Modes of information delivery in radiologic anatomy education: Impact on student performance.

RATIONALE AND OBJECTIVES: This study provides a systematic assessment of different methods of delivering radiologic teaching content (lecture, printed text, and digital content delivery) under standard conditions, enabling comparison of the effectiveness of these methods. MATERIALS AND METHODS: A printed atlas of sectional anatomy was used as a standard. Digital content was developed on the basis of the printed atlas. Lecturers used both the printed and the digital content to prepare lectures. Standardized teaching material thus created was presented to second-term undergraduate students who had attended the school's anatomy course, but had not received any radiology teaching. Multiple choice examinations were used to assess the students' ability to recognize anatomical structures in known as well as unknown images. In a survey, the students' subjective experience of the learning process was assessed. RESULTS: No difference was seen between the groups regarding examination results. Students preferred a combination of digital media and lectures by enthusiastic teachers. CONCLUSIONS: The shortage of teachers requires a compromise concerning the delivery of radiologic anatomy content in a medical school setting. Based on our results, we recommend a combined approach of lecture and digital content delivery.

A review of rosiglitazone in type 2 diabetes mellitus.

The thiazolidinedione rosiglitazone maleate works primarily to improve insulin sensitivity in muscle and adipose tissue. It may have additional pharmacologic effects, however, as its main target is peroxisome proliferator-activated receptor-gamma. Data using the homeostasis model assessment and proinsulin:insulin ratio in patients with type 2 diabetes mellitus suggest that rosiglitazone may have the potential to sustain or improve beta-cell function. In these patients the drug reduces fasting plasma glucose, glycosylated hemoglobin, insulin, and C-peptide. In clinical trials, rosiglitazone monotherapy significantly reduced glycosylated hemoglobin by 1.5% compared with placebo and led to significant improvements in glycemic control when given in combination with metformin, sulfonylureas, or insulin. A dosage of 4 mg twice/day significantly reduced fasting plasma glucose levels and produced comparable reductions in glycosylated hemoglobin compared with glyburide. Rosiglitazone has a low risk of gastrointestinal side effects and hypoglycemia, reduced insulin demand, potential sparing effects on beta-cells, and favorable drug interaction profile. Adverse events of clinical significance are edema, anemia, and weight gain. Premarketing data indicate no significant difference in liver enzyme elevations for rosiglitazone, placebo, or active controls. Another drug in the thiazolidinedione class, troglitazone, was associated with idiosyncratic hepatotoxicity and was removed from the market. Therefore, until long-term data are available for rosiglitazone, liver enzyme monitoring is recommended.

Simulated reflux and laryngotracheal reconstruction: a rabbit model.

OBJECTIVES: (1) To test the feasibility of a rabbit model using a pharyngostomy tube to simulate gastroesophageal reflux and (2) to study the effects of gastroesophageal reflux on laryngotracheal reconstruction using a new rabbit model. DESIGN: Prospective randomized trial. SUBJECTS: Thirty-three New Zealand white rabbits. INTERVENTIONS: Anterior cartilage laryngotracheoplasty and pharyngostomy tube placement into the pyriform sinus were performed in 33 rabbits, 22 of which are included in this analysis. Beginning postoperative day 1, hydrochloric acid at a pH of 1.5 with pepsin (n = 7) or at a pH of 4.0 with pepsin (n = 8) was irrigated twice daily through the pharyngostomy tube to simulate gastroesophageal reflux, and a control group received twice-daily isotonic sodium chloride solution irrigations (n = 7). MAIN OUTCOME MEASURES: Specimens were scored by a pathologist masked to individual groups using a newly modified inflammation scoring system. In addition, cross-sectional areas of the cartilage grafts and subglottic airway lumina were compared. RESULTS: Inflammation scores were significantly higher in rabbits receiving hydrochloric acid and pepsin irrigations at a pH of 4.0 (P =.04) but not in those in the pH 1.5 group. Cartilage necrosis was prominent in all groups, and airway sizes and cross-sectional areas of the grafts were not significantly different among the 3 groups. CONCLUSIONS: Cartilage necrosis is prominent during the early stages after laryngotracheoplasty. Inflammation can be increased using hydrochloric acid and pepsin irrigations but is difficult to predict based on this study. Although we confirmed the feasibility of this model, further modifications of this study are proposed to improve animal survival and data collection.

Relationship between colorectal cancer glutathione levels and patient survival: early results.

PURPOSE: Elevated glutathione is a cause of resistance to anticancer agents and x-rays. The purpose of this study was to determine the frequency and clinical significance of glutathione elevation in human colorectal cancer. METHODS: Glutathione levels were measured in 41 colon cancers, 24 rectal cancers, and corresponding normal tissues. The patients were then followed up prospectively for tumor recurrence and survival. Survival was analyzed by the Kaplan-Meir method and Cox proportional hazards regression. RESULTS: Glutathione levels in primary colorectal cancers were significantly higher than in the corresponding normal tissues. Elevated glutathione levels had a significant negative effect on survival in patients with colorectal cancer, whether based on the mean (P = 0.02) or median (P = 0.04) normal tissue levels. A negative effect of glutathione levels on survival was apparent in patients with colorectal cancer, whether or not they were treated with postoperative therapy. The larger the ratio of tumor glutathione to normal tissue glutathione, the poorer the prognosis. When adjusted for other covariates, glutathione was still a significant predictor of survival. CONCLUSIONS: An elevated tumor glutathione level at the time of diagnosis appears to confer a poor prognosis in patients with colorectal cancer. Longer-term study using a larger number of patients will be required to confirm these findings. Knowledge of tumor glutathione content may help identify patients requiring more intensive therapy.

Radial microbrain form of micrencephaly: possible association with carbamazepine.

A premature infant exposed to carbamazepine in utero had a markedly undersized brain on cranial ultrasonogram. Postmortem examination of the brain revealed no evidence of hypoxic-ischemic injury, hemorrhage, infarction, congenital infection, or calcification. The normal cortical gyral pattern, normal residual germinal matrix, and normal cortical lamination suggested the diagnosis of a radial microbrain form of micrencephaly.

Antiinflammatory effects of human milk on chemically induced colitis in rats.

We examined the effects of a human milk diet on rats with chemical colitis induced with a 4% acetic acid enema. Colonic myeloperoxidase activity was used as a surrogate marker for neutrophil infiltration. Control rats fed rat chow had little colonic myeloperoxidase activity; geometric mean, 0.27 U/g of tissue. Rats with colitis fed rat chow had significantly increased colonic myeloperoxidase activity (geometric mean, 6.76 U/g, p < 0.01 versus no colitis), as did rats with colitis fed infant formula or Pedialyte (geometric mean, 6.92 and 8.13 U/g, respectively, both p < 0.01 versus no colitis). Animals with colitis fed human milk had significantly lower colonic myeloperoxidase activity (geometric mean, 2.34 U/g) than did animals with colitis fed either chow or infant formula (p < 0.001). Similar effects were seen in rats with colitis fed infant formula supplemented with recombinant human IL-1 receptor antagonist (geometric mean, 1.95 U/g). These data show that orally administered human milk has an antiinflammatory effect on chemically induced colitis in rats, which may be mediated in part by IL-1 receptor antagonist contained in human milk.

Rapid decompression of congenital hydrocephalus associated with parenchymal hemorrhage.

A newborn boy with congenital hydrocephalus was diagnosed with aqueductal stenosis using magnetic resonance imaging. Low-resistance ventriculoperitoneal shunt placement was followed by clinical deterioration. Repeat imaging studies revealed a collapsed cortical mantle with subdural hemorrhage. In addition to subdural blood, often associated with marked cerebral conformational changes, extensive intraparenchymal hemorrhage was seen. For extreme congenital hydrocephalus, ventriculoperitoneal shunts with greater resistance to flow than the currently used neonatal shunt devices may be indicated, to allow a more gradual ventricular decompression.

Gastrospirillum hominis-associated chronic active gastritis.

A 16-year-old Caucasian male presented with nausea, vomiting, and abdominal pain. Endoscopy revealed erythematous antral mucosa with four discrete gastric ulcers. Biopsies showed multiple spiral organisms, 4-6 microns in length, lying in the mucous layer on the surface. The organisms were strongly Giemsa positive and weakly CLOtest positive. They did not stain with Warthin-Starry silver or Gram-Weigert stains. Electron microscopy revealed fragments of Gastrospirillum hominis, with its characteristic spiral shape and length of 4 microns in the plane of section. We believe that this is one of the first reported pediatric cases in North America.

Nephrocalcinosis in very low birth weight neonates: sonographic patterns, histologic characteristics, and clinical risk factors.

Fifty infants weighing less than 1200 grams at birth who survived at least 3 weeks were enrolled in this study, of whom 14 (28%) developed sonographic evidence of nephrocalcinosis by 9 weeks, despite median total furosemide dose of only 2 mg/kg. Risk factors for development of neonatal nephrocalcinosis were white race (P < 0.01) and positive family history of kidney stones (P < 0.001). Sonography demonstrated echogenic foci measuring 2 to 9 mm near the papillary tips in most infants with nephrocalcinosis even though the kidneys apparently had not progressed through the stages of diffuse medullary echogenicity that Patriquin and Robitaille postulated are the sonographic correlates of the Anderson-Carr-Randall progression, a leading theory of renal calculus formation. The presence of intratubular calcifications in the two patients studied post mortem also is contrary to the Anderson-Carr-Randall theories that center on interstitial calcium deposition. Although neonatal nephrocalcinosis shares some clinical risk factors (white race and positive family history of renal calculi) with renal calcium deposition in older children and adults, the prevalent theories of renal calcium deposition do not account for its sonographic or histologic manifestations.

Intratumor variability in prognostic indicators may be the cause of conflicting estimates of patient survival and response to therapy.

The DNA index, percentage of S-phase cells, proliferation fraction, and glutathione (GSH) content were determined at more than 1100 separate sites in 140 human tumors and 140 normal tissues. The study showed that the variability was so great from site to site within a tumor that there was only a 61% chance of identifying an aneuploid tumor clone (when present) if only a single site sample was analyzed for DNA content. Similar broad variability was observed in the percentage of S-phase cells, proliferation fraction, and glutathione content. Since these tumor characteristics are often used to predict the outcome of therapy and patient survival, the inaccuracy and underestimation of the test results may cause conflicting or erroneous predictions. The probability of finding an aneuploid clone or elevated percentage of S-phase cells proliferation fraction and GSH content increased dramatically as the number of sample sites studied per tumor was increased. Statistical analyses indicated that in order to achieve a 90% probability that the test results for these parameters were representative of the whole tumor: (a) all single site testing should be abandoned; (b) assays should be performed on samples taken from 3-7 different sites within each tumor; or (c) samples from each tumor should be pooled and the analyses run on a thoroughly mixed or homogenized aliquot of the multisite sample.

In situ fixation of the neonatal brain and spinal cord.

A delay in the autopsy can result in significant tissue autolysis, especially in the central nervous system. We have developed a rapid technique of in situ fixation that preserves central nervous system tissues until the formal autopsy can be performed. Through the lateral margin of the anterior fontanelle, Zamboni's solution is injected percutaneously into the lateral ventricles and allowed to exit via an intrathecal spinal needle. The choice of fixative allows a wide array of postmortem studies to be done.

National acceptability of American Association of Blood Banks Pediatric Hemotherapy Committee guidelines for auditing pediatric transfusion practices.

In 1989, guidelines for the auditing of pediatric transfusion practices were developed by the Pediatric Hemotherapy Committee of the American Association of Blood Banks (AABB) and made available to AABB members. A survey of members who requested the guidelines was conducted to determine how consistent the guidelines were with local transfusion practices and how useful they were for the conduct of audits. The majority of respondents indicated that the recommended audit criteria agreed with local practices and that most of them could be applied to their transfusion practice audits with little or no modification. An exception was that criteria for the transfusion of platelets to premature infants were considered by some to be too liberal. However, after review of the comments and the published information available, the committee elected not to revise the guidelines pertaining to platelet transfusions for premature infants. Bearing in mind that audit criteria are intended to identify circumstances in which transfusions are acceptable as reasonable therapy without need for further justification, rather than to serve as indications for transfusions, the AABB Pediatric Hemotherapy Committee guidelines for auditing pediatric transfusion practices are fairly representative of national practice.

Placental histology in fetuses between 18 and 23 weeks' gestation with abnormal karyotype.

Placentas from karyotypically abnormal fetuses (18 to 23 weeks' gestation) were analyzed prospectively at the light microscopic level. Group I consisted of 14 control placentas. Group II consisted of 14 placentas from fetuses with an abnormal karyotype. Secondary and tertiary stem villi counts, small muscular artery counts, and total vessel counts were determined per 100 x field. There were no differences in secondary and tertiary stem villi counts between groups. A significant decrease in small muscular artery counts (p less than 0.01) and total vessel counts (p less than 0.01) was noted in group II. Placental and fetal weights were comparable between groups. This undervascularization may represent placental immaturity as a result of arrested or delayed angiopoiesis. It appears that this abnormality is established before the third trimester and may be enhanced by late vascular obliteration as reported by others. These data substantiate the concept that the structure and function of the placenta is determined to a great degree by fetal karyotype and may help explain the morbidity and mortality seen in these fetuses.

Wilms' tumors in adults.

Four cases of adult Wilms' tumor are reported comparing their diagnoses, treatment, and survival with the world literature. The oldest recorded patient is herein described at age 84. Aggressive surgical and medical therapy is necessary to improve survival. Surgical exploration should be through a transperitoneal approach with the patient positioned such that access to the chest can be obtained for maximum exposure and resection. Chemotherapy consisting of actinomycin D and vincristine should be instituted in all patients. Radiation therapy must also be considered in any patient with the diagnosis of nephroblastoma.