Biomedical subjects

R Zurcher

Publications and source records attributed to R Zurcher.

3 recordsLinked to original sources

PubMed1993

Primary mediastinal masses. A comparison of adult and pediatric populations.

Since 1944 62 pediatric patients with primary cysts and tumors of the mediastinum have been operated on at our institution. We compared this group with 195 adult patients with similar diagnoses who were operated on during this period. Comparisons were made with regard to histologic type, location, presenting symptoms, physical findings, and surgical complications. We found significant increases in the prevalence of lymphoma in adults (41/195 versus 4/62, p < 0.05) and of neurogenic tumors in children (21/62 versus 24/195, p < 0.05). There were no significant differences in the prevalence of thymic tumors (51/195 versus 22/62), germ cell tumors (24/195 versus 4/62), and cysts (32/195 versus 15/62). There was no difference in the prevalence of symptomatic patients (99/195 versus 36/62). The prevalence of malignancy has increased in both groups since 1970 (2/28 versus 16/34 in children, p < 0.01; and 14/56 versus 69/139 in adults, p < 0.05). This is attributed to a rise in the prevalence of malignant neurogenic tumors in children and to an increase in the prevalence of lymphomas in adults. Tumor size, location, and the presence of symptoms were predictive of malignancy in the adult population but not in the pediatric population. No difference existed in mortality and morbidity between the two groups. All three pediatric deaths were directly related to loss of airway control as a result of mass effect from the tumor. Definite differences exist between the adult and pediatric populations with regard to mediastinal tumors. These differences need to be considered carefully when evaluating and planning treatment for a child with a mediastinal mass.

Adolescent↗

PubMed1992

Vascular ring: does magnetic resonance imaging replace angiography?

The records of 21 patients who underwent operation for symptoms attributable to vascular ring were reviewed. The study covered 33 years, 1958 to 1991, and the mean follow-up was 6.8 years. The patients ranged from 7 days to 26 years old with a mean age of 2.9 years. Twenty patients were symptomatic. Symptoms were due to tracheal compression in 16 patients, esophageal compression in 2, and both causes in 2. During the first 30 years, chest roentgenography, barium swallow, and aortography constituted the diagnostic workup in the majority of the patients. During the last 3 years, magnetic resonance imaging replaced aortography. The surgical diagnosis included five variants of vascular ring. The surgical approach consisted of left thoracotomy in 19 patients and right thoracotomy in 2. These 2 had the diagnosis of right aortic arch with posterior left subclavian artery. In both instances, preoperative angiographic data determined the surgical approach. Barium swallow may be sufficient for the diagnosis of vascular ring; however, additional data are useful in determining the surgical approach. Magnetic resonance imaging can yield accurate data without subjecting the patient to the risks associated with angiography.

Adolescent↗

PubMedDate not supplied

The validity and comparability of entrance examination scores after accommodations are made for students with LD.

Every year, thousands of college and university applicants with learning disabilities (LD) present scores from standardized examinations as part of the admissions process for postsecondary education. Many of these scores are from tests administered with nonstandard procedures due to the examinees' learning disabilities. Using a sample of college students with LD and a control sample, this study investigated the criterion validity and comparability of scores on the Miller Analogies Test when accommodations for the examinees with LD were in place. Scores for examinees with LD from test administrations with accommodations were similar to those of examinees without LD on standard administrations, but less well associated with grade point averages. The results of this study provide evidence that although scores for examinees with LD from nonstandard test administrations are comparable to scores for examinees without LD, they have less criterion validity and are less meaningful for their intended purpose.

Adolescent↗