Faculty Bibliography

Fabrication of a well-behaved superconductor microband electrode fashioned from the edges of thin films of Bi2Sr2CaCu2O8 sandwiched between two insulating layers is demonstrated. In room temperature solutions of redox species, these microbands exhibit well-defined voltammograms and currents interpretable by standard microband electrode theory. The behavior of freshly cleaved electrodes indicates preparation of reasonably pristine surfaces. The new superconductor electrode geometry along with the recently reported fluid electrolyte cryosolvent will be useful in the context of future experiments with superconductor electrodes at temperatures below their T(c) values. The first results for double-layer capacitance of a superconductor/electrolyte solution interface are also provided.

Heart rate variation was studied in 56 healthy subjects from ages 20-81 while supine and standing during spontaneous and metronome breathing. Time domain analyses revealed no age effect on supine heart rate but standing heart rate decreased with aging (p less than .008). The SD of R-R intervals decreased with increasing age in both positions (p less than .001). Frequency domain analysis (Fast Fourier Transformation of R-R interval data) showed total spectral content to decrease with aging (p less than .001). Both high frequency (0.20-0.32 Hz) and low frequency (0.04-0.12 Hz) content were reduced with aging (p less than .001). The ratio of high to low frequency content, however, was not affected by age in the supine position nor were changes in this ratio in response to standing during spontaneous breathing. Although the absolute increase in low frequency content upon standing was less with aging (p less than .001), the percent increase in low frequency content was not related to age. Metronome breathing decreased total spectral content (p less than .001) but increased high frequency content, especially in younger subjects (p less than .03). In response to standing, greater proportional and absolute decreases in high frequency content occurred in younger subjects resulting in age differences in the changes in ratios of high to low frequency content with standing during metronome breathing. In summary, decreased heart rate variation was seen with aging, but the balance between parasympathetic and beta-adrenergic input at rest and in response to postural changes does not appear to be influenced by age during spontaneous breathing. Metronome breathing altered spectral content within subjects and produced age-related differences in responses to postural maneuvers not seen during spontaneous breathing.

Confocal laser scanning microscopy has been used to study the localization of myelin basic proteins expressed in nonglial cells, and to probe the three-dimensional structure of central auditory neurons in the lateral superior olive. The paper focuses on the techniques used to obtain the results. The key roles of confocal microscopy and computer image processing of the images obtained are emphasized as they relate to the discovery of essential structural information about these specimens

The passage of mandatory seat belt legislation has markedly decreased the incidence of head and neck trauma to passengers in private automobiles. However, taxicabs are exempt from seat belt laws in many states. Seat belts, which are included as standard equipment by automobile manufacturers, are often made inaccessible by taxicab operators. We present five cases of head and neck trauma sustained by passengers in taxicabs in which seat belts were not accessible. Injuries included laryngeal fractures, maxillofacial trauma, and severe trauma to the cervical spine. All injuries could have been avoided by the use of an accessible safety belt. The nationwide scope of this problem and strategies for modification of existing laws for better protection of passengers in cars for hire are presented

The ability of surgery or bromocriptine to produce endocrine control of a prolactin macroadenoma decreases as the prolactin level increases. Guidelines for the use of multimodality therapy have not been developed for tumors associated with markedly elevated prolactin levels. We reviewed the records of 21 patients with prolactin levels greater than 200 ng/ml treated by transsphenoidal surgery and postoperative radiotherapy with or without a dopamine agonist. Values before and after treatment were available for 19 patients (13 men and 6 women). The mean basal prolactin level before treatment for the entire group was 2410 ng/ml. Surgery and radiotherapy resulted in a 90% reduction and serum prolactin levels within normal limits in 0 of 7 patients, versus the combination of surgery, radiotherapy, and dopamine agonist, which resulted in a 99.5% reduction and values within the normal range in 12 of 12 patients. Spontaneous physiological improvement was not often observed. One woman and two men were able subsequently to have children. A plan for these patients is discussed.

Spontaneous cerebrospinal fluid (CSF) rhinorrhea constitutes only 3% to 4% of CSF fistulas. Nontraumatic, normal pressure CSF fistulas with resultant rhinorrhea, in which no cause can be identified, or primary spontaneous CSF rhinorrhea, is considerably rarer. Presented here are two cases of CSF rhinorrhea of this nature, including the diagnostic workup and treatment. Reviews of literature support laboratory quantitative glucose determination as the most effective and least morbid method for confirming the presence of CSF. Iodine-contrast (metrizamide/lohexol) computerized tomographic cisternography has been shown to be the most effective and least morbid method for localizing the fistula. For inactive, intermittent, small, or questionable CSF leaks, radionuclide cisternography has been shown to be more effective in identifying the presence of these leaks, although not necessarily the location. Numerous reports provide evidence to support the use of an extracranial rhinologic approach for surgical repair of the leak, as a more successful yet less morbid procedure than a craniotomy when used appropriately