N′-Benzylidene-2-chloro-N-(4-chlorophenyl)acetohydrazide

In the title compound, C₁₅H₁₂Cl₂N₂O, the atoms not making up the chloro­benzene ring are approximately coplanar (r.m.s. deviation = 0.073 Å). The dihedral angle between these 13 atoms and the chloro­benzene ring is 67.37 (10)°. The C=O and Csp²—Cl groups are almost eclipsed [Cl—C—C=O = −6.5 (3)°]. In the crystal, C(6) chains linked by C—H⋯O hydrogen bonds result in [100] chains.

(1Z)-1-(1-Benzo-furan-2-yl)ethanone oxime

The title compound, C₁₀H₉NO₂, is almost planar (r.m.s. deviation for the non-H atoms = 0.027 Å) and the conformation across the C=N bond is syn. Further, the O atom of the benzo­furan ring is syn to the CH₃ group in the side chain. In the crystal, mol­ecules are linked into C(3) chains propagating in [010] by O—H⋯N hydrogen bonds.

1-(4-Methylphenylsulfonyl)-2-{[3-methyl-4-(2,2,2-trifluoroethoxy)pyridin-2-yl]methylsulfanyl}-1H-1,3-benzimidazole

In the title compound, C23H20F3N3O3S2, the benzoimidazole unit makes dihedral angles of 5.02 (1) and 76.42 (1)°, respectively, with the pyridine and methylbenzene rings; the dihedral angle between the pyridine and methylbenzene rings is 72.19 (1)°. In the crystal, molecules are connected by weak C—H...F, C—H...O and C—H...N hydrogen bonds. Weak C—H...π interactions and π–π stacking [centroid–centroid distance = 3.6485 (14) Å] are also observed. The overall packing shows a three-dimensional architecture. The crystal structure contains a void of 51 Å3, but no solvent molecule (hexane or ethyl acetate) is located within it.

5-[(2-Methyl-4-nitro-1H-imidazol-1-yl)meth-yl]-1,3,4-thia-diazol-2-amine

In the title compound, C7H8N6O2S, the dihedral angle between the imidazole and thia-diazole rings is 70.86 (15)°. In the crystal, mol-ecules are linked into [10-1] chains by N-H⋯N hydrogen bonds, which incorporate centrosymmetric R 2 (2)(8) and R 2 (2)(18) loops. The chains are linked by C-H⋯O and C-H⋯N inter-actions, generating a three-dimensional network. Very weak π-π stacking [centroid-centroid distance = 3.901 (17) Å] is also observed.

5-[(1-Benzyl-1H-1,2,3-triazol-4-yl)meth-yl]-5H-dibenzo[b,f]azepine

In the title compound, C₂₄H₂₀N₄, the azepine ring adopts a boat conformation. The dihedral angle between the benzene rings fused to the azepine ring is 49.40 (9)°. The triazole ring makes a dihedral angle of 77.88 (9)° with the terminal phenyl ring. In the crystal, mol­ecules are linked via C—H⋯π inter­actions and a parallel slipped π–π inter­action [centroid–centroid distance = 3.7324 (9), normal distance = 3.4060 (6) and slippage = 1.526 Å], forming a three-dimensional network.

1-(3-Oxo-3-phenyl-prop-yl)piperidinium chloride

In the title salt, C₁₄H₂₀NO⁺·Cl⁻, the piperidine ring adopts a chair conformation. In the crystal, the cations and anions are linked by classical N—H⋯Cl hydrogen bond and weak C—H⋯Cl and C—H⋯O hydrogen bonds; the C—H⋯O hydrogen bonds exhibit R₂²(14) ring motifs while the C—H⋯Cl hydrogen bonds link the mol­ecules into chains along the a-axis direction. π–π stacking is observed between parallel phenyl rings of adjacent cations, the centroid–centroid distance being 3.8164 (15) Å.

1-[5-Methyl-1-(4-nitro-phen-yl)-1H-1,2,3-triazol-4-yl]ethanone

The asymmetric unit of the title compound, C₁₁H₁₀N₄O₃, contains two independent mol­ecules in which the benzene rings make dihedral angles of 38.3 (2) and 87.1 (2)° with respect to the triazole rings. In the crystal, the mol­ecules are linked by C—H⋯O hydrogen bonds, forming chains along [021]. Further, weak C—O⋯π [3.865 (5) Å, 83.8 (3)°] and N—O⋯π [3.275 (5) and 3.240 (6) Å, 141.8 (4) and 102.8 (3)°] inter­actions are observed.

1-(3,5-Di-fluoro-phen-yl)-4,4,4-tri-fluoro-butane-1,3-dione

In the title compound, C10H5F5O2, the C=O bonds are syn to one another. In the crystal, mol-ecules are linked into C(9) chains parallel to [101] through weak C-H⋯O inter-actions, with the O atom adjacent to the -CF3 group acting as the acceptor.

Methyl 4-(tri-fluoro-meth-yl)-1H-pyrrole-3-carboxyl-ate

In the title compound, C₇H₆F₃NO₂, all the non-H atoms except for one of the F atoms lie on a crystallographic mirror plane. In the crystal, the mol­ecules are linked into inversion dimers by pairs of C—H⋯F inter­actions, forming R₂²(10) loops. These dimers are connected into C(6) chains along [001] through N—H⋯O hydrogen bonds. Aromatic π–π stacking inter­actions [centroid-centroid separation = 3.8416 (10) A°] connect the mol­ecules into a three-dimensional network.

1-{3-(4-Methyl-phen-yl)-5-[5-(2-nitro-phen-yl)furan-2-yl]-4,5-di-hydro-1H-pyrazol-1-yl}ethanone

In the title compound, C₂₂H₁₉N₃O₄, the dihedral angle between the furan and pyrazole rings is 82.73 (19)° while the dihedral angles between the furan and pyrazole rings and their attached benzene rings are 31.93 (18) and 1.88 (18)°, respectively. In the crystal, inversion dimers linked by pairs of C—H⋯O hydrogen bonds generate R₂²(16) loops. In addition, weak C—H⋯π and aromatic π–π stacking [minimum centroid–centroid distance = 3.5374 (17) Å] inter­actions are observed.

Ethyl (2E)-2-cyano-3-(4-meth-oxy-phen-yl)acrylate

In the title compound, C₁₃H₁₃NO₃, the conformation across the C=C bond is synperiplanar, the torsion angle of the segment C(ring)—C=C—C(N) being 3.2 (5)°. In the crystal, mol­ecules are linked into inversion dimers, arranged in a zigzag pattern, through two C—H⋯O inter­actions generating R₂²(10) and R₂²(14) motifs. These dimers are arranged in a zigzag pattern in the crystal structure. The mol­ecules are further linked along the c axis through weak C—H⋯π inter­actions, and weak π⋯π inter­actions [centroid–centroid separation = 3.9986 (17) Å] are also observed.

4-(4,5-Diphenyl-1H-imidazol-2-yl)-N,N-di-methyl-aniline

The asymmetric unit of the title compound, C₂₃H₂₁N₃, consists of two symmetry-independent and conformationally different mol­ecules [the comparable dihedral angles between the imidazole ring and the three benzene rings being 38.5 (2)/61.5 (3)/3.37 (17) and 45.8 (2)/36.01 (19)/46.94 (17)°]. In the crystal, inter­molecular imidazole N—H⋯N hydrogen-bonding inter­actions give a one-dimensional chain extending along [101].

A triclinic polymorph of (E)-2-(4-isobutylphenyl)-N′-[1-(4-nitrophenyl)ethylidene]propanohydrazide

The asymmetric unit of the triclinic polymorph of the title compound, C₂₁H₂₅N₃O₃, consists of two mol­ecules, whereas for the monoclinic polymorph Z′ = 1 [Fun et al. (2009 ▶). Acta Cryst. E65, o445]. The two mol­ecules exhibit an E configuration with respect to the C=N bond. The mol­ecules are linked into dimers by N—H⋯O and C—H⋯O hydrogen bonds forming R₂²(8) ring motifs. In addition, π–π inter­actions occur between nitro­phenyl groups [minimum centroid–centroid distance 3.940 (2) Å], stacking the molecules along the ac plane.

5-[(4-Benzyl-1H-1,2,3-triazol-1-yl)meth-yl]-5H-dibenzo[b,f]azepine

In the title compound, C24H20N4, the azepine ring adopts a boat conformation and the dihedral angle between the benzene rings fused to it is 57.95 (8)°. The bond-angle sum at the azepine N atom is 346.6°, indicating a significant deviation from planarity. The triazole ring subtends a dihedral angle of 71.45 (10)° with the terminal phenyl group. A weak intra-molecular C-H⋯Na (a = azepine) inter-action occurs, which closes an S(6) ring.

4-[5-(4-Benzoyloxyphenyl)-1,2,4-oxadiazol-3-yl]phenyl benzoate

In the title compound, C₂₈H₁₈N₂O₅, the dihedral angle between the terminal benzoate rings is 20.67 (12)°. The central oxadiazole ring is almost coplanar with its two benzene ring substituents, making dihedral angles of 4.80 (16) and 5.82 (16)°. In the crystal, pairs of C—H⋯O hydrogen bonds form inversion dimers with R₂²(40) ring motifs. The structure also features C—H⋯O, C—H⋯π and π–π inter­actions [centroid–centroid separation = 3.695 (4) Å].

4-[Amino-(3-methyl-phen-yl)methyl-idene]-2-(3-methyl-phen-yl)-1H-imidazol-5(4H)-one ethanol hemisolvate

In the title compound, C₁₈H₁₇N₃O·0.5C₂H₅OH, the dihedral angles between the central imidazole rings and the pendant benzene rings are 42.06 (15) and 2.01 (16)° in one asymmetric mol­ecule and 47.91 (15) and 7.31 (14)° in the other. An intra­molecular N—H⋯O hydrogen bond occurs in each imidazole mol­ecule. In the crystal, the components are connected by O—H⋯N, N—H⋯O, C—H⋯O and N—H⋯N hydrogen bonds. Weak aromatic π–π inter­actions also occur [shortest centroid–centroid distance = 3.684 (3) Å].

Human skin neural crest progenitor cells are susceptible to BRAF(V600E)-induced transformation

Adult stem cells are multipotent and persist in small numbers in adult tissues throughout the lifespan of an organism. Unlike differentiated cells, adult stem cells are intrinsically resistant to senescence. It is unclear how adult stem cells in solid organs respond to oncogenic stimulation and whether these cells have a role in tumor initiation. We report here that expression of BRAF(V600E) in human neural crest progenitor cells (hNCPCs) did not induce growth arrest as seen in human melanocytes, but instead, increased their cell proliferation capacity. These cells (hNCPCs(V600E)) acquired anchorage-independent growth ability and were weakly tumorigenic in vivo. Unlike in human melanocytes, BRAF(V600E) expression in hNCPCs did not induce p16(INK4a) expression. BRAF(V600E) induced elevated expression of CDK2, CDK4, MITF and EST1/2 protein in hNCPCs, and also induced melanocytic differentiation of these cells. Furthermore, overexpression of MITF in hNCPCs(V600E) dramatically increased their tumorigenicity and resulted in fully transformed tumor cells. These findings indicate that hNCPCs are susceptible to BRAF(V600E)-induced transformation, and MITF potentiates the oncogenic effect of BRAF(V600E) in these progenitor cells. These results suggest that the hNCPCs are potential targets for BRAF(V600E)-induced melanocytic tumor formation.

5-(Prop-2-yn-1-yl)-5H-dibenzo[b,f]azepine: ortho-rhom-bic polymorph

In the title ortho-rhom-bic polymorph (space group Iba2), C17H13N, the dihedral angle between the benzene rings is 55.99 (10)° and the azepine ring adopts a boat conformation. In the crystal, mol-ecules are linked by C-H⋯π contacts. The previously-reported polymorph [Yousuf et al. (2012 ▶). Acta Cryst. E68, o1101] crystallizes in the monoclinic system (space group P21/c) with two mol-ecules in the asymmetric unit.

Ethyl 2-cyano-5-oxo-5-(thio-phen-2-yl)-3-(3,4,5-trimeth-oxy-phen-yl)penta-noate

In the title compound, C21H23NO6S, the dihedral angle between the thio-pene and benzene rings is 88.66 (6)°. In the crystal, mol-ecules are connected by C-H⋯N and C-H⋯O hydrogen bonds, forming a tape along [10-1]. In addition, C-H⋯π and π-π stacking [centroid-centroid distance = 3.879 (2) Å between the thio-phene rings] inter-actions are observed.

1-(2-Fluoro-phen-yl)-3-(2,4,6-trimeth-oxy-phen-yl)prop-2-en-1-one

In the title compound, C₁₈H₁₇FO₄, the dihedral angle between the aromatic rings is 32.29 (8)°. The C atoms of the meth­oxy groups deviate from their attached ring plane by 0.018 (2), −0.006 (2) and −0.094 (2) Å. In the crystal, C—H⋯O hydrogen bonds link the mol­ecules into C(6) [001] chains.

2-(4-Chloro-phen-yl)-6-methyl-4-(3-methyl-phen-yl)quinoline

In the title compound, C(23)H(18)ClN, the dihedral angles between the quinoline unit and the chloro-benzene and methyl-benzene rings are 2.57 (9) and 56.06 (9)°, respectively. The crystal structure is stabilized by π-π inter-actions [minimum ring centroid separation = 3.733 (2) Å].

Carotid Stump Syndrome: Outcome from Surgical Management

OBJECTIVES

in patients with occluded internal carotid arteries the carotid stump is a potential source of microemboli resulting in the persistence of retinal or cerebral ischaemic symptoms. We report 25 patients who had persistent cerebral and retinal ischaemic symptoms with an occluded ipsilateral ICA and a carotid stump who underwent surgical exclusion of the stump.

METHODS

between January 1988 and January 1998, 332 patients underwent carotid endarterectomy. Twenty-five patients (20 males: five females; mean age 58.9 (range 44-78 years)) had carotid stump exclusion. Indications for surgery were transient ischaemic attack (22), amaurosis fugax (eight) and cerebrovascular accident (13). Three patients had undergone contralateral carotid endarterectomy and 12 had significant contralateral stenosis. Twenty patients were being treated with aspirin and four with warfarin at the time of presentation.

RESULTS

the diagnosis of carotid stump was made in 22 patients by angiography. In the remaining three patients duplex alone was diagnostic in two patients. In the third case duplex was combined with magnetic resonance angiography (MRA) to confirm the diagnosis. Stump exclusion was carried out by oversewing the ICA origin. All but one patient remained symptom free at follow-up.

CONCLUSION

carotid stump syndrome should be considered as a likely clinical entity in patients with an occluded ICA and persisting cerebral and retinal microembolic symptoms. Surgical exclusion of the carotid stump is a safe and effective method of treatment.

Nerve injury induces a rapid efflux of nitric oxide (NO) detected with a novel NO microsensor

An early step in repair of the leech CNS is the appearance of endothelial nitric oxide synthase (eNOS) immunoreactivity and NOS activity, but coincident generation of NO at the lesion after injury has not been shown. This is important because NO can regulate microglial cell motility and axon growth. Indirect measurement of NO with the standard citrulline assay demonstrated that NO was generated within 30 min after nerve cord injury. A polarographic NO-selective self-referencing microelectrode that measures NO flux noninvasively was developed to obtain higher spatial and temporal resolution. With this probe, it was possible to demonstrate that immediately after the leech CNS was injured, NO left the lesion with a mean peak efflux of 803 +/- 99 fmol NO cm(-2) sec(-1). NO efflux exponentially declined to a constant value, as described through the equation f(t) = y(o) + ae(-t/tau), with tau = 117 +/- 30 sec. The constant y(o) = 15.8 +/- 4.5 fmol cm(-2) represents a sustained efflux of NO. Approximately 200 pmol NO cm(-2) is produced at the lesion (n = 8). Thus, injury activates eNOS already present in the CNS and precedes the accumulation of microglia at the lesion, consistent with the hypothesis that NO acts to stop the migrating microglia at the lesion site.