Biomedical subjects

A Safavi

Publications and source records attributed to A Safavi.

21 records · Page 2Linked to original sources

PubMed1994

A dramatic change in the interaction of Cu(II) with bio-peptides promoted by SDS--a model for complex formation on a membrane surface.

The extent of complex formation between Cu(II) and many biologically active oligopeptides has been shown to change significantly in the presence of SDS micelles, a recognized model for cell lipid membranes. Protonation constants of peptides can be increased by up to 2 log unit, especially when they contain hydrophobic side chains. Metal complex formation is generally less extensive and the conformations of peptides can be altered dramatically when compared to those in simple aqueous solution.

Amino Acid Sequence↗

PubMed1991

Anorectal surgery in the HIV+ patient: update.

Anorectal surgery in HIV+ patients historically has been viewed with a great deal of nihilism. Advances in medical therapy and better understanding of unique pathophysiologic processes have afforded the colorectal surgeon the ability to treat better and sometimes cure the anorectal complications of AIDS. We present a series of 75 consecutive surgical procedures (1-year accrual) on HIV+ (40) and CDC AIDS (22) patients. Surgical procedures, perioperative T cell counts, and outcome will be presented; 53 percent of procedures resulted in complete healing of anal wounds; 30 percent resulted in partial healing with symptomatic relief; 17 percent resulted in symptomatic relief or tissue diagnosis without appreciable wound healing. The healing rate was significantly higher in the HIV+ group (69 percent) compared to the AIDS group (26 percent). Perioperative T cell counts did not have predictive value on outcome. No patients suffered significant unexpected morbidity, mortality, or incontinence. Pathophysiologic mechanisms of several disease processes unique to HIV+ patients and data from our ongoing investigation using RNA hybridization are presented.

Acquired Immunodeficiency Syndrome↗

PubMedDate not supplied

Flow injection analysis of riboflavin with chemiluminescence detection using a N-halo compounds-luminol system.

A chemiluminescent method for the determination of riboflavin is described. The method is based on the chemiluminescence (CL) generated during the oxidation of luminol by N-bromosuccinimide (NBS) and N-chlorosuccinimide (NCS) in alkaline medium. It was found that riboflavin could greatly enhance this CL intensity when present in the luminol solution. Based on this observation, a new flow-injection CL method for the determination of riboflavin is proposed in this paper. The detection limits were 7.5 ng/mL and 3.5 ng/mL of riboflavin for the NBS- and NCS-luminol CL systems, respectively. The relative CL intensity was linear, with riboflavin concentration in the range 19-600 ng/mL and 600-2000 ng/mL for the NBS-luminol CL system, and 12-200 ng/mL and 200-2000 ng/mL for the NCS-luminol CL system. The results obtained for the assay of pharmaceutical preparations compared well with those obtained by the official method and demonstrated good accuracy and precision.

Bromosuccinimide↗