Improved computer-assisted nuclear imaging in renovascular hypertension.

Computer-assisted dynamic renal studies using both the 90 second 99mTc-DTPA and the conventional 30 minute 131I-Hippuran methods were performed in nine patients with angiographically proven renal artery stenosis. Time activity curves for both studies were derived from regions of interest selected from the computer-acquired dynamic images. The following parameters were used to assess renal blood flow: differential maximum activity, minimum/maximum activity ratio, and peak width.

Technetium-99m DTPA renal flow studies in Goldblatt hypertension.

Computer-assisted dynamic renal studies were performed on a group of 14 mongrel dogs before and after the induction of unilateral renal artery stenosis. Ninety-second technetium-99m diethylenetriaminepentaacetic acid ( [99mTc]DTPA), 15-min [99mTc]DTPA, and 30-min iodine-131 orthoiodohippurate ( [131I]hippuran) time-activity curves were analyzed and correlated with reduction of renal blood flow as measured by electromagnetic flow probe and PAH clearance techniques. Parameters of the 90-sec [99mTc]DTPA curves found to be significantly different for the same kidney before and after stenosis were: upslope, curve width at 75% maximum, maximum activity value, and differential (stenotic/contralateral) maximum activity ratio.

[New control technic for tooth mobility].

The method described, used to establish tooth mobility, is a refinement of the method of Mühlemann, 30 years old. The improvements include a larger sensitivity of the chain of measures, a better stabilizatiin of the intraoral fixatioin of the instruement, the utilization of a retainer on the tooth to be tested, which ensures the precision of the point of forcetesting. This point remains the same for all measurements.

[Removable partial denture. Excerpts from the literature 1977--1979].

In partial denture prosthesis research and advances were made principally on: -- the fundamental biomechanical properties of the demodont and the fibromucosa. In the light of these findings, the justification of stressbreaking as a principle is questioned -- the mechanical properties of chromium-cobalt alloys -- checking of castings by radiography -- simplification of the designs for removable partial denture frameworks -- impression materials and techniques (fluid-wax functional impression and altered cast-procedure) -- the combination of restauration and plaque control for successful dentistry.

Evaluation of alternative alloys to precious ceramic alloys. 1. Mechanical properties.

In the first part of this study, the microstructures and the mechanical properties of precious, semi-precious, and nonprecious dental casting alloys for the porcelain-baked-to-metal technique have been determined. The semi-precious alloys contained only 50% gold, and palladium, silver, and some base metals. The nonprecious alloys were of the nickel-chromium type.

Acute thrombotic thrombocytopenic purpura. Another cause for hemolytic anemia and thrombocytopenia in cirrhosis.

Severe hemolytic anemia and thrombocytopenia developed in a 56-year-old man with Laennec's cirrhosis. Rather than having one or more of the expected causes for these problems associated with cirrhosis, he proved to have acute thrombotic thrombocytopenic purpura. Treatment with platelet antiaggregant drugs and exchange plasmapheresis was ineffective in controlling the disease.

[Movements of the supporting teeth in Kennedy-Applegate class III and IV restorations].

Two types of restoration of the class III and two types of the class VI have been tested on a test bench. These restorations react differently to vertical forces than to oblique ones. The fixed bridge reacts best to vertical forces.

[Principles and indications for prosthetic restorations].

Once it has been explained and defined what a prosthesis and what the masticatory apparatus and its function are, the author defines the three principles of a prosthetic restauration: --Any prosthetic restauration should be conceived and realized only after a complete study of the odontostomatognathic system. --Any prosthetic restauration must reestablish the health of the masticatory apparatus. --Any prosthetic restauration must assist in the conservation of the remaining teeth.

[Comparative study of 3 irreversible hydrocolloids].

This study was realized: to determine the best manipulation of 3 alginates; to compare their dimensional stability; to compare their reproduction of detail; to evaluate, through these 3 criteria, the best of the 3 alginates. It seems necessary to point out that: The 3 examined alginates show a poor dimensional stability on account of the deformations produced during the setting time and the removal of the impression. The immediate pouring of the model gives the best results, because storing the impression is accompanied by dimensional changes.

[Experimental study of the value of 2 types of class III Kennedy-Applegate dentures].

This experimental research shows that a class III clasp partial dentures should present four Akers clasps. This way the occlusal rests are placed as closely as possible to the edentulous area on both sides of the arch and the abutment teeth are less stressed than if the occlusal rests are further away from saddles. On the other hand, a lingual bar of average rigidity i.

Accuracy of six elastic impression materials used for complete-arch fixed partial dentures.

1. The accuracy of four types of impression materials used to make a complete-arch fixed partial denture was evaluated by visual comparison and indirect measurement methods. 2.

Alcoholysis of medicinally active 5-aminodibenzo(a,d)cycloheptenes.

The rate constants for alcoholic solvolysis of the hydrochloride salts of diethylaminodibenzo(a,d)cycloheptene and related amino congeners were determined. The objective was a study of the comparative ease of cleavage of the C-N amino linkage by various aliphatic alcohols. The interaction of protonated amines of this series with alcoholic hydroxyls presumably leads to formation of the corresponding ethers in a manner somewhat analogous to alkoxide reaction with alkyl bromides.