Pneumococcal meningitis secondary to otitis media in two patients with COVID-19 omicron variant.

Background: The SARS-CoV-2 omicron variant produces more symptoms in the upper respiratory tract than in the lower respiratory tract. This form of "common cold" can cause inflammation of the oropharynx and the Eustachian tube, leading to the multiplication of bacteria such as Streptococcus pneumoniae in the oropharynx. Eustachian tube dysfunction facilitates migration of these bacteria to the middle ear, causing inflammation and infection (otitis media), which in turn could lead to further complications such as acute mastoiditis and meningitis.

[Langerhans cell histiocytosis with atypical and early neonatal debut].

Langerhans cell histiocytosis is a systemic disease associated with the proliferation of this type of cells in tissues. Its prevalence is estimated at 1-9/100 000. Bone is the most frequently affected organ, followed by the skin, lymph nodes, haematopoietic system, pituitary gland, lungs and liver.

Neonatal fulminant type 2 infantile hepatic hemangioendothelioma involving skin, viscera and soft tissue.

We present the fulminant case of a neonate whose symptoms, lesions, imaging, and laboratory tests perfectly simulated a neonatal neuroblastoma and the definitive diagnosis was finally given by necropsy as follows: Infantile hepatic hemangioendothelioma type 2 with extrahepatic extension affecting skin, lung, intestine, suprarenal, and soft tissue.

Vanadium containing bromoperoxidase--insights into the enzymatic mechanism using X-ray crystallography.

The X-ray crystal structure of the vanadium bromoperoxidase from the red algae Corallina pilulifera has been solved in the presence of the known substrates, phenol red and phloroglucinol. A putative substrate binding site has been observed in the active site channel of the enzyme. In addition bromide has been soaked into the crystals and it has been shown to bind unambiguously within the enzyme active site by using the technique of single anomalous dispersion.

The Fasciola hepatica thioredoxin: High resolution structure reveals two oxidation states.

The Fasciola hepatica thioredoxin protein structure has been determined to 1.45A resolution. This is the first example of a single crystal structure to show the active site cysteine residues in both the reduced and disulfide oxidised form.

Enhancing effect of calcium and vanadium ions on thermal stability of bromoperoxidase from Corallina pilulifera.

Bromoperoxidase from the macro-alga Corallina pilulifera is an enzyme that possesses vanadate in the catalytic center, and shows a significant thermostability and stability toward organic solvents. The structural analysis of the recombinant enzyme overexpressed in yeast revealed that it contains one calcium atom per subunit. This has been confirmed by inductively coupled plasma emission spectrometry experiments.

Modification of halogen specificity of a vanadium-dependent bromoperoxidase.

The halide specificity of vanadium-dependent bromoperoxidase (BPO) from the marine algae, Corallina pilulifera, has been changed by a single amino acid substitution. The residue R397 has been substituted by the other 19 amino acids. The mutant enzymes R397W and R397F showed significant chloroperoxidase (CPO) activity as well as BPO activity.

Structural and functional comparisons between vanadium haloperoxidase and acid phosphatase enzymes.

The crystallographic structures of both the vanadium chloroperoxidase and bromoperoxidase enzymes have been determined with either vanadium or phosphate bound at their active site. The amino acids that are involved in phosphate binding in the acid phosphatase enzymes and those that are coordinated to vanadium in the haloperoxidases appear to be conserved between the two classes of enzyme. The detailed active site architecture for enzymes that recognize and use either vanadium or phosphate will be discussed in relation to their proposed enzymatic mechanism.

Molybdenum alkynyls as alkynyl transfer reagents.

Molybdenum alkynyl complexes [Mo(C identical to CR)(eta 3-allyl)(CO)2(phen)] feature long Mo-Calkynyl bond distances and propensity to undergo the cleavage of these bonds, a property that allowed their use as acetylide transfer reagents.

A Novel Domino Reaction: Cyclization of Alkynyl Sulfides by Reaction with IPy BF.

Formation of polycyclic structures within a few minutes: The intramolecular cyclization of diynes, activated by a benzenesulfenyl substituent, upon reaction with IPy BF proceeds as an efficient exo-endo coupling. A subsequent novel Friedel-Crafts-like ring closure provides the product [Eq. (1)].