Establishing a master's degree programme in bioinformatics: challenges and opportunities.

The development of the Bioinformatics MS degree program at the University of Illinois, the challenges and opportunities associated with such a process, and the current structure of the program is described. This program has departed from earlier University practice in significant ways. Despite the existence of several interdisciplinary programs at the University, a few of which grant degrees, this is the first interdisciplinary program that grants degrees and formally recognises departmental specialisation areas. The program, which is not owned by any particular department but by the Graduate College itself, is operated in a franchise-like fashion via several departmental concentrations. With four different colleges and many more departments involved in establishing and operating the program, the logistics of the operation are of considerable complexity but result in significant interactions across the entire campus.

Assessing clinical skills of medical students.

The clinical skills of sophomore medical students at the University of Arkansas are being assessed through the use of the Objective Structured Clinical Examination (OSCE). This exam was developed in order to better standardize the evaluation of practical clinical skills. The exam uses standardized patients, who are lay people trained to accurately and consistently portray a patient encounter. Faculty members at UAMS authored clinical cases for 20 patient encounters that test history taking, physical examination and communication skills. Each student interacts with the patient while being assessed in a standardized way, and then is given educational feedback by a faculty member. Students who do not pass the exam, undergo a remediation program prior to entering the junior year.

The advantages of a microcomputer-based procedure log.

Residency training programs in Internal Medicine have come under increasing pressure to document the diagnostic and therapeutic procedures performed by their residents. We initially attempted to do this by asking the residents to fill out log books. We were disappointed in this method because the residents did not keep the log books up-to-date and because the program and division directors did not receive ongoing feedback. We therefore changed to a microcomputer-based procedure log. We have been pleased with this system not only because the information is more complete, but because we are able to use the cumulative data generated in ways we did not originally anticipate. For example, the data can be used to improve quality assurance and to make adjustments in our educational efforts. The method would seem readily applicable to any residency training program and could easily be useful to any non-teaching hospital required to document the performance of procedures for purposes of staff privileges and quality assurance.

Subdural hematoma in a patient on continuous ambulatory peritoneal dialysis.

A patient on continuous ambulatory peritoneal dialysis developed a subdural hematoma. This problem is common among hemodialysis patients but is rare in patients on peritoneal dialysis, possibly because peritoneal dialysis offers protective advantages, including the lack of anticoagulation, better control of hypertension and milder fluid shifts leading to diminished changes in brain volume. Recently described changes in vascular structures in polycystic kidney disease may contribute to the risk of subdural hematoma in these patients.

Adaptation to metabolic acidosis by turtle urinary bladder.

We utilized the turtle urinary bladder to study the mechanisms responsible for adaptation to metabolic acidosis. Bladders removed from acidotic turtles had a higher rate of H+ secretion in vitro than bladders from control turtles, despite identical extracellular pH. HCO3 secretion, however, was not different between the two groups. The increase in H+ secretion could be mediated by a decrease in intracellular pH and/or by an increase in the number of cells thought to be responsible for H+ secretion. To study this issue, we measured intracellular pH with the fluorescent dye 6-carboxyfluorescein diacetate and quantified the number of cells by fluorescence microscopy utilizing acridine orange, rhodamine 123, and 6-carboxyfluorescein diacetate in turtles receiving different acid loads. Urinary acidification measured in vivo was increased in turtles fed a low-acid load for 48 h and in turtles fed a high-acid load for 24-48 h. Intracellular pH was lower in bladders from turtles fed a high-acid load for 48 h but it was not different from controls in the other groups, indicating that intracellular pH cannot account for the adaptive increase in H+ secretion. Bladders from all groups fed an acid load had a higher number of cells with positive staining for acridine orange compared with controls. Double labeling with acridine orange and the mitochondrial stain rhodamine 123 or 6-carboxyfluorescein showed a significant increase in the number of mitochondria-rich cells between control and bladders from turtles fed an acid load. The increase in the number of rhodamine 123- or 6-carboxyfluorescein-positive cells was lower than the increase in acridine orange-positive cells, suggesting that the apparent increase in the number of acridine orange-positive cells is due to an increase in the number of acidic vesicles in the mitochondria-rich cells and in the granular cells rather than solely to an increase in the number of mitochondria-rich cells. Plasma membrane fraction prepared from control and acidotic bladders failed to disclose an increase in the putative H+-ATPase as assessed by enzymatic activity and transport studies. In conclusion, the present study suggests that the adaptive increase in H+ secretion in metabolic acidosis is associated both with an increase in the number of mitochondria-rich cells as well as with an increase in the number of acidic vesicles in these cells.

Intracellular pH of the turtle bladder assessed with fluorescent probes.

Intracellular pH of the turtle bladder was measured with fluorescent probe 6-carboxyfluorescein (6-CF) diacetate. In isolated cells this probe provides reliable, reproducible and fast measurements of intracellular pH. The probe was mainly located in the cytosol and thus the values of intracellular pH mainly reflect cytosolic pH. The values of intracellular pH obtained with 6-CF were very similar to those measured with 14C-methylamine and 'null point' technique. The 6-CF technique was capable of detecting small changes in intracellular pH induced by acetazolamide. The intracellular pH of the mitochondrial-rich and granular cell fraction was not different. In addition to assessing intracellular pH of isolated cells, it was possible to monitor the intracellular pH of whole bladders continuously with 6-CF. Addition of CO2 to serosal solution decreased intracellular pH while perfusion with NH3 increased intracellular pH. Thus, 6-CF provides reliable and accurate measurements of intracellular pH in isolated cells and in whole bladders. This technique is capable of detecting rapid changes in intracellular pH and provides continuous monitoring of intracellular pH and thus should allow correlation of changes in urinary acidification with intracellular H+ concentration.