Synthesis engineering of iron oxide raspberry-shaped nanostructures.

Magnetic porous nanostructures consisting of oriented aggregates of iron oxide nanocrystals display very interesting properties such as a lower oxidation state of magnetite, and enhanced saturation magnetization in comparison with individual nanoparticles of similar sizes and porosity. However, the formation mechanism of these promising nanostructures is not well understood, which hampers the fine tuning of their magnetic properties, for instance by doping them with other elements. Therefore the formation mechanism of porous raspberry shaped nanostructures (RSNs) synthesized by a one-pot polyol solvothermal method has been investigated in detail from the early stages by using a wide panel of characterization techniques, and especially by performing original in situ HR-TEM studies in temperature. A time-resolved study showed the intermediate formation of an amorphous iron alkoxide phase with a plate-like lamellar structure (PLS). Then, the fine investigation of PLS transformation upon heating up to 500 °C confirmed that the synthesis of RSNs involves two iron precursors: the starting one (hydrated iron chlorides) and the in situ formed iron alkoxide precursor which decomposes with time and heating and contributes to the growth step of nanostructures. Such an understanding of the formation mechanism of RSNs is necessary to envision efficient and rational enhancement of their magnetic properties.

[The effect of entomopathogenic fungi on the activity of detoxicating enzymes of larvae of bee pyralid Galleria mellonella L. (Lepidoptera, Pyralidee) and the role of detoxicating enzymes in the formation of the insect' resistance to entomopathogenic fungi].

In the work it was shown that fungal infection of insects increased the total esterase and glutathione-S-transferase activities of hemolymph. Acid and alkaline phosphatase activity in infected larvae remained at the same level as in intact larvae. Fungi-infected bee pyralid larvae turned out to be 1.46 times more resistant to phosphoorganic insecticide malation as compared to intact larvae. On the other hand, treating insects with the inhibitors of detoxicating enzymes caused a sharp decrease in the insects' resistance to entomophathogenic fungi. The work discusses possible participation of detoxicating enzymes in the formation of the insects' resistance to entomopathogenic fungi as well as new strategies of the development and creation of complex biopreparations based on entomopathogenic microorganisms and inhibitors of detoxicating enzymes.

Vasculitis owing to infection.

Infections are a recognized cause of secondary vasculitis. A variety of pathogens have a propensity to involve blood vessels. Vasculitis, non-vasculitic vasculopathy, and mycotic aneurysms lead to infarction and hemorrhage of nervous system tissue. Treatment of infection-related vasculitis should include appropriate antimicrobial therapy directed against the offending pathogen, and appropriate management of cerebrovascular complications.

Lissencephaly gene (LIS1) expression in the CNS suggests a role in neuronal migration.

Miller-Dieker lissencephaly syndrome (MDS) is a human developmental brain malformation caused by neuronal migration defects resulting in abnormal layering of the cerebral cortex. LIS1, the gene defective in MDS, encodes a subunit of brain platelet-activating factor (PAF) acetylhydrolase which inactivates PAF, a neuroregulatory molecule. We have isolated murine cDNAs homologous to human LIS1 and mapped these to three different chromosomal loci (Lis1, Lis3, Lis4). The predicted sequences of murine Lis1 protein and its human homolog LIS1 are virtually identical. In the developing mouse and human, Lis1 and LIS1 genes were strongly expressed in the cortical plate. In the adult mouse Lis1 transcripts were abundant in cortex and hippocampus. The direct correlation between cortical defects in MDS patients and Lis1 expression in the murine cortex suggest that the mouse is a model system suitable to study the mechanistic basis of this intriguing genetic disease.

Delayed neurotoxicity after ingestion of carbamate pesticide.

We studied a patient who ingested 27 gm (500 mg/kg) of carbaryl (1-naphthyl N-methylcarbamate), a popular carbamate pesticide. After he recovered from acute cholinergic toxicity, acute weakness of arms and legs was accompanied by electrophysiologic findings consistent with axonal peripheral neuropathy. Recovery began at 1 week and continued for 9 months. A similar delayed neuropathy has been described with organophosphates but not with carbamate insecticides.

[Quasi-normal cerebrospinal fluid in patients with acquired immunodeficiency syndrome and cryptococcal meningitis]. / Liquide céphalo-rachidien quasi-normal chez des patients atteints du syndrome d'immunodéficience acquise et d'une méningite à cryptocoque.

We report eight patients with cryptococcal meningitis and a cerebrospinal fluid characterized by few or no white blood cells and chemistries that may be near normal. In four of these patients, only testing for cryptococcal antigen allowed the initial diagnosis. Seven of the patients had a certain diagnosis of AIDS. Six have died. Autopsies performed in two cases indicated a poor meningeal inflammatory response. Contrary to the findings in most immunodeficient patients, in AIDS cryptococcal meningitis may present with few cellular or biochemical abnormalities in the cerebrospinal fluid. In AIDS patients presenting with headache and fever or change in mental status, examination of the cerebrospinal fluid should not be limited to routine studies.

Painless dissections of the aorta presenting as acute neurologic syndromes.

We describe three patients who had painless dissections of the aorta which resulted in neurologic syndromes at the time of presentation. Two patients had acute hemimotor and sensory findings. In one of these cases progression to paraplegia occurred. In a third patient, acute weakness and ischemia of a leg occurred at presentation. We review previously described painless aortic dissections. Such aortic dissections may be suspected in the setting of an acute neurologic event by abnormalities in the examination of the peripheral pulses and the heart and by attention to characteristic chest x-ray changes.

Bilateral paramedian thalamic infarctions: a CT study.

We describe eight patients with bilateral paramedian thalamic infarction on CT scanning. Clinically, these patients had infarctions of either the paramedian thalamus alone or the paramedian thalamus with a variable extension to contiguous structures. A single occlusion may result in bilateral paramedian thalamic lesions because of the common occurrence of a single trunk of origin for the paramedian thalamic arteries.