Evolving magnetic resonance spinal cord trauma in child: from hemorrhage to intradural arachnoid cyst

Acquired arachnoid cysts of the spinal cord are uncommon causes of spinal cord compression in the pediatric group. Meningitis, trauma and hemorrhage are considered to be causative or contributing factors. Interestingly, no spinal arachnoid cysts have been reported in patients after subarachnoid hemorrhage or meningitis, conditions expected to cause arachnoid scarring. We describe a child of 1 year and 10 months with thoracic spine trauma with crural paraplegia and anesthesia at level T5 submitted to serial magnetic resonance imagery at 5 days and 18 months, after trauma showing evolution from subarachnoid hemorrhage and adhesions of the arachnoid space to a posterior hypertensive thoracic intradural arachnoid cyst.     

Molecular modeling of immunoglobulin light chains implicates hydrophobic residues in non-amyloid light chain deposition disease

Light chain deposition disease is a severe complication of certain immunoproliferative disorders, due to the secretion of a monoclonal light chain which precipitates close to basement membranes of several tissues. A kappa isotype restriction and an unusual frequency of a variable region subgroup (VkappaIV) suggest that precise structural features govern the propensity of pathogenic light chains to precipitate in extracellular spaces. We studied primary structures of light chains from six patients with light chain deposition disease in comparison with light chains from other pathological conditions. Sequence alignment revealed the presence of certain amino acids only in light chain deposition disease, in particular non-polar replacing hydrophilic residues. To determine the role of these residues, structures of the variable domain from four kappa chains belonging to VkappaI and VkappaIV subgroups responsible for deposition disease were modeled using known immunoglobulins as templates. The most evident structural features shared by all pathogenic light chains were hydrophobic residues exposed to the solvent in complementarity determining regions 1 or 3. In contrast to immunoglobulin light chain- related amyloidosis, where deposition of organized material might be due to electrostatic interactions between light chain dimers, hydrophobic interactions could enhance amorphous precipitation in non- amyloid light chain deposition disease.      

Chemical Mediation of Ternary Interactions Between Marine Holobionts and Their Environment as Exemplified by the Red Alga Delisea pulchra

The need for animals and plants to control microbial colonization is important in the marine environment with its high densities of microscopic propagules and seawater that provides an ideal medium for their dispersal. In contrast to the traditional emphasis on antagonistic interactions of marine organisms with microbes, emerging studies lend support to the notion that health and performance of many marine organisms are functionally regulated and assisted by associated microbes, an ecological concept defined as a holobiont. While antimicrobial activities of marine secondary metabolites have been studied in great depth ex-situ, we are beginning to understand how some of these compounds function in an ecological context to maintain the performance of marine holobionts. The present article reviews two decades of our research on the red seaweed Delisea pulchra by addressing: the defense chemistry of this seaweed; chemically-mediated interactions between the seaweed and its natural enemies; and the negative influence of elevated seawater temperature on these interactions. Our understanding of these defense compounds and the functional roles they play for D. pulchra extends from molecular interactions with bacterial cell signaling molecules, to ecosystem-scale consequences of chemically-controlled disease and herbivory. Delisea pulchra produces halogenated furanones that antagonize the same receptor as acylated homoserine lactones (AHL)-a group of widespread intercellular communication signals among bacteria. Halogenated furanones compete with and inhibit bacterial cell-to-cell communication, and thus interfere with important bacterial communication-regulated processes, such as biofilm formation. In a predictable pattern that occurs at the ecological level of entire populations, environmental stress interferes with the production of halogenated furanones, causing downstream processes that ultimately result in disease of the algal holobiont.     

Erosion behavior of EB-PVD 7YSZ coatings under corrosion/erosion regime: Effect of TBC microstructure and the CMAS chemistry

Aero-engines operating in dust-laden environments often encounter a lot of dust/sand that causes a severe problem to the TBCs by means of erosion. As the turbine entry temperatures are rising, molten sand is also a big concern to the life-time of TBCs.This paper deals with the TBC behavior under the combined influence of erosion and corrosion attack. Variations in TBC morphology, CMAS infiltration time and CMAS composition and their influence on the erosion resistance at room temperature were investigated. Two different EB-PVD 7YSZ morphologies consisting of a different porosity arrangement were tested in the erosion/corrosion regime. The more ‘Feathery’ structure has a better resistance to erosion compared to a more columnar ‘Normal’ structure, which leads to less degradation of the TBC. However, under the influence of CMAS infiltration the effect was found to be reversed. In general, CMAS-infiltrated EB-PVD TBCs exhibit a higher erosion resistance than the non-infiltrated ones.     

DEHYDRATION BY DESORPTION AND BY SPRAY DRYING OF DAIRY PROTEINS: INFLUENCE OF THE MINERAL ENVIRONMENT

A drying method by desorption in a water activity meter was used to simulate the conditions of spray drying and to determine the water transfer inside dairy concentrates towards the surface and from the surface to the drying air. The concentrates were also spray dried and solubility index of powders were determined during reconstitution. Whey protein concentrates (WPC) and native phosphocaseinate suspensions (NPCS) were used to study the effect of NaCl (420 mM), CaCl₂ (222 raM), sodium phosphate (173 mM) and sodium citrate (238 mM) on the water transfers. The decrease in water transfer during drying was explained by the high hygroscopicity of added mineral salts to WPC. NaCl addition to NPCS decreased the water transfer during drying, but increased the solubility index. Citrate and phosphate addition to NPCS increased the water transfer during drying and reconstitution. CaCl₂ increased the water transfer during drying but the solubility index was always low. Results are discussed as a function of the aqueous environment, of the nature of mineral salts, of the structure of dairy proteins and of protein solvation.     

美试射小功率战术激光炮

据外电报道．美国空军首次试验了一种新式激光武器．并成功击中标靶。美军提供的录像显示,一架在高空飞行的C-130H“大力神”运输机利用其装备的“先进战术激光”系统．准确命中了位于白沙导弹靶场的目标——一辆汽车前发动机盖上手帕大小的区域．激光束融化了发动机盖．并产生了大量火花。     

Plasma concentrations of ethynyl oestradiol and norethindrone after oral administration to women

Rapid vasicular resistance adjustments in the brain and in the circle of Willis have been continuously measured and enhanced by signal averaging methods. Naftidrofuryl, a drug chemically similar to local anesthetics and to beta adrenergic blocking agents, increases local CBF by reducing resistance in brain and in extracerebral supply arteries. It has also been reported to affect brain metabolism. Other similar drugs merit study for potential effects on CBF and brain metabolism which may be useful in treatment.     

A surgical technique for resecting malignancies invading the facial nerve and petrous pyramid

Certain head and neck malignancies tend to invade branches of the cranial nerves and progress centripetally. The maxillary and mandibular divisions of the V (trigeminal) nerve are the most commonly invaded, but the VII (facial) nerve may harbor extensions of primary parotid malignancies and/or skin cancers originating in or near the ear. Paresis of the VII nerve signifies a serious but not entirely hopeless situation if countered with an appropriate surgical procedure. The optimal treatment of malignancies invading cranial nerves is surgical excision, which may necessitate removal of substantial portions of the cranium. Surgical pursuit of a malignancy in the facial nerve leads to a direct confrontation with the petrous pyramid of the temporal bone. Resection of the petrous pyramide is surgically feasible, but, if performed en bloc, extracts a high morbidity and mortality. An alternate technique in which the soft tissue and bones are removed disjunct is advocated. In this technique, the soft tissues are excised flush with the surface of the temporal bone. After making perforator and burr openings in the squamous temporal bone, a subtotal temporal craniectomy is completed with rongeurs. A prerequisite for success with this technique is the rotation of a large scalp flap and other local flaps to cover the exposed meninges and carotid arteries. A resume of four cases using this technique is presented. The age of the patients, the type, stage, and duration of the malignancies, and other factors which might influence the end stage results are given.     

Big and little forms of osteoclast activating factor

We have further characterized osteoclast activating factor (OAF) using a bioassay for bone resorption which utilizes the release of previously incorporated (45)Ca from fetal rat long bones in organ culture. When supernatant media from activated leukocyte cultures were concentrated on Amicon PM10 membranes (assigned molecular weight cutoff 10,000 daltons) and chromatographed on Sephadex G-50 columns, the bone-resorbing activity eluted between the molecular weight markers chymotrypsinogen (25,000 daltons) and cytochrome c (12,500 daltons). This peak of biological activity has been called big OAF. When filtrates from the PM10 membranes were concentrated on Amicon UM2 membranes (assigned molecular weight cutoff 1,000 daltons) and chromatographed on Sephadex G-50 columns, some of the biological activity eluted between the molecular weight markers chymotrypsinogen and cytochrome c (big OAF), but there was a separate peak of biological activity which eluted with [(3)H]proline (140 daltons). This second peak has been called little OAF. Little OAF was eluted from Bio-Gel P6 columns between the molecular weight markers calcitonin (approximately 3,500 daltons) and vitamin B(12) (1,330 daltons), but was retained by Spectrapor dialysis tubing (nominal molecular weight cutoff 3,500 daltons). Big OAF was converted to little OAF by equilibration in 1 M NaCl or 2 M urea. Little OAF was self-associated back to big OAF by equilibration in buffers of low ionic strength (Tris-HCl 10-50 mM). Little OAF was extracted into the organic phase in ethyl acetate after acidification of the sample to pH 3.5. The biological activity remained in the aqueous phase after ethyl acetate extraction at pH 7.5-8.4. Little OAF has been purified more than 6,000-fold compared with the original material so that bone-resorbing activity is maximal in a sample with a protein concentration of 80 ng/ml.