The complete anion of the title hydrated mol-ecular salt, 2C(5)H(8)N(3) (+)·C(8)H(4)O(4) (-)·2H(2)O, is generated by a crystallographic twofold axis. In the crystal, the cations, anions and water mol-ecules are connected by N-H⋯O, O-H⋯O and C-H⋯O hydrogen bonds, forming a three-dimensional network. The crystal structure also features C-H⋯π inter-actions.
The asymmetric unit of the title compound, C(5)H(8)N(3) (+)·C(7)H(4)ClO(2) (-)·C(7)H(5)ClO(2), contains an ion pair and a 3-chloro-benzoic acid mol-ecule. In the cation, the pyridine N atom is protonated. In the crystal, the components are connected via N-H⋯O, O-H⋯O and C-H⋯O hydrogen bonds, thereby forming sheets lying parallel to (100).
In the title mol-ecular salt-adduct, C(5)H(8)N(3) (+)·C(6)H(7)O(2) (-)·C(6)H(8)O(2), the 2,3-diamino-pyridinium cation is essentially planar, with a maximum deviation of 0.013 (2) Å, and is protanated at its pyridine N atom. The sorbate anion and sorbic acid mol-ecules exist in extended conformations. In the crystal, the protonated N atom and one of the two amino-group H atoms are hydrogen bonded to the sorbate anion through a pair of N-H⋯O hydrogen bonds, forming an R(1) (2)(6) ring motif. The carboxyl groups of the sorbic acid mol-ecules and the carboxyl-ate groups of the sorbate anions are connected via O-H⋯O hydrogen bonds. Furthermore, the ion pairs and neutral mol-ecules are connected via inter-molecular N-H⋯O hydrogen bonds, forming sheets lying parallel to (100).
In the title mol-ecular salt, C(5)H(8)N(3) (+)·C(7)H(5)O(3) (-), the 2,3-diamino-pyridinium cation is essentially planar, with a maximum deviation of 0.006 (2) Å. In the crystal, adjacent cations and anions are linked by pairs of N-H⋯O hydrogen bonds, generating R(2) (2)(8) loops. These dimers are linked by further N-H⋯O hydrogen bonds and C-H⋯O inter-actions to form sheets lying parallel to (001). A typical intra-molecular O-H⋯O hydrogen bond is also observed in the salicylate (2-hy-droxy-benzoate) anion, which generates an S(6) ring. The crystal structure also features π-π stacking inter-actions between the pyridinium rings of the cations, with a centroid-centroid distance of 3.5896 (15) Å.
In the title mol-ecular salt, C(5)H(8)N(3) (+)·C(5)H(7)O(4) (-), the 2,3-diamino-pyridine mol-ecule is protonated at the pyridine N atom. The cation is essentially planar, with a maximum deviation of 0.015 (2) Å, and the anion adopts an extended conformation. In the crystal, the hydrogen glutarate (4-carb-oxy-butano-ate) anions are self-assembled through O-H⋯O hydrogen bonds, forming chains. The cations are connected to the anion chains via N-H⋯O hydrogen bonds, forming a three-dimensional network. The crystal structure also features aromatic π-π inter-actions between the pyridinium cations, with a centroid-centroid distance of 3.4464 (10) Å.
In the title hydrated mol-ecular salt, C(5)H(8)N(3) (+)·C(7)H(5)O(6)S(-)·H(2)O, the ion pairs and water mol-ecules are connected by N-H⋯O, O-H⋯O and C-H⋯O hydrogen bonds, thereby forming a three-dimensional network. There is an intra-molecular O-H⋯O hydrogen bond in the 3-carb-oxy-4-hy-droxy-benzene-sulfonate anion, which generates an S(6) ring motif.
We report a case of a 21 years old female who presented with a history of anterior knee pain for previous 3 months. Pain was localized to the anteromedial aspect of the left knee and aggravated by flexion. Clinical examination revealed a 2x2cm painful lump on the anteromedial aspect of the left medial condyle with no effusion. Magnetic resonance imaging revealed an anterosuperior tear of the medial collateral ligament. The patient subsequently underwent left knee arthroscopic examination. Two yellowish pedunculated masses arising from the anteromedial portion of the synovium were discovered and completely excised. Histopathological examination of the excision biopsy revealed pigmented villonodular synovitis (PVNS) with marked central necrosis. One year post excision, she is well with no signs or symptoms of recurrence. This case highlights an uncommon cause of anterior knee pain. Localized PVNS typically presents with mechanical symptoms, however, pain could arise from pedicle torsion and necrosis.
Spinal tuberculosis is not common in the paediatric age group. Initial clinical features are often vague and non specific until the disease progresses to later stages. We highlight the diagnostic difficulties and management challenges of a complicated extradural tuberculoma with neurological deficits in a very young girl.
Instances of neurological recovery after early decompression of the spine in non-traumatic spinal cord compression are well documented. We present a patient with paraplegia of 11 months' duration due to atypical spinal tuberculosis who showed complete neurological recovery in three months.