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Biomedical subjects

J A Curtis

Publications and source records attributed to J A Curtis.

30 records · Page 2Linked to original sources
PubMed1977

Malposition of the colon in right renal agenesis, ectopia, and anterior nephrectomy.

Right renal agenesis, ectopia, or anterior nephrectomy can be identified by a characteristic malposition of the right colon. Barium enemas show that the posterior portion of the right colic (hepatic) flexure occupies the area of the right renal fossa. This change in position of the right colon was not observed as a normal variant in 100 randomly selected patients but was present in each of eight patients with agenesis, ectopia, or anterior nephrectomy. This malposition should not be mistaken for internal hernia, malrotation, or displacement by tumor mass or organomegaly. Nonvisualization of the right kidney on excretory urography with normal position of the colon excludes agenesis or ectopia as diagnostic considerations.

Adult↗
PubMed1975

Fracture of the first rib as a complication of midline sternotomy.

Fracture of the first rib occurred in six patients after cardiac surgery through a midline sternotomy. Two of the fractures could not be seen on the chest films and were demonstrated only on oblique radiographs of the cervical spine. Symptoms simulating myocardial infarction and/or pulmonary embolism were present in three of the six cases. In a review of 50 randomly selected cases of midline sternotomy, first-rib fractures were found in 3(6%).

Adult↗
PubMedDate not supplied

Sequential changes in the CT numbers of the normal canine kidney following intravenous contrast administration. I. The renal cortex.

Using a 30-second computed tomography (CT) scanner, the sequential changes in CT numbers of the kidney were determined in three healthy dogs after intravenous administration of sodium and meglumine diatrizoate and iothalamate. For all contrast media, the mean CT number of the cortex was greatest within 2 minutes of rapid intravenous administration. At doses comparable to those used clinically, a linear relationship was demonstrated between the amount of iodine administered (in mg/kg body weight) and the corrected peak mean CT number of the cortex, such that doubling the amount of iodine caused the corrected peak mean CT number of the cortex to approximately double. Following the peak, the mean CT number of the cortex gradually declined. For all contrast media, the corrected mean CT number to corrected peak mean CT number ratios at 5, 10 and 20 minutes were 58 +/- 3%, 39 +/- 3%, and 28 +/- 5% respectively. Our data suggest that rapid-sequence CT may be a valuable tool for evaluating the physiology of renal contrast media excretion.

Animals↗
PubMedDate not supplied

CT-determined canine kidney and urine iodine concentration following intravenous administration of sodium diatrizoate, metrizamide, iopamidol, and sodium ioxaglate.

Following 24-hour fasting and fluid deprivation, sequential changes in CT numbers of the canine kidney were determined in 4 dogs, each of whom received, at intervals, IV sodium diatrizoate, metrizamide, iopamidol, and sodium ioxaglate at a dose of 500 mgI/kg body weight. The urinary bladder was catheterized for baseline determination of urine osmolality and, subsequently, urine volume and CT number, CT number of the bladder urine from 0 to 10 minutes and from 10 to 20 minutes post-injection was obtained by scanning known dilutions of urine in vitro. Peak renal cortical enhancement occurred within 2 minutes of bolus injection and was not dependent on the chemical make-up of the contrast agent. Peak medullary enhancement occurred within 3 minutes of bolus injection. Peak medulla CT number following sodium diatrizoate was significantly less than that following metrizamide (P less than 0.025) or iopamidol (P less than 0.01). Peak medulla CT number was significantly less following sodium diatrizoate (P less than 0.01), metrizamide (P less than 0.01) and iopamidol (P less than 0.05) than following sodium ioxaglate. Urine iodine concentrations followed a similar pattern, with significant differences as follows: sodium diatrizoate less than metrizamide = iopamidol less than sodium ioxaglate. It was concluded that the investigational agents metrizamide, iopamidol, and sodium ioxaglate have theoretical advantage for excretory urography. Differences in renal handling of these agents are detectable, with CT scanning as differences in renal medullary enhancement and urine iodine concentration.

Animals↗
PubMedDate not supplied

Successful use of problem-based learning in a third-year pediatric clerkship.

OBJECTIVE: To determine the effect of changing from lectures to a problem-based learning (PBL) curriculum on student knowledge accrual and satisfaction with the didactic portion of a clerkship. DESIGN: Study of cohorts before and after PBL introduction and in comparison with unchanged medicine clerkship. SETTING: Third-year pediatric clerkship at 5 clinical sites. PARTICIPANTS: The PBL curriculum was introduced in the 1996 academic year. The 2 classes before the intervention served as historic controls (n = 319), whereas the 2 classes after PBL served as the intervention group (n = 320). INTERVENTION: Small groups of students worked through 6 PBL cases representing common pediatric illnesses. MAIN OUTCOME MEASURES: Knowledge was assessed with the pediatric and internal medicine subject examination of the National Board of Medical Examiners (NBME); student satisfaction was assessed by an anonymous end-of-rotation questionnaire. RESULTS: Scores on the pediatric subject examination improved significantly from means of 69.2 and 70.0 in the historic control group to 73.6 and 74.2 in the PBL cohort (P <.01). Scores on the internal medicine subject exam during the same time periods remained unchanged until the second year after the change (69.1 and 70.2, respectively, before the change; 70.1 and 72.4, respectively, after the change). Analysis of variance results indicated a significant increase in pediatric subject examination scores associated with the introduction of PBL (P <.01). Overall student satisfaction with the pre-PBL lecture series was 3.3, whereas PBL sessions received a score of 4.3. CONCLUSION: Use of PBL in a clinical clerkship was associated with higher scores on the NBME subject examination and increased student satisfaction. These results should encourage the use of PBL during the clinical years.

Analysis of Variance↗
PubMedDate not supplied

Sequential changes in the CT numbers of the normal canine kidney following intravenous contrast administration. II: The renal medulla.

Following the intravenous administration of sodium and meglumine salts of both diatrizoate and iothalamate (at doses of 310-880 mg I/kg body weight) sequential changes in computed tomographic (CT) numbers of the inner medulla were determined in three dogs, using a 30-second CT scanner. Peak medullary enhancement was greater than, and usually occurred 1-2 minutes after, peak cortical enhancement. The CT number of the medulla increased linearly with increasingly large doses of the contrast agent. At peak enhancement, the meglumine salts produced a significantly lower (p less than 0.025) mean CT attenuation value of the medulla than did the sodium salts. The difference in mean attenuation values between the sodium salts and meglumine salts was maximum (50-60 HU)at peak enhancement. Our data indicate the known difference in renal handling of the meglumine and sodium salts is readily detectable by CT.

Animals↗