is estimated to be 0.009. A similar measurement using B 0 → K + π - π 0 γ decays in a Belle II data sample corresponding to an integrated luminosity of 5  ab - 1 would lead to a statistical uncertainty of 0.018.

Do stochastic inhomogeneities affect dark-energy precision measurements?

The effect of a stochastic background of cosmological perturbations on the luminosity-redshift relation is computed to second order through a recently proposed covariant and gauge-invariant light-cone averaging procedure. The resulting expressions are free from both ultraviolet and infrared divergences, implying that such perturbations cannot mimic a sizable fraction of dark energy. Different averages are estimated and depend on the particular function of the luminosity distance being averaged. The energy flux being minimally affected by perturbations at large z is proposed as the best choice for precision estimates of dark-energy parameters. Nonetheless, its irreducible (stochastic) variance induces statistical errors on Ω(Λ)(z) typically lying in the few-percent range.

Supersymmetry relics in one-flavor QCD from a new 1/N expansion.

We suggest a new large-N(c) limit for multiflavor QCD. Since fundamental and two-index antisymmetric representations are equivalent in SU(3), we have the option to define SU(N(c)) QCD keeping quarks in the latter. We can then define a new 1/N(c) expansion (at a fixed number of flavors N(f)) that shares appealing properties with the topological (fixed N(f)/N(c)) expansion while being more suitable for theoretical analysis. In particular, for N(f)=1, our large-N(c) limit gives a theory that we recently proved to be equivalent, in the bosonic sector, to N=1 supersymmetric gluodynamics. Using known properties of the latter, we derive several qualitative and semiquantitative predictions for N(f)=1 massless QCD that can be easily tested in lattice simulations. Finally, we comment on possible applications for pure SU(3) Yang-Mills theory and real QCD.

Causal entropy bound for a spacelike region.

The identification of a causal-connection scale motivates us to propose a new covariant bound on entropy within a generic spacelike region. This "causal entropy bound," scaling as sqrt[EV], and thus lying around the geometric mean of Bekenstein's S/ER and holographic S/A bounds, is checked in various "critical" situations. In the case of limited gravity, Bekenstein's bound is the strongest while naive holography is the weakest. In the case of strong gravity, our bound and Bousso's holographic bound are stronger than Bekenstein's, while naive holography is too tight, and hence typically wrong.

Congenital dyserythropoietic anaemia type II associated with a new type of G6PD deficiency (G6PD Gabrovizza).

A 6-year-old boy with chronic haemolytic anaemia was found to have glucose 6-phosphate dehydrogenase (G6PD) deficiency and the morphological, ultrastructural and serological features of congenital dyserythropoietic anaemia (CDA) type II. The patient's mother was heterozygous for G6PD deficiency. G6PD from the patient's red cells, upon partial purification and full characterization, was found to be a new variant designated G6PD Gabrovizza. We conclude that two distinct genetic abnormalities coexisted in this patient. We suggest that CDA type II may become clinically more expressed when another abnormality of the erythrocytes coexists.

High dose bolus methylprednisolone for the treatment of acute graft versus host disease.

Nineteen patients with acute graft versus host disease (GvHD) following bone marrow transplantation (BMT) were treated with high dose bolus 6-methylprednisolone (BMPr), at the dose of 20 mg/kg/day i.v. for the first 3 days, 10 mg/kg/day i.v. for the following 4 days, and then at doses gradually tapered down to 1 mg/kg/day. All patients except one, who was given preventive BMPr 5 mg/kg/day i.v. on alternate days, were placed on preventive methotrexate therapy after BMT. Sixteen patients were grafted with an HLA matched, and three patients with an HLA mismatched marrow. Overall complete response rate in the HLA matched group was 43%, with an additional 50% showing a partial response. In the HLA mismatched group there were no responses and all three patients proved refractory to BMPr. With respect to organ involvement the complete and partial response rates were respectively 50% and 33% in the skin, 36% and 28% in the liver, 18% and 55% in the gut. Six of sixteen patients in the HLA matched group and none of the three in the HLA mismatched group are surviving. Thirteen patients died: nine patients for causes directly or indirectly related to GvHD, four of other causes (relapse, rejection, hemorrhage and idiopathic interstitial pneumonia). Side effects of BMPr consisted in hyperglicemia, and steroid associated gastritis in 2/3 of the patients, both of which responded well to conventional treatment. This study indicates that high dose BMPr is an effective form of treatment for established acute GvHD, and has no major side effects. The efficacy of BMPr is less clear in recipients of HLA mismatched grafts.

[Use of Blasto-Kit for cytogenetic analysis]. / Impiego del "Blasto-Kit" nell'indagine citogenetica.

We have considered the possibility of using commercial Blasto-Kit, with AB pool, for chromosome analysis. Comparative researches have been made between Blasto-Kit-AB and Blasto-Kit in which AB serum was replaced by FCS. Using 0.1 ml of whole blood lymphocyte response to PHA after incorporation of thymidine H3 and the mitotic rate obtained have been evaluated. The Blasto-Kit-AB gives better results if compared with Blasto-Kit-FCS either in lymphocyte response to PHA or in chromosome analysis.