Clinical long-term results of percutaneous transluminal angioplasty in patients with peripheral arterial occlusive disease.

BACKGROUND: We investigated the long-term clinical results of percutaneous transluminal angioplasty (PTA) in patients with peripheral arterial occlusive disease (PAOD) and the influence of different parameters on the primary success rate, the rate of complications and the long-term outcome. PATIENTS AND METHODS: We reviewed clinical and hemodynamic follow-up data of 166 consecutive patients treated with PTA in 1987 in our department. RESULTS: PTA improved the clinical situation in 79.4% of patients with iliac lesions and in 88.3% of patients with femoro-popliteal lesions. The clinical stage and ankle brachial index (ABI) post-interventional could be improved significantly (each P < 0.001), the same results were observed at the end of follow-up (each P < 0.001). Major complications occurred in 11 patients (6.6%). The rate of primary clinical long-term success for suprainguinal lesions was 55% and 38% after 5 and 10 years (femoro-popliteal 44% and 33%), respectively, the corresponding data for secondary clinical long-term success were 63% and 56% (60% and 55%). Older age (P = 0.017) and lower ABI pre-interventional (P = 0.019) significantly deteriorated primary clinical long-term success for suprainguinal lesions, while no factor could be identified influencing the outcome of femoro-popliteal lesions significantly. CONCLUSION: Besides an acceptable success rate with a low rate of severe complications, our results demonstrate favourable long-term clinical results of PTA in patients with PAOD.

Oil production, agriculture, and groundwater quality in the southeastern Gulf Coast Aquifer, Texas.

Associations between groundwater quality and land use were evaluated in the southeastern Gulf Coast Aquifer, Texas. Data from 19234 oil/gas wells and 256 water wells were mapped with a geographic information system (GIS) and statistically analyzed. Water wells near oil/gas wells had significantly higher levels of chloride, bromide, and total dissolved solids (TDS). Bromide-chloride ratios were also higher at water wells near oil/gas wells. Shallower water wells had significantly higher chloride, bromide, TDS, and nitrate concentrations. Nitrate concentrations were higher beneath cropland compared to other land uses. Results of this study suggest that oil/gas production and agriculture have impacted water quality in the Gulf Coast Aquifer.

Automated sampling of stormwater runoff in an urban watershed, north-central Texas.

Automated samplers were used to collect urban runoff in Pecan Creek, Denton, Texas. Runoff from four storm events was sampled at four stations. Concentrations of some heavy metals (cadmium and arsenic), as well as pesticides (atrazine and diazinon), exceeded maximum contaminant levels for drinking water, but were within ranges typical for urban runoff. Calcium and phosphorous concentrations were high compared to previous studies, which was attributed to soils, building materials, and fertilizer applications in the study area. First flush samples were more concentrated than composite samples for most of the constituents analyzed, but statistically different for only five constituents. Concentrations of four constituents differed significantly among stations, and six differed significantly among storms, due to variations in land use, channel composition, and storm conditions. Overall, the automated samplers were an effective way to sample urban runoff in Pecan Creek.

Splinting and radial nerve palsy: a single-subject experiment.

This study examines which of three splint designs most effectively improved hand function in a patient with radial nerve palsy, and demonstrates the application of a single-subject experimental design. The static volar wrist cock-up splint (splint 1), dynamic tenodesis suspension splint (splint 2), and dorsal wrist cock-up with dynamic finger extension splint (splint 3) were evaluated. Each splint was worn for 3 weeks, and hand function was assessed by means of standardized measures of function and disability. Statistical significance was calculated using the minimal level of detectable change (MDC) at the 95% confidence level. Only with splints 2 and 3 did a true change in function occur, compared with baseline scores (no splint). In addition, the patient completed all tasks while using splints 2 and 3 but did not complete three tasks while using splint 1. The hand therapists' goal is to fabricate a splint that improves function and that the patient will wear. Only splint 3 met these criteria. This experiment highlights the need to evaluate both the statistical and the clinical significance of treatment interventions.

Effects of brine injection wells, dry holes, and plugged oil/gas wells on chloride, bromide, and barium concentrations in the Gulf Coast Aquifer, southeast Texas, USA.

Data from 1,122 brine injection wells, 24,515 dry holes, 20,877 plugged oil/gas wells, and 256 water wells were mapped with a geographic information system (GIS) and statistically analyzed. There were 9, 107, and 58 water wells within 750 m of a brine injection well, dry hole, or plugged oil/gas well, respectively. Computed median concentrations were 157 mg/l for chloride, 0.8 mg/l for bromide, and 169 microg/l for barium. The maximum chloride concentration was 2,384 mg/l, close to 10 times the secondary drinking water standard. Shallow water wells and water wells near plugged oil/gas wells had significantly higher chloride and bromide levels.

Water hardness and sodium trends in Texas aquifers.

Median hardness and sodium levels in groundwater were calculated for 244 Texas counties from measurements at 7728 water wells. The data were mapped and analyzed with a geographic information system (GIS). County median hardness levels varied widely, from 4-2304 mg L-1. More than 60% of the counties had hardness medians above 180 mg L-1. County medium sodium concentrations ranged from 6-1170 mg L-1, with more than 90% of those values exceeding 20 mg L-1. There was a significant positive correlation between hardness and sodium concentrations in six of Texas' nine major aquifers. A significant negative correlation between hardness and sodium was observed in two aquifers. Several factors control hardness and sodium variations in Texas aquifers including rock/sediment composition, groundwater chemical evolution, and seepage from nearby formations. Probable human controls include agricultural return flow and pumping-induced saltwater intrusion.

Effects of groundwater velocity on sampling intervals for contaminant-detection networks in aquifers.

This study evaluated how groundwater velocity affects the sampling interval of a groundwater monitoring network and its ability to intercept contaminant plumes before reaching a buffer zone boundary. A computer simulation model tested the detection capability of a groundwater-monitoring network in different groundwater velocity settings. A 0.4-m/d velocity registered a maximum sampling interval of four months. By comparison, decreasing the velocity to 0.04 m/d resulted in a 3-year maximum sampling interval. Groundwater velocity exerts a strong control on the maximum sampling interval of contaminant detection networks in aquifers. Assigning an arbitrary sampling interval, that does not take into account a site's hydrogeology, could waste financial resources or allow contaminants to reach a buffer zone boundary without being detected.

Validity of health status measures in patients with ulnar wrist disorders.

PURPOSE: To assess measurement properties and construct validity of health status measures. METHOD: Forty-three patients with surgically managed ulnocarpal impingement completed a self-report mail survey, including regional (Disabilities of the Arm, Shoulder and Hand [DASH] questionnaire), disease-specific (Brigham Functional Scale), and generic (Short Form 36 [SF-36] Acute Health Survey) health status measures and questions on condition severity and work status. STATISTICAL ANALYSIS: Scores were transformed and frequency distributions constructed to compare the distribution of responses to the measures. Correlation analysis and analysis of variance were applied to assess construct validity. RESULTS: The DASH and Brigham questionnaires had similar distributions of scores, with a slightly greater spread of responses and no ceiling effect on the DASH. Patients appeared slightly less healthy on the basis of the SF-36 scores, which reflected in part the effect of comorbidities. Both the DASH and the Brigham discriminated across levels of severity and work status; the DASH also discriminated on the basis of type of surgery. The SF-36 was able to discriminate some constructs but not as well as the regional and disease-specific measures. CONCLUSION: This study provides evidence of construct validity for the DASH and Brigham questionnaires in patients with ulnar wrist problems in the late post-operative period.

A comparison of patients' responses about their disability with and without attribution to their affected area.

The purpose of this study was to determine whether individual items in a disability questionnaire were answered differently depending on whether or not the questions were attributed to the upper limb (i.e., "do you have difficulty eating due to your arm or hand problem?" or "do you have difficulty eating?", respectively). The a priori hypothesis was that the same or more disability would be detected by nonattributed items. Four hundred sixty-seven patients with upper extremity disorders completed the SF-36 general health survey, which does not attribute health problems to affected areas. Patients also completed six additional questions, modified from the SF-36, regarding work (four questions) and social function with friends and family (two questions), which attributed their disability to their affected upper extremity. Of 467 patients, 419-431 (89-92%) responded to both versions of the questions. Although we demonstrated a significant order effect (Generalized Estimating Equation; P=.003), comparison of the responses to the six questions showed that for five of the six questions (Generalized Estimating Equation; P< or = .001) patients reported more disability when the questions were worded with attribution to the upper extremity. Even considering the order effect, patients demonstrated a counterintuitive result by reporting more disability when questions were attributed to their affected area. Thus, both the wording of questions and order of questions can significantly affect patients' responses about their disability and raises questions about the validity of patients' reports of their disability.

Effective contaminant detection networks in uncertain groundwater flow fields.

A mass transport simulation model tested seven contaminant detection-monitoring networks under a 40 degrees range of groundwater flow directions. Each monitoring network contained five wells located 40 m from a rectangular landfill. The 40-m distance (lag) was measured in different directions, depending upon the strategy used to design a particular monitoring network. Lagging the wells parallel to the central flow path was more effective than alternative design strategies. Other strategies allowed higher percentages of leaks to migrate between monitoring wells. Results of this study suggest that centrally lagged groundwater monitoring networks perform most effectively in uncertain groundwater-flow fields.

The characteristics of patient satisfaction measures.

Information on patient satisfaction is considered a way of including patients' perspectives in the planning and assessment of services. The study of patient satisfaction is a relatively new field, and despite the surge in popularity and use of satisfaction measures during the past three decades, different issues remain to be explored. This is not meant to dissuade clinicians from using satisfaction measures, but rather to allow them to proceed in a thoughtful way, recognizing what these measures can reasonably show us about patients' perceptions of the care and treatment interventions they receive. The proposed approach to classifying the characteristics of patient satisfaction measures should help to highlight potential reasons for variation in results when satisfaction measures perform differently and will be of value if it increases the specificity with which clinicians select measures to achieve their purposes.

Health status following recessional ulnar osteotomy.

This study describes the health status of 31 patients who underwent recessional ulnar osteotomy for ulnocarpal impingement. An additional lunotriquetral fusion was performed in 11/31 patients for joint degeneration. Outcomes included the DASH (Disability of arm, shoulder and hand) questionnaire, SF-36 Acute Health Survey, complications, and satisfaction with surgical outcome. Patients were stratified into two groups for analysis: osteotomy alone and osteotomy + fusion. The overall results indicated that osteotomy plus fusion in patients with more advanced ulnocarpal impingement did not equalise patients' post-operative health status to that reported by patients requiring osteotomy alone. Mean DASH and SF-36 physical component scores indicated better health status in the osteotomy group compared with the osteotomy + fusion group after surgery. Forty-one point nine per cent of patients required plate removal, and scar pain persisted in 58%. One patient in each group developed a non-union requiring revision surgery. Patients in both groups were generally satisfied with their surgical result, with a higher proportion of very or completely satisfied patients in the osteotomy group (65%) compared to the osteotomy + fusion group (27%). Overall, recessional ulnar osteotomy appears to be a successful procedure for the treatment of ulnocarpal impingement.