Operative and postoperative choledochofiberoscopy.

Choledochofiberoscopy is effective for both diagnosis and therapy. It is a valuable diagnostic technic because it permits a definite diagnosis and it allows the surgeon to determine the operative method by direct viewing and by biopsy of the biliary tract wall. Choledochofiberoscopy is therapeutically valuable because it permits cleaning of the bile duct, the removal of retained or remnant stones in the common and intrahepatic ducts, and the removal of granuloma and benign tumor with forceps under direct vision.

Cell-mediated immunity to measles virus in subacute sclerosing panencephalitis.

Four patients with subacute sclerosing panencephalitis were investigated for their specific cellular and humoral immunities against measles virus. Lymphocytotoxicity mediated by peripheral blood lymphocytes was evaluated with the colony inhibition test of target cells having measles antigen. The lymphocytes from two patients of subacute sclerosing panencephalitis (SSPE) specifically destroyed the carrier cells; however, no significant lymphocytotoxicity was observed in the other two patients.

Effects of detergents on the conformation of Escherichia coli tRNA as measured by circular dichroism.

The effect of a cationic detergent, lauryl pyridiniumchloride (LPC), and an anionic one, sodium n-octylbenzenesulfonate (SOBS), on the conformation of unfractionated Escherichia coli tRNA was investigated at various molar ratios of detergent to tRNA (D/R) in the presence and absence of Mg2+ and Na+ ions by measuring the circular dichroism (CD) at 265 nm and 340 nm, which reflects conformational change involving base pairs and/or base stacking, and the disymmetry in the vicinity of 4-thiouridylate (4-TU), respectively. In the presence of Mg2+ and Na+ ions, the tRNA retains its native structure even in the presence of high molar ratios of detergent to tRNA (D/R congruent to 40 at 265 nm and D/R congruent to 20 at 340 nm). However, in the absence of these metal ions, the ellipticity at 340 nm was very sensitive to LPC concentration and decreased from 5,600 to nearly--1,600 at 25 degrees C with the increase of D/R ratios up to 20, and a similar decrease in the ellipticity at 340 nm was observed on thermal denaturation.

Interaction of diiodo-L-tyrosine and triiodophenol with bovine serum albumin. Circular dichroism and fluorescence studies.

As a model study to investigate the binding mechanism between thyroid hormones and carrier protein, the interaction of diiodo-L-tyrosine (DIT) and triiodophenol (I3phi) with bovine serum albumin (BSA) was investigated by circular dichroism (CD) and fluorescence methods. In both the DIT-BSA system and the I3phi-BSA system, induced Cotton effect was observed in the wavelength region near 320 nm. This induced Cotton effect was measured at various molar ratios of ligands to BSA (L/P).

Fluorescence polarization studies on the local conformation of yeast tRNA.

The effects of temperature and guanidine hydrochloride (GuHC1) on the fluorescence polarization of Y base in partially purified yeast phenylalanine tRNA (p.p.tRNAPhe) and in acriflavine conjugates of crude yeast tRNA were investigated to elucidate the stability of the conformation at the 3'-CpCpA terminus and the anticodon loop of tRNA.

The binding of thyroid hormones to bovine serum albumin as measured by circular dichroism.

The circular dichroism (CD) spectra of 3,5,3'-triiodothyronine-bovine serum albumin (T3-BSA) and thyroxine-bovine serum albumin (T4-BSA) complexes were measured at the various ratios of T3 or T4 to BSA (T/P) in the wavelength region of 200-350 nm. No spectral change was observed in the chromophoric wavelength region of 250-350 nm. The value of [omicron] at 319 nm of the induced Cotton effect increased with increase of the T/P ratio in both complexes, and in T4-BSA complex, it increased remarkably.