Invasive pulmonary aspergillosis: effects of early resection in a neutropenic rat model

Objective: Invasive pulmonary aspergillosis is frequent in neutropenic patients. Usually localized in the beginning, the disease spreads and mortality is high despite antifungal treatment. The role of early adjuvant surgery is not clear. Surgery may help to confirm fungal disease, may control fungal disease locally and may prevent systemic spreading. This study examines effects of early resection on survival and dissemination in a rat model of localized invasive pulmonary aspergillosis. Methods: Forty persistently neutropenic male albino rats were challenged with standardized conidial aspergillus inoculum injected into peripheral lung tissue of the right upper lobe under direct vision. Animals were divided into four groups. Twenty animals were treated with amphotericin B at 1 mg/kg per day beginning 48 h after inoculation, 20 animals were left untreated. In each group half the animals underwent early resection of localized invasive aspergillosis by lobectomy. Animals were checked daily and mortality was recorded up to 28 days after which surviving animals were sacrificed. Results: Significantly higher survival was observed in resected animals in the non-Am B groups (survival: 10±19% without early resection and 50±32% with early resection; P=0.044). However, early resection did not lead to improved survival in animals treated with amphotericin B (survival 70±29% without early resection and 50±32% with early resection; P=0.316). Conclusions: In this rat model of localized invasive pulmonary aspergillosis effects of early resection on survival could be demonstrated only in animals not receiving amphotericin B treatmen

Upregulation of peroxisome proliferator-activated receptor gamma coactivator gene ( PGC1A ) during weight loss is related to insulin sensitivity but not to energy expenditure

Aims/hypothesis: We investigated whether skeletal muscle peroxisome proliferator-activated receptor gamma coactivator-1 (PGC1A; also known as PPARGC1A) and its target mitofusin-2 (MFN2), as well as carnitine palmitoyltransferase-1 (CPT1; also known as carnitine palmitoyltransferase 1A [liver] [CPT1A]) and uncoupling protein (UCP)3, are involved in the improvement of insulin resistance and/or in the modification of energy expenditure during surgically induced massive weight loss. Materials and methods: Seventeen morbidly obese women (mean BMI: 45.9 ± 4kg/m2) were investigated before, and 3 and 12months after, Roux-en-Y gastric bypass (RYGB). We evaluated insulin sensitivity by the euglycaemic-hyperinsulinaemic clamp, energy expenditure and substrate oxidation by indirect calorimetry, and muscle mRNA expression by PCR. Results: Post-operatively, PGC1A was enhanced at 3 (p = 0.02) and 12months (p = 0.03) as was MFN2 (p = 0.008 and p = 0.03 at 3 and 12months respectively), whereas UCP3 was reduced (p = 0.03) at 12months. CPT1 did not change. The expression of PGC1A and MFN2 were strongly (p < 0.0001) related. Insulin sensitivity, which increased after surgery (p = 0.002 at 3, p = 0.003 at 12months), was significantly related to PGC1A and MFN2, but only MFN2 showed an independent influence in a multiple regression analysis. Energy expenditure was reduced at 3months post-operatively (p = 0.001 vs before RYGB), remaining unchanged thereafter until 12months. CPT1 and UCP3 were not significantly related to the modifications of energy expenditure or of lipid oxidation rate. Conclusions/interpretation: Weight loss upregulates PGC1A, which in turn stimulates MFN2 expression. MFN2 expression significantly and independently contributes to the improvement of insulin sensitivity. UCP3 and CPT1 do not seem to influence energy expenditure after RYG

Jahn-Teller versus quantum effects in the spin-orbital material LuVO3

We report on combined neutron and resonant x-ray scattering results, identifying the nature of the spin-orbital ground state and magnetic excitations in LuVO3 as driven by the orbital parameter. In particular, we distinguish between models based on orbital Peierls dimerization, taken as a signature of quantum effects in orbitals, and Jahn-Teller distortions, in favor of the latter. In order to solve this long-standing puzzle, polarized neutron beams were employed as a prerequisite in order to solve details of the magnetic structure, which allowed quantitative intensity-analysis of extended magnetic excitation data sets. The results of this detailed study enabled us to draw definite conclusions about classical vs quantum behavior of orbitals in this system and to discard the previous claims about quantum effects dominating the orbital physics of LuVO3 and similar systems.Comment: Phys. Rev. B 91, 161104(R) (2015

Excitations from a Bose-Einstein condensate of magnons in coupled spin ladders

The weakly coupled quasi-one-dimensional spin ladder compound (CH$_3$)$_2$CHNH$_3$CuCl$_3$ is studied by neutron scattering in magnetic fields exceeding the critical field of Bose-Einstein condensation of magnons. Commensurate long-range order and the associated Goldstone mode are detected and found to be similar to those in a reference 3D quantum magnet. However, for the upper two massive magnon branches the observed behavior is totally different, culminating in a drastic collapse of excitation bandwidth beyond the transition point.Comment: 4 pages, 4 figure

Excitations in a four leg antiferromagnetic Heisenberg spin tube

Inelastic neutron scattering is used to investigate magnetic excitations in the quasi one dimensional quantum spin liquid system Cu2Cl4 D8C4SO2. Contrary to previously conjectured models that relied on bond alternating nearest neighbor interactions in the spin chains, the dominant interactions are actually next nearest neighbor in chain antiferromagnetic couplings. The appropriate Heisenberg Hamiltonian is equivalent to that of a S 1 2 4 leg spin tube with almost perfect one dimensionality and no bond alternation. A partial geometric frustration of rung interactions induces a small incommensurability of short range spin correlations

Social Experimentation as Reflection-in-A ction

We present the results of our review of some forty community-level interventions undertaken in the developing world over the past twenty years m order to reduce malnourishment in children. We argue that such interventions, if they are considered as social experiments, cannot be assimilated to models of quasi-experimental method. We propose an alternative model of experimentation, which we call "reflection-in-action", which seems to us better suited to account for the kinds ofvahdity and rigor attainable in situations such as these.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68568/2/10.1177_107554708400600101.pd