1,346 research outputs found
Insulin as a Primary Autoantigen for Type 1A Diabetes
Type 1A diabetes mellitus is caused by specific and progressive autoimmune
destruction of the beta cells in the islets of Langerhans whereas the other cell
types in the islet (alpha, delta, and PP) are spared. The autoantigens of Type
1A diabetes may be divided into subgroups based on their tissue distributions:
Beta-cell-specific antigens like insulin, insulin derivatives, and IGRP (Islet-specific
Glucose-6-phosphatase catalytic subunit Related Peptide); neurendocrine antigens
such as carboxypeptidase H, insulinoma-associated antigen (IA-2), glutamic acid
decarboxylase (GAD65), and carboxypeptidase E; and those expressed
ubiquitously like heat shock protein 60 (a putative autoantigen for type 1 diabetes).
This review will focus specifically on insulin as a primary autoantigen, an essentia
l target for disease, in type 1A diabetes mellitus. In particular, immunization with
insulin peptide B:9-23 can be used to induce insulin autoantibodies and diabetes
in animal models or used to prevent diabetes. Genetic manipulation of the insulin
1 and 2 genes reciprocally alters development of diabetes in the NOD mouse,
and insulin gene polymorphisms are important determinants of childhood
diabetes. We are pursuing the hypothesis that insulin is a primary autoantigen
for type 1 diabetes, and thus the
pathogenesis of the disease relates to specific recognition of one or more peptides
CT and ultrasonographic findings in jugular vein ectasia.
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/135231/1/jum198439417.pd
(E)-2-[(2-Hydroxy-5-nitrophenyl)iminiomethyl]-4-nitrophenolate
The title molecule, C13H9N3O6, consists of a 2-hydroxy-5-nitrophenyliminio group and a 4-nitrophenolate group bonded to a methylene C atom with both of the planar six-membered rings nearly in the plane of the molecule [dihedral angle = 1.3 (4)°]. Each of the nitro O atoms is twisted slightly out of the plane of the molecule. The amine group forms an intramolecular hydrogen bond with both nearby O atoms, each of which has partial occupancy of attached H atoms [0.36 (3) and 0.64 (3)]. An extended π-delocalization throughout the entire molecule exists producing a zwitterionic effect in this region of the molecule. The shortened phenolate C—O bond [1.2749 (19)°], in concert with the slightly longer phenol C—O bond [1.3316 (19) Å], provides evidence for this effect. The crystal packing is influenced by extensive strong intermolecular O—H⋯O hydrogen bonding between the depicted phenolate and hydroxy O atoms and their respective H atoms within the π-delocalized region of the molecule. As a result, molecules are linked into an infinite polymeric chain diagonally along the [110] plane of the unit cell in an alternate inverted pattern. A MOPAC AM1 calculation provides support for these observations
Phosphorus recovery: a need for an integrated approach
Increasing cost of phosphate fertilizer, a scarcity of high quality phosphate rock (PR)and increasing surface water pollution are driving aneed to accelerate the recovery and re-use ofphosphorus (P) from various waste sectors. Options to recover P occur all along the open P cycle from mining to households to oceans. However, P recovery as a regional and global strategy towards P sustainability and future food, bio energy and water security is in its infancy because of a number of technological, socio-economic and institutional constraints. There is no single solution and resolving these constraints requires concerted collaboration betweenrelevant stakeholders and an integrated approach combiningsuccessful business models withsocio-economic and institutional change. We suggest that an operational framework is developed for fast tracking cost-effective recovery options
(E)-2-[(2-Hydroxy-5-nitrophenyl)iminiomethyl]phenolate
In the title molecule, C13H10N2O4, the dihedral angle between the mean planes of the benzene and phenolate rings is 21.6 (4)°. The nitro O atoms are twisted slightly out of the plane of the ring to which the nitro group is attached [dihedral angle 8.4 (3)°]. The amine group forms an intramolecular hydrogen bond with both nearby O atoms. An extended π delocalization throughout the entire molecule exists producing a zwitterionic effect in this region of the molecule. The shortened C—O bond [1.2997 (15) Å] in concert with the slightly longer C—OH bond [1.3310 (16) Å] provide evidence for this effect. The crystal packing is influenced by strong intermolecular O—H⋯O hydrogen bonding. As a result, molecules are linked into an infinite zigzag chain running along the b axis. A MOPAC PM3 calculation provides support to these observations
[3-(5-Hydroxy-5H-dibenzo[a,d]cyclohepten-5-yl)propyl]dimethylammonium 3-carboxyprop-2-enoate
In the cation of the title salt, C20H24NO+·C4H3O4
−, the N atom in the dimethylammonium group is protonated. The dihedral angle between the mean planes of the two six-membered rings fused to the cyclohepten-5-yl ring is 54.4 (1)°. An intramolecular O—H⋯O hydrogen bond occurs in the anion. The crystal packing is stabilized by intermolecular O—H⋯O and N—H⋯(O,O) hydrogen bonds and weak C—H⋯O interactions, forming a two-dimensional network
Imatinibium dipicrate
In the crystal structure of imatinibium dipicrate [systematic name: 1-methyl-4-(4-{4-methyl-3-[4-(3-pyridyl)pyrimidin-2-ylamino]anilinocarbonyl}benzyl)piperazine-1,4-diium dipicrate], C29H33N7O2+·2C6H2N3O7
−, the imatinibium cation is protonated at both of the pyrimidine N atoms. Each of the two picrate anions interacts with the diprotonated cation through bifurcated N—H⋯O hydrogen bonds forming R
1
2(6) ring motifs. Also, an R
2
2(24) graph set is formed between the benzamidium –NH– group and the 4-pyridyl N atom interacting through N—H⋯N hydrogen-bond interactions. Additional weak C—H⋯Cg π-ring and π–π intermolecular interactions are observed which also influence crystal packing
N 1,N 2-Bis[(2-chloro-6-methylquinolin-3-yl)methylidene]ethane-1,2-diamine
The title molecule, C24H20Cl2N4, lies on an inversion center in an extended trans conformation. In the crystal, weak C—H⋯Cl interactions connect the molecules into chains along [010]
3-(2,6-Dioxopiperidin-3-yl)-3-azabicyclo[3.2.0]heptane-2,4-dione
The title molecule, C11H12N2O4, consists of a 3-azabicyclo[3.2.0]heptane group containing a nearly planar cyclobutane ring (r.m.s. deviation of fitted atoms is 0.0609 Å), fused to a pyrrolidine ring, bonded to a 2,6-dioxopiperidine ring at the 3-position. The angle between the mean planes of the cyclobutane and fused pyrrolidine ring is 67.6 (6)°. The dihedral angles between the mean planes of the pyrrolidine and cyclobutane rings and the dioxopiperidine ring are 73.9 (2) and 62.4 (4)°, respectively. The pyrrolidine and dioxopiperidine rings are twisted about the 3-yl group [torsion angles = −55.0 (1) and 115.0 (1)°] in a nearly perpendicular manner. Crystal packing is influenced by extensive intermolecular C—H⋯O and N—H⋯O interactions between all four carbonyl O atoms and H atoms from the cyclobutane and dioxopiperidine rings, as well as between the N atom and an H atom from the cyclobutane ring. In addition, weak π-ring interactions also occur between H atoms from the cyclobutane ring and the five-membered pyrrolidine ring. As a result, molecules are linked into infinite chains diagonally along the [101] plane of the unit cell in an alternate inverted pattern
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