Characterization of binding sites for sulfadimethoxine and its major metabolite, N4-acetylsulfadimethoxine, on human and rabbit serum albumin.

In order to gain an understanding of protein binding of sulfadimethoxine (SDM) and its major metabolite, N4-acetylsulfadimethoxine (N4-AcSDM), the binding of SDM and N4-AcSDM to human and rabbit serum albumin (HSA and RSA) was investigated using circular dichroism (CD), fluorescence and dialysis techniques. The CD spectral characteristics of the compounds bound to the albumins suggested that the drug-binding sites on the HSA and RSA had somewhat different asymmetries. The binding constants for SDM-HSA and -RSA interaction were smaller than those for N4-AcSDM. Two specific drug-binding sites were found on RSA, similarly to HSA, from the results of competitive displacement using fluorescence probes. Moreover, SDM and N4-AcSDM were found to share the same first binding site on the albumins. It can be presumed from the displacement data with a series of p-aminobenzoates that the characteristics of the binding sites (such as depth and width of the hydrophobic cleft) for SDM and N4-AcSDM on RSA may be almost the same, but the characteristics of these drug-binding sites on HSA may be somewhat different.

Inflammatory disease of the colon: ulcerative colitis and Crohn's colitis.

Ulcerative colitis differs from Crohn's colitis in several ways. In ulcerative colitis the disease is limited to the mucosa and, occasionally, the submucosa; Crohn's colitis may involve all layers of the large intestine. Ulcerative colitis almost always begins in the rectum, is diffuse, and spreads proximally. Crohn's colitis may spare the rectum and has a patchy distribution. Perianal fistulas and ulcers are rare in ulcerative colitis but are common in Crohn's colitis. Granulomas and giant cells are not found in ulcerative colitis but are seen in the majority of patients with Crohn's colitis. Colonic and extraintestinal symptoms in the two illnesses may be indistinguishable but growth failure is far more severe in Crohn's colitis and may precede intestinal symptoms by months to years. Cancer of the colon is a risk in patients with either ulcerative or Crohn's colitis but is far more common in the former. It is important to distinguish between ulcerative colitis and Crohn's colitis because response to treatment and prognosis are different. Although neither condition can be cured by medical management, patients with ulcerative colitis may respond more frequently. Unfortunately, in the pediatric age range most cases of ulcerative and Crohn's colitis may be classified as moderate to severe. Fortunately for patients with ulcerative colitis, total colectomy with ileostomy will result in cure of illness. Patients with Crohn's colitis who require surgery may obtain remission of symptoms, but the disease is likely to recur in the small intestine.

[Pyrazolic sulfanilamides. XIV. Hydroxyderivatives of 1-phenyl-5-sulfanilamidopyrazole and of 1-phenyl-3-methyl-5-sulfanilamidopyrazole]. / Sulfanilammidi pirazoliche. XIV. Idrossiderivati dell'1-fenil-5-sulfanilammmidopirazolo e dell'1-fenil-3-metil-5-sulfanilammidopirazolo

A report is given of the variations in bacteriostatic activity on introduction of a hydrophilic group, the hydroxyl group (-OH), at positions 2',3' and 4' of the phenyl group linked to the heterocyclic nitrogen os 1-phenyl-5-sulfanilamidopyrazole (I: R = -H) and of 1-phenyl-3-methyl-5-sulfanilamidopyrazole (II: R = -H). The substances prepared for this purpose: 1-(hydroxyphenyl)-5-sulfanilamidopyrazoles (Ia)(Ib))(Ic)(-OH at 2', 3',4') and 1-(hydroxyphenyl)-3-methyl-5-sulfanilamidopyrazoles (IIa)(IIb)(IIc)(-OH at 2',3'4') in vitro tests of bacteriostatic activity against strains of S. aureus and E. coli gave the following results: See journal for results.