A history of urolithiasis risk in space.

INTRODUCTION: The development of renal stones in space would not only impact the health of an astronaut but could critically affect the success of the mission. MATERIALS AND METHODS: We reviewed the medical literature, texts and multimedia sources regarding the careers of Dr. Abraham Cockett and Dr. Peggy Whitson and their contributions to the study of urolithiasis in space, as well as the studies in between both of their careers that helped to further characterize the risks of stone formation in space. RESULTS: Dr. Abraham T. K. Cockett (1928-2011) was Professor and Chair of the Department of Urology at the University of Rochester and served as AUA President (1994-1995). In 1962, Dr. Cockett was one of the first to raise a concern regarding astronauts potentially forming renal stones in space and suggested multiple prophylactic measures to prevent stone formation. Many of the early studies in this field used immobilized patients as a surrogate to a micro-gravity environment to mimic the bone demineralization that could occur in space in order to measure changes in urinary parameters. Dr. Peggy A. Whitson (1960-), is a biochemistry researcher and former NASA astronaut. She carried out multiple studies examining renal stone risk during short term space shuttle flights and later during long-duration Shuttle-Mir missions. CONCLUSION: From the early vision of Dr. Cockett to the astronaut studies of Dr. Whitson, we have a better understanding of the risks of urolithiasis in space, resulting in preventive measures for urolithiasis in future long duration space exploration.

The glucogram: A new quantitative tool for glycemic analysis in the surgical intensive care unit.

BACKGROUND: Glycemic control is an important aspect of patient care in the surgical intensive care unit (SICU). This is a pilot study of a novel glycemic analysis tool - the glucogram. We hypothesize that the glucogram may be helpful in quantifying the clinical significance of acute hyperglycemic states (AHS) and in describing glycemic variability (GV) in critically ill patients. MATERIALS AND METHODS: Serial glucose measurements were analyzed in SICU patients with lengths of stay (LOS) >30 days. Glucose data were formatted into 12-hour epochs and graphically analyzed using stochastic and momentum indicators. Recorded clinical events were classified as major or minor (control). Examples of major events include cardiogenic shock, acute respiratory failure, major hemorrhage, infection/sepsis, etc. Examples of minor (control) events include non-emergent bedside procedures, blood transfusion given to a hemodynamically stable patient, etc. Positive/negative indicator status was then correlated with AHS and associated clinical events. The conjunction of positive indicator/major clinical event or negative indicator/minor clinical event was defined as clinical "match". GV was determined by averaging glucose fluctuations (maximal - minimal value within each 12-hour epoch) over time. In addition, event-specific glucose excursion (ESGE) associated with each positive indicator/AHS match (final minus initial value for each occurrence) was calculated. Descriptive statistics, sensitivity/specificity determination, and student's t-test were used in data analysis. RESULTS: Glycemic and clinical data were reviewed for 11 patients (mean SICU LOS 74.5 days; 7 men/4 women; mean age 54.9 years; APACHE II of 17.7 ± 6.44; mortality 36%). A total of 4354 glucose data points (1254 epochs) were analyzed. There were 354 major clinical events and 93 minor (control) events. The glucogram identified AHS/indicator/clinical event "matches" with overall sensitivity of 84% and specificity of 65%. We noted that while the mean GV was greater for non-survivors than for survivors (19.3 mg/dL vs. 10.3 mg/dL, P = 0.02), there was no difference in mean ESGE between survivors (154.7) and non-survivors (160.8, P = 0.67). CONCLUSIONS: The glucogram was able to quantify the correlation between AHS and major clinical events with a sensitivity of 84% and a specificity of 65%. In addition, mean GV was nearly two times higher for non-survivors. The glucogram may be useful both clinically (i.e., in the electronic ICU or other "early warning" systems) and as a research tool (i.e., in model development and standardization). Results of this study provide a foundation for further, larger-scale, multi-parametric, prospective evaluations of the glucogram.

Electrodermal activities and autonomic nervous system in Behçet's patients.

Behçet's disease is often a progressive disorder. In some cases, there is a possibility of subclinical involvement without neurologic signs and symptoms. The autonomic nervous system is affected in Behçt's disease. The aim of the present study was to investigate autonomic nervous system functions in Behçt's patients by analyzing electrodermal activities. A total of 16 patients and 16 healthy volunteers were accepted for the study. Skin potential recordings were taken at room temperature in a quiet place within a Faraday's cage. The mean values of basal skin potentials and skin potential responses in the patients' group were reduced when compared with those of the control group ( p=0.0001). There was no difference between the groups regarding the mean values of latency ( p=0.09). The findings suggest that electrodermal activities may reflect autonomic nervous system dysfunction in Behçet's patients, and the measurement of electrodermal activities may be useful for the assessment of autonomic nervous system involvement in Behçet's disease.

Efficacy of treatment to relieve mucositis-induced discomfort.

To determine the efficacy of a mouthwash in relieving mucositis-induced discomfort in patients receiving chemotherapy, 31 (16 male, 15 female) with a mean age of 45 (range 16-80) were given an in-house three-drug (lidocaine, diphenhydramine and sodium bicarbonate in normal saline) mouthwash when they developed mucositis of any severity. The complications were assessed on the CALGB (Cancer and Leukemia Group B) scale. The response to the mouthwash was reported on a self-assessment scale. Patients' response data were analyzed with reference to: (1) relief throughout the duration of mucositis and (2) relief during the worst stage (for each episode) of mucositis. Five patients with fungal, viral or bacterial oral infection were excluded from study. Overall, 4 patients had grade I, 16 patients had grade II, 10 patients had grade III and 1 patient had grade IV mucositis. The average duration of mucositis was 7.9 days (range 3-23 days), and the mean duration of the worst stage of mucositis was 4.81 days (range 2-13 days). The mean mucositis severity score was 1.9 (range 1-4), and the average self-assessment (response) score was 0.81 (range 0-2). The mean mucositis score during the worst stage of mucositis was 2.25 (range 1-4), and the average self-assessment (response) score during the worst stage of mucositis was 0.91 (range 0-2.7). These results suggests that this three-drug mouthwash provides effective symptomatic relief in patients with chemotherapy-induced mucositis.

Comparison of the resin-dentin interface in primary and permanent teeth.

The purpose of the present study was to compare primary and permanent teeth in terms of the thickness of the hybrid layer developed with two bonding systems: Syntac (multi step) and Syntac Single Component. Fourteen sound primary first molars and 14 sound permanent first bicuspids, were removed for orthodontic reasons, and divided into 4 groups: 7 primary and 7 permanent teeth were restored with Syntac adhesive resin system (multi step); and 7 primary and 7 permanent teeth were restored with Syntac Single Component adhesive resin system. Measurements of hybrid layer thickness were performed by means of SEM and two teeth in each group were evaluated on TEM for further confirmation of resin-dentin interface. The result of this study indicated that the hybrid layer was significantly thicker in primary than in permanent teeth (p < 0.05). No difference was observed in the hybrid layers produced by two dentin bonding systems (p < 0.05).

Effect of acute exercise on skin potential in sedentaries and trained athletes.

Endosomatic electrodermal activity (skin potential level and skin potential response) as an indirect indicator of sympathetic nervous system activity was measured in 35 sedentary male students and 22 trained athletes of two groups during resting and after an acute exercise. The aim of this study was to investigate the difference of skin potential parameters between sedentaries and trained athletes before and after the acute exercise in bicycle ergometer. In sedentaries' group while skin potential level (SPL) and latency showed no significant variations, skin potential response (SPR) decreased significantly after the exercise (P < 0.001). In athletes' group SPL increased (P < 0.01) and SPR decreased (P < 0.05) after the exercise but latency had no significant difference. In addition, athletes had significantly higher SPL and lower SPR values before and after the exercise comparing with the sedentaries. The increase of SPL in athletes' group was thought to depend on sweat duct pores which have been more active and open than sedentaries. Also the decrease in SPR in athletes' group was thought to depend on the lower sweating threshold in athletes.

Projection of health benefits from ambient ozone reduction related to the use of methyl tertiary butyl ether (MTBE) in the reformulated gasoline program.

To estimate potential public health benefits from ozone (O3) pollution reduction attributable to the use of methyl tertiary-butyl ether (MTBE) in gasoline, O3 dose-response estimates from the biomedical literature were combined with model estimates of O3 reduction. Modeling employed EPA MOBILE5a and Complex models to predict emission changes, industry AQIRP techniques to predict ambient O3 changes, and the National Exposure Model to predict human exposures. Human health effects considered were lung function decrements and respiratory irritant symptoms (using dose-response functions measured in laboratory and field studies), and increased death rates (using concentration-response functions inferred statistically from public-health data). Other reported health effects, such as lung inflammation, increases in asthma attacks, and hospitalizations, were not addressed because of inadequate dose-response information. Even for the health responses considered, quantitation of improvements due to MTBE use is problematical, because MTBE affects only a small percentage of existing O3 pollution, and because exposure-response relationships are not well understood for population subgroups most likely to be affected. Nevertheless, it is reasonable to conclude that even small MTBE-associated reductions in peak ambient O3 levels (1-5 ppb, according to model estimates) should yield considerable public health benefits. Tens of millions of Americans are potentially exposed to O3 in the concentration range associated with health effects. Even if only a small percentage of them are susceptible, any incremental reduction in O3 (as with MTBE use) must mitigate or prevent effects for a meaningful number of people. Better quantitative estimates of benefit must await a more detailed understanding of each link in the chain of causation.

Human occupational and nonoccupational exposure to fibers.

Human exposure to fibers in occupational and nonoccupational environments has been a health concern for nearly a century. In this review, selected results from the literature are presented to highlight the availability, limitations, and interpretive difficulties associated with the past and current human fiber exposure data sets. In the traditionally defined asbestos fibers, large amounts of the data available suffer from the diversity of sample collection and analysis methods. Two simple generalizations suggest that occupational exposures are several orders of magnitude higher than that of environmental exposures; and currently extant data and the current routine measurement practices present significant difficulties in the consistent interpretation of the data with respect to health effects. The data on the human exposures to man-made vitreous fibers are much more complete than the data on asbestos exposure, while exposure data on other man-made fibrous materials are lacking. The human exposure data to many minerals which, at times, exist in fibrous habit, are very scanty, and in view of the biological activity of some of these fibers, this lack may be of significant concern.