Some aspects of protein folding.

The mechanisms by which a polypeptide chain reaches the three dimensional structure which generates its functional properties are not yet totally understood. The great amount of data now available in the field of protein structure and the data already obtained on protein folding by in vitro experiments allow some schematic representation as, at least, a working hypothesis. In this respect the emphasis is put on the hierarchy in protein structure and the possibility of a folding by stages, some elements or "building blocks" being able to reach independently a native structure and to refine this structure by interacting with each other in the whole molecule.

Dependence upon pH of steady-state parameters for the beta-galactosidase-catalysed hydrolyses of beta-D-galactopyranosyl derivatives of different chemical types.

The effect of pH upon the beta-galactosidase-catalyzed hydrolyses of aryl galactosides is essentially similar for each of the three steps of their hydrolysis. It differs markedly from that on the hydrolysis of galactosyl pyridinium salts; these proceed through a 'non-bottleneck' pathway. While pH increase abolishes the rate of every step of the reaction for aryl galactosides, it favors the first step of hydrolysis of the galactosyl pyridinium salts, which supports the hypothesis that catalysis of these compounds originates largely in non-covalent interactions.

Functional properties of beta-galactosidase from mutant strain 13 PO of Escherichia coli.

The functional properties of CZP protein, a mutant deriving from wild-type beta-galactosidase (beta-D-galactoside galactohydrolase; EC 3.2.1.

Conformational adaptability of the active site of beta-galactosidase. Interaction of the enzyme with some substrate analogous effectors.

The action of different effectors, glycosides, and alcohols on the reactions catalyzed by beta-galactosidase is analyzed in this paper. Effectors as large as tri- and tetrasaccharides have no effect on the enzyme activity, suggesting that the binding site has rather small size. Most of the beta-galactosides produce a competitive inhibition.

Evaluation of the Gravlee Jet Washer using combined cell block/cytologic interpretations.

Two hundred patients at high risk for endometrial adenocarcinoma were screened using the Gravlee Jet Washer. Tissue obtained from the first 100 patients was processed by cell block technic alone; tissue from the second 100 patients was processed by cell block plus direct smear and Nucleopore filtration stained by the Papanicolaou method. All patients had histologic diagnosis by fractional curettage.

Granulomatous hepatitis, increased platelet aggregation, and hypercholesterolemia.

Two young patients presented with an unusual liver disease, granulomatous hepatitis with postnecrotic cirrhosis, and both underwent a splenorenal shunt procedure. Each developed an arterial embolic episode probably related to increased platelet aggregation. This represents the first report of a liver disease associated with increased platelet aggregation that was clinically significant, a myocardial infarction in one and a posterior cerebral infarction in the other.

Binding of nucleotides ATP and ADP to sarcoplasmic reticulm: study by rate of dialysis.

Binding of the nucleotides ATP and ADP by preparations of sarcoplasmic reticulum was investigated by the method of flow dialysis. For ATP, experimental data could not be analyzed directly in terms of binding since a significant though small amount of hydrolysis could be observed even in presence of EDTA. ADP binding could be analyzed and gave a dissociation constant of 10-20 muM at neutral pH, and a stoichiometry of 0.

An uncontrolled comparison of treatments for achalasia.

A series of 78 patients with achalasia, seen during a 10-year period, was like those reported by others with regard to age at onset, nature of symptoms, and duration of symptoms. Analysis of the results of 5 different treatment modalities administered allows an uncontrolled comparison heretofore not available from an institution at which no one treatment was favored over all others. Those who were not treated or who received only anticholinergic medication did not become asymptomatic.

Resonance Raman spectroscopic studies of the interactions between trypsin and a competitive inhibitor.

Raman spectroscopy was used to study the interactions between bovine trypsin and a competitive inhibitor. For this purpose, a chromophoric substrate analogue, 4-amidino-4'-dimethylamine azobenzene, was synthesized. This compound competitively inhibits the enzyme with a 1:1 stoichiometry and an inhibition constant Ki of 2.

Adenosis and adenocarcinoma of the vagina in young women: a review.

Prior to 1971, adenosis and primary adenocarcinoma of the vagina were unusual entities. Since then, a marked increase in both processes has occurred, felt to be related to maternal ingestion of Diethylstibestrol (DES) and other estrogenic compounds during the first trimester, with subsequent abnormalities in female offspring. To date, there are over 170 cases of adenocarcinoma reported, and there may be as many as one million patients with adenosis.