Resolution of bilateral sensorineural hearing loss following ventriculoperitoneal shunt and literature review.

OBJECTIVE: The purpose of this study is to highlight the relationship between obstructive hydrocephalus, changes in intracranial pressure, and sensorineural hearing loss. METHODS: A case of a 10-month old infant with sensorineural hearing loss secondary to obstructive hydrocephalus is reported. A literature review, with a focus on sensorineural hearing loss in the setting of changes in intracranial pressure, was performed. RESULTS: The authors report the case of a 10-month old infant with metopic and bicoronal craniosynostosis who presented with bilateral moderately severe sensorineural hearing loss after failing newborn hearing screening. Imaging subsequently demonstrated obstructive hydrocephalus, which was treated with the insertion of a VP shunt. The patient had immediate improvement of her hearing post-operatively, with repeat hearing tests showed resolution of her hearing loss. CONCLUSION: Sensorineural hearing loss is a rare complication of hydrocephalus, but changes in intracranial pressure should be considered in the differential diagnosis. We put forth a flow diagram illustrating the hypothesized relationship between intracranial pressures, alterations in the levels of cochlear fluid, and hearing.

Hydrogen bonding in C-methylated nitroanilines: a room-temperature monoclinic polymorph of 4-methyl-3-nitroaniline with Z' = 2.

The title compound, C(7)H(8)N(2)O(2), is monoclinic (space group P2(1)/n) at 295 (2) K with Z' = 2. The two types of molecule form independent C(7) chains, and the structure is related to that of the low-temperature triclinic polymorph, where Z' = 4 in P1, by a simple displacive transformation.

Hydrogen bonding in nitroaniline analogues: a three-dimensional framework in 2-amino-6-nitro-1,3-benzothiazole.

In the title compound, C(7)H(5)N(3)O(2)S, the molecules are linked into a three-dimensional framework by a combination of a three-centre N-H...(O)(2) hydrogen bond, and two-centre N-H...N and C-H...O hydrogen bonds.

4-Iodo-2-methyl-5-nitroaniline exhibits neither strong hydrogen bonding nor intermolecular I...nitro interactions.

In the title compound, C(7)H(7)IN(2)O(2), the O atoms of the nitro group are disordered over two sets of sites and there is evidence that the intramolecular I...nitro interaction is repulsive. In the crystal structure, there are neither strong hydrogen bonds, nor intermolecular I...nitro interactions, nor aromatic pi-pi-stacking interactions.

Hydrogen-bonded adducts of ferrocene-1,1'-diylbis(diphenylmethanol): monomeric and dimeric 1:1 adducts with 1,2-bis(4-pyridyl)ethane and 1,2-diaminoethane.

In ferrocene-1,1'-diylbis(diphenylmethanol)-4,4'-ethylenedipyridine (1/1), [Fe(C(18)H(15)O)(2)].C(12)H(12)N(2), there is an intramolecular O-H...O hydrogen bond in the ferrocenediol component and a single O-H...N hydrogen bond linking the two components into a finite monomeric adduct. Ferrocene-1,1'-diylbis(diphenylmethanol)-ethylenediamine (1/1), [Fe(C(18)H(15)O)(2)].C(2)H(8)N(2), crystallizes with Z' = 2 in space group P1, and there are two independent four-component aggregates in the structure, both of which are centrosymmetric. In the first type of aggregate, the molecular components are linked by O-H...N and N-H...O hydrogen bonds, in which both diamine N atoms participate; in the second type of aggregate, the diamine component is disordered over two sets of sites, but only one N atom is involved in the hydrogen bonding.

[6-Amino-3-methyl-5-nitrosopyrimidine-2,4(1H,3H)-dionato]-sodium dihydrate at 150 K: coordination-polymer ladders linked by hydrogen bonds.

In the title compound, [Na(C(5)H(5)N(4)O(3))].2H(2)O, each Na cation is linked to three C(5)H(4)N(4)O(3)(-) anions and two water molecules, forming approximately octahedral NaNO(5) units; the cations and the anions form molecular ladders, and each ladder is linked to four neighbouring ladders by O-H...O and O-H...N hydrogen bonds.

Sodium 2-nitroethanaloximate forms a layered-framework structure.

In the title compound, [Na(C(2)H(3)N(2)O(3))], the Na(+) cation lies on a centre of inversion in space group P2(1)/m and all the atoms of the anion lie on a mirror plane. Na is octahedrally coordinated by four O and two N atoms from six different anions and each anion is coordinated to six different Na(+) cations, forming chains of confacial octahedra which link the anion layers. Within these layers, the individual anions are linked by both O-H...O and C-H...O hydrogen bonds.

Triclinic and orthorhombic polymorphs of 2-iodo-4-nitroaniline: interplay of hydrogen bonds, nitro...I interactions and aromatic pi-pi-stacking interactions.

In the triclinic polymorph of 2-iodo-4-nitroaniline, C(6)H(5)IN(2)O(2), space group P-1, the molecules are linked by paired N-H...O hydrogen bonds into C(8)[R(2)(2)(6)] chains of rings. These chains are linked into sheets by nitro...I interactions, and the sheets are pairwise linked by aromatic pi-pi-stacking interactions. In the orthorhombic polymorph, space group Pbca, the molecules are linked by single N-H...O hydrogen bonds into spiral C(8) chains; the chains are linked by nitro...O interactions into sheets, each of which is linked to its two immediate neighbours by aromatic pi-pi-stacking interactions, so producing a continuous three-dimensional structure.

Hydrogen-bonded chains in N-(2-nitrophenyl)phenylamine.

Molecules of the title compound, C(12)H(10)N(2)O(2), are markedly non-planar. There is an intramolecular N-H...O hydrogen bond, and the molecules are linked into zigzag chains by a single C-H...O hydrogen bond. Comparisons are made with the supramolecular aggregation in isomeric amino-nitro derivatives, and in some N-methylnitroanilines.

N,N'-Bis[tris(hydroxymethyl)methyl]-ethanediamide: six O-H...O hydrogen bonds generate only a two-dimensional structure.

Molecules of the title compound, C(10)H(20)N(2)O(8), adopt a conformation which is almost centrosymmetric. The molecules are disordered over two sets of sites with an occupancy ratio of 0.94:0.06. In the major form, there are two intramolecular O-H...O hydrogen bonds [O...O 2.756 (4) and 2.765 (4) A; O-H...O 144 and 146 degrees ], in which the two amidic O atoms act as acceptors. In addition, there are four intermolecular O-H...O hydrogen bonds [O...O 2.650 (3)-2.666 (3) A; O-H...O 158-171 degrees ]; these link each molecule to six others in a continuous sheet structure which contains five distinct ring motifs, two of the S(7) type, two of the R(3)(3)(10) type and one of the R(2)(2)(22) type.

N,N'-Dimethylpiperazinium(2+) phosphonoacetate: hydrogen-bonded anion sheets containing cation-templated R(6)(6)(28) rings.

In the title compound, C(6)H(16)N(2)(2+).2C(2)H(4)O(5)P(-), the cations lie across centres of inversion; in the anions, two of the H-atom sites have 0.50 occupancy. The anions are linked by short O-H...O hydrogen bonds [O...O 2.465 (3)-2.612 (3) A and O-H...O 165-171 degrees ] into sheets of alternating R(2)(2)(12) and R(6)(6)(28) rings, both of which are centrosymmetric; the cations lie at the centres of the larger rings linked to the anion sheet by N-H...O hydrogen bonds [N...O 2.642 (2) A and N-H...O 176 degrees ].

Hydrogen-bonded bilayers in piperazinium(2+) bis(mandelate) bis(methanol) solvate.

In the title compound, C(4)H(12)N(2)(2+).2C(8)H(7)O(3)(-).2CH(4)O, the cations lie across centres of inversion and are disordered over two orientations with equal occupancy; there are equal numbers of (R)- and (S)-mandelate anions present (mandelate is alpha-hydroxybenzeneacetate). The anions and the neutral water molecules are linked by O-H...O hydrogen bonds [O...O 2.658 (3) and 2.682 (3) A, and O-H...O 176 and 166 degrees] into deeply folded zigzag chains. Each orientation of the cation forms two symmetry-related two-centre N-H...O hydrogen bonds [N...O 2.588 (4) and 2.678 (4) A, and N-H...O 177 and 171 degrees] and two asymmetric, but planar, three-centre N-H...(O)(2) hydrogen bonds [N...O 2.686 (4)-3.137 (4) A and N-H...O 137-147 degrees], and by means of these the cations link the anion/water chains into bilayers.

Bis[N-(6-amino-3,4-dihydro-3-methyl-5-nitroso-4-oxypyrimidin-2-yl)glycyl-glycinato]triaquacalcium: coordination polymer chains linked by hydrogen bonds.

In the title compound, [Ca(C9H11N6O5)2(H2O)3], the Ca atom lies on a twofold rotation axis in C2/c and the three water molecules are all disordered, each over two sites having equal occupancy. The anion acts as a bridging ligand between pairs of Ca sites on the same twofold axis, thus forming a one-dimensional coordination polymer, with the chains lying along the twofold axes. These chains are linked by multiple O-H...O and N-H...O hydrogen bonds into a single three-dimensional framework.

Mu-1,4-benzenedicarboxylato-bis[trans-aqua(1,4,8,11-tetraazacyclotetradecane)nickel(II)] diperchlorate forms a three-dimensional hydrogen-bonded framework.

The title compound, [Ni2(C8H4O4)(C10H24N4)2(H2O)2](ClO4)2, contains two independent octahedral Ni(II) centres with trans-NiN4O2 chromophores. The bridging benzenedicarboxylate ligand is bonded to the two Ni atoms, each via one O atom of each carboxylate, while the other O atom participates in an intramolecular N-H...O hydrogen bond, forming an S(6) motif. The cations are linked to the perchlorate anions via O-H...O and N-H...O hydrogen bonds [O...O 2.904 (6) and 2.898 (6) A; O-H...O 158 (6) and 165 (6) degrees; N...O 3.175 (7) and 3.116 (7) A; N-H...O 168 and 166 degrees ] to form molecular ladders. These ladders are linked by further O-H...O and N-H...O hydrogen bonds [O...O 2.717 (6) and 2.730 (5) A; O-H...O 170 (4) and 163 (6) degrees; N...O 3.373 (7) and 3.253 (7) A; N-H...O 163 and 167 degrees ] to form a continuous three-dimensional framework. The perchlorate anions both participate in three hydrogen bonds, and both are thus fully ordered.

Ferrocenecarboxylic acid-1,4-diazabicyclo[2.2.2]octane (2/1): sheets built from O--H...N and C--H...O hydrogen bonds.

In the title compound, 2[Fe(C5H5)(C6H5O2)].C6H12N2, the molecular components are linked into finite three-component aggregates by strong O-H...N hydrogen bonds [O.N 2.578 (4) and 2.604 (5) A; O-H...N 170 (5) and 174 (6) degrees ]; these aggregates are further linked by C-H...O hydrogen bonds [C...O 3.327 (5)-3.401 (5) A; C-H...O 149-157 degrees ] into continuous sheets in the form of (6,3) nets.

Solvated and solvent-free forms of N,N'-dithiodiphthalimide.

N,N'-Dithiodiphthalimide, C16H8N2O4S2, crystallizes from ethyl acetate with two independent molecules in the asymmetric unit, in which the N-S-S-N torsion angles are -83.59 (19) and 92.9 (2) degrees. The molecules are linked by C-H...O hydrogen bonds and aromatic pi-pi-stacking interactions into a three-dimensional framework. When crystallized from either dichloromethane or ethanol, solvates are formed in which the molecules of the title compound lie across twofold rotation axes in space group C2/c, with N-S-S-N torsion angles of 93.54 (7) and 96.14 (11) degrees. There are no hydrogen bonds in these solvates, but the molecules are linked by aromatic pi-pi-stacking interactions into chains, between which there are continuous channels. Disordered solvent molecules occupy these channels, which account for ca 20% of the unit-cell volume.

[N-(6-amino-3,4-dihydro-3-methyl-5-nitroso-4-oxopyrimidin-2-yl)-glycylglycinato]aquapotassium, a three-dimensional coordination polymer.

In the title compound, polymeric potassium N-(6-amino-3,4-dihydro-3-methyl-5-nitroso-4-oxopyrimidin-2-yl)glycylglycinate hydrate, (K(+).C(9)H(11)N(6)O(5)(-).H(2)O)(n), the hexacoordinate K(+) cation is linked to five different anions as well as to the water molecule, with K-O distances in the range 2.617 (2)-2.850 (2) A. Four of the O atoms in each anion coordinate to K centres, one of them acting as a bridging ligand, leading to the formation of nearly square centrosymmetric K(2)O(2) rings. The structure is analysed in terms of (010) metal-ligand sheets linked by [010] chains of fused rings.

Methyl 4-amino-2,3-dihydro-6-methoxy-1,3-dioxo-1H-pyrrolo[3,4-c]-pyridine-7-carboxylate forms hydrogen-bonded sheets built from R2(2)(8) and R6(6)(42) rings.

In the title compound, C10H9N3O5, which was formed by the reaction of 6-amino-2-methoxy-4(3H)-pyrimidinone with dimethyl acetylenedicarboxylate, the molecules are linked by N-H...O hydrogen bonds [N...O 2.8974 (15) and 3.0300 (15) A, and N-H...O 165 and 174 degrees] into planar sheets built from alternating R2(2)(8) and R6(6)(42) rings.

Soft C-H.O hydrogen bonds in methyl 2,4-dinitrobenzenesulfenate: sheets built from R22(10) and R66(42) rings.

Molecules of the title compound, C(7)H(6)N(2)O(5)S, are linked into sheets containing R(2)(2)(10) and R(6)(6)(42) rings by C-H.O hydrogen bonds [C.O 3.405 (3) and 3.511 (2) A; C-H.O 159 and 169 degrees ], in which both acceptors are in the same nitro group. Comparisons are made with the hydrogen bonding in other nitrobenzenesulfenate esters.

N-(2-Amino-1,6-dihydro-5-nitroso-6-oxopyrimidin-4-yl)-L-isoleucine-water (4/1): interplay of molecular and supramolecular structures.

In the title compound, 2C10H15N5O4-0.5H2O, there are two independent molecules of the pyrimidinylisoleucine in general positions and a water molecule lying on a twofold rotation axis. The bond lengths within the organic moieties demonstrate significant polarization of the electronic structure. Each of the organic molecules participates in 12 intermolecular hydrogen bonds, of O-H...O and N-H...O types, while the water molecule acts as a double donor and as a double acceptor of O-H...O hydrogen bonds. The organic components are linked by the hydrogen bonds into a single three-dimensional framework, reinforced by the water molecules.