Search PubMed⌕ Search

Biomedical subjects

A Gross

Publications and source records attributed to A Gross.

At least 181 records · Page 10Linked to original sources
PubMed1983

The use of shunts in patients undergoing bilateral carotid endarterectomies. Help or hindrance.

A retrospective study was undertaken to help assess the influence of shunting or nonshunting in the performance of bilateral, staged carotid endarterectomies. During the years 1969 to 1979, 323 consecutive patients underwent 646 staged, bilateral carotid endarterectomies. The indications included 271 patients (83.5%) with hemispheric and nonhemispheric findings and 52 patients (16.5%) who were asymptomatic. Thirty-six patients had sustained a previous stroke. General endotracheal anesthesia and systemic heparinization were used in all operations. An indwelling shunt was used in 485 (75.1%) endarterectomies whereas 161 operations (24.9%) were done without a shunt, reflecting the surgeons' routine preferences rather than specific criteria of selection. There were 30 (4.6%) neurologic events in 29 patients. Five patients died, representing an operative mortality of 1.5 per cent. Neither carotid occlusion time, interval between operation, nor severity of extracranial occlusive disease correlated significantly with the occurrence of postoperative stroke. An analysis of the neurologic deficits revealed 27 in the shunted group (5.5%) and three in the nonshunted group (1.8%). Results of this study showed that shunting cannot be relied upon to decrease the risk of neurologic deficit and that superior results may be obtained without an indwelling shunt in performing carotid endarterectomy.

Adult↗
PubMed1982

Flow in coronary artery bypass grafts to totally and partially occluded left anterior descending coronary arteries.

Flow was determined by electromagnetic flowmeter in vein bypass grafts in 20 patients with a totally occluded left anterior descending (LAD) coronary artery and on 61 patients with a partially occluded LAD. The median flow in LAD grafts was 14.5 ml/min with total LAD occlusion, and 40 ml/min with partial LAD occlusion (p less than 0.001). In cases of total LAD occlusion, the presence of mild or moderate anteroseptal wall dysfunction was associated with more satisfactory flow than was the case with severe anteroseptal wall dysfunction (p less than 0.02). Flows over 25 ml/min were found only when the LAD distal to total occlusion was 1.5 mm or greater. Unsatisfactory flows were consistently found with total LAD occlusion, poor ventricular function, and a distal LAD less than 1.5 mm. Repeat catheterizations to determine an unsatisfactory patency rate under these conditions would be necessary to alter our policy of grafting all suitable vessels beyond a total occlusion.

Coronary Artery Bypass↗
PubMed1981

Fracture of the atlas associated with fracture of the odontoid process.

A case of burst fracture of the atlas associated with a type II fracture of the odontoid is presented. In this instance no atlanto-axial instability was detected clinically. Treatment consisted of 1 week of rest in bed followed by 3 months in a collar. Management, though conservative, resulted in full recovery.

Adult↗
PubMed1981

Elevation of voice volume in young developmentally delayed children via an operant shaping procedure.

Unusually low voice volume was identified by teachers as a significant impediment to the academic and social progress of two preschool students. A simple operant shaping procedure was conducted by teachers to increase voice volume using a voice-activated apparatus with attractive visual display. Setting generalization of volume increases to the classroom was achieved and maintained at one- and four-month follow-ups.

Behavior Therapy↗
PubMed1980

Use of the carbon dioxide laser in sterilization of endodontic reamers.

The object of this study was to test a new method of sterilizing endodontic instruments by using a carbon dioxide laser system. This was done by contaminating endodontic reamers with spores, exposing them to a CO2 laser beam, and checking for their viability by standard microbiologic techniques. It was found that 100 percent of the spores were killed by the CO2 laser. This holds promise as an effective method of sterilizing endodontic instruments in the future.

Bacillus subtilis↗
PubMed1980

Immunoglobulins in periodontal tissues. II. Concentrations of immunoglobulins in granulation tissue from pockets of periodontosis and periodontitis patients.

In recent years evidence in the literature has indicated that the immune response may play an important role in the initiation and progression of the periodontal diseases. A study was initiated to determine the IgA, IgG, and IgM concentrations in the granulation tissue removed from deep infrabony pockets of patients with periodontosis and advanced periodontitis. Comparison of mean immunoglobulin levels between the periodontosis and periodontitis groups revealed a statistically significant increase (P less than 0.05) for IgG in the granulation tissue from the periodontosis group. The possible implications of these findings are discussed.

Adolescent↗
PubMed1980

Immunoglobulins in periodontal tissues. III. Concentrations of immunoglobulins in dilantin-induced and idiopathic gingival hyperplastic tissues.

Immunoglobulin levels in both Dilantin-induced and idiopathic hyperplastic gingiva were determined and compared with the concentrations in normal gingival tissue. A statistically significant increase in IgG was found in Dilantin hyperplastic tissue, but no significant difference could be shown for idiopathic gingival hyperplasia. IgA levels did not differ significantly in the three types of tissue assayed. IgM was detected in 90% of the Dilantin hyperplastic gingival specimens assayed (mean GI = 1.2) and in 75% of the idiopathic hyperplastic tissue (mean GI = 0.7). This incidence of IgM detection was higher than that reported for normal and inflamed gingiva from periodontitis patients. The significance of these findings and possible correlation with the degree of tissue inflammation are discussed.

Adolescent↗
PubMed1980

Understanding visual metaphor: developmental and individual differences.

The development of an instrument--the Metaphoric Triads Task (MTT)--for the assessment of metaphoric comprehension is described. In the tradition of earlier cognitive-style research, a visual triad format was adopted that offered three possible pairings of pictorial stimuli, one of which was metaphorical in character. A subject's score reflects the number of metaphoric pairings formed (with appropriate metaphoric explanations) across all of the triads of the task. Data are reported for 12 samples of subjects (ranging from 7 1/2 to 28 years of age) who responded to the MTT in a diverse array of studies. Internal analyses of the MTT yielded satisfactory reliabilities (interjudge and internal consistency) and item-sum correlations. Sex differences were negligible, but progressive improvement in MTT score with age was noted. At the same time, a slight modification of the MTT triad format generated performance levels from younger children that approximated those of children 1--3 years older who had taken the MTT in its standard form. Higher MTT scores were generally obtained by those subjects who attempted more pairings, spent more time at the task, and chose the metaphoric pair as "best" among the alternative pairing possibilities. Correlations of MTT performance with standardized tests of intellective aptitudes and achievements were inconsistent across samples and between the sexes within samples. In contrast, MTT scores were quite consistently related to solving difficult analogies, generating high-quality responses to divergent-thinking tasks, and manifesting broad categorizing and physiognomic sensitivity. Significant correlations between the MTT and a set of verbal metaphoric triads offered convergent validational evidence suggestive of a general metaphoric style. Some relation was found between MTT performance and teacher ratings of figurative language appreciation and esthetic sensitivity, though it appeared that these might be mediated by the teachers' estimate of the child's overall capability. Finally, three experimental training studies were carried out. A requirement of exhaustive pairing and informative feedback on pretest items significantly enhanced the MTT performance of the younger children. The provision of appropriate verbal labels for each picture in a triad also significantly enhanced performance by insuring that children's encoding of the pictures was consistent with the metaphoric linkage in each item.

Adolescent↗
PubMed1979

Investigations with bioactivated polymethylmethacrylates.

Compound bone cement on a PMMA base with an additive of bioactive glass ceramic particles in different portions and different particle sizes are tested in animal experiments. The tissue reactions to extracorporal polymerized specimens and to in situ polymerized specimens are observed. The experiments with an implantation period up to six months demonstrate a tight bonding between the newly formed osseous tissue and the glass ceramic particles at the interface. The inflammatory reactions in the vicinity of the implant are small. It is the objective of the investigations to improve the adherance of the bone cement at the interface to achieve a more durable anchorage of bone cement in the tissue.

Animals↗