Interpretation of water level changes in the high plains aquifer in Western Kansas.

Water level changes in wells provide a direct measure of the impact of groundwater development at a scale of relevance for management activities. Important information about aquifer dynamics and an aquifer's future is thus often embedded in hydrographs from continuously monitored wells. Interpretation of those hydrographs using methods developed for pumping-test analyses can provide insights that are difficult to obtain via other means. These insights are demonstrated at two sites in the High Plains aquifer in western Kansas. One site has thin unconfined and confined intervals separated by a thick aquitard. Pumping-induced responses in the unconfined interval indicate a closed (surrounded by units of relatively low permeability) system that is vulnerable to rapid depletion with continued development. Responses in the confined interval indicate that withdrawals are largely supported by leakage. Given the potential for rapid depletion of the unconfined interval, the probable source of that leakage, it is likely that large-scale irrigation withdrawals will not be sustainable in the confined interval beyond a decade. A second site has a relatively thick unconfined aquifer with responses that again indicate a closed system. However, unlike the first site, previously unrecognized vertical inflow can be discerned in data from the recovery periods. In years of relatively low withdrawals, this inflow can produce year-on-year increases in water levels, an unexpected occurrence in western Kansas. The prevalence of bounded-aquifer responses at both sites has important ramifications for modeling studies; transmissivity values from pumping tests, for example, must be used cautiously in regional models of such systems.

Challenges for coring deep permafrost on Earth and Mars.

A scientific drilling expedition to the High Lake region of Nunavut, Canada, was recently completed with the goals of collecting samples and delineating gradients in salinity, gas composition, pH, pe, and microbial abundance in a 400 m thick permafrost zone and accessing the underlying pristine subpermafrost brine. With a triple-barrel wireline tool and the use of stringent quality assurance and quality control (QA/QC) protocols, 200 m of frozen, Archean, mafic volcanic rock was collected from the lower boundary that separates the permafrost layer and subpermafrost saline water. Hot water was used to remove cuttings and prevent the drill rods from freezing in place. No cryopegs were detected during penetration through the permafrost. Coring stopped at the 535 m depth, and the drill water was bailed from the hole while saline water replaced it. Within 24 hours, the borehole iced closed at 125 m depth due to vapor condensation from atmospheric moisture and, initially, warm water leaking through the casing, which blocked further access. Preliminary data suggest that the recovered cores contain viable anaerobic microorganisms that are not contaminants even though isotopic analyses of the saline borehole water suggests that it is a residue of the drilling brine used to remove the ice from the upper, older portion of the borehole. Any proposed coring mission to Mars that seeks to access subpermafrost brine will not only require borehole stability but also a means by which to generate substantial heating along the borehole string to prevent closure of the borehole from condensation of water vapor generated by drilling.

Measurement of glomerular filtration rate in ICU patients using 99mTc-DTPA and inulin.

Improved and reliable methods for assessing glomerular filtration rate (GFR) in intensive care patients are needed in light of known deficiencies using creatinine clearance. We compared simultaneous two-hour clearances of inulin (CIn), creatinine (CCr), and 99mTc-diethylenetriaminepentaacetic acid (CDTPA) in 18 medical or surgical intensive care patients (range, 49 to 92 years old) with blood urea nitrogen (BUN) levels greater than 17.9 mmol/liter (0.5 mg/ml), serum creatinine levels greater than 150 mumol/liter (0.02 mg/ml), or estimated Cockcroft clearance less than 60 ml/min. Patients had severe renal dysfunction with average GFR of 35 ml/min (range, 2 to 69 ml/min). CDTPA and CCr correlated significantly with CIn, although CDTPA tended to provide a closer approximation. Cockcroft clearance (32 +/- 4 ml/min) was grossly similar to CDTPA and CIn and correlated significantly, especially when weight was calculated using actual as opposed to ideal body weight. In a subset of 13 patients with CIn less than 30 ml/min, only CDTPA was significantly correlated with CIn. In patients in the intensive care unit, CDTPA provides a rapid, accurate, and inexpensive clinical assessment of GFR, even at very low GFRs.

Pharmacy practice in the United States Army.

The current status of pharmaceutical services in the United States Army Medical Department is described. The mission of the Army Medical Department is to ensure the health of the soldier during times of peace and war. Of the 225 commissioned pharmacy officers currently on active duty, 156 are assigned to U.S. Army medical centers and community hospitals in the United States, and 29 are stationed at hospitals in Europe, Korea, Panama, and Japan. Army pharmacy officers are supported by 879 Army-trained pharmacy technicians and 319 civilian pharmacists employed by the Army. Army Medical Department hospital pharmacies provide inpatient and ambulatory-care services as well as specialized nuclear pharmacy, oncology, investigational drug, and materials development services. Pharmacy officers assigned to the Pharmacy Branch of the U.S. Army Academy of Health Sciences conduct 17-week technician training programs six times a year and provide other pharmacy courses and continuing education programs. The U.S. Army Allergen Extract Laboratory dispenses diagnostic and immunotherapy agents by mail in response to prescriptions submitted by military allergy clinics. Pharmacy officers may be deployed with field hospitals during times of combat or for extended training exercises in places such as Egypt, Grenada, and Honduras. Pharmacy officers may also be assigned to three- or four-year tours of duty in Army hospitals located in Europe. In the future, the emphasis of Army pharmacy practice will be on the expansion of clinical pharmaceutical services and the development of advanced interactive communication systems, quality assurance programs, and peer-review programs.

Update and evaluation of the AutoMicrobic yeast identification system.

The AutoMicrobic system (AMS) Yeast Biochemical Card (Vitek Systems Inc., Hazelwood, Mo.) is a system which has been designed for rapid and automated reporting of yeast identification in the clinical laboratory. Recent improvements have been implemented in the AMS data base to expand and enhance its yeast identification capabilities. These improvements include the addition of seven biotypes, changes in data analysis scheme, and construction of the taxonomic keys. The updated system was compared with the API 20C (Analytab Products, Plainview, N.Y.) yeast identification system and a rapid conventional method, using 1,106 clinical and stock yeast isolates. With these improvements, the AMS Yeast Biochemical Card had a correlation of 98.8% with the API 20C system and 93.4% with the rapid conventional method and significantly increased its capability of identifying Cryptococcus neoformans (98%). The most difficult organisms for the system to identify in 22 to 24 h were Cryptococcus terreus (58%) and Cryptococcus uniguttulatus (73%). The updated AMS not only provided more rapid results which were comparable to the other two systems but gave a substantial savings in set-up and reporting time as well.

Detection of oxacillin-resistant staphylococci by the AutoMicrobic system.

The AutoMicrobic system (Vitek Systems, Inc., Hazelwood, Mo.) is an automated instrument designed for rapid microbiological identification and susceptibility reporting in the clinical laboratory. The reliability of a rapid, automated approach to testing methicillin-resistant staphylococci was evaluated. To determine the accuracy in detecting oxacillin-methicillin resistance by the AutoMicrobic system, 746 staphylococci from seven different geographical areas were tested. Results were compared with the Bauer-Kirby agar disk diffusion technique as the reference method. Of the 304 staphylococci, 209 coagulase-positive and 95 coagulase-negative strains were resistant to oxacillin-methicillin. These organisms fell into three categories of resistance detection. The first category had resistance levels high enough for initial detection, the second category had low resistance levels requiring modified data analysis techniques for detection, and the third category had resistance levels too low for detection. Of the resistant strains tested, 21% showed a category two resistant growth pattern. Major errors, as a result of hetero-resistant growth patterns of the tested strains, were resolved by computer analysis of growth curves. These data analysis applications enabled detection of 96% of the oxacillin-methicillin-resistant organisms. Results for all resistant staphylococci tested were available in an average time of 5.5 h.

Value of selective spleen scintigraphy when liver/spleen image shows equivocal spleen defects: concise communication.

A retrospective review was performed to determine the utility of selective spleen scintigraphy (SSS) in the evaluation of equivocal defects on liver/spleen (LS) image. Six of seven questionable features on LS image were classified on SSS to be definite defects in three, and normal in three. Three of seven patients had defects on SSS that were not seen on LS image. The inability of the LS image to exclude or delineate an abnormality in the spleen was attributed to an overlying left lobe of the liver in five, and to technique in one. The SSS is a valuable diagnostic tool in the further evaluation of equivocal spleen defects on LS image, and SSS may demonstrate abnormalities not demonstrated on LS image.

Radioiodine volatilization from reformulated sodium iodide I-131 oral solution.

By changing the pH and adding buffers, antioxidants, and stabilizers to a sodium iodide (I-131) oral solution, a reduced radioiodine volatilization was claimed by a commercial supplier of radiopharmaceuticals. This study compares the airborne radioactivity volatilized from the reformulated sodium iodide solution with that which became airborne from a previous formulation. Air samples were obtained from the fume hood's exhaust stack during initial venting, and from the breathing zones of physicians and technologists administering the solution to the patient. Analysis of the air samples indicates significant reduction in the airborne radioiodine following initial venting of the solution vial and during patient administration. Additionally, there has been a decline in the I-131 thyroid burdens for occupationally exposed personnel handling the reformulated sodium iodide solutions.