Hexaaquazinc(II) dipicrate

In the title compound, [Zn(H₂O)₆](C₆H₂N₃O₇)₂, the Zn^II ion is located on an inversion center and is coordinated by six water mol­ecules in an octa­hedral geometry. The picrate anions have no coordination inter­actions with the Zn^II atom. The three nitro groups are twisted away from the attached benzene ring by19.8 (3), 6.5 (4) and 28.6 (3)°. There are numerous O—H⋯O hydrogen bonds in the crystal structure.

Pityriasis lichenoides: the differences between children and adults

BACKGROUND

Pityriasis lichenoides (PL) is a skin disease that affects both children and adults. Anecdotally, it is said to run a more benign course in children, with a frequent tendency to self-resolution. However, to our knowledge, there have been no published studies comparing PL in both age groups.

OBJECTIVE

To evaluate the clinicopathological features, overall efficacy of treatments and disease outcomes in children and adults diagnosed with PL.

METHODS

A retrospective review of records was undertaken on all patients diagnosed with PL at two regional centres during an 8-year period (from 1998 to 2006). For each individual, data were collected on age, sex, number of lesions, lesional morphology and distribution, symptoms, histopathological features, treatment modalities (and response), overall follow-up and length of remission.

RESULTS

We recorded 25 children (median age 8 years, range 2-18) and 32 adults (median age 40 years, range 20-65) with PL. All the children and adults had more than 20 scaly, papular lesions. Children had greater lesional body involvement than adults. Lesions on the legs and trunk were present in 23 children (92%) compared with 19 adults (59%) (P < 0.01) and facial involvement was observed more commonly in children (n = 10, 40%) compared with adults (n = 8, 25%). Dyspigmentation was significantly more common in children (n = 18, 72%) compared with adults (n = 6, 19%) (P < 0.001). Topical corticosteroids were used by 16 children (64%) and 18 adults (56%) but only half in each group found these effective. Eight children (32%) were treated with erythromycin, with only two (25%) clearing, and one of these subsequently relapsing. In contrast, four adults (13%) received antibiotics, with three (75%) clearing and none relapsing thereafter. Ultraviolet B phototherapy was used in eight children (32%), with seven (88%) completely or almost clearing, but four (57%) subsequently relapsed. Fourteen adults (44%) received phototherapy; 10 (71%) completely cleared and only two of these (20%) subsequently relapsed. Strikingly, after a median disease duration of 30 months, only five children (20%) went into complete remission compared with 25 adults (78%) (P < 0.001).

CONCLUSIONS

This is the first study to compare PL in children and adults. Our findings suggest that, compared with adults, PL in children is more likely to run an unremitting course, with greater lesional distribution, more dyspigmentation and a poorer response to conventional treatment modalities.

Combined aniridic intraocular lens implantation and vitreoretinal surgery

A 45-year-old man presented with post-traumatic aniridia. We describe the combined surgery done to treat both aniridia and epiretinal membrane simultaneously. A combined aniridia intraocular lens and vitreoretinal surgery was done. The case report highlights the advantage of combined surgery in terms of cost factor and surgical time.

1'-Methylcyclooctane-1-spiro-3'-pyrrolidine-2'-spiro-3''-indoline-2,2''-dione and 1,1'-dimethylpiperidine-3-spiro-3'-pyrrolidine-2'-spiro-3''-indoline-2'',4-dione

In both title compounds, C(19)H(24)N(2)O(2), (I), and C(17)H(21)N(3)O(2), (II), respectively, there are two molecules in the asymmetric unit and the pyrrolidine rings adopt envelope conformations. The conformations of the cyclooctane [in (I)] and 1-methylpiperidone [in (II)] rings are boat-chair and chair, respectively. The indolin-2-one group is almost perpendicular to the pyrrolidine ring. Intermolecular C-H...O, N-H...O and N-H...N interactions provide stability to the structures.

4-Carboxyanilinium (2R,3R)-tartrate and a redetermination of the α-polymorph of 4-aminobenzoic acid

In the title compounds, 4-carboxyanilinium (2R,3R)-tartrate, C(7)H(8)NO(2)+.C(4)H(5)O(6)-, (I), and 4-aminobenzoic acid, C(7)H(7)NO(2), (II), the carboxyl planes of the 4-carboxyanilinium cations/4-aminobenzoic acid are twisted from the aromatic plane. In (I), the characteristic head-to-tail interactions are observed through the tartrate anions, forming two C2(2)(7) chain motifs propagating parallel to the a and c axes of the unit cell. Also, the tartrate anions are connected through two primary C1(1)(6) and C1(1)(7) chain motifs, leading to a secondary R4(4)(22) ring motif. In (II), head-to-tail interaction is seen through a discrete D1(1)(2) motif and carboxyl group dimerization is observed through centrosymmetrically related R2(2)(8) motifs around the inversion centres of the unit cell. The crystal structures of both compounds are stabilized by intricate three-dimensional hydrogen-bonding networks. Alternate hydrophobic and hydrophilic layers are observed in (I) as a result of a column-like arrangement of the anions and the aromatic rings of the cations.

(R)-3,5-Bis[(E)-benzylidene]-1-(1-phenylethyl)piperidin-4-one, 3,5-bis[(E)-4-chlorobenzylidene]-1-[(R)-1-phenylethyl]piperidin-4-one and 3,5-bis[(E)-2-chlorobenzylidene]-1-[(R)-1-phenylethyl]piperidin-4-one

Polysubstituted piperidones, viz. the title compounds, C(27)H(25)NO, (I), C(27)H(23)Cl(2)NO, (II), and C(27)H(23)Cl(2)NO, (III), adopt sofa conformations. The molecular packing in (I) and (II) is a result of van der Waals interactions, whereas in (III), a C-H...O interaction is also found.

Phacoemulsification and pars plana vitrectomy: a combined procedure

AIM

To describe the results of a combined procedure including phacoemulsification, insertion of posterior chamber intraocular lens (PCIOL) and pars plana vitrectomy (PPV) in eyes with vitreoretinal pathology and coexisting significant cataract.

DESIGN

Retrospective, consecutive, noncomparative, interventional case series.

MATERIALS AND METHODS

Medical records of patients who had undergone phacoemulsification, PPV and PCIOL implantation as a combined procedure between January 2000 and December 2004 were retrospectively reviewed. The main outcome measures were the anatomical success of retina, defined as reattached retina, intraoperative and postoperative complications and functional success in terms of final best corrected visual acuity.

RESULTS

In all, 65 eyes of 64 patients were included. The mean age of the patients was 50.9 years +/- 17.1 (range, five to 82 years). Vitreous hemorrhage with or without retinal detachment (19 eyes, 29.2%) was the most common indication for the vitreoretinal procedure. Primary anatomical success of retina was achieved in 59 eyes (90.7%). Visual acuity improved in 48 eyes (73.8%), was unchanged in 12 eyes (18.5%) and deteriorated in five eyes (7.7%). Postoperative inflammation was significantly more in the subgroup of previously vitrectomized eyes (42%) (P =0.014, Fisher exact test) compared to those which underwent primary vitrectomy.

CONCLUSIONS

Combined surgery is a feasible option for patients with vitreoretinal diseases and cataract.

Hydrogen-bonding features in the 1:2 adduct of 4-aminobenzoic acid andL-proline

The title adduct, 4-aminobenzoic acid-L-proline-water (1/2/1), C(7)H(7)NO(2).2C(5)H(9)NO(2).H2O, contains two independent proline chains with a C(5) motif, each of the head-to-tail type and each held together by N-H...O hydrogen bonds, propagated parallel to the b and c axes of the unit cell. Thus, the proline residues aggregate parallel to the ac plane. 4-Aminobenzoic acid (PABA) residues are arranged on both sides of the proline aggregate and are connected through water O atoms, which act as acceptors for PABA and as hydrogen-bond donors to the amino acids. The characteristic features of PABA, viz. twisting of the carboxyl plane from the aromatic ring and the formation of a head-to-tail chain motif [C(8)] along the b axis, are observed. A distinct feature of the structure is that no proton transfer occurs between proline and PABA.

Lamellar aggregation and hydrogen-bonding motifs in 3-(aminocarbonyl)pyridinium perchlorate and hydrogen oxalate

In the title compounds, C(6)H(7)N(2)O(+).ClO(4)(-), (I), and C(6)H(7)N(2)O(+).C(2)HO(4)(-), (II), the carboxamide plane is twisted from the plane of the protonated pyridine ring. Lamellar or sheet-like structural features are observed through N-H...O and O-H...O hydrogen-bonded motifs of cations and anions in (I) and (II), respectively. These sheets are aggregated through C(4) and C(5) chain motifs in (I) and (II), respectively. R(1)(2)(4) ring motifs in (I) and R(1)(2)(5) motifs in (II) are formed via pyridine-anion bifurcated N-H...O interactions. In (II), carboxamide groups form N-H...O dimers around the inversion centres of the unit cell, with R(2)(2)(8) ring motifs. A 2(1) screw-related helical or ribbon-like structure along the b axis is formed in (II) through carboxamide and pyridinium N-H...O hydrogen bonds with the oxalate anions.