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Biomedical subjects

A Schulman

Publications and source records attributed to A Schulman.

At least 19 recordsLinked to original sources
PubMed1994

Regional changes in amino acid levels of the neonate rat brain during anoxia and recovery.

The aim of this study was to compare the changes in amino acids (alanine, aspartate, GABA, glutamate, glutamine, glycine, serine taurine) that are produced in different regions of the neonate brain (telencephalon, diencephalon cerebellum, brain stem) following a survivable period of anoxia and after the re-establishment of air respiration. Anoxia provoked different responses in the different regions. The changes during the anoxic period were as follows. In the brain stem there was a decrease in aspartate, in the telencephalon there was a significant increase in GABA and alanine and a decrease in aspartate, in the diencephalon, glutamate and GABA increased, and in the cerebellum, glycine and alanine levels were enhanced. The changes during recovery were even more dissimilar. Here the greatest shifts were seen in the brain stem with increases in glutamine, GABA, aspartate, glycine, serine, alanine, and taurine. In the telemcephalon glutamate fell and alanine increased, in the diencephalon GABA increased, and in the cerebellum, glutamate fell while glycine and alanine increased. In none of the major brain regions did the pattern of changes in neurotransmitters correspond to that seen in anoxic tolerant species.

Amino Acids↗
PubMed1994

A comparison of the apical seals achieved using retrograde amalgam fillings and the Nd:YAG laser.

The purpose of this in vitro study was to compare the apical seals achieved using retrograde amalgam fillings or the Nd:YAG laser. Freshly extracted teeth were randomly separated into groups that would have their apices treated either with a Nd:YAG laser or retrograde amalgam. After instrumentation and obturation, bacterial reservoirs were prepared in the coronal portion of canals. Teeth to receive retrofillings had their apices prepared and amalgams placed. Teeth to be lasered had no apical preparations. Teeth and culture media were then sterilized by irradiation. Streptococcus salivarius was deposited in the opened bacterial reservoirs. At intervals, culture media with an indicator in culture chambers was observed for color change. Specimens that demonstrated color change were cultured for S. salivarius. Under the conditions of this in vitro study, no statistically significant difference was found in bacterial leakage between the laser-treated group and the retrograde amalgam group.

Apicoectomy↗
PubMed1994

[Crisis intervention and requests for organ donation--impossible to reconcile?].

A request for organ donation after a patient's death imposes a strong emotional impact both on the family and on the medical staff. How well the family copes with the loss of a close relative is subject to a variety of factors including the immediate emotional support provided by the staff. On the other hand, a donation request, if made with sensitivity, may in combination with adequate psychological support facilitate the grieving process. Health care professionals need emotional support and training to help them deal with the difficulties of caring for bereaved families, of breaking bad news, and of making organ donation requests.

Crisis Intervention↗
PubMed1991

A compressive strength study of complete ceramic crowns. Part II.

The original study by this group compared the crushing strength of Cerestore crowns with porcelain-fused-to-metal crowns and porcelain jackets. Since that time, two porcelains, Dicor and Renaissance, have become available. This study compares Cerestore, Dicor, and Renaissance crowns using a porcelain-fused-to-metal crown as a standard for the type of crown with maximum strength that is currently available and an all-porcelain crown to represent the porcelain with the least strength. All of the methods used in the first study were used again. The results demonstrated that these new porcelains have strengths that make them questionable for routine use in every posterior crown situation.

Aluminum Oxide↗
PubMed1991

Tarnish of dental alloys by oral microorganisms.

Five dental alloys, on exposure to blood and chocolate media with and without inoculated microorganisms, showed varying degrees of tarnish. The results indicated a composition-dependent tarnish behavior of alloys in microorganism-inoculated media, indicating a potential role for the oral microorganisms in inducing clinically observed tarnish of dental alloys. Actinomyces viscosus and periodontal pocket specimens show a similarity in their activity to induce tarnish in base metal-containing dental alloys.

Actinomyces viscosus↗
PubMed1990

Interactive effects of etching and pre-oxidation on porcelain adherence to non-precious alloys: a guided planar shear test study.

Interactive effects of etching and pre-oxidation on porcelain adherence to non-precious alloys were studied by a guided planar shear bond test under non-cantilever conditions. The results indicated that electrolytic etching decreases bond strength, but that oxidation of etched surfaces restores the bond strength level. The results are explained by a hypothesis that depletion of critical elemental species occurs during etching. Potential replenishment of the lost elements during subsequent oxidation, although not confirmed, may assist in improving bond strength.

Acid Etching, Dental↗
PubMed1990

Establishment of an implant selection protocol for predetermined success.

Previously, implant selection was confined to radiographs and to plastic implant templates for evaluation of existing bone. The aim of this study was to determine implant support areas in a compressive mode and to establish a standard via an implant selection protocol. Successful implant selection, regardless of the device design, is relevant to a patient's muscular efficiency and implant support values based on bone quality and size of prescribed bridge. The compressive areas of support, in mm2, of 15 implant designs were computer-analyzed and graph-evaluated. Major/minor diameters and the lengths of screws and cylindrical types of devices were calculated. In addition, the length, width, vents, and any lateral support areas of blade types were recorded. Average muscular force data, provided by clinical transducer studies, and literature reports of the mechanical properties of trabecular bone were correlated with computer bone analyses. These studies determined the quality of maxillary and mandibular bone to be 10 MPa and 15 MPa, respectively. Results indicated that four-unit bridges, at 50 lbs of applied force, require an area 31.14 mm2 of implant support in a compressive mode in the maxilla, and a support area of 20.76 mm2 in the mandible. Five-unit bridges require 40.84 mm2 in the maxilla and 27.23 mm2 for the mandible, because of the moment force, or torque, on the implant. Findings indicated that by determining: (1) the patient's muscular efficiency at implant sites (quantifying dynamic values of the forces and moments on implants supporting functioning bridges); (2) implant support values based on the compressive strength of the cancellous bone at implant sites; and (3) the size of the prescribed bridge, it is possible for the success (or failure) of a selected implant to be predetermined.

Alveolar Process↗
PubMed1987

The 'amputated right colon'--a diagnostic pitfall on barium enema examination. A report of 6 cases.

Six patients had strictures of the right colon not causing clinical obstruction. The strictures did not fill during barium enema tests resulting in the 'amputated' proximal right colon mimicking the caecum and/or terminal ileum. Positive caecal identification relies on terminal ileal and appendiceal filling. In 4 patients, a barium follow-through study, performed immediately after a barium enema allowed quick and safe identification of a proximal colonic stricture.

Adult↗