[Clinicopathologic analysis of 34 patients with microscopic polyangitis].

OBJECTIVE: To study the clinicopathologic features of microscopic polyangitis (MPA), and to compare the differences in anti-neutrophil cytoplasmic autoantibody (ANCA)-positive and ANCA-negative patients, as well as in ANCA-positive cases with or without glomerular immunoglobulin deposition. METHODS: Thirty-four biopsy-proven cases of MPA were retrieved from the archival files of the Department during the past 7 years. The clinicopathologic characteristics between ANCA-positive and negative patients, as well as between ANCA-positive cases with and without glomerular immunoglobulin deposition, were compared. RESULTS: Amongst the 34 MPA patients studied, about one-fifth to one-half were accompanied by various extrarenal symptoms. Serum ANCA was positive in 26 patients (76.5%). A slight to moderate increase in urinary protein was demonstrated in 31 patients, while 3 patients had nephrotic syndrome. Elevated serum creatinine was detected in 32 cases. Renal biopsy revealed crescentic glomerulonephritis in 24 cases, focal segmental glomerulonephritis in 8 cases, vascular fibrinoid necrosis with inflammation in 7 cases, intimal thickening of arterioles in 24 cases, interstitial inflammatory cells, including neutrophil infiltration (21 cases), in 29 cases. Crescentic formation was more common in the ANCA-positive group than in the ANCA-negative group (P < 0.05). Amongst the 26 ANCA-positive cases, 10 had glomerular immunoglobulin deposits (including 1 case with IgA nephropathy). In general, these cases had a greater degree of proteinuria than those without glomerular immunoglobulin deposits (P < 0.05). CONCLUSIONS: The diagnosis of MPA relies on histologic examination of renal biopsy and clinicopathologic correlation. Serum ANCA seems important for glomerular crescent formation. Glomerular immunoglobulin deposition may also play a significant role in the exacerbation of proteinuria.

Shedding light on the interactions of guanine quadruplexes with tricationic metalloporphyrins.

G-quadruplex DNA presents a potential target for the design and development of novel anticancer drugs. The porphyrin TMPyP4 was early reported to be a suitable motif for G-quadruplex DNA interaction. We inserted various metal ions such as Zn(II), Cu(II), Co(III) in the center of the aromatic core of tricationic TMPyP4-like porphyrin and examined their interactions with an antiparallel G-quadruplex DNA by a combination of spectroscopy and Job plot methods. Porphyrin metallation allowed the conclusion that the presence of one axial ligand perpendicular to the aromatic plane did not hamper π-π stacking interactions between quadruplex and the aromatic parts of porphyrin on the other face while porphyrin with two axial ligands was unable to undergo such interaction due to geometrical factors. Free base porphyrin and porphyrin without axial ligands are able to stabilize the quadruplex structure to a greater extent than the other metal complexes and thus may be potential anti-cancer drugs.