Iniencephaly: clinical, radiological and surgical findings

The authors report a case of iniencephaly in a 6-year-old boy with a huge occipital bone defect and encephalocele, extensive spina bifida of the cervical vertebrae and fixed retroflexion of the head due to Sprengel's deformity. He presented with some cerebellar and cranial nerve symptoms and new episodes of neck pain and drop attacks. Brain imaging confirmed progressive deformity of the brain stem, cerebellar herniation into the encephalocele sac and ventriculomegaly. Surgical repair of the encephalocele was performed with preservation of all herniated cerebellar tissue and the release of thick arachnoid adhesions to make more space to return the herniated neural tissue from the sac to the cranium. The patient was found to have progressive facial palsy and intracranial hypertension 3 days after surgery, which improved with ventriculoperitoneal shunting. Iniencephaly is generally a fatal anomaly, and only 7 such patients have been reported to have survived. Because of the fatality of this anomaly, prenatal diagnosis of iniencephly and pregnancy termination are important. The patient presented herein is only the second patient with iniencephaly and encephalocele to be operated on. The severity of associated systemic and cranial abnormalities is fundamental with regard to survival. Essential points for surgery are preparing enough space to save herniated functional neural tissues, management of associated hydrocephalus and brain stem rotation/compression due to decreased postoperative space. In the surviving child, early correction of Sprengel's deformity would provide a better aesthetic position of the neck with preservation of brachial plexus integrity.     

Three-dimensional mapping of oxygen tension in cortical arterioles before and after occlusion

Occlusions in single cortical microvessels lead to a reduction in oxygen supply, but this decrement has not been able to be quantified in three dimensions at the level of individual vessels using a single instrument. We demonstrate a combined optical system using two-photon phosphorescence lifetime and fluorescence microscopy (2PLM) to characterize the partial pressure of oxygen (pO₂) in single descending cortical arterioles in the mouse brain before and after generating a targeted photothrombotic occlusion. Integrated real-time Laser Speckle Contrast Imaging (LSCI) provides wide-field perfusion maps that are used to monitor and guide the occlusion process while 2PLM maps changes in intravascular oxygen tension. We present the technique’s utility in highlighting the effects of vascular networking on the residual intravascular oxygen tensions measured after occlusion in three dimensions.OCIS codes: (170.0170) Medical optics and biotechnology, (170.3650) Lifetime-based sensing, (170.1460) Blood gas monitoring, (170.5380) Physiology, (180.4315) Nonlinear microscopy, (110.6150) Speckle imaging     

Mutually exclusive redox forms of HMGB1 promote cell recruitment or proinflammatory cytokine release

Tissue damage causes inflammation, by recruiting leukocytes and activating them to release proinflammatory mediators. We show that high-mobility group box 1 protein (HMGB1) orchestrates both processes by switching among mutually exclusive redox states. Reduced cysteines make HMGB1 a chemoattractant, whereas a disulfide bond makes it a proinflammatory cytokine and further cysteine oxidation to sulfonates by reactive oxygen species abrogates both activities. We show that leukocyte recruitment and activation can be separated. A nonoxidizable HMGB1 mutant in which serines replace all cysteines (3S-HMGB1) does not promote cytokine production, but is more effective than wild-type HMGB1 in recruiting leukocytes in vivo. BoxA, a HMGB1 inhibitor, interferes with leukocyte recruitment but not with activation. We detected the different redox forms of HMGB1 ex vivo within injured muscle. HMGB1 is completely reduced at first and disulfide-bonded later. Thus, HMGB1 orchestrates both key events in sterile inflammation, leukocyte recruitment and their induction to secrete inflammatory cytokines, by adopting mutually exclusive redox states.     

Dual-wavelength multifrequency photothermal wave imaging combined with optical coherence tomography for macrophage and lipid detection in atherosclerotic plaques using gold nanoparticles

The objective of this study was to assess the ability of combined photothermal wave (PTW) imaging and optical coherence tomography (OCT) to detect, and further characterize the distribution of macrophages (having taken up plasmonic gold nanorose as a contrast agent) and lipid deposits in atherosclerotic plaques. Aortas with atherosclerotic plaques were harvested from nine male New Zealand white rabbits divided into nanorose- and saline-injected groups and were imaged by dual-wavelength (800 and 1210 nm) multifrequency (0.1, 1 and 4 Hz) PTW imaging in combination with OCT. Amplitude PTW images suggest that lateral and depth distribution of nanorose-loaded macrophages (confirmed by two-photon luminescence microscopy and RAM-11 macrophage stain) and lipid deposits can be identified at selected modulation frequencies. Radiometric temperature increase and modulation amplitude of superficial nanoroses in response to 4 Hz laser irradiation (800 nm) were significantly higher than native plaque (P<0.001). Amplitude PTW images (4 Hz) were merged into a coregistered OCT image, suggesting that superficial nanorose-loaded macrophages are distributed at shoulders on the upstream side of atherosclerotic plaques (P<0.001) at edges of lipid deposits. Results suggest that combined PTW-OCT imaging can simultaneously reveal plaque structure and composition, permitting characterization of nanorose-loaded macrophages and lipid deposits in atherosclerotic plaques.     

Outbreak of Burkholderia cepacia complex among ventilated pediatric patients linked to hospital sinks

We investigated a cluster of Burkholderia cepacia complex colonization in ventilated pediatric patients. Isolates from 15 patients, 2 sink drains, and several ventilator components were found to belong to a single B cenocepacia clone. Hospital tap water used during oral and tracheostomy care was identified as the most likely mechanism for transmission.